Biology – Energy, Enzymes, Cellular Respiration, Photosynthesis, and Metabolic Pathways Practice Test

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• Which molecule carries two-carbon units from beta-oxidation into the TCA cycle?
• Signal transduction pathways involve intracellular events stimulated by an extracellular signal.
• What is the functional outcome of Netrin-1 binding to its receptor in gut epithelium?
• What is the difference between small G proteins like Ras and GPCR proteins?
• During glycolysis, what happens to the NADH produced in the cytosol if oxygen is available?
• Which statement about CO2 production in cellular respiration is correct?
• Changes in temperature and pH affect what in enzymes?
• What are the products of glycolysis per glucose under anaerobic conditions in humans?
• Which statement best describes the major ATP-yield-limiting steps in glycolysis and the TCA cycle?
• What is the link between electron transport and ATP synthesis?
• What can the electrons carried by NADH and FADH2 do?
• Which molecule is the final electron acceptor in aerobic respiration?
• What defines a spontaneous reaction?
• During the Calvin cycle, which phase reduces the captured CO2 to triose phosphates?
• Which statement best describes anaerobic respiration?
• Beta-oxidation links fatty acids to the Krebs cycle by producing which products?
• Which statement correctly contrasts substrate-level phosphorylation and oxidative phosphorylation?
• Which statement best describes paracrine signaling?
• In chloroplasts, how does the thylakoid lumen become acidic?
• What is the overall flow of electrons in the light reactions?
• How do competitive and noncompetitive inhibitors affect Km and Vmax?
• What happens to the excited electron from Photosystem I?
• Which statement best describes autotrophs?
• What are common features of cellular signaling?
• What type of signaling involves secreted factors acting on nearby cells?
• Where does CO2 fixation occur in the Calvin cycle?
• How many ATP are produced from one glucose molecule in the electron transport chain, and why can this vary?
• What happens to the enzyme at around 40°C in a reaction?
• How is pyruvate oxidized in aerobic respiration, and what are the products?
• Which statement about the Calvin cycle is true?
• What happens to the reaction rate if cellular ATP levels are low?
• If the thylakoid membrane were disrupted, which process would be most directly affected?
• What is the induced fit model of enzyme action?
• ATP and NADPH produced by the light reactions are used in which process?
• Why are steroid hormones longer-lived than peptide hormones?
• Which statement best describes the initial event in most cellular signaling pathways?
• What is an autotroph?
• Why can different receptors have the same effect on a cell?
• Which statement correctly describes exergonic and endergonic reactions and the role of ATP?
• What is the function of a protein phosphatase?
• Where do the reactions of the citric acid cycle occur?
• Which statement best describes the role of electron carriers NADH and FADH2 in cellular respiration?
• Which of the following statements about ATP and NADPH produced during the light reactions is accurate?
• Which molecule acts as the energy currency to power cellular reactions?
• How does substrate availability influence metabolic pathway flux?
• What is photorespiration and why can it be detrimental to C3 plants under high O2 and low CO2?
• Which statement best describes substrate-level phosphorylation?
• If the thylakoid membrane becomes leaky to ions, what happens?
• What is a by-product of cellular respiration?
• What is cellular respiration?
• Outline glycolysis: the investment and payoff phases; name two key irreversible kinase steps.
• What is the temperature optimum for a human enzyme?
• If a reaction is exergonic, what is true about its ΔG?
• What happens to the reaction rate if cellular ATP levels are very high?
• Which sequence correctly describes the flow of electrons in the light-dependent reactions?
• What is the source of carbon in photosynthesis and the role of light energy?
• Explain substrate-level phosphorylation and where it occurs in cellular respiration.
• What role does the mitochondrial membrane potential play in ATP production?
• In mitochondria, where is ATP synthase located?
• In chloroplasts, the proton motive force across the thylakoid membrane drives which processes during the light reactions?
• Which process explains how steroid hormone signaling can produce long-lasting cellular effects?
• Which stage of aerobic respiration directly produces the most ATP under typical conditions?
• Which coenzymes carry high-energy electrons in cellular respiration, and what are their reduced forms?
