BIOCHEMISTRY – BIOCHEMISTRY – Part IPart I
The highest courage is to The highest courage is to dare to appear to be what dare to appear to be what
one is.one is.
John SpaldingJohn Spalding
Hydrogen BondHydrogen Bond
A type of Van der Waals forceA type of Van der Waals forceAttractive force BETWEEN Attractive force BETWEEN
moleculesmoleculesNOT a true chemical bondNOT a true chemical bondLinks two Links two polar moleculespolar molecules
together.(not atoms)together.(not atoms)
Hydrogen BondHydrogen Bond
Hydrogen bonds are Hydrogen bonds are individually very individually very weakweak..
Hydrogen bonds only form Hydrogen bonds only form when molecules are very when molecules are very close close togethertogether..
Hydrogen bonds determine the Hydrogen bonds determine the shapes of shapes of DNA and proteins.DNA and proteins.
Hydrogen BondingHydrogen Bonding
Properties of Water to DiscussProperties of Water to DiscussCohesionCohesionSurface TensionSurface TensionAdhesionAdhesionImbibitionImbibitionHigh Specific HeatHigh Specific HeatHigh Heat of VaporizationHigh Heat of VaporizationExpansion upon FreezingExpansion upon FreezingVersatile SolventVersatile Solvent
Polar vs.Nonpolar MoleculePolar vs.Nonpolar Molecule
Nonpolar molecule – a Nonpolar molecule – a molecule with equal areas of molecule with equal areas of chargecharge
Polar molecule - A molecule Polar molecule - A molecule with unequal areas of with unequal areas of chargecharge
Polar MoleculePolar MoleculeExample: In water, electrons Example: In water, electrons
are shared are shared unequallyunequally, so , so different parts of the different parts of the molecule have different molecule have different charges.charges.
Polar MoleculePolar MoleculeAny molecules with charges Any molecules with charges
like to STICK to other like to STICK to other molecules with charges molecules with charges (opposites attract !!!)(opposites attract !!!)
CohesionCohesion
Attraction between Attraction between water moleculeswater molecules that that creates surface tension..creates surface tension..
Water sticks to water Water sticks to water due to Hydrogen due to Hydrogen BondingBonding
Hydrogen BondingHydrogen Bonding
Hydrogen Hydrogen BondingBonding
Surface Surface TensionTension
AdhesionAdhesion
Attraction of water to Attraction of water to other other polarpolar molecules molecules. .
Water sticks (adheres) to Water sticks (adheres) to other things.other things.
Capillary action: allows water Capillary action: allows water to move up small tubes to move up small tubes against gravityagainst gravity– Example: helps plants “drink”Example: helps plants “drink”
Solvent PropertiesSolvent PropertiesWater is called the Water is called the universal universal
solventsolvent; many things can dissolve ; many things can dissolve in water because it is a polar in water because it is a polar molecule.molecule.
HydrationHydration
SOLUTIONS & SUSPENSIONSSOLUTIONS & SUSPENSIONS
Examples to discuss: Don’t have to Examples to discuss: Don’t have to memorizememorize
Solutions:Solutions:– Very evenly dispersed small particlesVery evenly dispersed small particles– SOLUTE is dissolved into the SOLVENTSOLUTE is dissolved into the SOLVENT
Example: salt into water, fluids around your cellsExample: salt into water, fluids around your cells
Suspensions:Suspensions:– Larger particlesLarger particles– Will settle out if let to sitWill settle out if let to sit
Example: bloodExample: blood
Solvent properties allow transport of many Solvent properties allow transport of many substances in our bodiessubstances in our bodies
Density of WaterDensity of Water
Water is unique because its solid Water is unique because its solid form (ice) is form (ice) is lessless dense than the dense than the liquid form due to expansion.liquid form due to expansion.
