Bio 20 - In-Depth Final Review Guide

7/31/2019 Bio 20 - In-Depth Final Review Guide

1/20


2/20

Organisms inside a food web have evolved over time, and have changed due to several factors. Adaptionoccurs as a result of mixing alleles, or mutation. Mutation can occur as a result of UV radiation, or anunexpected change in the DNA when meiosis occurs. Several mutations are more noticeable in groups

than individuals. These adaptations can be passed on to the next generation if they are helpful. Forexample, giraffes have evolved because their long necks were once adaptations that now help them

today. Adaptations are structural (camouflage), behavioral, or modes of life (reproductive mating call).

In order to trace evolution, we have used fossils found in sedimentary rock as a practical, direct tool tohelp understand evolution. Fossils essentially are teeth, shells, bones, or soft tissues that have beenpreserved over long periods of time. Teeth, shells, and bones (hard matter), can be preserved in dry

environments; soft tissues can be preserved in frozen, icy environments. Impressions of foot prints, fecal

matter, and tissue can be also be found along with these fossils. As fossils develop in the ground, the cellcavities can be replaced with minerals (petrification).

There are two ways to track the dating of fossils: absolute, and relative. Relative dating involves using thelayers of strata to find the relative age of fossils; older fossils are found deeper, younger fossils are foundcloser to the surface. Absolute dating involves tracking the half lives of substances inside the fossils, such

as uranium. Tracking these fossils indicates that evolution and change within a species has occurred.

Although there are direct ways to track evolution such as fossils, and dating, there are indirect methodsas well:

! -Embryology: similarities in embryos suggest common ancestor (tetrapod)

! -Homologous structures: different in structure, but originated from common ancestor (divergent

evolution)! -Analogous structures: similar in structure, but originated from different ancestors (convergent

evolution)

! -Physiological evidence: similarities between organisms suggesting common ancestor

! -Biochemical similarities: similarities in chemical makeups

! -Biogeography: gives insight into evolutionary events by studying global distribution of particularorganisms


3/20

! Before modern evolutionary theories took place, spontaneous generation was a popular theory

created by Aristotle. Aristotle stated that abiogenesis occurred to produce organisms, which wasdisproven by biogenesis. Other theories occurred at the time as well:

! Buffon: challenged non-evolution, noted similarities between apes and humans

! Cuvier: studied fossils, revolutions caused extinctions, relative dating!

Lyell: gradualism, slow changes, inspired Darwin! Lamarck: believed in evolution, compared fossils, thought nurtured characteristics could be

passed on, heredity was a mechanism of evolution (similar to Darwin)

! Darwin and Wallace combined to make the theory of natural selection:

1. Overproduction: all organisms produce more offspring than can possibly survive2. Variation: no two individuals are alike, the best variations are passed on, mutation3. Competition: overproduction forces competition for life necessities

4. Natural Selection: best will survive (selective advantaged ones will reproduce, unfit will die off)

Before adaptation can occur, usually Darwins law of survival of the fittest applies, as the weaker

individuals would die off in a short time.

Speciation is a key aspect of evolution that can occur in two forms: allopatric, and sympatric. Allopatric isa geographical separation that results in the formation of a new species, while sympatric results in theformation of a new species in the same area. Allopatric occurs more often. A variation of speciation is

adaptive radiation (Galapagos Finches). This occurs as a result of one species diversifying into manyothers with separate adapted trait.

Allopatric speciation often causes the origin of endemic species. Because the organisms are isolated

from their native environment, they cannot reproduce with the original species until they have alreadygotten past the point where they had the potential to reproduce with the original species.

Today, there are some modern evolutionary theories: punctuated equilibrium, and gradualism. Punctuatedequilibrium occurs as a result of rapid change in short bursts interspersed in between periods of lack of

change. Gradualism is a result of change that doesnt occur rapidly, but continuously over long spans oftime.

!

All organisms require water. This unique molecule can do so many different things because of its uniqueproperties, which stem from its hydrogen bonds:

! -High heat capacity (requires a large amount of energy in order to be broken down)

! -Adhesion (water molecules sticking to other surfaces)

! -Cohesion (water molecules sticking to each other)

! -Polarity (one end, hydrogen is ionized, oxygen is not)! ! -ability to carry solutes

Plants use photosynthesis in order to help animals respire. Photosynthesis is a process that takes lightenergy, and converts it into storable chemical energy in glucose bonds. CO2 is also used from the outside

environment. This process takes place in the chloroplast of the organelle; however, the light reactiontakes place in the thylakoid disc (inner part is called lumen), and the light independent reaction takes

place in the stroma. During photosynthesis, oxidation (removing electron) and reduction (gaining electron)are used to transfer positive hydrogen ions, and negative electrons. Electrons and protons, both key partsof making energy, are carried by NAD+, NADP+, FAD+ transport these to the electron transport chain.

