exam 2

Question 1

how energy and matter flow through living things

Answer 1

energy enters living systems as sunllight and leaves as heat, but matter is recycled within ecosystem

Question 2

which law is consistent with second law of thermodynamics

Answer 2

energy transfer results in increases entropy (disorder) in the system

Question 3

3) in the reaction where K > 1, which statement is correct

Answer 3

the reaction is exergonic (Change G > O)

Question 4

4) in the reaction where K < 1, which statement is correct

Answer 4

the rxn is endergonic (Change G > O)

Question 5

The process of cellular respiration is

Answer 5

Both exergonic and catabolic

Question 6

Many enzymes require thiamin (Vitamin B1) in this role, thiamin is acting as a

Answer 6

Coenzyme

Question 7

Competitive Inhibitors affect enzyme function by

Answer 7

Binding to the active site of the enzyme

Question 8

A reaction requiring NADH oxidation to NAD+ is likely to

Answer 8

Involve electron transfer

Question 9

Enzymes lower activation energy by

Answer 9

Stabilizing the transition state of a reactiom

Question 10

There is a molecule that changes the shape of an enzyme’s active site so that a substrate can no longer bind. This molecule is most likely

Answer 10

A noncompetitive inhibitor

Question 11

11) Which molecule in the image above is ATP

Answer 11

Molecule D

Question 12

The role of oxygen in cellular respiration is to

Answer 12

Accept electrons from NADH in the electron transport train

Question 13

Which of the following is NOT an example of stored potential energy

Answer 13

Na+ flowing through a channel

Question 14

Which of the following reactions is not part of the complete oxidation of glucode

Answer 14

The Calvin Cycle

Question 15

The pH in the mitochondria inter-membrane space is lower than in the matrix because

Answer 15

The electron transport chain pumps proton (H+) into the inter-membrane space

Question 16

if the pH in the mitochondrial inter-membrane space decreases further what does this indicate?

Answer 16

More H+ ions are being pumped across the membrane due to electron transport

Question 17

A drug inhibits pyruvate dehydrogenase, preventing pyruvate oxidation. What is the result?

Answer 17

The cell would not produce CO₂ from cellular respiration.

Question 18

Which of the following is NOT a product of the Citric Acid Cycle?

Answer 18

Acetyl-CoA.

Question 19

Which of the following is returned to the cytoplasm following aerobic cellular respiration?

Answer 19

NAD⁺

Question 20

Which step of cellular respiration is directly affected by the lack of oxygen?

Answer 20

Electron Transport Chain.

Question 21

How is energy extracted from starch molecules?

Answer 21

By hydrolysis into monosaccharides that enter glycolysis.

Question 22

CO₂ is produced from all of the following EXCEPT:

Answer 22

Glycolysis.

Question 23

NAD⁺ is required for all of the following EXCEPT:

Answer 23

Fermentation

Question 24

Both alcohol and lactate fermentation use which molecule as a reactant?

Answer 24

Pyruvate

Question 25

The leaves are involved in all of the following EXCEPT:

Answer 25

Production of glucose.

Question 26

Electrons received by the primary electron acceptor in Photosystem I or II have energy transferred from:

Answer 26

Light energy.

Question 27

A region with few primary producers will likely have:

Answer 27

Much less energy available for transfer to other organisms.

Question 28

Which color of light has the least energy?

Answer 28

Red, with a wavelength of 665 nm.

Question 29

Light is captured by:

Answer 29

Chlorophyll

Question 30

What does the Calvin Cycle provide for the light reactions?

Answer 30

NADP⁺ and ADP.

Question 31

(MATCHING) A spontaneous reaction

Answer 31

(ΔG < 0)

Question 32

(MATCHING) An anabolic reaction

Answer 32

(ΔG = 0)

Question 33

(MATCHING) A common mechanism to block synthesis of intermediates when there is a high enough concentration of the final product

Answer 33

Feedback inhibition

Question 34

(MATCHING) Includes Allosteric Inhibition

Answer 34

Noncompetitive Inhibition

Question 35

(MATCHING) A molecule that binds to the active site and prevents substrate binding:

Answer 35

Competitive inhibition.

Question 36

(MATCHING) A molecule that fits into the active site and helps the reaction proceed more efficiently:

Answer 36

Cofactor

Question 37

(MATCHING) Site of ATP production in anaerobic conditions:

Answer 37

Cytoplasm

Question 38

(MATCHING) The source of H⁺ ions for ATP synthase:

Answer 38

Mitochondrial Matrix

Question 39

(MATCHING) Where CO₂ is produced during cellular respiration:

Answer 39

Mitochondrial Matrix

Question 40

(MATCHING) Location of the enzyme that reduces O₂ to H₂O:

Answer 40

Mitochondrial inner membrane.

Question 41

(MATCHING) The source of H⁺ for ATP synthase in photosynthesis:

Answer 41

Thylakoid interior.

Question 42

(MATCHING) Location of rubisco enzyme in photosynthesis:

Answer 42

Stroma

Question 43

(MATCHING) Location of photosystems in photosynthesis:

Answer 43

Thylakoid membrane

Question 44

The fluid surrounding the chloroplasts in plant cells:

Answer 44

Stroma

Question 45

(SHORT ANSWER) How does the formation and hydrolysis of ATP help cells couple exergonic and endergonic reactions?

Answer 45

ATP acts as an energy carrier. When exergonic reactions release energy, ATP stores it in high-energy phosphate bonds. The hydrolysis of ATP releases energy, which drives endergonic processes such as active transport, biosynthesis, and muscle contractions.

Question 46

(SHORT ANSWER) How do cells extract energy from non-glucose food molecules?

Answer 46

Cells break down fats and proteins through metabolic pathways. Fatty acids undergo β-oxidation to generate Acetyl-CoA, which enters the Citric Acid Cycle. Proteins are broken into amino acids, which are deaminated and fed into glycolysis or the Citric Acid Cycle. These processes produce NADH and FADH₂, which drive ATP synthesis in the Electron Transport Chain.

Question 47

(SHORT ANSWER) Explain how the electrochemical gradient is used for ion transport.

Answer 47

Cells establish electrochemical gradients across membranes using active transport, such as the Na⁺/K⁺ pump. These gradients store potential energy, which ions utilize to move across membranes via facilitated diffusion or ATP-driven transport. In mitochondria, the proton gradient powers ATP synthase to produce ATP.

Question 48

(SHORT ANSWER) How is the bulk of ATP generated in cellular respiration?

Answer 48

Most ATP is produced through oxidative phosphorylation in the electron transport chain (ETC). Electrons from NADH and FADH₂ travel through the ETC, generating a proton gradient across the inner mitochondrial membrane. Protons flow back through ATP synthase, driving ATP production from ADP and inorganic phosphate.

Question 49

(SHORT ANSWER) When light energy is captured by chloroplasts, what form is it first transferred to?

Answer 49

Light energy excites electrons in chlorophyll, which are transferred to the photosynthetic electron transport chain. This process generates ATP and NADPH, which are used in the Calvin Cycle to fix carbon and synthesize glucose.