1.
Explain how a MFC works to light up a light bulb. Be specific. This is worth 4 points.
2.
Overall cellular respiration creates _____ molecules of ATP.
Correct Answer
D. 36-38
Explanation
Cellular respiration is the process by which cells convert glucose and oxygen into energy in the form of ATP. This process occurs in multiple stages, including glycolysis, the Krebs cycle, and oxidative phosphorylation. During these stages, a total of 36-38 molecules of ATP are produced. This range is due to the fact that the exact number of ATP molecules generated can vary depending on factors such as the efficiency of cellular respiration and the specific conditions within the cell.
3.
The process of cellular respiration
Correct Answer
A. Is performed by plants and animals
Explanation
Cellular respiration is the process by which cells convert glucose and oxygen into energy, carbon dioxide, and water. This process occurs in both plants and animals. Plants perform cellular respiration in their mitochondria, just like animals do. While plants also undergo photosynthesis to produce glucose, they still need to perform cellular respiration to release energy from glucose. Animals rely solely on cellular respiration to obtain energy from the food they consume. Therefore, the correct answer is that cellular respiration is performed by both plants and animals.
4.
If cellular respiration was divided into only 2 stages....they would be....
Correct Answer
C. Glycolysis and oxidative respiration
Explanation
If cellular respiration was divided into only 2 stages, they would be glycolysis and oxidative respiration. Glycolysis is the initial step of cellular respiration, where glucose is broken down into two molecules of pyruvate. Oxidative respiration, also known as aerobic respiration, occurs in the mitochondria and involves the complete breakdown of pyruvate to produce ATP through the Krebs cycle and electron transport chain. These two stages are essential for the production of energy in the form of ATP during cellular respiration.
5.
When glycolysis occurs
Correct Answer
D. All of the above
Explanation
Glycolysis is the metabolic pathway that breaks down glucose into pyruvate. During glycolysis, a molecule of glucose is indeed split into two molecules of pyruvate. Additionally, glycolysis is an anaerobic process and produces a small amount of ATP. Therefore, all of the statements mentioned in the options are correct.
6.
The name of the process that takes place in the absence of oxygen is called
Correct Answer
C. Fermentation
Explanation
Fermentation is the correct answer because it is the process that occurs in the absence of oxygen. During fermentation, glucose is broken down into simpler molecules such as lactic acid or ethanol, releasing energy in the process. This process is commonly observed in microorganisms like yeast and bacteria, as well as in some muscle cells when oxygen supply is limited. Respiration and reduction both require the presence of oxygen, while exergonic refers to any reaction that releases energy, regardless of oxygen availability.
7.
When muscles are exercised strenuously in the absence of sufficient oxygen,
Correct Answer
B. Lactic acid is formed
Explanation
During strenuous exercise, the muscles require more energy than can be supplied by oxygen alone. In this anaerobic condition, glucose is broken down through a process called glycolysis to produce ATP, the energy currency of cells. However, glycolysis also produces lactic acid as a byproduct. This buildup of lactic acid in the muscles causes the sensation of muscle fatigue and soreness. Therefore, the correct answer is that lactic acid is formed when muscles are exercised strenuously in the absence of sufficient oxygen.
8.
Which process occurs in the cytoplasm?
Correct Answer
D. Glycolysis
Explanation
Glycolysis is the process that occurs in the cytoplasm. It is the initial step in cellular respiration, where glucose is broken down into pyruvate molecules. This process does not require oxygen and can occur in both aerobic and anaerobic conditions. The other options mentioned (Krebs, ETS, and formation of acetyl CoA) are all processes that occur in the mitochondria, not in the cytoplasm.
9.
As a result of glycolysis, glucose is broken down into two molecules of
Correct Answer
A. Pyruvate
Explanation
Glycolysis is the process by which glucose is broken down in the cytoplasm of cells to produce energy. During glycolysis, glucose is converted into two molecules of pyruvate. Pyruvate is a three-carbon compound that can be further metabolized in the presence of oxygen to produce more energy through the Krebs cycle and oxidative phosphorylation. Therefore, pyruvate is the correct answer as the end product of glycolysis.
10.
What would be the most likely reason a distance swimmer would suffer from extreme fatigue and soreness?
Correct Answer
B. Not getting enough oxygen
Explanation
A distance swimmer requires a significant amount of oxygen to support their muscles during prolonged physical activity. If they are not getting enough oxygen, it can lead to extreme fatigue and soreness. Oxygen is essential for the production of energy in the body, and without sufficient oxygen, the muscles cannot function optimally, leading to fatigue and soreness.
11.
Glycolysis means...
Correct Answer
C. The splitting of glucose
Explanation
Glycolysis is a metabolic pathway that occurs in the cytoplasm of cells. It involves the breakdown of glucose into two molecules of pyruvate. Therefore, the correct answer is "the splitting of glucose." This process is an important step in cellular respiration, as it produces ATP, the main energy currency of the cell.
12.
Which of the following is a coenzyme?
