1.
What is the term for " partial degradation of sugars or other organic fuel without the use of oxygen ?
Correct Answer
C. Fermentation
Explanation
Fermentation is the correct answer because it refers to the process of breaking down sugars or organic fuel without the use of oxygen. This process occurs in the absence of oxygen and produces energy in the form of ATP. Fermentation is commonly used by microorganisms to convert sugars into alcohol or lactic acid.
2.
What is the stage of cellular respiration that can occur with or without the use of O2?
Correct Answer
A. Glycolysis
Explanation
Glycolysis is the stage of cellular respiration that can occur with or without the use of O2. It is the initial step in breaking down glucose and does not require oxygen. During glycolysis, glucose is converted into pyruvate, producing a small amount of ATP and NADH. This process occurs in the cytoplasm of the cell and is the first step in both aerobic and anaerobic respiration.
3.
In reduction reaction the amount of positive charge of the atom is reduced when adding negatively charged electron.
Correct Answer
A. True
Explanation
In a reduction reaction, the amount of positive charge of an atom is indeed reduced when adding negatively charged electrons. This is because electrons have a negative charge, and when they are added to an atom, they neutralize some of the positive charge, resulting in a reduction of the overall positive charge of the atom. Therefore, the statement is true.
4.
When electrons move closer to a more electronegative atom, what happens?
Correct Answer
A. The more electronegative atom is reduced, and energy is released.
Explanation
When electrons move closer to a more electronegative atom, the atom gains electrons and is reduced. This reduction process releases energy.
5.
How many CO2 molecules will result from 15 pyruvate molecules during citric acid cycle?
Correct Answer
D. 30
Explanation
During the citric acid cycle, each pyruvate molecule is converted into one molecule of acetyl-CoA, which then enters the cycle. In one round of the citric acid cycle, each acetyl-CoA molecule produces 3 molecules of NADH and 1 molecule of FADH2. These electron carriers are then used in the electron transport chain to produce ATP. Since each pyruvate molecule produces 3 molecules of NADH, and there are 15 pyruvate molecules, the total number of NADH molecules produced is 15 x 3 = 45. During the electron transport chain, each NADH molecule produces 3 molecules of ATP, so the total number of ATP molecules produced is 45 x 3 = 135. Finally, during oxidative phosphorylation, each ATP molecule produces 1 molecule of CO2, so the total number of CO2 molecules produced is 135. Therefore, the correct answer is 30.
6.
When a molecule of NAD+ gains a hydrogen atom (not a proton), the molecule
becomes
Correct Answer
B. Reduced
Explanation
When a molecule of NAD+ gains a hydrogen atom, it undergoes a reduction reaction. Reduction is the gain of electrons or a decrease in oxidation state. In this case, NAD+ is gaining a hydrogen atom, which includes an electron, causing a reduction in NAD+. Therefore, the correct answer is "Reduced".
7.
How many ATP's are produced from 10 glucose by substrate level phosphorylation during cellular respiration?
Correct Answer
A. 40
Explanation
During cellular respiration, each molecule of glucose can produce a maximum of 4 ATP molecules through substrate level phosphorylation. Since there are 10 glucose molecules, multiplying 4 ATP by 10 gives us a total of 40 ATP molecules. Therefore, the correct answer is 40.
8.
Where does glycolysis take place in eukaryotic cells?
Correct Answer
D. cytosol
Explanation
Glycolysis takes place in the cytosol of eukaryotic cells. This is the process in which glucose is broken down into pyruvate, producing ATP and NADH. The cytosol is the fluid portion of the cell where many metabolic reactions occur. The mitochondria, on the other hand, are responsible for the aerobic respiration of pyruvate, which occurs after glycolysis.
9.
How many carbon atoms are fed into the citric acid cycle as a result of the oxidation of one molecule of pyruvate?
Correct Answer
A. 2
Explanation
During the citric acid cycle, one molecule of pyruvate is oxidized to produce one molecule of acetyl-CoA. Acetyl-CoA is a two-carbon molecule, which enters the citric acid cycle. Therefore, the oxidation of one molecule of pyruvate results in the entry of two carbon atoms into the citric acid cycle.
10.
Which downhill route does the electrons travel throgh during cellular respiration
Correct Answer
A. Glucose----NADH-----electron transport chain-----oxygen
Explanation
During cellular respiration, the electrons travel through the downhill route of glucose-NADH-electron transport chain-oxygen. This is because glucose is broken down into NADH during glycolysis and the Krebs cycle. NADH then donates its electrons to the electron transport chain, which is a series of protein complexes in the inner mitochondrial membrane. The electrons are passed along the chain, creating a proton gradient, and ultimately combine with oxygen to form water. Therefore, the correct route is glucose-NADH-electron transport chain-oxygen.
