C1.1 Enzymes & Metabolism

Question 1

What are enzymes?

Answer 1

specialized, globular proteins which catalyse the chemical reaction by lowering its activation energy

Question 2

Active site

Answer 2

region on the enzyme designed for only one other substance to fit

Question 3

Catalytic site

Answer 3

where the catalysis happen

Question 4

Binding site

Answer 4

recognizes substrate and ensures the correct subtrate fits into the active site

Question 5

What is enzyme-substrate specificity?

Answer 5

ability of the enzyme to recognize and bind to specific substrate

Question 6

What is induced fit bonding?

Answer 6

the active site changes its shape (conformational change) so substrate will fit better

Question 7

What is transition state?

Answer 7

The point of energy that must be reached for reaction to happen

Question 8

Activation energy

Answer 8

energy needed to reach transition state

Question 9

What type of reaction is formation of bonds? (exo/endo)

Answer 9

exothermic

Question 10

What type of reaction is breakdown of bonds? (exo/endo)

Answer 10

Endothermic

Question 11

Metabolism

Answer 11

all chemical reactions taking place in the body that build or break the molecules

Question 12

Anabolic reaction (e.g. peptide bond formation)

Answer 12

building molecules up, monomers build up to form polymers

Question 13

Catabolic reaction (e.g. digestion)

Answer 13

breaking down the molecules

Question 14

Active sites and substrates function via ______ and _____

Answer 14

molecular motion, collision

Question 15

What factors affect the rate of enzyme activity?

Answer 15

temperature, pH, substrate concentration

Question 16

How temperature affects the rate of enzyme activity?

Answer 16

in higher temperature (up to 37 C), molecules move faster and bump into each other more often

Question 17

How pH affects the rate of enzyme activity?

Answer 17

enzymes work better in different range of pH, but any shift from this range decreases the rate

Question 18

What are the main properties and structure of enzymes?

Answer 18

• globular proteins
• soluble

Question 19

What are extracellular enzymes and how are they produced?

Answer 19

used outside the cell, produced by ribosomes on rough ER and then modified and packed into vesicles in Golgi to be released through cell membrane

Question 20

What are intracellular enzymes and how are they produced?

Answer 20

used within the cell and produced by free ribosomes in cytoplasm

Question 21

What is non-competitive inhibition?

Answer 21

when a substance binds to the allosteric site and change the shape of the active site making it impossible for the substrate to bind

Question 22

What is an allosteric site?

Answer 22

regulatory site as binding there changes thr enzyme

Question 23

What is competitive inhibition?

Answer 23

when a competitor with similar shape to the substrate binds to active site, blocking it

Question 24

How do warm-blooded animals use heat generated from metabolic reactions?

Answer 24

to maintain body temperature

Question 25

What are statins?

Answer 25

example of competitve inhibitor that inhibit the enzyme that produces cholesterol

Question 26

What is end-product inhibition?

Answer 26

final product becomes a non-competitve inhibitor of the first enzyme in the chain

Question 27

What's the function of end-product inhibition?

Answer 27

it prevents a build up of the final product

Question 28

What's the example of end-product inhibition?

Answer 28

threonine (enzyme) to isoleucine (product)

Question 29

Compare competitive and non-competitve inhibition

Answer 29

Question 30

What is mechanism-based inhibition?

Answer 30

inhibitor binds permanently to the active site by covalent bond

Question 31

What the example of mechanism-based inhibition?

Answer 31

- treatment for HIV (AZT) - penicillin

Question 32

How penicilin works?

Answer 32

it binds to an enzyme transpeptidase in the bacterial cell wall that makes the cell wall and cause it to burst