• How does glycerol contribute to cellular respiration when glycolysis is impaired?
• How many CO2 molecules are fixed to synthesize one hexose (glucose) in the Calvin cycle, and how many turns are required?
• Which plant type fixes carbon at night to reduce water loss?
• Which statement correctly distinguishes the light-dependent reactions from the Calvin cycle?
• Which of the following statements about cellular respiration are true?
• Which enzyme in glycolysis is allosterically regulated by ATP and AMP?
• In the absence of oxygen, which process allows NAD+ to be regenerated for glycolysis?
• Which statement is true about carbon fixation in C3 plants?
• Which region of a chloroplast captures light energy?
• After ligand binding to a G protein-coupled receptor, what immediate event occurs to the G protein?
• Absence of Netrin-1 would most likely lead to increased what in gut epithelium?
• What distinguishes steroid hormones from peptide hormones?
• What is the role of enzymes in cellular respiration?
• What is the role of RuBisCO in carbon fixation and why is it potentially problematic?
• Name the three main phases of the Calvin cycle.
• What does phosphofructokinase do?
• Which plant type fixes carbon through a four-carbon compound to minimize photorespiration?
• Where would you expect the highest rate of cell turnover in the intestinal lining?
• In the gut epithelium, where is the greatest amount of cell growth expected?
• Where is energy stored in a molecule of ATP?
• Which statement best describes the role of phosphofructokinase-1 (PFK-1) in glycolysis?
• Netrin-1 receptor loss in colon tissue is associated with what potential outcome?
• What is G3P (glyceraldehyde-3-phosphate) and its role in photosynthesis?
• What is the term for chemiosmotic ATP production in the light-dependent reactions of photosynthesis?
• What is the role of Ras in tyrosine kinase signaling?
• Activation energy is defined as the energy barrier that must be overcome for a reaction to proceed. How do enzymes affect this barrier?
• In the context of tissue development, Netrin-1 has roles in guiding what processes?
• Which of the following is NOT a property of a catalyst?
• How do C4 plants initially fix carbon?
• In the Calvin cycle, which molecule exits the cycle to form glucose and other carbohydrates?
• Which products are formed during the light-dependent reactions?
• Which statement about C4 plants is true?
• Which statement about glycolysis is true?
• What is chemiosmosis and how is ATP formed in mitochondria?
• In feedback inhibition, which enzyme is inhibited by the end product?
• Which of the following is NOT a product of glycolysis?
• Which statement describes intracellular receptor activity?
• Define photosystem II reaction center P680 and photosystem I reaction center P700.
• What is activation energy?
• How does glycolysis produce ATP?
• What is oxidative phosphorylation and where does it occur?
• How many NADH, FADH2, and GTP/ATP are produced per acetyl-CoA in the citric acid cycle?
• Which statement about Ras signaling termination?
• What are the light-dependent reactions of photosynthesis responsible for?
• In the Calvin cycle, what happens to ribulose-1,5-bisphosphate (RuBP) when CO2 is fixed?
• Which processes are required for the complete oxidation of glucose?
• Which statement about entropy is compatible with why perpetual-motion machines are impossible?
• What is the overall purpose of the Calvin cycle?
• Netrin-1 signaling is best described as which of the following types?
• Can an endergonic reaction with a ΔG of 12 kcal/mol be driven by ATP hydrolysis?
• The Calvin cycle and light reactions relationship?
• What is feedback inhibition in metabolic pathways?
• What is fermentation?
• What is the role of NADP+ reductase in photosynthesis?
• What are the roles of NADH and FADH2 in oxidative phosphorylation?
• Why does the reaction rate touch the x-axis at approximately 20°C and 45°C?
• Which statement about spontaneous reactions is true?
• A mutation that causes loss of certain receptors can contribute to tumor formation by disrupting signaling that regulates what?
• Explain the concept of energy coupling in metabolism with an example.
• Which statement describes the difference between intracellular and membrane receptors?
• Which shuttle transfers cytosolic NADH into mitochondria and yields NADH in the mitochondrial matrix?
• Outline the Krebs cycle: main products generated per acetyl-CoA turn.
