Bio Chapter 6 Review

Question 1

What is the “law” governing chemical reactions?

Answer 1

law thermodynamics: - energy can be transferred and transformed but can not be created or destroyed
tranfering of enrgy inc entropy: measure of molecular disorder

Question 2

How does a spontaneous process differ from a non-spontaneous process?

Answer 2

spontneous - inc. entropy
exergonic
loss potential energy
Thus, spontaneous chemical reactions (–∆G) release energy (are
exergonic)

nonspontaneous-
endergonic
gain potential enrgy
Non-spontaneous reactions (+∆G): require an input of energy (are
endergonic)

Question 3

During a spontaneous process, what changes occur to the total free energy, the
potential energy, and the entropy of the system, i.e., the universe? What is the
mathematical formula expressing these changes?

Answer 3

ΔG (Gfinal – Ginitial state)
Only reactions with a negative ΔG can
occur spontaneously

Question 4

Exergonic reactions?

Answer 4

• release free energy
  G is in negative
  ex. complex molecule broken to simpler molecules

Question 5

Endergonic reactions?

Answer 5

• ## abosrbs energy and is nonspontaneous,G is positive

Question 6

What is the full name and structural formula of ATP, and what are the 2 main reasons
for its high potential energy? What is the source of the energy used to make ATP?

Answer 6

Full name: adenosine triphosphate
2 main reasons:
Hydrolysis of ATP makes exergonic rection

ATP hydrolysis leads to protein shape
ATP binds directly to protein

Source of energy: mitochondria

Question 7

Activation energy?

Answer 7

initial investment of energy

Question 8

What are 1 problem that causes spontaneous reactions in cells to occur slowly?

Answer 8

Enzymes lower the required activtion energy

Question 9

What are the steps that take place during an enzyme-catalyzed reaction?

Answer 9

Substrate enter the active site
Enzyme lowers activation energy
Reaction occurs
Products released

Question 10

What are the general characteristics of enzymes?

Answer 10

affected by temperature
ph 6-8

Question 11

Competitive inhibition

Answer 11

mimics substrate to compete for active site

Question 12

Noncompetitive inhibition

Answer 12

binds to enzyme away from active site to alter to shape of enzyme (less effective)

Question 13

How does the regulation of enzymes help to control metabolism?

Answer 13

• ## all reactions can not be at the same time

Question 14

Allosteric regulation
* A protein’s function at one site is affected by binding of a regulatory molecule
to a separate site

Answer 14

ADP: activator
ATP: inhibitor

Question 15

Feedback inhibition