The reaction first starts when light splits a water molecule (photolysis) into H+, O2, and e-. These arecarried from photosystem II down a channel; along the way, the electrons make ATP by donating their


4/20

energy. After passing through this channel, they reach photosystem I, replenishing the energy there. At

photosystem I, another ray of light reenergizes the electron. Soon after, the particles reach the electrontransport chain in the thylakoid membrane. Here, the electrons help to make ATP by providing movement

energy, while the H+ move down the gradient to turn ATP synthase, which synthesizes ADP and P intoATP. There is more hydrogen found in the thylakoid membrane than in the stroma, because of the

electron transport chain. The light independent reaction (Calvin Cycle in the stroma) starts when CO2

bonds with RuBP (six carbon). This RuBP molecule is broken down into two PGA (three carbon) then intoPGAL (three carbon). These two PGAL then form into glucose after six cycles. Along the way, ATP is split

into ADP, NADPH is split into NADP to help move the PGA, and PGAL molecules.

Chlorophyll is an important pigment in photosynthesis. It is a green pigment that reflects the greenwavelength so it appears green.

Cellular respiration is an aerobic process used by all organisms. This process takes oxygen and glucose,and turns them into CO2, H2O, and ATP. The first phase, glycolysis (anaerobic), takes place in thecytoplasm where 2 ATP are put into a reaction in order to have a gain of 2 ATP (4 ATP total), while NAD isreduced to NADH. Electrons are carried by NADH. This reaction helps break down glucose into pyruvate.

Pyruvate is a three carbon compound. Before the pyruvate reaches the Krebs cycle, the pyruvate entersthe mitochondrion and is transformed into a 2 carbon compound. In the process, a NADH gets made, and

a CO2 molecule is released. Coenzyme A is added to the modified pyruvate to make acetyl CoA. At theKrebs cycle, pyruvate helps reduce NAD+ molecules into NADH and H+, and convert ADP and P into

ATP, and FAD into FADH2. Each pyruvate generates 1 ATP, 3 NADH, and 1 FADH; other substances are


5/20

released such as CO2. Both the electron transport channel, and Krebs cycle are aerobic. The electron

transport chain works much like the one in photosynthesis. The NADH and FADH donate their e- to theelectron transport chain in the inner mitochondrial membrane. Protons are pumped through the

surrounding area and through ATP synthase in order to generate high levels of ATP (chemiosmosis). ATPis made from adenosine diphosphate and a phosphate. When broken down, ATP generates energy; it

provides energy for active transport. If ATP is used, an exothermic reaction takes place. Meanwhile, the

electrons provide the energy, and excess protons are carried by oxygen, resulting in water. If oxygen isnot present, ethanol and lactic acid can be made through fermentation. Ethanol is produced by yeasts,

and lactic acids are produced in animals. In order to create energy, pyruvate is broken down in a series ofchemical reactions.

Outside of the water cycle, there are four main cycles of other atomic substances: carbon (CO2), nitrogen

(N2 - product of denitrification (takes N2 from NO3, and NO2, NO3, NO2, NH4), sulfur (S8, SO4, SO2,H2S), and phosphorus (PO4 - can create algal bloom, which can harm aquatic organisms by using the

oxygen supply). These cycles illustrate the movements of those substances in the atmosphere andbiosphere.

Acid rain can be formed from the sulfur and carbon cycles. NO2, and CO2 can accumulate in the

atmosphere resulting in rain with a low pH.

In the sulfur cycle, there is a unique flow of energy because plants cannot photosynthesize. Instead,

chemosynthesis is used. Chemosynthesis creates energy through chemical reactions, usually in deepsea vents.

In ecosystems, there are a variety of terms that help to explain ecosystems:

! Species: organisms that able to breed with one another and produce fertile offspring

! Population: group of individuals of the same species living in a specific area at the same time(predator-prey relationships do not exist)

! Community: all individuals in all populations in certain area (predator-prey relationships exist)

! Niche: role that organisms play in community and the total range of biotic and abioticrequirements needed for its survival


6/20

In a lake, there can be a variety of species with different niches because of the sunlight. The sunlight

affects visibility and temperature, resulting in different abiotic requirements for organisms. Fish that l ikewarm water would likely be near the surface, while fish that thrive in dark environments would be near the

bottom.

The growth of ecosystems is limited by both biotic and abiotic factors:

! -Soil, moisture, temperature, humidity, competition, predators, parasites, vegetation, etc.

Digestion is made up of four non-metabolic processes: ingestion, digestion, elimination, and absorption.

Unicellular organisms digest in the cell, but multicellular organisms digest outside of the cell. Physicaldigestion increases SA for absorption, a metabolic (takes place in cells) reaction. As the body processes

these ingredients, the law of thermodynamics apply:

1. Energy is not created or destroyed; energy is only transferred from one form to another.

2. Heat energy is always released during a transfer; therefore, no transfer is 100% efficient.

When a person ingests food, the teeth break down the food physically, while the salivary amylasechemically digests the food by breaking its bond through a catabolic chemical reaction. Mechanical

digestion increases the surface area for particles to be absorbed after chemical digestion. Amylase is anenzyme that breaks down amylose (starch) into disaccharides, present in the pancreas and mouth is

made of a protein with an active site specific to its substrate.

