Biology 10

Biochemistry

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Biochemistry

Element - A substance consisting entirely of one type of atom, for instance, carbon, hydrogen or oxygen. Elements can combine into compounds to form other substances.

Ion – an atom or group of atoms that have a charge

Atom - The smallest particle of an element

Compound - A substance consisting of more than one atom or one type of element, e.g. carbon dioxide is a compound.

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Biochemistry

Covalent bond - Chemical bond formed by the sharing of one or more electron pairs between two atoms

Isotope - atoms containing the same number of protons but different numbers of neutrons. E.g Carbon -14

Ionic bond - Chemical bonding resulting from the transfer of one or more electrons from one atom or a group of atoms to another.

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BiochemistrypH scale - scale is commonly used over a range 0 (acidic) to 14 (basic).

Acid - Substances that have a pH of lower than 7 (neutral) that can dissolve in water.

Base - Substances that have a pH of higher than 7 (neutral) that can dissolve in water.

Buffer - Solution that resists change in pH;

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Chemistry Review

Organic Compounds

contain carbon atoms that are linked together

Inorganic Compounds

do not contain linked carbon atoms.

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Chemistry ReviewMonomer - a simple compound whose molecules can join together to form polymers e.g. amino acids

Polymer - A large molecule consisting of chains or rings of linked monomer units e.g. protein

Dimer - a compound composed of two monomers e.g. dipeptide

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Chemistry ReviewIsomer - A chemical with the same number and types of atoms as another chemical, but possessing different properties.

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Textbook Questions

Page 159 Questions 1-8

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4 TypesThere are 4 major types of organic molecules important in Biology 20. Carbohydrates

monosaccharides, disaccharides, polysaccharides Lipids

Triglycerides, Phospholipids, Waxes, Steroids Proteins

Primary, Secondary, Tertiary, Quaternary Nucleic Acids

DNA, RNA

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Carbohydrates

Characteristics A Carbohydrate can be a single sugar or a

polymer of many sugars. Carbohydrates contain CHO

Carbon, Hydrogen, Oxygen

Ratio of carbon, hydrogen, oxygen = 1:2:1

Purpose Source of energy for cellular respiration Structural material

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Types of Carbohydrates

MonosaccharidesSingle sugar = C6H12O6

Three common isomeresGlucose

blood sugar

Fructose fruit, honey, twice as sweet as glucose

Galactose milk sugar, rarely found alone.

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Three Monosaccharides

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Three Monosaccharides

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Disaccharides

Formed by the joining of 2 monosaccharidesProcess called

DEHYDRATION SYNTHESIS

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Dehydration Synthesis

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Dehydration Synthesis

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Disaccharides

Formed by the joining of 2 monosaccharidesProcess called DEHYDRATION

SYNTHESISThe reverse process is called

HYDROLYSIS

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DisaccharidesThree Common Isomeres Sucrose

Glucose + Fructose sugar cane, table sugar

Maltose Glucose + Glucose found in seeds of germinating plants

Lactose Glucose + Galactose Found in milk Lactose Intolerance is common Bad smells from bodily orifice. (gas)

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Important Polysaccharides

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PolysaccharidesFormed by the union of many monosaccharides by dehydration synthesis

Types: Starch

Multiple sub-units of glucose Storage form of energy in plants

Glycogen Branched chains of glucose Storage of of glucose in animals

liver and muscle cells High Blood Glucose -- Glycogen formed in the liver (insulin) Low Blood Glucose -- Glycogen converted to glucose

(glucagon)

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Starch Synthesis

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Starch Synthesis

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CelluloseStructural material found in plant cell wallsglucose is linked together differently compared to starch and therefore only organisms with cellulase can digest it. Microbes in cow’s first stomach cleave the bonds with

cellulase The cow regurgitates (vomits into his own mouth) chews again (gross!) swallows into second stomach (yummy)

What is it good for?? Roughage -- retains water in feces = soft poo

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Lipids - think Mr. Balog’s stomach

StructureContains CHORatio of H to O is greater than 2 to 1

PurposeLong Term Energy Storage

1 gram of lipids contains > twice the calories compared to carbohydrates or proteins

Structural Materialcell membranescushion for organscarriers for vitamins

raw material for synthesis of hormones

insulator

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Classification of Lipids

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Types of Lipids

TriglyceridesFormed from 1 glycerol and 3 fatty acids formed by dehydration synthesis

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Classification of Lipids

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Triglyceride Formation

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Triglyceride Formation

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Types of Lipids

TriglyceridesFormed from 1 glycerol and 3 fatty acids formed by dehydration synthesis1) FAT

usually from animalssaturated fatty acids only contain single bondsVery Stable -- hard to break downsolid or semi-solid at room temperatureExample: Butter

