Question 1

Which of the following statements best describes glycolysis?

Accepted Answer

Glycolysis is a metabolic pathway that occurs in the cytosol, where glucose is broken down into pyruvate.

Question 2

The final step of the cellular respiration process in which the electrons are passed to oxygen is

Accepted Answer

The transfer of electrons in the electron transport chain is the final step of cellular respiration in which the electrons are passed to oxygen. This generates a proton gradient that powers ATP synthesis by ATP synthase. Glycolysis and the Krebs cycle do not involve the transfer of electrons to oxygen.

Question 3

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. Where does this process take place?

Accepted Answer

The process of metabolizing pyruvic acid to CO₂ and H₂O in aerobic conditions occurs in the mitochondria, specifically in the Krebs cycle and the electron transport chain. The cytosol is where glycolysis occurs, but further oxidation of pyruvic acid requires the mitochondrial enzymes. Lysosomes and peroxisomes are not involved in this process.

Question 4

Glycogen is a

Accepted Answer

Glycogen is a polysaccharide, which means it is made up of multiple monosaccharide units linked together. It is a form of stored carbohydrate found in animals, including humans.

Question 5

Glucose is labeled with radioactive 14C and followed as it is oxidized to CO₂ and H₂0 in a mammalian liver cell. During this process the radioactive labeling will be detectable in?

Accepted Answer

Glucose is oxidized to pyruvate in the cytoplasm through glycolysis, where a small amount of energy is produced. Pyruvate then enters the mitochondria, where it undergoes the process of oxidative phosphorylation to produce a large amount of energy in the form of ATP. Therefore, the radioactive labeling will first be detectable in the cytoplasm during glycolysis, and then in the mitochondria during oxidative phosphorylation. It will not be detectable in the nucleus or on the ribosomes.

Question 6

A nutritional deficiency of niacin will manifest itself with

Accepted Answer

Niacin is a component of NAD and NADP, which are important coenzymes in cellular metabolism. Without adequate niacin, cells may not be able to produce enough NAD and NADP to support energy production, leading to lower energy availability for the cell. This can lead to symptoms such as fatigue, weakness, and decreased appetite.

Question 7

Pyruvate kinase deficiency is a genetic condition resulting from a mutation in the gene coding for one of the enzymes of glycolysis, pyruvate kinase. It mostly affects red blood cells, and leads to irregular morphology of red blood cells and hemolytic anemia. Yet, pyruvate kinase is present in all cells where it catalyzes one step of glycolysis. Which of the following best explain why red blood cells are MOST affected in this disorder?

Accepted Answer

Red blood cells are uniquely affected by pyruvate kinase deficiency because they rely exclusively on glycolysis for ATP production, cannot perform beta oxidation of fatty acids due to the lack of mitochondria, and thus a defect in glycolysis significantly reduces their ATP levels, impacting their function and survival.

Question 8

KCN (potassium cyanide) blocks the mitochondrial cytochrome c-oxidase (one of the complexes in electron transport chain). What would this most likely do?

Accepted Answer

KCN blocks the electron transport chain by inhibiting cytochrome c-oxidase, which is a key enzyme necessary for oxidative phosphorylation. Since oxidative phosphorylation is the process that generates ATP in aerobic respiration, inhibiting this process will decrease the production of ATP, leading to cellular energy depletion and potentially cell death. Therefore, the best choice is D, which describes the inhibition of aerobic respiration and decrease in ATP production.

Question 9

What is the only component of the electron transport chain that is NOT a protein?

Accepted Answer

Coenzyme Q, also known as ubiquinone, is a small molecule that shuttles electrons between the protein complexes in the electron transport chain. Unlike the other components in the chain, it is not a protein.

Question 10

What is the net ATP gain after a single round of glycolysis (breakdown of one molecule of glucose)?

Accepted Answer

After a single round of glycolysis, there is a net gain of 2 ATP molecules. This is because 2 ATP molecules are produced during the energy payoff phase (steps 6-10) of glycolysis, while 4 ATP molecules are produced during the energy investment phase (steps 1-5). However, 2 ATP molecules are consumed during the energy investment phase, resulting in a net gain of 2 ATP molecules.

