Photosynthesis Flashcards
What is photosynthesis?
The process by which plants, algae, and some bacteria convert light energy into chemical energy (glucose).
Where exactly does photosynthesis occur?
In chloroplasts, more exactly
1st stage in thylacoid membranes
2nd stage in stroma
What are key stages of photosynthesis?
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Light-dependent reactions (occur in thylakoid membranes)
- Calvin Cycle (Light-independent reactions, occur in stroma)
What is Z-Scheme in photosynthesis?
Z-Scheme describes the electron flow during the light-dependent reactions.
What happens to NADP+ during photosynthesis?
NADP+ → NADPH;
NADP+ is reduced to NADPH, which is used in the Calvin cycle.
When and how is oxygen produced during photosynthesis ?
Oxygen is a by-product of the splitting of water in the light-dependent reactions.
What is PAR in photosynthesis?
PAR (Photosynthetically Active Radiation)
Light in the range of 400-700 nm.
What is Rubisco in photosynthesis?
An enzyme that fixes CO₂ during the Calvin cycle.
What does Rubisco do during photorespiration?
Rubisco can also bind O₂, leading to the production of CO₂ and reducing the efficiency of photosynthesis.
What are C4 plants?
C4 Plants are plants that adapted to hot and dry environments, e.g., sugarcane.
C4 plants are special. They have a special type of leaf anatomy (Kranz anatomy), they tolerate high temperatures, they show a response to high light intensities, they lack a process called photorespiration and have greater productivity of biomass.
What does C4 mean in C4 photosynthesis?
four-carbon sugar compounds
How is C4 photosynthesis different from normal photosynthesis?
In C4 photosynthesis, where a four-carbon compound is produced, unique leaf anatomy allows carbon dioxide to concentrate in ‘bundle sheath’ cells around Rubisco. This structure delivers carbon dioxide straight to Rubisco, effectively removing its contact with oxygen and the need for photorespiration.
What are some key features of C4 photosynthesis?
C4 Photosynthesis Key Features:
- Spatial Separation: CO₂ is fixed in mesophyll cells and processed in bundle sheath cells.
- Enzymes: PEP carboxylase fixes CO₂ efficiently; Rubisco operates in bundle sheath cells.
- Reduced Photorespiration: Concentrates CO₂ around Rubisco, minimizing wasteful oxygenation.
- Kranz Anatomy: Specialized leaf structure with distinct mesophyll and bundle sheath cells.
- Energy Use: Requires more ATP but is efficient in hot, dry environments.
- Common in: Maize, sugarcane, sorghum, and tropical grasses.
What is an advantage of C4 photosynthesis?
Reduces photorespiration by minimizing oxygen’s impact on CO₂ fixation.
TF
Photorespiration is a fruitful process
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