Question: Why is this property Question: Why is this property important to aquatic plant and important to aquatic plant and animal life?animal life?– Discuss the answerDiscuss the answer
Hydrogen Bonding (ICE)Hydrogen Bonding (ICE)
Notice the “hole” Notice the “hole” in the hexagonal in the hexagonal structure and all structure and all the H-Bondsthe H-Bonds
The “hole” is why The “hole” is why the ice floats – it the ice floats – it makes it less makes it less dense than waterdense than water
ImbibitionImbibition
Water will Water will soak into a soak into a hydrophilic hydrophilic substance.substance.
High Specific HeatHigh Specific Heat
Water can absorb Water can absorb a lot of energy a lot of energy before its before its temperature temperature changes.changes.
This helps us to This helps us to maintain our body maintain our body temperaturetemperature
High Heat of Vaporization High Heat of Vaporization Water absorbs a Water absorbs a
lot of energy (576 lot of energy (576 cal/g) to change cal/g) to change states-our sweat states-our sweat carries away that carries away that energy when it energy when it evaporates!!!evaporates!!!
ACIDS, BASES, AND ACIDS, BASES, AND pHpH
pH ScalepH Scale
pH of Common SubstancespH of Common SubstancespH of Common SubstancespH of Common Substances
pH ScalepH Scale
Indicates concentration of H+ ions in Indicates concentration of H+ ions in a solutiona solution
Neutral = 7 = concentrations of H+ Neutral = 7 = concentrations of H+ and OH- are equaland OH- are equal
Acids are below 7 = higher H+ Acids are below 7 = higher H+ concentrationsconcentrations
Bases are above 7 = lower H+ Bases are above 7 = lower H+ concentrationsconcentrations
BuffersBuffers BUFFERS ARE VERY IMPORTANT!!!BUFFERS ARE VERY IMPORTANT!!! EVERYTIME YOU EAT, DRINK, OR BREATHE EVERYTIME YOU EAT, DRINK, OR BREATHE
YOU CHANGE YOUR pH YOU CHANGE YOUR pH Buffers help maintain your pH homeostasis Buffers help maintain your pH homeostasis
by resisting large, abrupt changes in the by resisting large, abrupt changes in the pHpH
This is important because all chemical This is important because all chemical reactions are affected by pH (we will reactions are affected by pH (we will discuss this with proteins)discuss this with proteins)
Buffers are a combo of a weak acid and a Buffers are a combo of a weak acid and a weak baseweak base
Pre AP Biology Pre AP Biology Biochemistry Part II - Biochemistry Part II -
MacromoleculesMacromolecules
The molecules that make up and The molecules that make up and run your bodyrun your body
4 Types of Macromolecules4 Types of Macromolecules
REVIEW CONCEPTSREVIEW CONCEPTS
ALL of these Macromolecules are ALL of these Macromolecules are Organic moleculesOrganic molecules
What does that mean?What does that mean? It means they have carbon in the It means they have carbon in the
presence of hydrogenpresence of hydrogen
MacromoleculesMacromolecules
ORGANICORGANIC molecules that weigh molecules that weigh more than more than 100,000100,000 Daltons are Daltons are referred to as macromoleculesreferred to as macromolecules
Macromolecules are constructed of Macromolecules are constructed of smaller units called smaller units called POLYMERSPOLYMERS
Polymers are subdivided into their Polymers are subdivided into their basic units called basic units called MONOMERS.MONOMERS.
MacromoleculesMacromolecules
Polymers account for the molecular Polymers account for the molecular uniqueness of organisms. uniqueness of organisms.
FOR EXAMPLE: ~20 amino acids are FOR EXAMPLE: ~20 amino acids are responsible for all forms of life. responsible for all forms of life. These amino acids form every These amino acids form every conceivable protein known to man.conceivable protein known to man.