Enzymes catalyze anabolic (store energy) or catabolic reactions (release energy) by lowering the

activation energy required by increasing the concentration of reactants. While enzymes are useful, theycan be denatured or coagulated by high or low pH (drastic environmental changes) or high (weakens

bonds) or low temperatures (lack of flexibility to perform chemical reaction); the concentration of substrateand amount of inhibitor can affect reaction speed as well. Inhibitors can compete for the active site, or

they can alter the enzymes shape by occupying an allosteric site. Increasing the amount of substrate willnot affect speed but increasing enzyme concentration will slightly speed up the reaction. Enzymes canrely on coenzymes which can be organic (vitamins) or inorganic (minerals). Vitamins are water or fat

soluble. Minerals are used in chemical reactions. While enzymes are catalysts that are used frequently,they are reusable.

In the mouth, catabolic reactions take place. Before the initial digestion of sugars (carbohydrates) begin,

iodine would indicate the presence of the polysaccharide, starch. After the process, Benedicts solutionwill indicate simple sugars. The starch in the mouth is usually organic, because of the carbon atomsbonded to hydrogen. In addition, the organic compound may contain HNOPS. After the mouth, the

epiglottis closes over the trachea before the esophagus uses peristalsis to move the bolus through theesophageal sphincter.

When carbohydrates (sugars) have their glycosidic bonds broken down, they become mono/di-

saccharides (maltose). Carbohydrates, composed of CHO (1:2:1 for monosaccharides), provide energy inmono or disaccharide form. Examples of monosaccharides include When they are broken down, water

must be added; anabolism removes water. Monosaccharides, come in two forms; aldose and ketose,which are trioses, pentoses or hexoses. The heads are formed by carbon, and hydrogen. Carbon musthave four bonds. However, polysaccharides (complex sugars) store energy and provide structure in four

forms: chitin, cellulose, which are structural; starch and glycogen, which are storage. Chitin and celluloseare structural carbohydrates, while starch and glycogen are storage carbohydrates. Starch is processed

in photosynthesis, and glycogen is synthesized from monosaccharides in the liver.


7/20

In the stomach, hydrochloric acid activates inactive pepsinogen into pepsin. Gastrin, a digestive hormone,

signals the making of HCl. Hydrochloric acid is important because it provides an acidic environment to killbacteria and break down proteins. The muscular stomach secretes mucus around the rugae, whichprevents the acid from damaging the stomach. After digestion of water, salts, and lipid-soluble substances

(alcohol), the acidic chyme is directed to the pyloric sphincter.

Proteins (CHONS) are broken down in the stomach by pepsin with the aid of hormones into amino acids.They are indicated by Biurets Solution. Amino acids can be essential or unessential. Essential amino

acids are needed in the diet, while non-essential amino acids must be obtained through the diet. Proteinsare used for growth, repair, and immunity, and hormones, as well as emergency energy. They come infour types: the sequence of amino acids, helix, wrap/sheet, and rope. In molecular form, they are

composed of two carbons attached to a nitrogen, followed by a carbon attached to a peptide group and ahydrogen, followed by a carbon bonded to an oxygen and a nitrogen in a peptide bond (assuming

bonded). The peptide bonds are between the carboxyl and hydroxyl group of amino acids.


8/20

After passing through the pyloric sphincter, the chyme goes to the small intestine, which contains villi, andmicrovilli, which increase SA for diffusion. In the small intestine, enzymes activate:

!-Secretin: tells pancreas to release bicarbonate

! -CCK: tells gallbladder to release bile (emulsifies fats) and the pancreas to release digestive

enzymes (amylase (pancreatic amylase is the final processing of starch), lipase, trypsin)

! -Trypsin: breaks polypeptides into smaller polypeptides

! -Erepsin: converts smaller polypeptides into amino acids

The small intestine is composed of the duodenum, jejunum, and ileum. Segmentation (physical digestion)also occurs. The duodenum is important because it contains villi for lipid digestion. The jejunum furtherbreaks down food particles, while the ileum is responsible for absorbing nutrients and sending the

remaining matter to the large intestine.

Bile salts emulsify lipids so they can be absorbed into lacteals, where they are transported to lymphvessels.

Lipids come in four forms: triacylglycerides, phospholipids, steroids/cholesterols, and waxes. They

provide energy, insulation, and aid in vitamin absorption. Triglycerides are made from three fatty acidsester bonded to a glycerol. If there are double bonds, an unsaturated, liquid, plant fat is present. Theliquid, plant fats are also known as oils. If there are singular bonds, a saturated, solid, animal fat is

present. This saturated fat is straighter than its unsaturated counterpart. Phospholipids are made ofhydrophilic heads, and hydrophobic tails. Lipids are dangerous in LDL form because they can cause

atherosclerosis.


9/20

Before the remaining nutrients and wastes reach the large intestine, it passes through the caecum. In thelsmall intestine, nucleotides, part of DNA (genes), or RNA (copy of genes), formed from a phosphate

group, sugar, and nitrogen base are broken down by nucleotidases. The nucleosides then are brokendown by nucleosidases into their individual parts. The large intestine then absorbs the remaining vitamins,

and water, with the help of symbiotic bacteria, before excretion begins.