11.
What is the process that is used in both fermentation and respiration and is known as the most widespread metabolic pathway on earth ?
Correct Answer
B. Glycolysis
Explanation
Glycolysis is the process that is used in both fermentation and respiration and is known as the most widespread metabolic pathway on earth. It is the initial step in the breakdown of glucose, where glucose is converted into pyruvate. This process occurs in the cytoplasm of cells and does not require oxygen. In fermentation, pyruvate is further metabolized to produce energy in the absence of oxygen, while in respiration, pyruvate enters the citric acid cycle and oxidative phosphorylation to generate energy in the presence of oxygen.
12.
In anaerobic conditions the electrons transfer from NADH to Pyruvate
Correct Answer
A. True
Explanation
In anaerobic conditions, when there is a lack of oxygen, the process of cellular respiration cannot proceed normally. Instead, the electrons from NADH molecules are transferred to pyruvate molecules. This process is known as fermentation and it allows the regeneration of NAD+ so that glycolysis can continue to produce ATP. Therefore, the statement "in anaerobic conditions, the electrons transfer from NADH to pyruvate" is true.
13.
Lactic acid fermentation is used in ?
Correct Answer
D. 1+2
Explanation
Lactic acid fermentation is used in both the dairy industry and human muscle cells. In the dairy industry, lactic acid fermentation is used to produce yogurt, cheese, and other dairy products. In human muscle cells, lactic acid fermentation occurs during intense exercise when the body cannot supply enough oxygen to the muscles. This process helps convert glucose into energy and produces lactic acid as a byproduct. Therefore, the correct answer is 1+2, indicating that lactic acid fermentation is used in both the dairy industry and human muscle cells.
14.
The final electron acceptor in Alcohol fermentation is acetaldehyde
Correct Answer
A. True
Explanation
In alcohol fermentation, the final electron acceptor is acetaldehyde. During this process, glucose is converted into ethanol and carbon dioxide through a series of biochemical reactions. Acetaldehyde is formed as an intermediate product, and it accepts the electrons generated during the breakdown of glucose. Eventually, acetaldehyde is further reduced to ethanol, which is the final product of alcohol fermentation. Therefore, the given statement that acetaldehyde is the final electron acceptor in alcohol fermentation is true.
15.
During aerobic respiration, which of the following directly donates electrons to the electron transport
chain at the lowest energy level?
Correct Answer
C. FADH2
Explanation
FADH2 directly donates electrons to the electron transport chain at the lowest energy level during aerobic respiration. FADH2 is a high-energy molecule that is produced during the Krebs cycle. It carries electrons to the electron transport chain, where the electrons are passed along a series of protein complexes, ultimately generating ATP. NADH also donates electrons to the electron transport chain, but at a higher energy level. NAD+ is the oxidized form of NADH and does not directly donate electrons to the electron transport chain. ATP is not involved in directly donating electrons to the electron transport chain.
16.
Where is ATP synthase located in the mitochondrion?
Correct Answer
D. inner membrane
Explanation
ATP synthase is located in the inner membrane of the mitochondrion. This is where the electron transport chain takes place, and ATP synthase plays a crucial role in this process. It uses the energy from the movement of protons across the inner membrane to generate ATP, which is the main energy currency of the cell. Therefore, it is essential for ATP synthase to be located in the inner membrane to efficiently produce ATP.
17.
Which one do you like?
Correct Answer
A. Option 1
18.
Approximately how many molecules of ATP are produced from the complete oxidation of two
molecules of glucose (C6H12O6) in aerobic cellular respiration?
Correct Answer
D. 60-64
Explanation
During aerobic cellular respiration, each molecule of glucose produces a net gain of 36-38 ATP molecules. Since two molecules of glucose are being completely oxidized, the total number of ATP molecules produced would be approximately double that, resulting in a range of 60-64 ATP molecules.
19.
What is proton-motive force?
Correct Answer
B. The force exerted on a proton by a transmembrane proton concentration gradient
Explanation
The proton-motive force refers to the force exerted on a proton by a transmembrane proton concentration gradient. This means that when there is a difference in proton concentration on either side of a membrane, there is a force that pushes the protons across the membrane. This force is important in various biological processes, such as ATP synthesis in mitochondria, where the movement of protons across the membrane drives the production of ATP.