Making & Breaking of Making & Breaking of PolymersPolymers
MakingMaking of Polymers of Polymers
Dehydration Synthesis – is Dehydration Synthesis – is an an anabolicanabolic process by process by which two molecules are which two molecules are chemically joined through chemically joined through the use of enzymes and a the use of enzymes and a lossloss of water of water
AKA: PolymerizationAKA: Polymerization
Dehydration Synthesis Dehydration Synthesis Example: Example:
Glucose + Fructose = SucroseGlucose + Fructose = Sucrose
Making & Making & BreakingBreaking of Polymers of Polymers
HydrolysisHydrolysis – is a – is a cataboliccatabolic process by process by which the bonds which the bonds between monomers are between monomers are broken by the enzyme broken by the enzyme and the and the additionaddition of of water.water.
Hydrolysis Example: Hydrolysis Example: Sucrose = Glucose + FructoseSucrose = Glucose + Fructose
(just reverse dehydration synthesis) (just reverse dehydration synthesis)
MacromoleculesMacromolecules
CarbohydratesCarbohydrates
CarbohydratesCarbohydrates
Molecules made of C,H,and OMolecules made of C,H,and OMonosaccharides = monomerMonosaccharides = monomerDisaccharide = polymerDisaccharide = polymerPolysaccharide = Polysaccharide =
macromoleculemacromolecule
MonosaccharidesMonosaccharides
Single Single SugarsSugars
MonosaccharidesMonosaccharides
Basic Formula: Basic Formula: CCnnHH2n2nOOn
examples: – CC66HH1212OO6
– CC55HH1010OO5
– 1:2:1 ratioFunction: To supply Function: To supply IMMEDIATEIMMEDIATE
energy for all cell activitiesenergy for all cell activities
Monosaccharide ExamplesMonosaccharide Examples
Triose sugarsTriose sugars– 3 carbons3 carbons– Glyceraldehyde & dihydroxyacetoneGlyceraldehyde & dihydroxyacetone
Pentose sugarsPentose sugars– 5 carbons5 carbons– Ribose, deoxyribose, and ribuloseRibose, deoxyribose, and ribulose
Hexose sugarsHexose sugars– 6 carbons6 carbons– Glucose, galactose, fructoseGlucose, galactose, fructose
Glucose: Your brain’s favorite foodGlucose: Your brain’s favorite food
Glucose MetabolismGlucose Metabolism
DisaccharidesDisaccharides DoubleDouble sugars sugars Basic Formula: Basic Formula: CC12HH2222OO1111
Same formula but different structural Same formula but different structural arrangementsarrangements
Notice that one molecule of Notice that one molecule of waterwater is is missing from the formulamissing from the formula
2 x2 x CC66HH1212OO6 = = CC12HH2222OO11 11 + H + H22OO
Making a DisaccharideMaking a Disaccharide
Dehydration SynthesisDehydration Synthesis
DisaccharidesDisaccharides Bond holding monomers together is Bond holding monomers together is
called a 1-4 or 1-2 called a 1-4 or 1-2 glycosideglycoside linkage linkage (the #s refer to the position of the (the #s refer to the position of the carbons that are bonded)carbons that are bonded)
Examples:Examples:– SucroseSucrose– MaltoseMaltose– LactoseLactose– NOTICE: Mono & Disaccharides end in NOTICE: Mono & Disaccharides end in
the suffix the suffix -ose-ose
PolysaccharidesPolysaccharides
ManyMany sugars sugarsBasic FormulaBasic Formula: : ( C( C66HH1010OO55))nn
Act as structural or Act as structural or storage moleculesstorage molecules
Storage PolysaccharidesStorage Polysaccharides
These are our “complex These are our “complex carbohydrates” (carbohydrates” (ENERGY ENERGY STORAGESTORAGE))
STARCH is a PLANT storage STARCH is a PLANT storage polysaccharide that is composed polysaccharide that is composed entirely of glucose joined by 1-4 entirely of glucose joined by 1-4 glycoside linkagesglycoside linkages
Amylose is the simplest form of Amylose is the simplest form of starchstarch
Amylopectin is more complex with a Amylopectin is more complex with a branched structurebranched structure
Storage PolysaccharidesStorage Polysaccharides
Glycogen is an animal starch stored Glycogen is an animal starch stored in the liver and skeletal muscles of in the liver and skeletal muscles of vertebrates.vertebrates.