• What is the direct source of energy for ATP produced by ATP synthase?
• Loss of the Netrin-1 receptor can disrupt signaling regulating which cellular outcomes?
• What does the carbon fixation reaction convert?
• What is the overall outcome of photosynthesis?
• Which statement is NOT true about enzymes?
• Compare aerobic respiration and anaerobic respiration.
• What is the C4 pathway?
• Which shuttle produces FADH2 when transferring cytosolic NADH into mitochondria?
• Describe the intracellular receptor characteristic.
• Which statement best describes the relationship between light reactions and the Calvin cycle?
• What are photophosphorylation and photochemical reactions?
• What is photolysis of water and what are its products?
• Which enzyme complex utilizes the proton gradient to synthesize ATP?
• Which statement accurately describes RuBisCO in the Calvin cycle?
• Which of the following illustrates energy coupling in metabolism?
• In a crypt-villus axis scenario, what is the primary function of the crypt region?
• Contrast lactic acid fermentation and alcoholic fermentation in terms of organisms and end products.
• What occurs if the Calvin cycle runs through six turns?
• Which term best describes signals that influence only the cell that produced them?
• What is the typical optimum temperature for many human enzymes, and what happens if temperature rises above this range?
• What is the fate of electrons carried by NADH and FADH2 in aerobic respiration?
• What happens if there are holes in the inner membrane of mitochondria?
• During the light reactions of photosynthesis, which reducing agent is produced?
• Why do cells use ATP to drive endergonic reactions?
• In GPCR signaling, what happens to the G protein after ligand binding?
• Why can Ca2+ act as a second messenger?
• How can yeast cells grow on glycerol despite mutations in glycolysis?
• Why can the same signal have different effects in different cells?
• Which statement best describes the ATP yield from fermentation compared with respiration?
• In metabolic regulation, feedback inhibition is best described as?
• What are anabolic precursors and why are they important in metabolism?
• Which signaling mode requires direct cell-to-cell contact through membrane-bound signals?
• What is the effect of enzymes on activation energy and ΔG?
• What is the consequence of Netrin-1 receptor loss on signaling pathways as related to cancer risk?
• ATP hydrolysis releases energy by breaking what kind of bond?
• What is the function of photosystem II in noncyclic photosynthesis?
• Why can't you bid on a perpetual-motion machine?
• Which of the following statements about oxidative phosphorylation is correct?
• Which statement describes the generation of the proton motive force used by ATP synthase?
• In a redox reaction, if a molecule gains an electron, what has occurred and how is its energy level affected?
• What effect does high citrate have on glycolysis via PFK-1?
• Which photosystems are involved in the light-dependent reactions and what are their roles?
• What is Netrin-1?
• In paracrine signaling, where do signaling molecules act?
• What is fermentation and when does it occur?
• How do chloroplasts generate reducing power (NADPH) during photosynthesis?
• What colors of light are most effective for photosynthesis?
• The products of cellular respiration include
• What is the function of a protein kinase?
• What is the role of NAD+ in cellular respiration?
• In photosynthesis, the energy stored as ATP and NADPH as a result of light-dependent reactions is later used in which process?
• What kind of energy does a covalent bond represent?
• Where does the TCA cycle occur and what is its primary purpose?
• During the light-dependent reactions of photosynthesis, which energy carriers are produced using light energy?
• During pyruvate oxidation, which molecule is released as a waste product?
• What is the function of photosystem I in noncyclic photosynthesis?
• How does oxygen act as the final electron acceptor in aerobic respiration?
• During noncyclic electron flow, which component ultimately reduces NADP+ to NADPH?
• Which of the following is a plausible implication of Netrin-1 signaling disruption in colorectal tissue?
• Which of the following defines an endergonic reaction?
• Which statement best describes paracrine signaling?
• What is a common consequence of enzyme denaturation?
• Define anabolic and catabolic pathways and give an example each within energy metabolism.
• What is the major difference between chloroplasts and mitochondria in energy metabolism?
• How does the reaction center pigment differ from antenna pigments in photosynthesis?
• Which statement best describes RuBisCO's dual activity?
• What are similarities between mitochondria and chloroplasts?