CMB Lecture 5

Question 1

What do enzymes do to the Ea?

Answer 1

Lower the activation energy

Question 2

Anabolic reactions are also called ___

Answer 2

Endergonic

Question 3

Catabolic reactions are also called ___

Answer 3

Exergonic

Question 4

What kind of reaction is an anabolic reaction?

Answer 4

“Energy enters” reaction, stored in large molecular products. Large molecules synthesized from small molecules. “Build up” reaction.

Question 5

Catabolic reactions are:

Answer 5

“Energy exits” reaction, becomes available for cellular work. Breakdown of large molecules into energy and smaller molecules. “Break down” reaction.

Question 6

Energy is produced by ______

Answer 6

Catabolic or exergonic energy releasing processes.

Question 7

ATP _____ to produce energy.

Answer 7

hydrolysis to ADP

Question 8

ATP synthesis from ____

Answer 8

ADP needs energy.

Question 9

When energy is required it is released _____

Answer 9

via hydrolysis, and becomes ADP + P.

Question 10

ATP consists of ____

Answer 10

3 phosphate groups, ribose, and adenine.

Question 11

Activation energy is:

Answer 11

The energy required to start reaction.

Question 12

T/F? Enzymes are not consumed by the reaction and can be used again.

Answer 12

T.

Question 13

What is active transport?

Answer 13

When ATP is required to move the molecules against the concentration gradient.

Question 14

How does ATP provide energy in carrier proteins?

Answer 14

Donates a phosphate group, one of which binds to the carrier protein.

Question 15

What happens when the phosphate is bound to the carrier protein?

Answer 15

It induces a change in shape. As this happens, this gives ADP +P

Question 16

ATP ___ in the motor protein.

Answer 16

Induces a change in shape.

Question 17

Enzymes are ____ about the reactions they catalyze.

Answer 17

highly selective.

Question 18

What are cofactors? (x2)

Answer 18

Non protein helpers for catalytic activity. Some are permanently bound, some are reversible.

Question 19

Two categories of cofactors:

Answer 19

Prosthetic (organic/inorganic bound tightly to protein), and Coenzymes (small organic molecules, non covalently bound to protein.

Question 20

Substrates are held on active site by ____

Answer 20

weak interactions.

Question 21

Enzyme concentration is directly proportional to:

Answer 21

reaction rate, so long as sufficent substrate.

Question 22

Rate of reaction will plateau when:

Answer 22

The available enzyme becomes saturated with substrate.

Question 23

Env factors influencing reaction rate:

Answer 23

Temp, pH, and enzyme/substrate conc.

Question 24

Metabolic pathways are:

Answer 24

Controlling when and where certain enzymes are active. Switching on/off the genes that encode particular enzymes.

Question 25

Some enzymes can ___ between active and inactive forms.

Answer 25

Oscillate.

Question 26

An allosteric activator:

Answer 26

Stabilises the active form to prevent it from oscillating. Binds away from active site and binds to site inbetween the subunit. Only one inhibitor is required.

Question 27

Allosteric regulation may result in:

Answer 27

Either stimulation or inhibition of enzyme activity.

Question 28

Regulatory molecules bind via ____

Answer 28

non-covalent interactions.

Question 29

Feedback inhibition is:

Answer 29

Metabolic pathway is switched off by the end product binding to and inhibiting an enzyme that acts early in the pathway.

Question 30

Which reaction converts one amino acid to another?

Answer 30

Allosteric regulation, 5 reactions need to occur.