Exam #2

Question 1

What is metabolism?

Answer 1

All chemical & physical activity of a cell

Question 2

What is catabolism?

Answer 2

Breaks the bonds of macromolecules releasing smaller molecules; releases energy

Question 3

What is anabolism?

Answer 3

Biosynthesis; formation of macromolecules from small molecules; requires energy input

Question 4

What are enzymes?

Answer 4

Protein catalysts that increase the rate of a chemical reaction by lowering the energy of activation

Question 5

What is the role of the active site in an enzyme?

Answer 5

Serves as a physical site for specific substrate molecules to position

Question 6

What is an apoenzyme?

Answer 6

Protein portion of a conjugated enzyme

Question 7

What are cofactors?

Answer 7

Nonprotein portions of enzymes that assist in enzyme activity

Question 8

List examples of metallic cofactors.

Answer 8

• Iron
• Copper
• Magnesium
• Zinc

Question 9

What are coenzymes?

Answer 9

Organic molecules that assist enzymes, often vitamins

Question 10

What is the induced fit model?

Answer 10

Temporary enzyme-substrate union when substrate moves into active site

Question 11

What are exoenzymes?

Answer 11

Enzymes transported extracellularly to break down large molecules or harmful chemicals

Question 12

What are endoenzymes?

Answer 12

Enzymes retained intracellularly and function there

Question 13

What are constitutive enzymes?

Answer 13

Always present, produced in equal amounts regardless of substrate concentration

Question 14

What are regulated enzymes?

Answer 14

Production is turned on or off in response to changes in substrate concentration

Question 15

What factors influence enzyme activity?

Answer 15

• Temperature
• pH
• Osmotic pressure

Question 16

What is denaturation?

Answer 16

Breaking of weak bonds that maintain the shape of the apoenzyme

Question 17

What is energy?

Answer 17

The capacity to do work or to cause change

Question 18

List forms of energy.

Answer 18

• Thermal
• Radiant
• Electrical
• Mechanical
• Atomic
• Chemical

Question 19

What are endergonic reactions?

Answer 19

Reactions that consume energy

Question 20

What are exergonic reactions?

Answer 20

Reactions that release energy

Question 21

What is a redox reaction?

Answer 21

A reaction that involves an electron donor and an electron acceptor

Question 22

What happens to the electron donor in a redox reaction?

Answer 22

It becomes oxidized

Question 23

What happens to the electron acceptor in a redox reaction?

Answer 23

It becomes reduced

Question 24

What are electron carrier molecules?

Answer 24

Molecules that shuttle electrons along bioenergetic pathways

Question 25

What is ATP?

Answer 25

Metabolic 'currency' consisting of adenine, ribose, and three phosphate groups

Question 26

What is substrate-level phosphorylation?

Answer 26

Transfer of phosphate group from a phosphorylated compound directly to ADP

Question 27

What is oxidative phosphorylation?

Answer 27

A series of redox reactions occurring during the respiratory pathway

Question 28

What is photophosphorylation?

Answer 28

ATP formation utilizing the energy of sunlight

Question 29

What is bioenergetics?

Answer 29

The study of the mechanisms of cellular energy release

Question 30

What are the three coupled pathways resulting in ATP production?

Answer 30

* Glycolysis * Kreb’s cycle * Respiratory chain

Question 31

What is aerobic respiration?

Answer 31

Involves glycolysis, Kreb’s cycle, and respiratory chain; oxygen is the final electron acceptor

Question 32

What is anaerobic respiration?

Answer 32

Similar to aerobic but uses oxidized ions, not free oxygen, as the final electron acceptor

Question 33

What is fermentation?

Answer 33

Incomplete oxidation of carbohydrates in the absence of oxygen

Question 34

What is the primary product of pyruvate fermentation by yeast?

Answer 34

Ethanol

Question 35

What is photosynthesis?

Answer 35

The process that converts light energy into chemical energy stored in glucose

Question 36

What are the light-dependent reactions in photosynthesis?

Answer 36

Reactions that absorb photons, split water, and synthesize ATP and NADPH

Question 37

What is the Calvin cycle?

Answer 37

Light-independent reaction that uses ATP to fix CO2 to ribulose-1,5-bisphosphate and convert it to glucose