Basics Of Cellular Respiration
This is a quiz regarding cellular respiration. All the best for this biological quiz!
Questions and Answers
- 1.
Cellular Respiration begins with _____________.
- A.
Glycolysis
- B.
Aerobic respiration
- C.
Oxidization
- D.
Anaerobic respiration
Correct Answer
A. GlycolysisExplanation
Cellular respiration is the process by which cells break down glucose to produce energy. It begins with glycolysis, which takes place in the cytoplasm and does not require oxygen. During glycolysis, glucose is converted into two molecules of pyruvate, releasing a small amount of ATP. This is the first step in cellular respiration and occurs in both aerobic and anaerobic conditions. Therefore, glycolysis is the correct answer.Rate this question:
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- 2.
True or False? Fermentation is a set of anaerobic pathways in which pyruvic acid is converted into other organic molecules in the cytosol.
- A.
True
- B.
False
- C.
Maybe
Correct Answer
A. TrueExplanation
Fermentation is a set of anaerobic pathways where pyruvic acid is converted into other organic molecules in the cytosol. This process occurs without the presence of oxygen. Therefore, the statement is true.Rate this question:
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- 3.
When organic compounds are broken down and energy is released, what is created?
- A.
ATP
- B.
ADP
- C.
Phosphate
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
When organic compounds are broken down and energy is released, several molecules are created. One of these molecules is ATP (adenosine triphosphate), which is the main energy currency of cells. ADP (adenosine diphosphate) is also formed, which can be converted back into ATP to store more energy. Additionally, phosphate molecules are released during this process. Therefore, all of the above options are correct as they represent the different molecules created when organic compounds are broken down and energy is released.Rate this question:
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- 4.
When glycolysis occurs, the products can follow three pathways
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
When glycolysis occurs, the products can follow two pathways, depending on the presence or absence of oxygen. In the presence of oxygen, the products of glycolysis enter the aerobic respiration pathway, where they undergo further breakdown in the mitochondria. In the absence of oxygen, the products enter the anaerobic fermentation pathway, where they are converted into lactic acid or ethanol. Therefore, the statement that the products of glycolysis can follow three pathways is false.Rate this question:
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- 5.
Pathways that operate without the presence of oxygen are called _______
- A.
De-oxygenated pathways
- B.
Aerobic pathways
- C.
Anerobic pathways
- D.
Pyruvic pathways
Correct Answer
C. Anerobic pathwaysExplanation
The correct answer is "Anerobic pathways". Anerobic pathways are pathways that can operate without the presence of oxygen. These pathways are used by organisms when there is a lack of oxygen available for energy production. During anerobic respiration, glucose is broken down into smaller molecules to release energy without the use of oxygen. This process is less efficient than aerobic respiration, but it allows organisms to continue producing energy in oxygen-deprived environments.Rate this question:
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- 6.
When one six-carbon molecule of glucose is oxidized, what is created?
- A.
Citric acid
- B.
Pyruvic acid
- C.
Lactic acid
- D.
Glucose
Correct Answer
B. Pyruvic acidExplanation
When one six-carbon molecule of glucose is oxidized, it is converted into pyruvic acid. This process is known as glycolysis, which occurs in the cytoplasm of cells. During glycolysis, glucose is broken down into two molecules of pyruvic acid, along with the production of a small amount of ATP. Pyruvic acid can then be further metabolized in the presence of oxygen to produce more ATP through the citric acid cycle and oxidative phosphorylation.Rate this question:
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- 7.
When an enzyme converts pyruvic acid into another three-carbon compound, it's called:
- A.
Glycolysis
- B.
Energy yielding
- C.
Lactic acid fermentation
- D.
The Calvin Cycle
Correct Answer
A. GlycolysisExplanation
Glycolysis is the correct answer because it is the process in which pyruvic acid, a three-carbon compound, is converted into another three-carbon compound. This process occurs in the cytoplasm of cells and is the first step in both aerobic and anaerobic respiration. Glycolysis is an energy-yielding process that breaks down glucose to produce ATP, NADH, and pyruvate. It does not directly produce lactic acid or occur in the Calvin Cycle, making those options incorrect.Rate this question:
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- 8.
________ is a product of alcoholic fermentation
- A.
Ethyl alcohol
- B.
Yeast
- C.
Phosphates
- D.
Glucose
Correct Answer
A. Ethyl alcoholExplanation
Ethyl alcohol is a product of alcoholic fermentation. Alcoholic fermentation is a metabolic process carried out by yeast in which glucose is converted into ethyl alcohol and carbon dioxide. Therefore, ethyl alcohol is the correct answer as it is the end product of this fermentation process.Rate this question:
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- 9.
Aerobic respiration has two stages.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Aerobic respiration actually consists of three main stages: glycolysis, the citric acid cycle (Krebs cycle), and the electron transport chain. These stages occur in the presence of oxygen and are part of the metabolic process by which cells produce energy (in the form of adenosine triphosphate or ATP) from glucose and other organic moleculesRate this question:
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- 10.
The________ is when the oxidation of glucose that began with glycolysis is completed
- A.
Electron Transport Chain
- B.