The urinary system is responsible for removing wastes (carbon dioxide, water, indigestible molecules from

food, broken down hemoglobin, proteins and nucleic acids. and excess fluids from the body. It iscomposed of the liver (glycogen storage, detoxify drugs, break down hemoglobin, nucleic acids, and

deamination (removal of amino group) of amino acids), kidneys (2), urinary bladder, ureters (2), andurethra, not including the smaller tissues used. Male urethras are longer, which makes them less

susceptible to bladder infection. In males, the urethra is used for both the urinary and reproductive

systems, while in females, there are two body organs used. While most excess molecules are removedthrough diffusion, the urinary/excretory system gets rid of other substances. In the excretory system,

blood containing nitrogenous wastes travels to the kidney. This nitrogenous waste combines with water,salt, and sugars in the kidney before traveling through the ureter into the bladder. The bladder stores this

urine (aqueous waste) until it reaches between 200-600 mL. At this stage, the sphincter muscles areunder voluntary control until the bladder is overfull, where it becomes involuntary, As the urinary

sphincters relax, urine travels out through the urethra.


10/20

The liver is responsible for the deamination of amino acids. When proteins are broken down, the aminogroup falls off, which contains nitrogen. These amino acids are processed in the urinary system, or

redistributed into the body cells. The nitrogen is converted into ammonia, which is toxic. Therefore, theliver changes it to non-toxic urea, a metabolic waste. This urea travels through the blood into the kidney

from the liver, where it is filtered out of the blood and combines with water, salts, and sugars to form urine.

The kidneys are the first part of the excretory system, where primary functions occur. These include bloodfiltration, waste excretion, and regulation of blood pressure, volume, and salt balance. The cortex is madeof three layers. The outer part of the kidney is called the cortex, and the inside, the medulla (high salt

content), and the pelvis, which consists of calyces (projections) around the renal pyramids.

There is a set of path of excretion, mainly passing through the nephron, which puts vital nutrients andwater back into the blood and the renal tubule. The nephron is the site of filtration for blood plasma. The


11/20

composition of the filtrate. Before the blood containing wastes gets to the kidney, it passes through the

renal artery. If there is high pressure, the rate of filtration is increased. First, the waste passes through theglomerulus inside the Bowmans capsule, which only allow water and small ions to pass through (proteins

remain). This is called glomerular filtration. In the afferent arteriole, the glomerulus receives blood at highpressure. In the glomerulus, the urea passes into the nephron ducts, and the blood passes through blood

vessels until returning to the heart. The filtrate then leaves the glomerulus via the efferent arteriole. This

filtrate passes through the Bowmans or glomerular capsule. In the afferent arteriole, the glomerulus

receives blood at high pressure. This then passes through the renal vein, into the proximal convoluted

tubule (no proteins). This is where tubular reabsorption occurs. From then on, it passes to the Loop ofHenle, where there is an adjustment of salt balance, as the water flows out at the bottom of the loop of

Henle, which in itself contains a high concentration of sodium ions. As the loop of Henle ascends, it isnow slightly permeable to ions, so minerals such as sodium can pass through Then, the waste travels

through the distal tubule, the last segment of the nephron. Finally, the urine travels to the collecting duct,where it can be sent to the bladder.

Two processes mainly occur tubular reabsorption and tubular secretion. For tubular reabsorption, cells inthe proximal tubule remove water and nutrients from the filtrate and pass them back into the blood, while

wastes are retained. For tubular secretion, wastes, such as hydrogen,and potassium remaining, areremoved from the blood into the distal tubule. In the collecting duct, water reabsorption can occur, so it

can be reused.

The formation of urine is dependent on three factors: filtration, reabsorption, and secretion. Filtrationoccurs as a result of the movement of fluids/urea from the Bowmans capsule. This all takes place in thesequence of afferent arteriole, glomerulus, efferent arteriole and renal capillary. The high pressure of the

blood in the glomerulus moves solutes into the Bowmans capsule, along with diffusion. Even thoughthere are blood cells, plasma proteins, and platelets, they are too big to move into the Bowmans

Capsule, so they stay in the blood stream. Reabsorption occurs in the loop of Henle, and the proximaltubule where sodium ions are reabsorbed into intracellular spaces outside the nephron. Chlorine and

other negative ions also follow because of the charge attraction. The high concentration of solutes outsidethe nephron draws water outside through osmosis. Secretion can also occur. Waste in the blood cantravel into the nephron, such as hydrogen ions, histamines, ions, and minerals. This occurs in the distal

tubule.

The ADH hormone is secreted by the pituitary gland. ADH increases water absorption in the collectingduct. If there is lots of this hormone, lots of the hormone will result in concentrated urine and plenty of

reabsorbed water. Little ADH amounts will result in little water reabsorbed and dilute urine. This hormoneis triggered by osmoreceptors in the hypothalamus, located above the pituitary gland. They areresponsible for detecting change in osmotic pressure (water content of blood). High osmotic pressure, or

high concentration of blood plasma (dehydration) will result in high ADH, as the body seeks to retain thewater inside. Low osmotic pressure will result in less ADH, meaning the person is healthy. This signals the

collecting duct and distal tube to be less permeable to water, so water can be excreted, whichconcentrates solutes in the blood. When there is low water in the blood, the water moves into the blood

from the tissues. These tissues shrink, which allow the osmoreceptors to detect the change in osmoticpressure.The hypothalamus then sends a nerve stimulus to the pituitary to release ADH, while also

creating a thirst sensation. As the ADH travels to the nephron, it signals the blood to reabsorb water intothe blood. When the water returns to the blood, there is an in osmotic pressure. If there is less water,there is more ADH released. If the water returns to the tissues, the hypothalamus swells.

