ProteinsProteins

Organic compoundsOrganic compounds made of C, O, H, N made of C, O, H, N and Sand S

Building blocks – 20 different amino acidsBuilding blocks – 20 different amino acids

Peptide and Polypeptides: Peptide and Polypeptides:

Dehydration (Condensation)/ Hydrolysis Dehydration (Condensation)/ Hydrolysis ReactionsReactions

20 Amino Acids

Amino Acids *Amino Acids *color sheetcolor sheet

Which part of this structure gives an amino acid its uniqueness? a. amino group b. side chain c. carboxyl group d. central carbon

Reviewhttps://www.wisc-online.com/learn/natural-science/chemistry/bic007/peptide-bond-formation

www.rand.org/.../Rosetta/images/Proteins.gif

Protein Structure

*pipe cleaners

4 Classes of 4 Classes of Protein StructureProtein Structure

1.Primary Structure-chain sequence of amino acids

Phenylalanine

b. Pleated Sheeta. alpha

helix

The Secondary Structure is a. hydrogen bonds making alpha helix and pleated sheets b. chain of amino acids c. chain of monosaccharides d. folded chains of many amino acids

3. 3. Tertiary Tertiary Structure-Structure-Attractions between alpha helix and beta sheets folding onto each other

• Hydrophobic interactions

• Disulfide bridges (bonding of 2 cysteine molecules)

4. 4. Quarternary Structure- Quarternary Structure- more than more than one amino acid chainone amino acid chain

Ex: Hemoglobin (transport protein)

FunctionsFunctions of proteins (directly related of proteins (directly related to the shape of the protein)to the shape of the protein)

Contraction of musclesContraction of muscles Hormones (signals our cells)Hormones (signals our cells) Receptors (found on surface of cells)Receptors (found on surface of cells) Carriers (oxygen to cells)Carriers (oxygen to cells) Antibodies (fight off invaders)Antibodies (fight off invaders) EnzymesEnzymes

FUNCTIONSFUNCTIONS

LET’S REVIEW ON THE BOARDLET’S REVIEW ON THE BOARD

The following is what gives a protein its particular The following is what gives a protein its particular function.function.

a. polaritya. polarity

b. shapeb. shape

c. activation energyc. activation energy

d. number of substratesd. number of substrates

EnzymesEnzymes

EnzymesEnzymes - catalytic organic - catalytic organic moleculesmolecules

Lock & Key model Lock & Key model Induced fit modelInduced fit model Enzyme Reactions – temperature & Enzyme Reactions – temperature &

pH dependantpH dependant

Enzyme SpecificityEnzyme Specificity

Enzymes Enzymes are nature’s catalystsare nature’s catalysts Proteins or RNAProteins or RNA Are reuseableAre reuseable Generally catalyze only Generally catalyze only oneone reaction reaction

Enzyme-substrate complexEnzyme-substrate complex SubstrateSubstrate – reactant(s) an enzyme acts on – reactant(s) an enzyme acts on Active siteActive site – where substrate binds to the – where substrate binds to the

enzyme; has a specific shape created by enzyme; has a specific shape created by foldsfolds

This enzyme model is an example of lock and key or induced fit.

a. lock and key

b. induced fit

Induced Fit ModelInduced Fit Model

What happens to the enzyme after the product leaves? a. retains the shape of the substrate b. does not change at all c. goes back to its original shape d. keeps the shape of the product

Factors that affect enzyme Factors that affect enzyme activityactivity

1.1. TemperatureTemperature – optimal – optimal temperature at which rate of temperature at which rate of reaction in fastestreaction in fastest

2. 2. pHpH – optimal pH at which rate of – optimal pH at which rate of reaction is fastestreaction is fastest

DenaturationDenaturation

Protein Protein loses structureloses structure due to some other due to some other outside compound or stress outside compound or stress

- adding acid or base- adding acid or base - change in temperature- change in temperature - large amounts of certain chemicals- large amounts of certain chemicals Enzymes will not function Enzymes will not function May or may not be reversableMay or may not be reversableEx: eggs and meat Ex: eggs and meat

DenaturationDenaturation

ClosingClosing 1. What is the building blocks of proteins?1. What is the building blocks of proteins? 2. What are 2 functions of proteins?2. What are 2 functions of proteins? 3. What controls the function of a protein?3. What controls the function of a protein? 4. Explain what an enzyme is?4. Explain what an enzyme is? 5. Why is it important for your body to 5. Why is it important for your body to

maintain its internal temperature?maintain its internal temperature? 6. What does it mean for an enzyme to be 6. What does it mean for an enzyme to be

denatured?denatured?

Animated Denaturation Animated Denaturation

http://highered.mcgraw-hill.com/sites/0072943696/student_view0/chapter2/animation__protein_denaturation.html

Nucleic AcidsNucleic Acids

Very large & complex moleculesVery large & complex molecules Store hereditary information for cellsStore hereditary information for cells DNA & RNADNA & RNA Building blockBuilding block: Nucleotide : Nucleotide A nucleotide contains a A nucleotide contains a Phosphate Group Phosphate Group 5 – C sugar 5 – C sugar Nitrogen BaseNitrogen Base

Differences between DNA and Differences between DNA and RNARNA

DNADNA Double strandedDouble stranded Deoxyribose sugar Deoxyribose sugar

(5C)(5C)

Nitrogen basesNitrogen bases Thymine Thymine AdenineAdenine GuanineGuanine CytosineCytosine

RNA RNA Single strandSingle strand Ribose sugar (5C)Ribose sugar (5C)

Nitrogen basesNitrogen bases Uracil Uracil AdenineAdenine GuanineGuanine CytosineCytosine

Nucleic Acid

www.steve.gb.com/.../nucleotides/ssRNA.png