Photosynthesis Flashcards
What is photosynthesis?
Photosynthesis is the process by which plants convert light energy, into chemical energy stored in the form of glucose. This process also produces oxygen as a byproduct.
What is the chemical equation for photosynthesis?
6CO2 +6H2O+lightenergy→C6H12O6+6O2
Which organelle is responsible for photosynthesis in plant cells?
Chloroplasts are the organelles in plant cells that carry out photosynthesis. They contain chlorophyll, the pigment that absorbs light energy.
What is the role of chlorophyll in photosynthesis?
Chlorophyll is the green pigment in chloroplasts that absorbs light, primarily blue and red wavelengths, and reflects green. It plays a crucial role in capturing the light energy needed for photosynthesis.
What are the two main stages of photosynthesis?
- Light-dependent reactions: Occur in the thylakoid membranes of the chloroplast, where light energy is absorbed and converted into ATP and NADPH.
- Calvin Cycle (Light-independent reactions): Occur in the stroma of the chloroplast, where ATP and NADPH are used to convert carbon dioxide into glucose.
Where do the Calvin Cycle (light-independent reactions) occur?
The Calvin Cycle occurs in the stroma of the chloroplast, where ATP and NADPH are used to convert CO_2 into glucose.
What happens during the light-dependent reactions of photosynthesis?
Chlorophyll absorbs light energy.
This energy splits water molecules (photolysis), releasing oxygen.
ATP and NADPH are produced and used in the Calvin Cycle.
What is the importance of water in the light-dependent reactions?
Water is split into oxygen, protons, and electrons during photolysis in the light-dependent reactions. The electrons replace those lost by chlorophyll, and the oxygen is released as a byproduct.
What happens during the Calvin Cycle?
In the Calvin Cycle, carbon dioxide is fixed into a 5-carbon molecule called ribulose bisphosphate (RuBP), which is then converted into glucose using energy from ATP and NADPH produced in the light-dependent reactions.
What is carbon fixation in the Calvin Cycle?
Carbon fixation is the process where carbon dioxide is incorporated into an organic molecule, forming a 6-carbon molecule that quickly breaks down into two molecules of 3-phosphoglycerate (3-PGA).
What is the final product of the Calvin Cycle?
The final product of the Calvin Cycle is glucose (C₆H₁₂O₆), a simple sugar that the plant can use for energy or store as starch.
What are the main factors that affect the rate of photosynthesis?
Light intensity – More light increases the rate of photosynthesis.
Carbon dioxide concentration – Higher CO₂ levels can increase the rate of photosynthesis.
Temperature – Photosynthesis occurs more efficiently within a certain temperature range.
How does carbon dioxide concentration affect photosynthesis?
As CO₂ concentration increases, the rate of photosynthesis also increases, as carbon dioxide is a key reactant. However, once a certain concentration is reached, the rate levels off.
How does light intensity affect photosynthesis?
As light intensity increases, the rate of photosynthesis increases until it reaches a maximum point, beyond which the rate no longer increases due to other limiting factors (e.g., carbon dioxide, temperature).
How does temperature affect photosynthesis?
Temperature affects the enzymes involved in photosynthesis. If the temperature is too low, the enzymes work slowly, and if it is too high, enzymes may denature, slowing down or halting the process.
How are photosynthesis and cellular respiration related?
Photosynthesis and cellular respiration are complementary processes:
Photosynthesis converts light energy into chemical energy stored in glucose.
Cellular respiration breaks down glucose to produce ATP, the energy currency of cells.
What is phytoplankton?
Phytoplankton are tiny, photosynthetic organisms in oceans and freshwater. They are a key part of aquatic ecosystems, producing oxygen and serving as the base of the food chain.