Aldosterone, another key hormone, is responsible for regulating blood pressure. They do this by adjusting

blood volumes. This hormone is released from the adrenal cortex, and sent to the nephron. It tells thenephron to increase sodium reabsorption into the blood. When the aldosterone causes reabsorption inthe distal tubule and collecting ducts, the osmotic gradient draws water with the sodium, increasing blood

pressure. It also can stimulate secretion of potassium ions into distal tubes and collecting ducts if theconcentration is too high.


12/20

There are a few disorders of the kidney system. Kidney stones can be formed in the renal medulla andpelvis of the kidney. It is a result of excess calcium in the urine, which creates calcium stones that must

painfully pass through the urinary tract. Kidneys can fail during periods of high blood pressure, becausethe blood vessels get ripped apart. Polycystic kidney disease is a result of high blood pressure. Blood

appears in the urine, along with back and abdominal pain. The abdomen enlarges, and indicates kidney

failure. Diabetes mellitus occurs as a result of high glucose levels, as a result of low insulin. Diabetesinsipidus occurs as a result of the kidneys inability to conserve water as a result of the failure to produce

the ADH hormone. This causes dehydration, and the person can urinated between 4-8 L/day. Renalinsufficiency occurs when homeostasis is not maintained due to nephron damage. Nephron damage can

be a result of, but is not limited to kidney infection, poisoning, atherosclerosis, or tubule blockage.

There are also diseases. A urinary tract infection occurs when bacteria enters the urinary tract. Symptomsinclude burning during urination, a need to frequently urinate, and discoloured urine. Also, chills, fever,nausea and vomiting may exist. These can result in kidney damage or failure.

Peritoneal dialysis and hemodialysis are used as treatments for kidney disorders. Dialysis is the diffusion

of dissolved materials through a semipermeable membrane. Hemodialysis uses an artificial membrane inan external device that is connected to an arm vein or artery. Peritoneal dialysis occurs in the stomach,

and uses the lining of the intestine as a dialysis membrane.

As a primary component of respiration, air is composed of four elements: N, O, Ar, and CO2. (Oral cavity,pharynx, larynx, trachea, bronchi, bronchioles, alveoli)When it first enters the body, it passes through the nasal cavity or mouth. In the nasal cavity, small hairs

filter air. In both the nasal cavity and trachea, mucus trap smaller pollutants, while keeping cell moist. Italso contains turbinate bones, which increase surface area. Mucus is an antiseptic enzyme composed of

proteins, salt, and water that should be clear when healthy. After the air has been partially filtered, itpasses through the pharynx, before going down the trachea, while the epiglottis covers the opening to the

trachea, the glottis. The trachea is lined with ciliated hair cells that help sweep mucus secreted by gobletcells; a mucociliary escalator is formed. Inside the trachea, if there is cigarette smoke, frequent coughingmay occur because mucus cannot be released because of paralyzed cilia cells. Soon after, the trachea

gives way to the larynx, two thin sheets of elastic ligaments (vocal chords) that vibrate with air. They areprotected by the Adams Apple. The trachea also carries air to two bronchi, containing cartilaginous rings,

before the bronchi branch into the lung. Bronchioles, or smaller bronchi, are made of smooth muscle.Asthma occurs as a result of bronchiole blockage; bronchodilators help to restore function. People with

asthma are sensitive to pathogens, but this cannot be cured. Inhalers, which inject medicine, and normalmedication to reduce inflammation is used. Both the bronchi and the bronchioles contain cilia and mucusproducing cells. The ends of the bronchioles lead to the alveoli, which are singular cell layered cells,

surrounded by capillaries, which aid in diffusion during external respiration. Alveoli lead to the capillaries,and use facilitated diffusion to help move the oxygen into the blood into the capillaries.The alveoli can be

affected by emphysema, which reduces their elasticity, which reduces surface area for gas exhcange, andis non-curable, resulting in shortness of breath. The main treatment is lung volume reduction surgery. The

lung, which contains the alveoli, have lobes. The right lobe has three, while the left lobe has two (-1 forheart space). They are sounded by a pleural membrane, which provides moisture for chemical reactions

and connects the two lungs.


13/20

There are some diseases in the respiratory system. Tonsillitis and laryngitis are infections andinflammations respectively caused by infection/virus. Laryngitis affects the larynx and reduces speaking

capability, and is shown by sore throat and hoarseness. Bronchitis is a result of mucus filled and inflamed

bronchi. There is acute, which is treated by antibiotics, and chronic, which is a long-term disorder. Chronicis most dangerous as it results in destroyed cilia cells, further inflaming the bronchi, and increasing thelikely hood of inflammation. The most likely cause is preventable, smoking. There is no cure, but

treatment can occur with medication and regular exercise. Pneumonia, a common disease that is lobular,or bronchial, occurs when the alveoli in the lungs become inflamed and filled with liquid. The bodybecomes starved for oxygen. The main causes are infection, and viruses, with the latter being less

dangerous as it can be treated with anti-viral medications. Cystic fibrosis, a genetic condition, affects thelungs, and results in a lack of homeostasis, which results in an accumulation of pathogens.

