exam 2 Flashcards
how energy and matter flow through living things
energy enters living systems as sunllight and leaves as heat, but matter is recycled within ecosystem
which law is consistent with second law of thermodynamics
energy transfer results in increases entropy (disorder) in the system
3) in the reaction where K > 1, which statement is correct
the reaction is exergonic (Change G > O)
4) in the reaction where K < 1, which statement is correct
the rxn is endergonic (Change G > O)
The process of cellular respiration is
Both exergonic and catabolic
Many enzymes require thiamin (Vitamin B1) in this role, thiamin is acting as a
Coenzyme
Competitive Inhibitors affect enzyme function by
Binding to the active site of the enzyme
A reaction requiring NADH oxidation to NAD+ is likely to
Involve electron transfer
Enzymes lower activation energy by
Stabilizing the transition state of a reactiom
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
A noncompetitive inhibitor
11) Which molecule in the image above is ATP
Molecule D
The role of oxygen in cellular respiration is to
Accept electrons from NADH in the electron transport train
Which of the following is NOT an example of stored potential energy
Na+ flowing through a channel
Which of the following reactions is not part of the complete oxidation of glucode
The Calvin Cycle
The pH in the mitochondria inter-membrane space is lower than in the matrix because
The electron transport chain pumps proton (H+) into the inter-membrane space
if the pH in the mitochondrial inter-membrane space decreases further what does this indicate?
More H+ ions are being pumped across the membrane due to electron transport
A drug inhibits pyruvate dehydrogenase, preventing pyruvate oxidation. What is the result?
The cell would not produce CO₂ from cellular respiration.
Which of the following is NOT a product of the Citric Acid Cycle?
Acetyl-CoA.
Which of the following is returned to the cytoplasm following aerobic cellular respiration?
NAD⁺
Which step of cellular respiration is directly affected by the lack of oxygen?
Electron Transport Chain.
How is energy extracted from starch molecules?
By hydrolysis into monosaccharides that enter glycolysis.
CO₂ is produced from all of the following EXCEPT:
Glycolysis.
NAD⁺ is required for all of the following EXCEPT:
Fermentation
Both alcohol and lactate fermentation use which molecule as a reactant?
Pyruvate
The leaves are involved in all of the following EXCEPT:
Production of glucose.
Electrons received by the primary electron acceptor in Photosystem I or II have energy transferred from:
Light energy.
A region with few primary producers will likely have:
Much less energy available for transfer to other organisms.
Which color of light has the least energy?
Red, with a wavelength of 665 nm.
Light is captured by:
Chlorophyll
What does the Calvin Cycle provide for the light reactions?
NADP⁺ and ADP.
(MATCHING) A spontaneous reaction
(ΔG < 0)
(MATCHING) An anabolic reaction
(ΔG = 0)
(MATCHING) A common mechanism to block synthesis of intermediates when there is a high enough concentration of the final product
Feedback inhibition
(MATCHING) Includes Allosteric Inhibition
Noncompetitive Inhibition
(MATCHING) A molecule that binds to the active site and prevents substrate binding:
Competitive inhibition.
(MATCHING) A molecule that fits into the active site and helps the reaction proceed more efficiently:
Cofactor
(MATCHING) Site of ATP production in anaerobic conditions:
Cytoplasm
(MATCHING) The source of H⁺ ions for ATP synthase:
Mitochondrial Matrix
(MATCHING) Where CO₂ is produced during cellular respiration:
Mitochondrial Matrix
(MATCHING) Location of the enzyme that reduces O₂ to H₂O:
Mitochondrial inner membrane.
(MATCHING) The source of H⁺ for ATP synthase in photosynthesis:
Thylakoid interior.
(MATCHING) Location of rubisco enzyme in photosynthesis:
Stroma
(MATCHING) Location of photosystems in photosynthesis:
Thylakoid membrane
The fluid surrounding the chloroplasts in plant cells:
Stroma
(SHORT ANSWER) How does the formation and hydrolysis of ATP help cells couple exergonic and endergonic reactions?
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.
(SHORT ANSWER) How do cells extract energy from non-glucose food molecules?
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.
(SHORT ANSWER) Explain how the electrochemical gradient is used for ion transport.
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.
(SHORT ANSWER) How is the bulk of ATP generated in cellular respiration?
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.
(SHORT ANSWER) When light energy is captured by chloroplasts, what form is it first transferred to?
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.