Question 11

When body activities require ATP, glucose can be retrieved from glycogen stores and used in ATP production. If the liver's glycogen stores are low you need to eat to provide more substrates for ATP synthesis. Which of the following processes happen if you are fasting in order to lose weight?

Accepted Answer

Gluconeogenesis is the process where the body produces glucose from non-carbohydrate sources, such as amino acids and glycerol, which is crucial during fasting or low carbohydrate intake to maintain blood glucose levels.

Question 12

If you have done the immunocytochemistry with fluorescently labeled antibodies against Krebs cycle enzymes, where in the cell would you expect to find fluorescence?

Accepted Answer

Krebs cycle enzymes are primarily found in the mitochondrial matrix. Therefore, if you have fluorescently labeled antibodies against these enzymes, you would expect to see fluorescence primarily in the mitochondrial matrix.

Question 13

Which process requires obligatory presence of oxygen during ATP production in human cells?

Accepted Answer

Oxidative phosphorylation is the only process that requires the obligatory presence of oxygen during ATP production in human cells. This is because oxygen serves as the final electron acceptor in the electron transport chain, which drives the production of ATP through the process of chemiosmosis. Substrate level phosphorylation does not require oxygen, and can occur under anaerobic conditions.

Question 14

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. This takes place in the ______.

Accepted Answer

The answer of In aerobic conditions pyruvic acid, the product...

Question 15

The majority of ATP in eukaryotic cells is synthesized in

Accepted Answer

The majority of ATP in eukaryotic cells is synthesized through oxidative phosphorylation in the mitochondria. The cytoplasm is mainly involved in glycolysis, which produces a small amount of ATP. The endoplasmic reticulum is involved in protein synthesis and lipid metabolism, but not in ATP synthesis. Lysosomes are involved in intracellular digestion and do not produce ATP.

Question 16

The formation of glucose molecules from non-carbohydrate precursors is called

Accepted Answer

Gluconeogenesis is the process of synthesizing glucose from non-carbohydrate sources such as amino acids, lactate, and glycerol. Glycogenesis is the formation of glycogen, glycogenolysis is the breakdown of glycogen into glucose, and glycolysis is the breakdown of glucose into pyruvate.

Question 17

What process of ATP production will still proceed normally in people with mitochondrial dysfunction diseases?

Accepted Answer

Substrate level phosphorylation occurs in the cytoplasm and does not require functioning mitochondria.

Question 18

Which two vitamins are necessary for the formation of NAD⁺ and FAD?

Accepted Answer

NAD⁺ and FAD are both involved in energy metabolism and require niacin and riboflavin as precursors, respectively. Thiamin and folic acid are involved in other metabolic pathways, while niacin and cyanocobalamin are involved in different aspects of energy metabolism. Thiamin and biotin are involved in carbohydrate and fat metabolism, respectively, but are not necessary for the formation of NAD⁺ and FAD.

Question 19

Before a marathon, many athletes "carb load" to increase their endurance. The excess of carbohydrates they consume is stored in the body until it is needed to create ATP. Which of the following most accurately describes the process of "carb loading"?

Accepted Answer

Carb loading involves consuming an excess of carbohydrates to increase glycogen stores in the muscles and liver. This stored glycogen is then used during exercise to create ATP, providing energy for the athlete to perform for a longer period of time. The other choices (A, C, and D) do not accurately describe the process of carb loading.

Question 20

Hydrogen atoms are carried by NADH + H⁺ and FADH₂ to the

Accepted Answer

Hydrogen atoms carried by NADH + H+ and FADH2 are transferred to the electron transport chain (ETC). The electrons from these hydrogen atoms flow through the ETC, releasing energy that is used to pump protons across the inner mitochondrial membrane. The proton gradient that is established drives the synthesis of ATP through ATP synthase. Therefore, NADH + H+ and FADH2 carry hydrogen atoms to the ETC, not directly to ATP, ADP or ATP synthase.

