2. Proteins
Made of amino acids in a specific sequence attached by peptide bonds. Consist primarily of carbon, hydrogen, oxygen, and nitrogen, but may include a few other elements.
Proteins can be enzymes or structural building blocks.
Proteins can vary from organism to organism. They are what make you unique.

3. Amino Acids
Amino acids ~ building blocks of proteins; contains an amino group (-NH2), a carboxyl group (-COOH), a central carbon, a Hydrogen, and an R group.
The R group is unique for the different amino acids
There are 20 different types of amino acids.
A protein may contain as few as 50 or as many as several thousand amino acids.
All proteins in all living things consist of these same 20 different amino acids, but the combination of the amino acids is unique for different living things.

5. Polypeptide Chain
Peptide bond ~ a bond that links the carboxyl and the amino groups of two amino acids. Dehydration synthesis occurs in peptide bonding.
Polypeptide chain ~ many amino acids joined together by peptide bonds, forming proteins.

6. Synthesis ~ process that forms a new substance
Dehydration/Condensation and Hydrolysis Reactions
(Making and Breaking Polymers)
Monomers are linked together to form polymers through dehydration synthesis aka condensation reactions, which remove water
Synthesis ~ process that forms a new substance
Polymers are broken apart by hydrolysis, the addition of water

7. Unlinked monomer Short polymer Figure 3.3A_s1
Figure 3.3A_s1 Dehydration reaction building a polymer chain (step 1) 7

8. Dehydration reaction forms a new bond
Figure 3.3A_s2
Unlinked monomer
Short polymer
Dehydration reaction forms a new bond
Figure 3.3A_s2 Dehydration reaction building a polymer chain (step 2)
Longer polymer 8

9. Figure 3.3B_s1
Figure 3.3B_s1 Hydrolysis breaking down a polymer (step 1) 9

10. Hydrolysis breaks a bond
Figure 3.3B_s2
Hydrolysis breaks a bond
Figure 3.3B_s2 Hydrolysis breaking down a polymer (step 2) 10

13. Protein Folding Four Levels of Protein Structure:
1. Primary structure ~ the sequence of amino acids in a single polypeptide chain. If even one amino acid is missing or out of place the protein will not function properly.
2. Secondary structure ~ the polypeptide chain forms either alpha helixes or beta pleated sheets. This is caused by hydrogen bonds that form at set intervals within the chain.
Tertiary structure ~ the alpha helixes or beta pleated sheets fold. Due to interactions between the R groups
Quaternary structure ~ Proteins that are composed of multiple polypeptide chains, called subunits.
Denatured- when a protein unfolds. If a protein isn’t folded right it won’t function right. Extreme heat and change in pH are a couple things that can denature proteins.

15. Enzymatic Function of Proteins
Enzyme ~ organic catalysts. They speed up a reaction but are not changed in the reaction. Most are proteins.
Substrate- the compound the enzyme is affecting
Active site ~ the area of the enzyme that combines with the substrate. The active site fits with the shape of the substrate like a lock and key.
When the enzyme binds to the substrate it changes shape and weakens some of the chemical bonds in the substrate
This lowers the activation energy which is the energy necessary to start a reaction, so it speeds up the reaction.
Specific enzymes only work for specific substrates and specific reactions.
Some enzymes in your body cause reactions to occur 1 million times faster.
Cold temperatures don’t denature a protein but they do cause molecules to move around slower so the enzyme and the substrate are less likely to come in contact with each other.

16. Enzyme available with empty active site
Figure 5.14_s1 1
Enzyme available with empty active site
Active site
Enzyme (sucrase)
Figure 5.14_s1 The catalytic cycle of an enzyme (step 1) 16

17. Enzyme available with empty active site
Figure 5.14_s2 1
Enzyme available with empty active site
Active site
Substrate (sucrose) 2
Substrate binds to enzyme with induced fit
Enzyme (sucrase)
Figure 5.14_s2 The catalytic cycle of an enzyme (step 2) 17

18. Enzyme available with empty active site
Figure 5.14_s3 1
Enzyme available with empty active site
Active site
Substrate (sucrose) 2
Substrate binds to enzyme with induced fit
Enzyme (sucrase)
H2O
Figure 5.14_s3 The catalytic cycle of an enzyme (step 3) 3
Substrate is converted to products 18

19. Enzyme available with empty active site
Figure 5.14_s4 1
Enzyme available with empty active site
Active site
Substrate (sucrose) 2
Substrate binds to enzyme with induced fit
Enzyme (sucrase)
Glucose
Fructose
H2O
Figure 5.14_s4 The catalytic cycle of an enzyme (step 4) 4
Products are released 3
Substrate is converted to products 19

20. Activation energy barrier
Figure 5.13A
Activation energy barrier
Enzyme
Activation energy barrier reduced by enzyme
Reactant
Reactant
Energy
Energy
Figure 5.13A The effect of an enzyme in lowering EA
Products
Products
Without enzyme
With enzyme 20

21. Activation energy barrier
Figure 5.13A_1
Activation energy barrier
Reactant
Energy
Figure 5.13A_1 The effect of an enzyme in lowering EA (part 1)
Products
Without enzyme 21

22. Activation energy barrier reduced by enzyme
Figure 5.13A_2
Enzyme
Activation energy barrier reduced by enzyme
Reactant
Energy
Figure 5.13A_2 The effect of an enzyme in lowering EA (part 2)
Products
With enzyme 22

23. Progress of the reaction
Figure 5.13Q a b
Energy
Reactants c
Figure 5.13Q Activation energy with and without an enzyme
Products
Progress of the reaction 23