Question
Explain how the light reactions and light-independent reactions (Calvin cycle) of photosynthesis are interdependent on each other.
The light reactions use NADPH and ATP, which are produced by the Calvin cycle.
The light reactions produce only NADPH, which is produced by the Calvin cycle.
The light reactions produce ATP and NADPH, which are then used in the Calvin cycle.
The light reactions produce NADP† and ADP, which are then used in the Calvin cycle.
55
Multiple Choice 2 points
In which situation would passive transport not use a transport protein for entry into a cell?
glucose being absorbed from the blood water flowing into a hypertonic environment
an ion flowing into a nerve cell to create an electrical potential oxygen moving into a cell after oxygen deprivation
56
Multiple Choice 2 points
At which of the cell-cycle checkpoints do external forces have the greatest influence?
GO checkpoint
G2 checkpoint
M checkpoint
G1 checkpoint
The light reactions use NADPH and ATP, which are produced by the Calvin cycle.
The light reactions produce only NADPH, which is produced by the Calvin cycle.
The light reactions produce ATP and NADPH, which are then used in the Calvin cycle.
The light reactions produce NADP† and ADP, which are then used in the Calvin cycle.
55
Multiple Choice 2 points
In which situation would passive transport not use a transport protein for entry into a cell?
glucose being absorbed from the blood water flowing into a hypertonic environment
an ion flowing into a nerve cell to create an electrical potential oxygen moving into a cell after oxygen deprivation
56
Multiple Choice 2 points
At which of the cell-cycle checkpoints do external forces have the greatest influence?
GO checkpoint
G2 checkpoint
M checkpoint
G1 checkpoint
Answers
GPT-4o mini
### Photosynthesis: Light Reactions and Calvin Cycle Interdependence
In photosynthesis, the light reactions and the light-independent reactions, also known as the Calvin cycle, are crucial components that are interdependent.
- **Light Reactions**: These occur in the thylakoid membranes of the chloroplasts and require light energy to produce ATP and NADPH from water and sunlight. The light reactions convert solar energy into chemical energy, which is then stored in the form of ATP and NADPH.
- **Calvin Cycle (Light-Independent Reactions)**: This occurs in the stroma of the chloroplasts and does not directly require light; instead, it uses the ATP and NADPH produced in the light reactions to fix carbon dioxide into glucose and other organic molecules.
The interdependence can be summarized as follows:
- **Correct Statement**: The light reactions produce ATP and NADPH, which are then used in the Calvin cycle.
The ATP provides the energy necessary for the various reactions in the Calvin cycle, while NADPH serves as a reducing agent, supplying the electrons needed to convert carbon dioxide into glucose.
### Passive Transport without Transport Proteins
In passive transport, substances cross cell membranes without the need for energy input. Transport proteins facilitate the movement of certain molecules across the membrane, especially those that are not freely permeable.
Among the options given in your question, **the situation where passive transport would not use a transport protein for entry into a cell** is:
- **Oxygen moving into a cell after oxygen deprivation**: Oxygen is a small, nonpolar molecule, and it can diffuse directly through the lipid bilayer of cell membranes without the need for a transport protein.
### Cell Cycle Checkpoints and External Forces
Cell cycle checkpoints are critical in ensuring that cells only proceed to the next phase of the cell cycle when conditions are favorable.
- **The checkpoint where external forces have the greatest influence is the:**
- **G1 checkpoint**: This checkpoint serves as a primary decision point in the cell cycle and is greatly influenced by external signals such as growth factors and nutrient availability. It assesses whether the cell has sufficient resources and appropriate signals to divide.
If you have any further questions or need clarification, feel free to ask!
In photosynthesis, the light reactions and the light-independent reactions, also known as the Calvin cycle, are crucial components that are interdependent.
- **Light Reactions**: These occur in the thylakoid membranes of the chloroplasts and require light energy to produce ATP and NADPH from water and sunlight. The light reactions convert solar energy into chemical energy, which is then stored in the form of ATP and NADPH.
- **Calvin Cycle (Light-Independent Reactions)**: This occurs in the stroma of the chloroplasts and does not directly require light; instead, it uses the ATP and NADPH produced in the light reactions to fix carbon dioxide into glucose and other organic molecules.
The interdependence can be summarized as follows:
- **Correct Statement**: The light reactions produce ATP and NADPH, which are then used in the Calvin cycle.
The ATP provides the energy necessary for the various reactions in the Calvin cycle, while NADPH serves as a reducing agent, supplying the electrons needed to convert carbon dioxide into glucose.
### Passive Transport without Transport Proteins
In passive transport, substances cross cell membranes without the need for energy input. Transport proteins facilitate the movement of certain molecules across the membrane, especially those that are not freely permeable.
Among the options given in your question, **the situation where passive transport would not use a transport protein for entry into a cell** is:
- **Oxygen moving into a cell after oxygen deprivation**: Oxygen is a small, nonpolar molecule, and it can diffuse directly through the lipid bilayer of cell membranes without the need for a transport protein.
### Cell Cycle Checkpoints and External Forces
Cell cycle checkpoints are critical in ensuring that cells only proceed to the next phase of the cell cycle when conditions are favorable.
- **The checkpoint where external forces have the greatest influence is the:**
- **G1 checkpoint**: This checkpoint serves as a primary decision point in the cell cycle and is greatly influenced by external signals such as growth factors and nutrient availability. It assesses whether the cell has sufficient resources and appropriate signals to divide.
If you have any further questions or need clarification, feel free to ask!