It is more highly branched than It is more highly branched than amylopectin.amylopectin.
PLANTS make their own PLANTS make their own carbohydrates carbohydrates
ANIMALS eat the plantsANIMALS eat the plants FOOD/ENERGY WEB IN ACTION!!FOOD/ENERGY WEB IN ACTION!!
Glycogen StorageGlycogen Storage
Using GlycogenUsing Glycogen
If your blood sugar (glucose) gets too If your blood sugar (glucose) gets too high:high:– Your body stores it in your liver and Your body stores it in your liver and
skeletal muscles as glycogenskeletal muscles as glycogen If your blood sugar gets too low:If your blood sugar gets too low:
– Your body breaks down the glycogen Your body breaks down the glycogen and releases glucose to your bloodand releases glucose to your blood
Structural PolysaccharidesStructural Polysaccharides
Cellulose and chitin are examples of Cellulose and chitin are examples of structural polysaccharidesstructural polysaccharides
Cellulose is the most abundant Cellulose is the most abundant organic compound on earth.organic compound on earth.
Chitin is found in arthropod Chitin is found in arthropod exoskeletons and the cell walls of exoskeletons and the cell walls of fungi (absorbs fat – remember fungi (absorbs fat – remember commercials for the fat absorbing commercials for the fat absorbing pill? It was chitin. It works but you pill? It was chitin. It works but you couldn’t eat enough of it to really couldn’t eat enough of it to really help lose weight!)help lose weight!)
Structural PolysaccharidesStructural Polysaccharides CelluloseCellulose
– Primarily found in cell walls of plantsPrimarily found in cell walls of plants– Must be broken down into glucose Must be broken down into glucose
before cells can use it for energybefore cells can use it for energy– Cows, termites, and roaches have Cows, termites, and roaches have
microbes in their digestive tracts that do microbes in their digestive tracts that do this for themthis for them
– WE DON’T – that is why we can’t graze WE DON’T – that is why we can’t graze on grass for lunch!!on grass for lunch!!
– However, we do need cellulose although However, we do need cellulose although we just call it FIBER in our diet: It scrubs we just call it FIBER in our diet: It scrubs out our intestines!out our intestines!
LIPIDSLIPIDS
Or fat fat fat fat fatOr fat fat fat fat fat
WARNING!!!!!WARNING!!!!!
YOU WILL HAVE TO CHOOSE ONE YOU WILL HAVE TO CHOOSE ONE DISCUSSION QUESTION ON YOUR DISCUSSION QUESTION ON YOUR TEST ABOUT THE FYI INFORMATION TEST ABOUT THE FYI INFORMATION CONTAINED IN THE REST OF THESE CONTAINED IN THE REST OF THESE NOTES NOTES
LipidsLipids
Contain C, H, and O but with a lower Contain C, H, and O but with a lower proportion of Oproportion of O
Do not mix with waterDo not mix with water They are HYDROPHOBIC because They are HYDROPHOBIC because
they are non polar.they are non polar. Examples: neutral fats, Examples: neutral fats,
phospholipids, and steroidsphospholipids, and steroids
LipidsLipids
KNOW THIS FACT: KNOW THIS FACT: Lipids are not Lipids are not solublesoluble in water. This is in water. This is
because water is polar and most lipids because water is polar and most lipids are nonpoloar.are nonpoloar.
Why are nonpolar substances unable Why are nonpolar substances unable to dissolve in a polar substance such to dissolve in a polar substance such as water?as water?
(can’t form hydrogen bonds)(can’t form hydrogen bonds)
Neutral Fats aka. TriglyceridesNeutral Fats aka. Triglycerides
Monomers:Monomers:–Glycerol: an alcohol Glycerol: an alcohol containing 3 Carbonscontaining 3 Carbons
–3 fatty acids3 fatty acidsAn ESTER bond connects An ESTER bond connects
the fatty acids with the the fatty acids with the glycerol.glycerol.
