Enzymes

Question 1

What are enzymes?

Answer 1

Proteins, and proteins are formed of amino acids. The R group is the only difference between them

Question 2

What is the R group?

Answer 2

A side chain functional group. Look at this group to determine non-polar covalent bonds

Question 3

What are hydrophobic R groups?

Answer 3

Non polar covalent bonds (C-H, C-C). Do not dissolve in water

Question 4

What are hydrophilic R groups?

Answer 4

full/partial charges, can bond and dissolve in H2O

Question 5

What are amino acids?

Answer 5

They are linked into peptides, and peptide bonds are covalent bonds between amino acids

Question 6

Describe the structure of a peptide.

Answer 6

Amino acid group at one end, carboxyl group at the other end, and a backbone of some sort

Question 7

What do amino acid polymers do?

Answer 7

Fold into proteins

Question 8

What is a peptide?

Answer 8

Polymer of amino acids

Question 9

What is a polypeptide?

Answer 9

More than 10 amino acids linked together

Question 10

What is a polymer?

Answer 10

Polypeptide folded into a 3D shape

Question 11

What is the 1st structure?

Answer 11

The polypeptide, a sequence of amino acids

Question 12

What is the 2nd structure?

Answer 12

Helices and sheets, stabilized by hydrogen bonds along the backbone

Question 13

What is the 3rd structure?

Answer 13

Protein, secondary structure turns into 3D protein shape due to different interactions (ionic, covalent, etc..) between the R groups

Question 14

How many subunits does hemoglobin have?

Answer 14

4 subunits (proteins) to make an enzyme

Question 15

What is a homotrimer?

Answer 15

All same subunits

Question 16

What is a heterotrimer?

Answer 16

1 or more different subunits

Question 17

What is energy required for in relation to enzymes?

Answer 17

Used to destabilize the substrate. The energy that gets a reaction started is activation energy (delta G or ea), then free energy is required to destabilize bonds in the reactants and form bonds that generate products

Question 18

How do you speed up a chemical reaction?

Answer 18

• Increase [reactant] so they collide more
• Increase temperature
• Add a catalyst

Question 19

Can enzymes act as catalysts?

Answer 19

Yes, reactions with a catalyst don’t require as much energy and affects activation energy (ea or delta G)

Question 20

What determines an enzymes function?

Answer 20

Its shape

Question 21

What happens when a substrate enters an enzymes active site?

Answer 21

Enzyme changes shape to produce enzyme-substrate complex and interact

Question 22

What does the enzyme-substrate complex do?

Answer 22

Forces reactants (substrate) into transition state by breaking bonds in reactants and causing formation of products

Question 23

What happens when products (substrates) are released from the enzyme?

Answer 23

Enzyme goes back to its 3D shape, ready to process again
- Enzymes do not supply energy

Question 24

What happens when a substrate is forced into a transition state?

Answer 24

Enzyme reduces the need for as much activation energy

Question 25

What is the rate of converting substrate to products?

Answer 25

Depends on enzyme and substrate concentration

Question 26

How do cells control enzyme kinetics?

Answer 26

They control it through inhibitor and activator concentrations
Increase in enzyme concentration = increase in rate of reaction

Question 27

What happens if there is too much substrate?

Answer 27

Plateau

Question 28

What is denaturation?

Answer 28

Partial or complete change to protein structure. It can be reversible or irreversible, it can be caused by; inhibitors, pH, and non-competitive inhibitors