Photosynthesis Flashcards
Where do light-dependent reactions occur?
In the chloroplast, specifically in the thylakoid membrane.
What are the inputs for light-dependent reactions?
Water (H₂O), light energy, ADP, and NADP⁺.
What is produced during light-dependent reactions?
O₂, ATP, and NADPH.
What is the role of Photosystem II (PSII) in light-dependent reactions?
Absorbs light energy and splits water to produce oxygen, protons, and electrons.
Fill in the blank: The proton concentration gradient drives ATP synthesis via _______.
ATP synthase.
What is the first step of the Calvin Cycle?
Carbon fixation of CO₂ onto RuBP.
What enzyme catalyzes the reaction in carbon fixation?
Rubisco.
What is produced during the reduction phase of the Calvin Cycle?
G3P (glyceraldehyde-3-phosphate).
How many G3P molecules exit the Calvin Cycle to form sugars?
1 out of 6 G3P molecules.
What happens to the remaining G3P molecules in the Calvin Cycle?
They regenerate RuBP using ATP.
What is the output of the Calvin Cycle?
Sugars, RuBP, ADP, and NADP⁺.
True or False: Photorespiration occurs when Rubisco fixes O₂ instead of CO₂.
True.
What are the consequences of photorespiration?
Loss of fixed carbon and inefficient use of energy.
What is C4 photosynthesis an adaptation for?
Hot climates with low CO₂ and high O₂ levels.
What enzyme is involved in C4 photosynthesis to fix CO₂?
PEPcase.
What is malic acid’s role in C4 photosynthesis?
It is formed from CO₂ and is transferred to bundle sheath cells.
What advantage does C4 photosynthesis have over C3 photosynthesis?
More efficient in hot, dry climates.
In CAM photosynthesis, when do stomata open?
At night.
What is the main advantage of CAM photosynthesis?
Minimizes water loss in extreme environments.
What is the equation for cellular respiration?
C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + ATP.
Where does glycolysis occur?
In the cytoplasm.
What are the outputs of cellular respiration?
ATP, CO₂, and H₂O.
What is a waste product of photorespiration?
Phosphoglycolate.
What is the primary function of photosynthesis?
To convert light energy into chemical energy in the form of glucose.
What are the two main stages of photosynthesis?
Light-dependent reactions and the Calvin cycle.
Where do light-dependent reactions occur?
In the thylakoid membranes of chloroplasts.
What is produced during the light-dependent reactions?
ATP, NADPH, and oxygen.
What absorbs light energy in plants?
Chlorophyll.
True or False: The Calvin cycle requires light directly.
False.
What is the main purpose of the Calvin cycle?
To synthesize glucose from carbon dioxide using ATP and NADPH.
Fill in the blank: The Calvin cycle occurs in the _____ of the chloroplast.
stroma.
What is the first stable product of the Calvin cycle?
3-phosphoglycerate (3-PGA).
What enzyme catalyzes the fixation of carbon dioxide in the Calvin cycle?
Ribulose bisphosphate carboxylase/oxygenase (RuBisCO).
What is CAM photosynthesis?
A photosynthetic pathway that allows plants to fix CO2 at night to minimize water loss.
Which types of plants typically use CAM photosynthesis?
Cacti and succulents.
What is the main advantage of C4 photosynthesis?
It allows plants to efficiently capture CO2 even in low concentrations.
Where does C4 photosynthesis occur in the plant?
In specialized bundle sheath cells.
Fill in the blank: In C4 plants, CO2 is initially fixed into a four-carbon compound called _____.
oxaloacetate.
True or False: Both CAM and C4 pathways are adaptations to hot and dry environments.
True.
What are the two types of cells involved in C4 photosynthesis?
Mesophyll cells and bundle sheath cells.
What is the role of NADPH in photosynthesis?
It provides reducing power for the synthesis of glucose in the Calvin cycle.
What byproduct is released during the light-dependent reactions?
Oxygen.
Which molecule acts as the energy currency in the cell during photosynthesis?
ATP.
What is the significance of water in photosynthesis?
It is a source of electrons and protons and is split to release oxygen.
Fill in the blank: The process of converting light energy into chemical energy occurs in the _____ reactions.
light-dependent.
What is the role of RuBP in the Calvin cycle?
It is the five-carbon sugar that reacts with CO2 to initiate the cycle.
What is the final product of the Calvin cycle that can be used to form glucose?
Glyceraldehyde-3-phosphate (G3P).
True or False: C4 photosynthesis is more efficient than C3 photosynthesis in high light and temperature conditions.
True.
What type of plants primarily utilize C3 photosynthesis?
Most temperate plants, including wheat and rice.