Neutral Fats:Neutral Fats:
Dehydration SynthesisDehydration Synthesis
Saturated Fats vs. UnsaturatedSaturated Fats vs. Unsaturated
Saturated Fats - all SINGLE C-C bondsSaturated Fats - all SINGLE C-C bonds Unsaturated Fats - have one or more Unsaturated Fats - have one or more
double C=C bonddouble C=C bond– The double bonds cut down on the # of The double bonds cut down on the # of
H atoms that can be attached. This H atoms that can be attached. This causes the molecule to bend at each of causes the molecule to bend at each of the double bond sites. the double bond sites.
Saturated Fats vs. UnsaturatedSaturated Fats vs. Unsaturated
WRITE THESE FACTS IN THE CHART WRITE THESE FACTS IN THE CHART ON YOUR NOTESON YOUR NOTES
Saturated Fats – Saturated Fats – – SINGLE BONDS, straight, pack SINGLE BONDS, straight, pack
closely together closely together – SOLID at room temp.SOLID at room temp.– ANIMAL FATSANIMAL FATS
Saturated Fats vs. UnsaturatedSaturated Fats vs. Unsaturated
WRITE THESE FACTS IN THE CHART WRITE THESE FACTS IN THE CHART ON YOUR NOTESON YOUR NOTES
Unsaturated Fats –Unsaturated Fats –– DOUBLE BONDS, Bent, can’t pack DOUBLE BONDS, Bent, can’t pack
closely togetherclosely together– LIQUID at room tempLIQUID at room temp– PLANT FATSPLANT FATS
Saturated vs. Unsaturated BondsSaturated vs. Unsaturated Bonds
http://biology.clc.uc.edu/courses/bio104/lipids.htm
Function of Neutral FatsFunction of Neutral Fats
INSULATION (subcutaneous fat)INSULATION (subcutaneous fat) ENERGY STORAGEENERGY STORAGE
– Very energy denseVery energy dense– Fat: 9 kcal of energy per gramFat: 9 kcal of energy per gram
Carbs & proteins 4 kcal of energy per gramCarbs & proteins 4 kcal of energy per gram
CUSHIONING FOR INTERNAL ORGANSCUSHIONING FOR INTERNAL ORGANS ABSORPTION OF FAT SOLUBLE VITAMINS:ABSORPTION OF FAT SOLUBLE VITAMINS:
– ADEKADEK– THESE VITAMINS CANNOT BE ABSORBED THESE VITAMINS CANNOT BE ABSORBED
UNLESS THEY ARE DISSOLVED IN FATUNLESS THEY ARE DISSOLVED IN FAT
FYI: CIS vs. TRANS ISOMERSFYI: CIS vs. TRANS ISOMERS
http://biology.clc.uc.edu/courses/bio104/lipids.htm
FYI: Trans FatsFYI: Trans Fats
Produced when cis vegetable oils are Produced when cis vegetable oils are heated.heated.