Respiration is an exothermic process occurs in inspiratory (body/lungs), expiratory (lungs (capillaries)/air)

and cellular forms. In cellular respiration, ATP fuels the reaction that exchanges sugars, and air reactantsfor carbon dioxide and water products. The purpose is to bring oxygen to key tissues of the body, whilealso removing excess carbon dioxide. The two systems that control this are the muscular and nervous

system.

Breathing involves pressure differences between the atmosphere, and the chest cavity. Gasses diffuseusing pressure differences to achieve inspiration and expiration. The diaphragm, which separates the

chest/stomach and thoracic cavity contracts to allow more volume and less pressure, resulting ininspiration/inhalation (reverse applies), aided by rib movements. Intercostal muscles work a directrelationship. When they contract, the ribs move up and down, inflating the lungs. The inverse applies. If

this process does not work, a mechanism called the iron lung can be used to create an artificial pressure


14/20

difference. Exhalation happens when the diaphragm and the rib muscles relax, reducing the voluming in

the lungs, so air moves from the lungs outside the body.

Chemoreceptors signal the medulla oblongata to increase breathing rate. The chemoreceptors detecthigh levels of carbonic acid. Low oxygen chemoreceptors are found in the aortic and carotid bodies,

which are responsible for high-altitude breathing rates. This is usually the first response at the high

altitude level. Carbon monoxide also competes with oxygen for hemoglobin (iron and protein) spots,which bypasses the chemoreceptors.

Spirometry is made of four components:

! Tidal Volume: the volume of exhaling/inhaling

! Expiratory: volume exhaled

! Inspiratory Reserve: what cant leave the lungs unless forced! Vital Capacity: Lung Volume

Oxygen and carbon dioxide transport is almost the same. Oxygen has high pressure, while carbon

dioxide has low pressure outside of the body. Oxygen requires this high pressure to stick to hemoglobin.Considering oxygen has low pressure in the capillaries, oxygen drops in this area so it can diffuse into

tissues. In cells, carbonic acid is formed by the enzyme, carbonic anhydrase, as the low pressure allowsdiffusion into the blood. Disassociation occurs to maintain pH. Once blood reaches the lung area, oxygendislodges the hydrogen, which forms carbon dioxide and hydrogen. The carbon dioxide then diffuses into

the alveoli. After the alveoli, the air goes to the alveolar sacs, which provide a large surface areasurrounded by capillaries.

The circulatory system revolves around the heart, an organ made of cardiomyogenic muscle (contractswithout nerve). Single celled organisms possess no circulatory system, while most multicellular ones do.

The main exception for the multicellular organism is the hydra, which uses simple diffusion across cellmembranes. The purpose of the circulatory system is to transport nutrients and oxygen for cellular

respiration, and to transport wastes. Secondary purposes include immunity, for defense, heat distributionand maintenance of It uses the sinoatrial node in the right atrium to act as a pacemaker to force atrial

contraction. The atrioventricular node in the bottom right section of the right ventricle forces ventricular

contraction. Atria and ventricles contract at the same time respectively. When the atrioventricular valvesclose, lub is made. The dub is produced as a result of the semilunar valves closing. Heart murmurs occur

when vein leakage is present.


15/20

There is a main passage for blood. The blood flows from the aorta to the arteries, which branch to the

arterioles, and then to the capillaries. After being used by the tissues, the blood flows back through thecapillaries, then to the venuoles and the veins.

The arteries are blood vessels that carry blood away from the heart. They carry oxygenated blood exceptfor the pulmonary artery, which itself has a high concentration of hydrogen ions. The blood is under high

pressure in the arteries, which are made of three layers. The outer and inner layer is made of rigidconnective tissue while the middle is made of muscle and elastic connective tissue. This allows the artery

to withstand the changes in pressure. The contraction of arteries is what creates the pulse. When thearteries branch off, the blood flows into arterioles, smaller arteries with a flexible diameter. Arterioles

leading to capillaries (precapillary sphincter) only open in that area when blood is required. There are twomain processes in the arterioles. Vasoconstriction occurs to decrease blood flow to tissues, whileincreasing pressure. When vasodilation occurs, there is increased blood flow to tissues, decreasing

pressure. This can occur when body temperature increases, such as during exercise, as there isincreased blood flow to the skin.

There are two main problems that can occur in the arteries. If there a fluid filled bulge in the artery wall,the artery can rupture, causing a stroke (aneurysm). The cells die because they cannot contain oxygen.Atherosclerosis, a form of arteriosclerosis, can also occur when there is fat and mineral accumulation,resulting in plaque in the coronary artery and can cause angina (chest pain). Treatment includes

angioplasty (opening arteries using tube), or coronary bypass surgery (skin graft internally that createspath around heart). In the heart, there are coronary arteries that branch off the aorta and supply the heart

with its own oxygenated blood. If angina occurs, it is a fault of the pulmonary system supplying thecoronary system as there is low oxygen.