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Types of Lipids

2) Oilusually from plantspolyunsaturated fatty acids have some double

bonds between carbon atomsmore reactive than fats therefore more easily

broken down liquid at room temperatureExample: Canola oil

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Types of LipidsPhospholipidsHave a phosphate molecule attached to a

glycerol backbone

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Classification of Lipids

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Types of LipidsPhospholipidsHave a phosphate molecule attached to a

glycerol backbonePolarized molecule

one side is relatively positive, other side negative

Major component of membranes

WaxesVery stable Insoluble in watervaluable waterproof coatings for plant

leaves, animal feathers and fur

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Types of Lipids

Steroidsstructure = four fused carbon rings

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Classification of Lipids

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Types of LipidsSteroidsstructure = four fused carbon rings Made from cholesterol

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Proteins

After water protein is the most abundant

molecule in body

17% of body weight

1000’s of types

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ProteinsPurposePurpose1) Cell Structure1) Cell Structure

Major part of muscle, skin, nerves …Major part of muscle, skin, nerves … Required for the building, repair and maintenance of cell Required for the building, repair and maintenance of cell

structure.structure.

2) Cell Function2) Cell Function Chemical messengerChemical messenger -- hormones -- hormones TransportTransport -- hemoglobin -- hemoglobin MovementMovement -- contractile proteins -- contractile proteins Catalysis of cell reactionsCatalysis of cell reactions -- enzymes -- enzymes Defence against foreign substancesDefence against foreign substances -- antibodies -- antibodies

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ProteinsStructureContains CHON and sometimes SCarbon, Hydrogen, Oxygen, NITROGEN

TermsProtein

A large molecule made of one or more polypeptide chains folded and coiled into a specific shape.

Polypeptide Chains polymers of amino acids arranged in a specific

order and linked by peptide bonds

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Proteins

Peptide BondCovalent bond between adjacent amino acids

Amino AcidsThe structural subunit of proteins20 Different types8 are “essential”

Cannot be manufactured by the body Must be obtained from food

Structure...

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Types of Proteins

Primaryorganized into linear arrangements

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Primary Protein

H2N

COOH

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Types of Proteins

Primaryorganized into linear arrangements

SecondaryThe amino acid chains are alpha helices -

coils and Beta pleated sheets – zigzagsHydrogen bonds cause this.

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Secondary Protein

H2N COOH

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Types of ProteinsPrimary organized into linear arrangements

Secondary The amino acid chains are alpha helices - coils and Beta

pleated sheets – zigzags Hydrogen bonds cause this.

TertiaryThe coiled molecule is further twisted into a

folded 3-D shape

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Tertiary Protein

H2N COOH

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Types of ProteinsPrimary organized into linear arrangements

Secondary The amino acid chains are coils

Hydrogen bonds cause this.

Tertiary The coiled molecule is further twisted into a folded 3-D shape

Quaternaryglobular proteins formed from the

interaction between different protein chainsExample: hemoglobin, enzymes

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Quaternary Protein

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Protein Changes

Denaturation Changes in the shape of the protein by physical or

chemical factors such as heat, radiation or pH changes.

Protein may uncoil or assume a new shape. Protein’s physical properties and biological

properties are changed.

Coagulation Permanent change in the shape of the protein

e.g. boiling egg white, acid in the eye.

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Nucleic Acids

Involved in heredity and protein synthesis

Polymer = long chains of nucleotides

Nucleotide = sugar, phosphate, nitrogen base

Diagram:

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Nucleotide

NITROGEN BASE

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2 TypesDNADeoxyribonucleic AcidDouble Stranded HelixSugar = deoxyriboseMaster blueprint for building proteinsGenetic code in chromosomes

RNARibonucleic acidSingle StrandedSugar = ribose3 Types (Messenger, Transfer, Ribosomal)Executes DNA’s instructions

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Vitamins

Characteristics:

Organic molecules

Not used for energy construction

Cannot be synthesized from food

Needed in small amounts for bodily

functions

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Inorganic Molecules

Mineralsbuilding materials for cell structures and

hormones -- calcium, iron, iodinecoenzymes -- magnesium activates enzymes

in protein synthesis regulating body’s acid-base balance --

potassium regulates the body’s water balance -- sodium

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Inorganic Molecules

WaterMost abundant molecule in the body60% of adult weightFunctions:

excellent solvent involved in chemical reactions

Hydrolysis & dehydration synthesis

maintains constant body temperature

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Textbook Questions

Page 172 questions 9-20

Study For Your Biochemistry Exam

Will be on Monday ( also known as “Monday”)

Lab will be due on Thursday (tomorrow)