Unit 2 - Ch 7 - Metabolism

Question 1

Types of metabolism

Answer 1

Catabolic and anabolic

Question 2

Catabolism

3 and examples

Answer 2

-break down large molecules into smaller ones
- releases energy (exergonic)
- produces raw materials for anabolism
= hydrolysis, cellular respiration

Question 3

Anabolism

2 and examples

Answer 3

-synthesize large molecules from small ones
- requires energy (endergonic)
= condensation, photosynthesis

Question 4

ATP - Adenosine Triphosphate

Answer 4

1. Adenine
   - nitrogenous base
   - also found in DNA and RNA
2. Ribose
   - pentose sugar (5C)

Adenine+Ribose=Adenosine

3. Phosphate Groups
   - 3 phosphate groups
   - stores and releases energy

Question 5

How is ATP cycled in our cells?

Answer 5

Hydrolysis of ATP 
- ATP+H2O>>>ADP+Pi+Energy 
(i subscript = inorganic) 
- exergonic 
- ADP = adenosine diphosphate

Phosphorylation

• adding a phosphate group to a molecule
• ADP+Pi+Energy»>ATP
• endergonic

Exergonic reaction provide energy for endergonic

ATP is constantly cycled in our cells (100 lbs daily at rest)

Question 6

What are the forms of oxidation? Is it exergonic or endergonic?

Answer 6

releases energy - exergonic

Forms

1. Gain of O2 - historical basis
2. Loss of e-
3. Loss of H (1 proton & 1 e-)

(2 and 3 are common biological forms of oxidation)

Question 7

Examples of oxidation

Wood, NAD & FAD

Answer 7

1. Wood Combustion/Decomposition

Cellulose + O2&raquo_space;> CO2 + H2O + Energy

• combustion requires activation energy making the reaction faster
• exergonic

2. NADH&raquo_space;> NAD+ + H+ + 2 e- + energy
   - exergonic
3. FADH2&raquo_space;> FAD + 2H+ + 2 e- + energy
   - exergonic

Question 8

Reduction forms?

Exergonic or endergonic?

Answer 8

endergonic - opposite of oxidation

Forms

1. Loss of O2
2. Gain of e-
3. Gain of H (1 proton & 1 e-)

(2 and 3 are common biologically)

Question 9

Examples of reduction of NAD & FAD

Answer 9

1. NAD+ + H+ + 2 e- + energy&raquo_space;> NADH
2. FAD + 2H+ + 2 e- + energy&raquo_space;> FADH2

right side: greater potential energy

Question 10

coupled reactions

Answer 10

energy requiring reactions are linked (coupled) with energy releasing reactions

Question 11

Examples of coupled reactions

Answer 11

• oxidation provides energy for reduction
• exergonic provides energy for endergonic
• ATP hydrolysis provided energy for phosphorylation

Question 12

Coenzymes

Answer 12

• involved in oxidation / reduction reactions in organisms
• also cofactors for conjugated enzymes

A. NAD - nicotinamide adenine dinucleotide (requires niacin)

B. FAD - flavin adenine dinucleotide (requires riboflavin)

Question 13

Metabolic Pathways. Importance and examples

Answer 13

Importance

1. Allow Warm chemistry - vs. hot
2. Precise regulation can occur - via enzyme regulation

Examples

1. Cellular respiration
2. Photosynthesis