Proteins

Examples of Proteins Horns Spider Webs Hair Egg Whites

Hair

Nails Muscles Enzymes

Functions of Proteins What do proteins do? Provide Structural Support Example: Collagen in Skin Make up Antibodies in your Immune System Transport Example: Hemoglobin carries Oxygen

Proteins: How They’re Made Made up of C, H, O, N, and sometimes S

Proteins: How They’re Made What are the monomers of a protein? Amino Acids How many amino acids are there? 20 What are the parts of an amino acid?

Amino Acids

With Peptide Bonds (in dehydration synthesis) Polymers How are amino acids joined? With Peptide Bonds (in dehydration synthesis) Two amino acids together are called a Dipeptide Many amino acids are called a Polypeptide

Polymers Which two groups of the amino acid form a peptide bond?

Polypeptide Amino Acid Peptide Bond

Proteins Does the order of the amino acids in a protein matter? Why? The order of the amino acids affects the SHAPE Why is the shape of the protein important? The shape determines the FUNCTION! Why?

Denaturing Proteins Two changes cause a change in the shape of the protein…this is known as DENATURATION. So if the shape changes, what’s affected? The Function of the Protein! Other Causes of Protein Denaturation salt concentration and environmental factors

What are some examples of Denatured Proteins? Raw Egg vs. Cooked Egg Raw Meat Vs. Grilled Meat How is the consistency of raw vs. cooked different?

A type of protein that speeds up metabolic (chemical) reactions. ENZYMES aka: Catalysts What is an enzyme? A type of protein that speeds up metabolic (chemical) reactions.

What is needed to start a reaction? Activation energy Energy absorbed reactant Energy released Products

Why is the activation energy lower? Energy absorbed Energy released reactant Products Activation energy A Catalyst was added! Enzymes lower the activation energy

Comparing Reactions Which line would represent a reaction with an enzyme present? Without an enzyme Energy absorbed Reactant Products Energy released

How Do Enzymes Work? Enzymes work like a lock and key. Specific enzymes work with specific substrates. enzyme Use the analogy of enzymes as a lock and key. Explain that substrates are reactants. Substrate (key) must fit exactly into the active site of and enzyme (lock), just like only specific keys fit certain locks. substrate

a substance on which an enzyme acts during a chemical reaction What’s a Substrate? a substance on which an enzyme acts during a chemical reaction *enzymes act only on specific substrates

The substance is formed in a chemical reaction What is a product? The substance is formed in a chemical reaction

Enzymes and Active Sites What is an Active Site? The site on an enzyme that attaches to the substrate Is the active site the same for all enzymes and substrates? NO! Only a certain substrate fits into a particular active site

Enzymes Activity Why is this not good? Changes in pH and temperature can affect the shape of an enzyme. What will happen if the shape changes? The enzyme can be denatured Why is this not good? Any factor that changes the shape of an enzyme can affect the enzyme’s activity

Enzymes in our Body Amylase Enzyme found in our saliva Breaks down some starches into glucose molecules So digestion of food occurs in the mouth before it reaches the stomach Pepsin First animal enzyme to be discovered Digestive protease in stomach that works with HCl acid to degrade food proteins into peptides