Correct Answer
C. NADH and FADH2
Explanation
NADH and FADH2 are both examples of coenzymes. Coenzymes are small organic molecules that assist enzymes in carrying out their catalytic functions. They often act as carriers of electrons or small chemical groups during metabolic reactions. NADH (nicotinamide adenine dinucleotide) and FADH2 (flavin adenine dinucleotide) are involved in cellular respiration, where they play crucial roles in transferring electrons from one molecule to another in the electron transport chain. This transfer of electrons is essential for the generation of ATP, the energy currency of cells. Therefore, NADH and FADH2 are considered coenzymes due to their involvement in enzymatic reactions.
13.
After glycolysis, pyruvate
Correct Answer
B. Travels to the mitochondria
Explanation
After glycolysis, pyruvate travels to the mitochondria. This is because the mitochondria is the site where the next stage of cellular respiration, the Krebs cycle, takes place. In the mitochondria, pyruvate is further broken down to produce energy in the form of ATP. The mitochondria is known as the powerhouse of the cell due to its role in generating energy through cellular respiration. Therefore, it is logical for pyruvate to travel to the mitochondria after glycolysis.
14.
During the Krebs cycle, the carbon molecule goes through many chemical reactions including a removal of carbon atoms. When this occurs __________ is released.
Correct Answer
B. Carbon dioxide
Explanation
During the Krebs cycle, the carbon molecule undergoes various chemical reactions, resulting in the removal of carbon atoms. This process is known as decarboxylation, where a carbon atom is removed from the molecule in the form of carbon dioxide. Therefore, carbon dioxide is released as a byproduct during the Krebs cycle.
15.
The inner membrane of a mitochondria is called the
Correct Answer
A. Cristae
Explanation
The inner membrane of a mitochondria is called cristae. Cristae are the folds or invaginations of the inner membrane that increase the surface area available for the electron transport chain and ATP synthesis. These folds play a crucial role in the production of ATP, the energy currency of the cell, by providing a large surface area for the enzymes and proteins involved in oxidative phosphorylation.
16.
In an anaerobic organism, fermentation would follow glycolysis.
Correct Answer
A. True
Explanation
In anaerobic organisms, fermentation is the process that occurs after glycolysis. This is because glycolysis is the initial step in the breakdown of glucose, which produces pyruvate. In the absence of oxygen, pyruvate is converted into different end products through fermentation, such as lactic acid or ethanol. Therefore, it is correct to say that fermentation follows glycolysis in anaerobic organisms.
17.
Acetyl CoA enters the Krebs cycle in cellular respiration.
Correct Answer
A. True
Explanation
Acetyl CoA enters the Krebs cycle in cellular respiration. This is because Acetyl CoA is produced from the breakdown of glucose during glycolysis, and it is the starting molecule for the Krebs cycle. In the Krebs cycle, Acetyl CoA is further broken down, releasing energy in the form of ATP and producing carbon dioxide as a waste product. Therefore, it is true that Acetyl CoA enters the Krebs cycle in cellular respiration.
18.
The electron transport chain is where most of the ATP is produced during cellular respiration.
Correct Answer
A. True
Explanation
The electron transport chain is the final step in cellular respiration, where electrons from molecules like glucose are passed along a series of proteins and enzymes. As the electrons move through the chain, energy is released and used to pump protons across a membrane. This creates a proton gradient, which is then used by ATP synthase to produce ATP. Since the electron transport chain is responsible for the majority of ATP production in cellular respiration, it is correct to say that most ATP is produced in this process.
19.
The correct chemical equation for cellular respiration is
Correct Answer
C. C6H12O6 + 6O2 --> 6CO2 + 6H20
Explanation
The correct chemical equation for cellular respiration is C6H12O6 + 6O2 --> 6CO2 + 6H2O. This equation represents the process of cellular respiration, where glucose (C6H12O6) is broken down in the presence of oxygen (O2) to produce carbon dioxide (CO2) and water (H2O). This equation accurately represents the reactants and products involved in cellular respiration.
20.
The gross total number of ATP molecules gained by the cell during glycolysis is
Correct Answer
A. 4
Explanation
During glycolysis, which is the first step of cellular respiration, a total of 4 ATP molecules are gained by the cell. This occurs through substrate-level phosphorylation, where 2 ATP molecules are produced directly during the energy payoff phase. Although 2 ATP molecules are consumed during the energy investment phase, the net gain of ATP is 4 because 4 ATP molecules are produced. Therefore, the correct answer is 4.
21.
Which direction do the electrons flow in a MFC?
Correct Answer
A. Anode to cathode
Explanation
In a Microbial Fuel Cell (MFC), the electrons flow from the anode to the cathode. This is because during the process of microbial metabolism, microorganisms at the anode release electrons as a byproduct. These electrons then travel through an external circuit towards the cathode, where they combine with protons and an electron acceptor (such as oxygen) to complete the overall reaction. This flow of electrons from the anode to the cathode generates an electric current, which can be harnessed for various applications.
22.
From the lemon battery lab, protons moved from the nail to the penny through the lemon juice. This suggested that the lemon juice acted as an electrolyte.
Correct Answer
A. True
Explanation
The movement of protons from the nail to the penny through the lemon juice in the lemon battery lab indicates that the lemon juice acted as an electrolyte. Electrolytes are substances that conduct electricity when dissolved in a solution, and in this case, the lemon juice facilitated the flow of electric current by allowing the movement of ions. Therefore, the statement is true.