Lec. 10 ATP and Enzymes

Question 1

Metabolism

Answer 1

The totality of an organism’s chemical reactions

Question 2

Free energy

Answer 2

The portion of a system’s energy that can preform work (change in free energy: ∆G)
Side note: the more free energy, the less stable

Question 3

Endergonic

Answer 3

Reaction where energy is required, and is non-spontaneous (products energy is greater than reactants)

Question 4

Exergonic

Answer 4

Reaction where energy is released, and is spontaneous (products energy is less than reactants)

Question 5

Energy Coupling

Answer 5

The cell couples exergonic and endergonic reactions

Question 6

Activation Energy

Answer 6

the minimum quantity of energy to undergo a reaction

Question 7

Enzyme

Answer 7

• Catalytic proteins for chemical reactions
• Lower energy barrier to drive chemical reactions

Question 8

Hydrolysis (of ATP)

Answer 8

Release of energy

Question 9

Competitive and noncompetitive inhibitors

Question 10

Work (Transport and Mechanical Work)

Answer 10

Work is something that requires input of energy
Transport: ATP phosphorylates transport proteins
Mechanical: ATP binds noncovalently to motor proteins and then is hydrolyzed

Question 11

What are the 3 components of ATP?

Answer 11

1. 3 phosphate groups
2. ribose sugar
3. adenine (attached to ribose)

Question 12

EA allows the cell to control _____ chemical reactions occur

Answer 12

When

Question 13

How does the activate site lower EA and speed up reaction? (3)

Answer 13

1. Substrates enter active site (in enzyme-substrate complexes) and held by weak interactions (lowers EA)
2. Substrates are converted to products and are released
3. Active site available for new substrates now

Question 14

ATP hydrolysis equation:
ATP+H20 —–> ____ + ___ +___

Answer 14

ADP + Pi + Energy

Question 15

Enzymes have structural _____ for their substrates

Answer 15

specificity