Multiple heatings, such as a fast food Multiple heatings, such as a fast food fryer, converts large quantities of cis fryer, converts large quantities of cis to trans bondsto trans bonds
Concern: trans fatty acids are Concern: trans fatty acids are carcinogeniccarcinogenic
PhospholipidsPhospholipids
Monomers are:Monomers are:– 2 fatty acids2 fatty acids– 1 phosphate1 phosphate
Both polar and non polar Both polar and non polar qualitiesqualities– Phosphate head is polarPhosphate head is polar– Fatty acid tail is non polarFatty acid tail is non polar
Function of PhospholipidsFunction of Phospholipids
Form cell membraneForm cell membrane–Phospholipid bilayerPhospholipid bilayer
Component of Nervous Component of Nervous TissueTissue
Phospholipid BilayerPhospholipid Bilayer
Myelin Sheath: Insulates NerveMyelin Sheath: Insulates Nerve
SteroidsSteroids
Monomers are carbon skeleton of 4 Monomers are carbon skeleton of 4 fused ringsfused rings
SteroidsSteroids Steroids are FAT SOLUBLE and Steroids are FAT SOLUBLE and
contain little oxygencontain little oxygen THE FOLLOWING ARE EXAMPLES:THE FOLLOWING ARE EXAMPLES: Cholesterol is found in all ANIMAL Cholesterol is found in all ANIMAL
tissue. Plants do NOT contain tissue. Plants do NOT contain cholesterolcholesterol– Cholesterol is the MOST IMPORTANT Cholesterol is the MOST IMPORTANT
steroid since it is essential for the steroid since it is essential for the manufacture of ALL other steroidsmanufacture of ALL other steroids
– It also helps to STABILIZE your cell It also helps to STABILIZE your cell membranes.membranes.
ExamplesExamples
Sex hormones: estrogen, Sex hormones: estrogen, testosterone, progesteronetestosterone, progesterone
Insulin: blood glucose regulationInsulin: blood glucose regulation Aldosterone: maintains water Aldosterone: maintains water
balancebalance Bile salts: digestion & absorption of Bile salts: digestion & absorption of
FATSFATS
FYI: HDL vs. LDLFYI: HDL vs. LDL LIPOPROTEINS are molecules that help LIPOPROTEINS are molecules that help
transport lipids in the blood (since lipids transport lipids in the blood (since lipids are NOT water soluble, they cannot are NOT water soluble, they cannot circulate by themselves)circulate by themselves)
HIGH DENSITY LIPOPROTEINSHIGH DENSITY LIPOPROTEINS– Transport excess cholesterol to liver for Transport excess cholesterol to liver for
breakdownbreakdown LOW DENSITY LIPOPROTEINSLOW DENSITY LIPOPROTEINS
– Transport excess cholesterol to cells for Transport excess cholesterol to cells for storage (can clog artery walls, etc.)storage (can clog artery walls, etc.)
YOU WANT YOUR HDL LEVEL TO BE YOU WANT YOUR HDL LEVEL TO BE HIGHER THAN YOUR LDL LEVELHIGHER THAN YOUR LDL LEVEL
PreLab RemarksPreLab Remarks Learn how to test for macromoleculesLearn how to test for macromolecules
– 1 Glucose—Benedicts test1 Glucose—Benedicts testTest tubes will be hot, handle carefullyTest tubes will be hot, handle carefully
– 2 Starch—iodine turns blue/black on 2 Starch—iodine turns blue/black on starchstarch
– 3 Proteins—Biuret’s test turns purple 3 Proteins—Biuret’s test turns purple on proteinon protein
– 4 Lipids---Sudan III stains fats pink4 Lipids---Sudan III stains fats pinkSuit up—goggles & apronsSuit up—goggles & aprons
Each group member performs a different test and shares results with group
ClosureClosureWhat test can be used to detect What test can be used to detect
the presence of starch? glucose? the presence of starch? glucose? protein?protein?
What elements do glucose, What elements do glucose, starch, and proteins have in starch, and proteins have in common?common?
Don’t forget the homework Don’t forget the homework assignment.assignment.