Quiz 4: Metabolism

Which of the following statements best describes glycolysis?

The final step of the cellular respiration process in which the electrons are passed to oxygen is

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. Where does this process take place?

Glycogen is a

Glucose is labeled with radioactive 14C and followed as it is oxidized to CO₂ and H₂0 in a mammalian liver cell. During this process the radioactive labeling will be detectable in?

A nutritional deficiency of niacin will manifest itself with

KCN (potassium cyanide) blocks the mitochondrial cytochrome c-oxidase (one of the complexes in electron transport chain) . What would this most likely do?

What is the only component of the electron transport chain that is NOT a protein?

What is the net ATP gain after a single round of glycolysis (breakdown of one molecule of glucose) ?

When body activities require ATP, glucose can be retrieved from glycogen stores and used in ATP production. If the liver's glycogen stores are low you need to eat to provide more substrates for ATP synthesis. Which of the following processes happen if you are fasting in order to lose weight?

If you have done the immunocytochemistry with fluorescently labeled antibodies against Krebs cycle enzymes, where in the cell would you expect to find fluorescence?

Which process requires obligatory presence of oxygen during ATP production in human cells?

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. This takes place in the ______.

The majority of ATP in eukaryotic cells is synthesized in

The formation of glucose molecules from non-carbohydrate precursors is called

What process of ATP production will still proceed normally in people with mitochondrial dysfunction diseases?

Which two vitamins are necessary for the formation of NAD⁺ and FAD?

Before a marathon, many athletes "carb load" to increase their endurance. The excess of carbohydrates they consume is stored in the body until it is needed to create ATP. Which of the following most accurately describes the process of "carb loading"?

Hydrogen atoms are carried by NADH + H⁺ and FADH₂ to the

Quiz 4: Metabolism

Which of the following statements best describes glycolysis?

The final step of the cellular respiration process in which the electrons are passed to oxygen is

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO2 and H2O. Where does this process take place?

Glycogen is a

Glucose is labeled with radioactive 14C and followed as it is oxidized to CO2 and H20 in a mammalian liver cell. During this process the radioactive labeling will be detectable in?

A nutritional deficiency of niacin will manifest itself with

KCN (potassium cyanide) blocks the mitochondrial cytochrome c-oxidase (one of the complexes in electron transport chain) . What would this most likely do?

What is the only component of the electron transport chain that is NOT a protein?

What is the net ATP gain after a single round of glycolysis (breakdown of one molecule of glucose) ?

When body activities require ATP, glucose can be retrieved from glycogen stores and used in ATP production. If the liver's glycogen stores are low you need to eat to provide more substrates for ATP synthesis. Which of the following processes happen if you are fasting in order to lose weight?

If you have done the immunocytochemistry with fluorescently labeled antibodies against Krebs cycle enzymes, where in the cell would you expect to find fluorescence?

Which process requires obligatory presence of oxygen during ATP production in human cells?

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO2 and H2O. This takes place in the ______.

The majority of ATP in eukaryotic cells is synthesized in

The formation of glucose molecules from non-carbohydrate precursors is called

What process of ATP production will still proceed normally in people with mitochondrial dysfunction diseases?

Which two vitamins are necessary for the formation of NAD+ and FAD?

Before a marathon, many athletes "carb load" to increase their endurance. The excess of carbohydrates they consume is stored in the body until it is needed to create ATP. Which of the following most accurately describes the process of "carb loading"?

Hydrogen atoms are carried by NADH + H+ and FADH2 to the

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. Where does this process take place?

Glucose is labeled with radioactive 14C and followed as it is oxidized to CO₂ and H₂0 in a mammalian liver cell. During this process the radioactive labeling will be detectable in?

In aerobic conditions pyruvic acid, the product of glycolysis, is transported and metabolized (oxidized) to CO₂ and H₂O. This takes place in the ______.

Which two vitamins are necessary for the formation of NAD⁺ and FAD?

Hydrogen atoms are carried by NADH + H⁺ and FADH₂ to the