Calvin Cycle
- C.
Kreb's Cycle
- D.
Benson Cycle
Correct Answer
C. Kreb's CycleExplanation
The Kreb's Cycle, also known as the citric acid cycle, is the correct answer. It is the second stage of cellular respiration and occurs in the mitochondria. During this cycle, the remaining energy stored in glucose is extracted through a series of chemical reactions. It involves the oxidation of acetyl-CoA and produces ATP, NADH, FADH2, and carbon dioxide as byproducts. The Kreb's Cycle is an essential part of aerobic respiration and plays a crucial role in generating energy for the cell.Rate this question:
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- 11.
When pyruvic acid is produced through glycolysis, it diffuses across the __________.
- A.
Mitochondrial membrane
- B.
Cristae
- C.
Mitochondrial Matrix
- D.
Shell
Correct Answer
A. Mitochondrial membraneExplanation
Pyruvic acid, a product of glycolysis, needs to enter the mitochondria to continue the process of cellular respiration. The mitochondrial membrane is responsible for regulating the movement of molecules in and out of the mitochondria. Therefore, pyruvic acid diffuses across the mitochondrial membrane to enter the mitochondrial matrix, where it undergoes further reactions in the Krebs cycle. The cristae are the inner folds of the mitochondrial membrane, and the shell is not a component of the mitochondria.Rate this question:
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- 12.
Where are the electron transport chains in eukaryotic cells?
- A.
Vacuoles
- B.
The Nucleus
- C.
The Nucleolus
- D.
Inner membranes of Mitochondria
Correct Answer
D. Inner membranes of MitochondriaExplanation
The correct answer is the inner membranes of mitochondria. Electron transport chains are a series of protein complexes located in the inner membranes of mitochondria in eukaryotic cells. These chains play a crucial role in the process of oxidative phosphorylation, where electrons are transferred along the chain, resulting in the production of ATP. This process is a key step in cellular respiration, which is responsible for generating energy in eukaryotic cells.Rate this question:
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- 13.
ATP can be synthesized by chemiosmosis only if electrons continue to move from molecule to molecule in the ETC.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
In chemiosmosis, ATP is synthesized when electrons move from molecule to molecule in the electron transport chain (ETC). This process involves the transfer of electrons through a series of protein complexes, creating a proton gradient across the inner mitochondrial membrane. The movement of protons back across the membrane through ATP synthase drives the synthesis of ATP. Therefore, if electrons do not continue to move through the ETC, the proton gradient will not be maintained, and ATP synthesis through chemiosmosis will not occur. Hence, the statement is true.Rate this question:
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- 14.
Once no more electrons enter the ETC, what happens?
- A.
Two times more ATP is synthesized than before
- B.
ATP synthesis slows down
- C.
ADP is no longer produced
- D.
ATP synthesis stops
Correct Answer
D. ATP synthesis stopsExplanation
When no more electrons enter the electron transport chain (ETC), ATP synthesis stops. This is because the ETC is responsible for generating a proton gradient, which is used to power the production of ATP. Without the flow of electrons in the ETC, the proton gradient cannot be maintained, and therefore ATP synthesis ceases.Rate this question:
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- 15.
The actual number of ATP molecules generated varies from cell to cell.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The actual number of ATP molecules generated can vary from cell to cell due to several factors. These factors include the efficiency of cellular respiration, the type of cell, the availability of oxygen and nutrients, and the metabolic activity of the cell. Additionally, different cells may have different energy demands and may produce ATP at different rates. Therefore, it is true that the actual number of ATP molecules generated can vary from cell to cell.Rate this question:
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- 16.
The input/output of Glycolysis is __________
- A.
Pyruvate/Glucose
- B.
Glucose/ Pyruvate
- C.
1 ATP/ NADH
- D.
None of the above
Correct Answer
B. Glucose/ PyruvateExplanation
Glycolysis is the metabolic pathway that converts glucose into pyruvate. It is the first step in cellular respiration and occurs in the cytoplasm of cells. During glycolysis, one molecule of glucose is broken down into two molecules of pyruvate. Therefore, the correct answer is "Glucose/Pyruvate".Rate this question:
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- 17.
The input/output of the Electron Transport Chain is __________
- A.
NADH+FADH2/ 34 or 36 ATP
- B.
Pyruvate/Glucose
- C.
Glucose/Glucose
- D.
2 ATP/ Pyruvate
Correct Answer
A. NADH+FADH2/ 34 or 36 ATPExplanation
The correct answer is NADH+FADH2/ 34 or 36 ATP. The electron transport chain is the final stage of cellular respiration, where NADH and FADH2 molecules generated from earlier steps donate their electrons to a series of protein complexes. As the electrons move through these complexes, energy is released and used to pump protons across the inner mitochondrial membrane. This creates an electrochemical gradient, which drives the synthesis of ATP through ATP synthase. The exact number of ATP molecules produced can vary, but on average, each NADH can generate about 3 ATP and each FADH2 can generate about 2 ATP. Therefore, the input/output of the electron transport chain is NADH+FADH2/ 34 or 36 ATP.Rate this question:
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