NUCLEIC ACIDSNUCLEIC ACIDS
GENETIC MATERIALGENETIC MATERIAL
Nucleic AcidsNucleic Acids
NUCLEOTIDESNUCLEOTIDES (monomers) (monomers) consist of:consist of:– 5-C ribose or 5-C ribose or
deoxyribose deoxyribose sugar (ribose sugar (ribose has one more has one more oxygen in its oxygen in its molecule)molecule)
Nucleic AcidsNucleic Acids Nucleotides con’t:Nucleotides con’t:
– PhosphatePhosphate– Nitrogenous baseNitrogenous base
Double ring purines: guanine (G) or Double ring purines: guanine (G) or adenine (A)adenine (A)
Single ring pyrimidine: Cytosine (C), Single ring pyrimidine: Cytosine (C), thymine (T), or uracil (U)thymine (T), or uracil (U)
Nucleotides are joined together by Nucleotides are joined together by phosphodiester bondsphosphodiester bonds
Nucleic acids contain (CHONP)Nucleic acids contain (CHONP)
NucleotidesNucleotides
DNA & RNA
DNA CHART INFODNA CHART INFO
Cellular site = nucleusCellular site = nucleus Function = Directs protein synthesis Function = Directs protein synthesis
(contains all the instructions)(contains all the instructions) Sugar = deoxyriboseSugar = deoxyribose Nitrogenous bases = A T C GNitrogenous bases = A T C G Structure = double helixStructure = double helix
RNA CHART INFORNA CHART INFO
Cellular site = in & out of nucleus Cellular site = in & out of nucleus (can travel)(can travel)
Function = Carries out protein Function = Carries out protein synthesis (makes it happen)synthesis (makes it happen)
Sugar = riboseSugar = ribose Nitrogenous bases = A U C GNitrogenous bases = A U C G Structure = single strandStructure = single strand
PROTEINSPROTEINS
In charge of all your body In charge of all your body functionsfunctions
ProteinsProteins
Monomer: Amino AcidsMonomer: Amino Acids– Each amino acid consists of a Each amino acid consists of a
central carbon bonded to:central carbon bonded to:Amino group (-NHAmino group (-NH22) ) HydrogenHydrogenR group – this is a functional group that R group – this is a functional group that
makes each amino acid unique in makes each amino acid unique in function and actionfunction and action
Carboxyl group (-COOH): an acid groupCarboxyl group (-COOH): an acid group
Basic amino acid structureBasic amino acid structure
20 main 20 main amino acidsamino acids
General structure Alanine Serine
Section 2-3
Figure 2-16 Amino Acids
Amino group Carboxyl group
Protein formationProtein formation
Dehydration synthesisDehydration synthesis joins the joins the amino acid monomers together by amino acid monomers together by use of a use of a peptidepeptide bond bond– Hydrolysis breaks them apartHydrolysis breaks them apart
You will sometimes hear proteins You will sometimes hear proteins called “polypeptides” for this reason.called “polypeptides” for this reason.
Proteins make up ~50% of dry Proteins make up ~50% of dry weight of most cells and contain the weight of most cells and contain the elements elements CHONCHON..
Functions of ProteinsFunctions of Proteins
Proteins have a wide variety of Proteins have a wide variety of functions. These functions can be functions. These functions can be divided into 2 categories:divided into 2 categories:– STRUCTURAL: support and strengthenSTRUCTURAL: support and strengthen– FUNCTIONAL: crucial roles in biological FUNCTIONAL: crucial roles in biological
processesprocesses
– Let’s take a look at a few of the Let’s take a look at a few of the examples in your notes: You do need to examples in your notes: You do need to memorize these examples. Proteins are memorize these examples. Proteins are VERY IMPORTANT!!!VERY IMPORTANT!!!
Structural ProteinsStructural Proteins
Functional Functional
Proteins Proteins
Cell Membrane Proteins Cell Membrane Proteins
Protein HormonesProtein Hormones
Functional ProteinsFunctional Proteins
Let’s take a look at the rest of the Let’s take a look at the rest of the examples in your notesexamples in your notes
Enzyme actionEnzyme action
Enzymes can act as a catalystEnzymes can act as a catalyst– A molecule that lowers A molecule that lowers ACTIVATION ACTIVATION
ENERGYENERGY– This can increase a reaction’s speed This can increase a reaction’s speed
(rate) up to 10(rate) up to 101010 times!! times!!– The enzyme is The enzyme is not changed at allnot changed at all by by
the chemical reaction so can be reused the chemical reaction so can be reused over and overover and over
Enzyme SpecificityEnzyme Specificity
SubstrateSubstrate: the molecule that is : the molecule that is affected by the enzymeaffected by the enzyme
Active siteActive site: place on the enzyme : place on the enzyme where the reaction occurswhere the reaction occurs
ONE ENZYME ACTS ON ONLY ONE ONE ENZYME ACTS ON ONLY ONE SUBSTRATE: VERY SPECIFIC !SUBSTRATE: VERY SPECIFIC !
