1.
The bond site at which energy is released as ATP changes to ADP is where ___.
Correct Answer
B. The last pHospHate attaches to another pHospHate.
Explanation
When ATP (adenosine triphosphate) changes to ADP (adenosine diphosphate), the bond site where energy is released is where the last phosphate group attaches to another phosphate group. This process is known as hydrolysis, where a water molecule is used to break the bond between the last phosphate and the rest of the molecule. This releases energy that can be used by the cell for various processes. The other options mentioned in the question (ribose and phosphate joining, ribose and adenine joining, and the middle phosphate attaching to the phosphate next to ribose) do not accurately describe the process of ATP changing to ADP.
2.
Cellular respiration uses oxygen to convert the chemical energy stored in organic molecules into
Correct Answer
B. ATP
Explanation
Cellular respiration is a metabolic process that occurs in cells to produce energy in the form of ATP. During this process, organic molecules are broken down in the presence of oxygen to release energy. ATP is the primary energy currency of cells, and it is produced through cellular respiration. Water and carbon dioxide are byproducts of this process. Therefore, the correct answer is ATP, as it is the main product of cellular respiration.
3.
The Krebs Cycle takes place in the matrix.
Correct Answer
A. True
Explanation
The Krebs Cycle, also known as the citric acid cycle, is a series of chemical reactions that occur in the mitochondria of cells. These reactions take place in the matrix, which is the innermost compartment of the mitochondria. Here, the cycle helps in the production of energy-rich molecules called ATP through the breakdown of carbohydrates, fats, and proteins. Therefore, the given statement that the Krebs Cycle takes place in the matrix is true.
4.
Choose the correct sequence of events in cellular respiration below.
Correct Answer
D. Glycolysis > Krebs Cycle > electron transport
Explanation
Cellular respiration is the process by which cells convert glucose into ATP (adenosine triphosphate) for energy. The correct sequence of events in cellular respiration is glycolysis, followed by the Krebs Cycle, and then electron transport. Glycolysis is the first step in cellular respiration, where glucose is broken down into pyruvate. The pyruvate then enters the Krebs Cycle, where it is further broken down to release energy-rich molecules. Finally, the energy-rich molecules produced in the Krebs Cycle are used in the electron transport chain to generate ATP. Therefore, the correct sequence is Glycolysis > Krebs Cycle > electron transport.
5.
Which of these processes takes place in the cytoplasm of the cell?
Correct Answer
A. Glycolysis
Explanation
Glycolysis is the process that takes place in the cytoplasm of the cell. It is the initial step in cellular respiration, where glucose is broken down into pyruvate to produce energy in the form of ATP. The cytoplasm is the fluid-filled region of the cell where many metabolic processes occur, including glycolysis. The Krebs Cycle and electron transport, on the other hand, occur in the mitochondria, while photosynthesis takes place in the chloroplasts.
6.
The main function of cellular respiration is to produce glucose.
Correct Answer
B. False
Explanation
Cellular respiration is a metabolic process that occurs in cells to convert glucose into energy in the form of ATP. It is not responsible for producing glucose, but rather for breaking it down. Glucose is produced through the process of photosynthesis in plants. Therefore, the statement that the main function of cellular respiration is to produce glucose is incorrect.
7.
What compound directly provides energy for cellular work?
Correct Answer
B. ATP
Explanation
ATP (adenosine triphosphate) is the correct answer because it is the molecule that directly provides energy for cellular work. ATP is a high-energy molecule that stores and releases energy when needed by breaking the bonds between its phosphate groups. This energy is used for various cellular processes such as muscle contraction, active transport, and synthesis of molecules. Glucose is a source of energy, but it needs to be broken down into ATP through cellular respiration before it can be used. DNA and fat are not directly involved in providing energy for cellular work.
8.
What molecule does the carbon in Carbon Dioxide and the hydrogen in water come from?
Correct Answer
D. Glucose
Explanation
The carbon in carbon dioxide and the hydrogen in water come from glucose. Glucose is a molecule that is broken down during cellular respiration to produce carbon dioxide and water as byproducts. This process occurs in the presence of oxygen and is essential for the production of energy in living organisms.
9.
ATP is an energy carrier. Where is the energy actually located?
Correct Answer
A. In the bonds between pHospHate groups
Explanation
The energy in ATP is actually located in the bonds between phosphate groups. When one of these phosphate groups is hydrolyzed, releasing a phosphate group, energy is released and can be used by the cell for various processes.
10.
What is the most common energy carrier molecule in living organisms?
Correct Answer
C. ATP
Explanation
ATP (adenosine triphosphate) is the most common energy carrier molecule in living organisms. It is responsible for storing and releasing energy during cellular processes. ATP is produced through cellular respiration and is used by cells as a source of energy for various metabolic reactions. It is often referred to as the "energy currency" of the cell because it provides the energy needed for essential cellular functions. Glucose is an important source of energy, but it is converted into ATP through cellular respiration. ADP (adenosine diphosphate) is a precursor to ATP, and DNA is a genetic material, not an energy carrier molecule.