16/20

The capillaries are tiny blood vessel connectors that are the primary site for diffusion. They are composed

of a single cell layer, and when many of them are together, a capillary bed is formed. These capillaries arealso quite fragile, and can be ruptured under high pressure. Bruising may occur when blood flows into the

interstitial space/fluid and rupture capillaries. When in clusters, a systemic capillary bed is formed; thisbed is a primary site for diffusion.

When the capillaries merge and become larger, venuoles, made of smooth muscles are formed. Thesevenuoles become veins, thin walled vessels, which return to the heart. All veins except for the pulmonary

vein carry deoxygenated blood under low pressure. They have valves to prevent backflow, and skeletalmuscles to help the push blood back.

The heart is made of four chambers, the right and left ventricle/atrium, which are surrounded by

pericardium, a fluid that prevents friction. Right and left sides of the heart are separated by the septum.The left ventricle is thicker because it pumps blood to all parts of the body. It also has the vena cava,which brings deoxygenated blood from the body to the right side of the heart. The top is superior, while

the bottom is inferior. The aorta, located at the top of the heart, which carries oxygenated blood from theleft side of the heart to the body (systemic circulatory system). In the heart, there are two types of valves:

the atrioventricular valves, which separate atria from the ventricles; the semilunar valves, which separatethe ventricle from blood vessels.

When the blood travels through the lungs, it is considered in the pulmonary system. The pulmonary artery

takes deoxygenated blood away from the right ventricle to the lung. The pulmonary vein takesoxygenated blood from lungs to the left atrium.

Cardiac output consists of stroke volume and cardiac output. Cardiac output composed of heart rate, andbeat/min., while stroke volume is the mL/beat. This affects blood pressure, which is systole/diastole.

Systole is the maximum pressure of ventricular contraction, while diastole is the lowest pressure of arteryrelaxation when the heart is full.

There are four potential blood types in the body: A, B, AB, and O. These blood types each have theirunique antigen and antibody. The A and B and AB types all possess their respective antigens, which are

displayed on the surface of the cells. Blood type O is unique, because it lacks this antigen, which isattacked by antibodies, a type of protein. Blood type A has B antibodies, while blood type B has A

antibodies. Blood type AB is unique, because it lacks antibodies. This is why it is considered the universalreceiver of blood (lack of antibodies). Blood type O possesses both A, and B antibodies, which prevents it

from receiving either types. However, the lack of antigens allows it to become the universal donor. Alltypes of blood may or may not possess a Rhesus protein. Rhesus protein is an added protein that can bedetected by antibodies. Mothers can encounter the problem if they are Rhesus negative, and their

husbands are Rhesus positive. During the formation of the baby, the Rhesus protein can be inherited.Because of this, there is a possibility that the babys blood (positive) can come in contact with the

mothers negative Rhesus blood. Her negative Rhesus blood possesses antibodies that will attackpositive Rhesus blood. Usually during the first birth, this is not a problem, as the babys blood does not

come into contact with the mothers. The second or later births may have problems if the mothers bloodcame in contact with the babys during birth. The activation of the antibody can result in the attacking of

the babys blood, deforming the baby, and possibly resulting in a miscarriage. This is callederythroblastosis fetalis.

Electrocardiographs map electrical fields within the heart; P waves represent activity before atrialcontraction, QRS waves represent before ventricular contractions, while T wave signal ventricle

contractions when they are recovering from contraction. They can detect high blood pressure, orhypertension, or low blood pressure, hypotension. Hypertension can rupture vessel walls (stroke), whilehypotension can reduce capacity to transport blood.


17/20

Homeostasis is the maintenance of consistency in the blood. Nerves and hormones (baroreceptors)

located in the aorta and carotid arteries help to maintain this. If there is high blood pressure, theparasympathetic nerve is turned on by the medulla oblongata, which lowers the heart rate and turns off

the sympathetic, which allows the arterioles to increase in diameter. If there is low pressure, thesympathetic nerve is turned on by the medulla oblongata, which increases blood pressure by constricting

the arterioles, and increasing cardiac output.

Adrenaline, also known as epinephrine, is an adrenal gland secreted hormone that increases the release

of red blood cells (erythropoiesis) in the bone marrow, and increases heart and breathing rate.

The blood consists of plasma, red blood cells, and white blood cells/platelets. Plasma consists of manydifferent components such as water, and waste. In the plasma, there are albumins (water balance),

globulins (produce antibodies), and fibrogen, which is key in blood clotting.

There are diseases that can occur in red blood cells, such as anemia, a lack of heme, in the hemoglobin;

and sickle cell anemia, which is a shape abnormality in the red blood cell. However, sickle cell anemiaalso helps to prevent malaria.

For every 700 red blood cells, there is a leukocyte, or white blood cell (has nucleus), which is produced in

the bone marrow. They aid in immune response. Leukemia is a disease where the white blood cells dontform properly.

There are three types of white blood cells: granulocytes, which are composed of neutrophils, basophils,and eosinophils; monocytes, which can leave bloodstream and become macrophages; and lymphocytes.