AmylAmylasease breaks down amyl breaks down amyloseose LactLactasease breaks down lact breaks down lactoseose
Enzyme ActionEnzyme Action
Lock and key fitLock and key fit: active site and : active site and substrate fit exactlysubstrate fit exactly
Induced fitInduced fit: active site can adjust to : active site can adjust to “wrap around” substrate to get “wrap around” substrate to get optimum fitoptimum fit
Protein DenaturationProtein Denaturation
Functional Proteins depend on their Functional Proteins depend on their structurestructure to do their job to do their job
STRUCTURE DETERMINES FUNCTIONSTRUCTURE DETERMINES FUNCTION Active siteActive site must be the correct must be the correct
shape for the substrateshape for the substrate H-bondsH-bonds hold these proteins hold these proteins
together in their correct shapetogether in their correct shape
Protein DenaturationProtein Denaturation
Extremes (too high or too low) in Extremes (too high or too low) in TEMPERATURETEMPERATURE and and pHpH can disrupt can disrupt the the H-bondsH-bonds causing the causing the active siteactive site to be destroyed.to be destroyed.
Then the enzyme CANNOT do its Then the enzyme CANNOT do its function! Thus it is said to be function! Thus it is said to be denatured (Not the same nature as denatured (Not the same nature as before)before)
Glucose
Substrates
ATP
Substratesbind toenzyme
Substratesare convertedinto products
Enzyme-substratecomplex
Enzyme(hexokinase)
ADPProducts
Glucose-6-phosphate
Productsare released
Section 2-4
Figure 2-21 Enzyme Action
Active site
FACT REVIEWFACT REVIEW
Put the info from the Put the info from the following charts into your following charts into your
notes chartsnotes charts
Elements in MacromoleculesElements in Macromolecules
CarbohydrateCarbohydrate C,H,OC,H,O
LipidsLipids C,H,O,(P)C,H,O,(P)
ProteinsProteins C,H,O,NC,H,O,N
NucleicNucleic
AcidsAcidsC,H,O,N,PC,H,O,N,P
MonomersMonomersCarbohydratesCarbohydrates Mono-Mono-
saccharidessaccharides
Lipids (neutral Lipids (neutral fats)fats)
Glycerol & Glycerol & fatty acidsfatty acids
ProteinsProteins AminoAmino
AcidsAcids
NucleicNucleic
AcidsAcidsNucleotidesNucleotides
BondsBonds
CarbohydratesCarbohydrates Glycoside Glycoside linkagelinkage
LipidsLipids Ester Ester linkageslinkages
ProteinsProteins Peptide Peptide
NucleicNucleic
AcidsAcidsPhospho-Phospho-diesterdiester
Major functionMajor functionCarbohydratesCarbohydrates Immediate Immediate
energy & storageenergy & storage
LipidsLipids Energy storageEnergy storage
Cell componentsCell components
Form steroidsForm steroids
ProteinsProteins FunctionalFunctional
Structural Structural
NucleicNucleic
AcidsAcidsGenetic infoGenetic info
NUTRITIONNUTRITION
LET’S TAKE A LOOK AT THE LET’S TAKE A LOOK AT THE NUTRITION NOTES NUTRITION NOTES
WORKSHEETWORKSHEET
Nutrition LabelNutrition Label
What are the labels valuable?What are the labels valuable? Consider the label in your notes:Consider the label in your notes:
– How many servings?How many servings?– What is a serving?What is a serving?– How much fat if I ate the whole How much fat if I ate the whole
package?package?