Granulocytes and monocytes typically engulf pathogens, while lymphocytes produce antibodies thatincapacitate pathogens and signal kil ler T cells for destruction.

Platelets (thrombocytes) without a nucleus)) are used to help clot. They are also produced in the bone

marrow. To initiate blood clotting:! -Thromboplastin (released) combines with calcium to catalyze the production of prothrombin. Theprothrombin mixes with the thromboplastin to form thrombin. This combines with water soluble fibrinogen

to make fibrin, a non-soluble substance.

Without platelets, hemophilia can occur, where blood cannot clot properly.

The immune response has two main types of defenses. Non-specific defenses occur in the form ofphysical barriers, and chemical barriers, which trigger inflammation and phagocytosis. Examples includethe skin, hair, coughing, and sneezing, sweat, tears, and acid. If a virus triggers a non-specific defense,

the cell secretes histamines, which dilates the blood vessel (inflammation). The capillaries in the infectedarea leak, and fluid leaves the blood vessels and enters the tissues (edema). During this time, there is

increased blood flow, and more macrophages (engulf pathogens using phagocytosis). A fever may start,which kills bacteria through high temperatures. This can be potentially harmful for the body if it persists,

because it can kill helpful enzymes, and antibodies in the body. Specific defenses are a result of cell-mediated immunity, and antibody mediated immunity. These take place after non-specific defense

mechanisms have taken place. Lymphocytes are released and directly attack the pathogen. The T-lymphocytes respond to antigens displayed on a macrophages surface (antigen presenting complex). B-Lymphocytes also exist, as they produce antibodies (plasma cell), which recognize foreign antigens. It

takes 14 days for the B-cell to make a correct antibody. After, it becomes a memory B-cell, which keepstrack, and can produce the antibody needed faster. Complimentary proteins also exist in the blood

plasma. They form a protective coating around the invader, which dissolves its cell membrane.

The purpose of the immune system is to protect the bodies from harmful pathogens that can inflict harm.

During times of good health, the body secretes suppressor T-cells, which prevent the overproduction ofkiller T cells. When a pathogen first enters the bloodstream, it is attacked by a macrophage, which digests


18/20

it whole, and displays its antigens. This macrophage then gets help from a helper-T cell, which signals the

rest of the body to send an immune response. During this reaction, the macrophage releasesinterleukin-1, which stimulates the helper T cell to secrete interleukin 2.This signals the body to rapidly

create killer T cells and B cells. The cytotoxic T cells can bind to a pathogen and puncture its cellmembrane. The B cells are used to produce antibodies that bind to the antigen on the pathogen. They

can also become memory B cells, which remember the pathogens antigens, so an immune response can

be stimulated in the future.

Antibiotics can be injected to a persons immune system. It contains a dead form of the virus that isdestroyed by the body, which creates memory cells to prevent against it in the future.

Allergies are basically an overreactive immune system. When a non-harmful pathogen enters the body,

the body recognizes it as dangerous, and attacks it, resulting in common sickness symptoms.

The body is composed of three types of muscles in the body: skeletal muscles are connected to the

bones to provide movement, smooth muscles form the walls of organs (eg. stomach), and cardiacmuscles keep the heart beating. These muscles are classified as involuntary, or voluntary. Between

bones, there is tendons, that connect them to muscles. Muscles can pull, but cannot push.

Skeletal muscles are striated and tubular muscles that are very long. They possess multiple nuclei, andare voluntary muscles attached to the bones of the skeleton. Smooth muscles are non-striated muscles

with a nucleus found in internal organs. Cardiac muscles are found in the heart, where they contractinvoluntarily. They are striated, tubular, and branched, while possessing a singular nucleus.Skeletal muscles are one of the more important muscles. They support the body, make the bones move,

maintain constant temperature, protect internal organs and stabilize the joints. These muscles are formedin pairs, and have opposites that do the inverse when an action is performed. The work done in a muscle

during contraction. During this contraction, there must always be a force available to stretch it.

Before contraction begins, calcium is needed. Tropomyosin, a protein on actin, blocks the myosin headbinding sites. When the muscle fibre is stimulated to contract, it calcium is released from the sacroplasmicreticlum. This calcium binds to troponin, a protein on tropomyosin, to move the tropomyosin so that the

contraction can occur. When the nerve impulse stops, calcium is returned to the sacroplasmic reticulum.

During contraction, there are two types of myofilaments: actin, and myosin. Actin is formed by two proteinstrands wrapped each other, while myosin is formed by two long protein strands with two heads and a

long rod shape. In the reaction, the myosin head attaches to the actin along with an ADP and P (brokendown ATP), before flexing. This slides the actin past the myosins original position. The myosin headdetaches, and then unflexes using ATP, before reattaching near the original position. Afterwards the

gained ATP breaks down into ADP and P, releasing energy that is stored in the myosin for movement. Inthis process, the actin is anchored at one end of each myofilament at the Z-line. The movement of action

moves the Z lines with it. Both are pulled inward (opposite directions), causing the plasma membrane topull together, causing the contraction of entire muscle fibre.


19/20


20/20

Documents

Bio 20 - In-Depth Final Review Guide