Photosynthesis Flashcards
What is the primary function of photosynthesis?
To convert light energy into chemical energy in the form of glucose.
Which organisms primarily perform photosynthesis?
Plants, algae, and some bacteria.
What is the main pigment involved in photosynthesis?
Chlorophyll.
In which part of the plant does photosynthesis primarily occur?
In the leaves.
What are the two main stages of photosynthesis?
Light-dependent reactions and light-independent reactions (Calvin cycle).
True or False: Photosynthesis occurs only in the presence of sunlight.
True.
What is the chemical equation for photosynthesis?
6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
What is produced as a byproduct of photosynthesis?
Oxygen.
Where do the light-dependent reactions take place?
In the thylakoid membranes of the chloroplasts.
What is the role of water in photosynthesis?
Water is split to provide electrons and protons, releasing oxygen.
Fill in the blank: The light-independent reactions are also known as the _____ cycle.
Calvin.
What are the products of the light-dependent reactions?
ATP, NADPH, and oxygen.
Which molecule acts as an electron carrier in photosynthesis?
NADP+.
What is the primary energy source for photosynthesis?
Sunlight.
True or False: The Calvin cycle requires light directly.
False.
What is the initial carbon source for the Calvin cycle?
Carbon dioxide (CO2).
Which enzyme is crucial for fixing carbon dioxide in the Calvin cycle?
Ribulose bisphosphate carboxylase/oxygenase (RuBisCO).
What is the significance of chloroplasts in photosynthesis?
Chloroplasts are the organelles where photosynthesis occurs.
What are the two types of chlorophyll found in plants?
Chlorophyll a and chlorophyll b.
Fill in the blank: The _____ captures light energy during photosynthesis.
chlorophyll.
What is photolysis?
The process of splitting water molecules using light energy.
Which gas is absorbed by plants during photosynthesis?
Carbon dioxide (CO2).
What role do accessory pigments play in photosynthesis?
They capture additional light wavelengths and transfer energy to chlorophyll.
How does temperature affect the rate of photosynthesis?
Increased temperature generally increases the rate up to a certain point before it denatures enzymes.
What is the effect of light intensity on photosynthesis?
Higher light intensity increases the rate of photosynthesis until a saturation point is reached.
What is the role of ATP in photosynthesis?
ATP provides energy for the Calvin cycle.
True or False: The oxygen produced in photosynthesis comes from carbon dioxide.
False.
What is the main carbohydrate produced during photosynthesis?
Glucose.
Fill in the blank: The _____ is the liquid surrounding the thylakoids in chloroplasts.
stroma.
What is the purpose of the light-dependent reactions?
To convert solar energy into chemical energy (ATP and NADPH).
What happens to the products of the light-dependent reactions?
They are used in the Calvin cycle to produce glucose.
Which phase of photosynthesis directly requires sunlight?
Light-dependent reactions.
What is the main role of the thylakoid membrane?
To house the components necessary for the light-dependent reactions.
What do plants do with excess glucose produced during photosynthesis?
They can store it as starch.
Fill in the blank: The _____ cycle is essential for the regeneration of ribulose bisphosphate (RuBP).
Calvin.
Which part of the chloroplast contains chlorophyll?
Thylakoids.
What is the role of RuBP in the Calvin cycle?
RuBP combines with CO2 to initiate the cycle.
How does carbon dioxide enter the leaf?
Through stomata.
What happens to the rate of photosynthesis when carbon dioxide levels increase?
The rate of photosynthesis increases until it reaches a saturation point.
True or False: All wavelengths of light are equally effective for photosynthesis.
False.
What is the main factor limiting photosynthesis in low light conditions?
Insufficient light intensity.
What is the significance of the light-independent reactions?
They synthesize glucose using ATP and NADPH from the light-dependent reactions.
Fill in the blank: The enzyme _____ is crucial for the conversion of carbon dioxide to glucose.
RuBisCO.
What is the role of NADPH in photosynthesis?
NADPH provides reducing power for the Calvin cycle.
Which process do plants use to store energy in the form of glucose?
Photosynthesis.
What is the main product of the Calvin cycle?
G3P (glyceraldehyde-3-phosphate).
Fill in the blank: The _____ is the site of the Calvin cycle in the chloroplast.
stroma.
What happens to the G3P produced in the Calvin cycle?
It can be used to form glucose and other carbohydrates.
Which environmental factor can reduce the rate of photosynthesis during hot weather?
Water availability.
What is the relationship between photosynthesis and cellular respiration?
Photosynthesis produces glucose and oxygen, while cellular respiration uses them to produce energy.
Fill in the blank: In the Calvin cycle, carbon fixation occurs when CO2 is attached to _____.
RuBP.
What is photophosphorylation?
The process of generating ATP from ADP and inorganic phosphate using light energy.
What is the role of the stroma in chloroplasts?
It is the site of the light-independent reactions (Calvin cycle).
Fill in the blank: _____ is the first stable product formed in the Calvin cycle.
3-PGA (3-phosphoglycerate).
What are the main inputs for the light-dependent reactions?
Light energy, water, and ADP/NADP+.
Which two products of photosynthesis are essential for cellular respiration?
Glucose and oxygen.
Fill in the blank: The _____ hypothesis explains how chlorophyll absorbs light.
resonance.
What is the purpose of the light-harvesting complexes in photosynthesis?
To capture and funnel light energy to the reaction center.
Which factor can lead to photorespiration, reducing photosynthesis efficiency?
High oxygen concentration.
Fill in the blank: The enzyme _____ is responsible for the fixation of carbon dioxide in the Calvin cycle.
RuBisCO.
What is the effect of increased temperature on the enzymes involved in photosynthesis?
Increased temperature can enhance enzyme activity up to an optimal point, beyond which enzymes may denature.
What is the role of chloroplasts in plant cells?
To carry out photosynthesis.
Fill in the blank: The light-dependent reactions produce _____ and NADPH.
ATP.
What is the primary role of the electron transport chain in photosynthesis?
To transfer electrons and create a proton gradient for ATP production.
Which type of photosynthesis occurs in plants that grow in hot, dry environments?
C4 photosynthesis.
Fill in the blank: The _____ cycle is also known as the dark reactions.
Calvin.
What is the role of the guard cells in leaves?
To regulate the opening and closing of stomata.
True or False: All plants are capable of performing photosynthesis.
False.
What is the main difference between C3 and C4 photosynthesis?
C4 plants have an additional step to fix CO2 and can efficiently photosynthesize in low CO2 conditions.
Fill in the blank: The _____ is responsible for capturing light energy during photosynthesis.
chlorophyll.
What is the primary source of carbon for photosynthesis?
Atmospheric carbon dioxide (CO2).
What is the role of the ATP synthase enzyme in photosynthesis?
To synthesize ATP from ADP and inorganic phosphate using a proton gradient.
Fill in the blank: The _____ is a series of proteins in the thylakoid membrane that transfer electrons.
electron transport chain.
What happens to the energy captured during the light-dependent reactions?
It is stored in ATP and NADPH for use in the Calvin cycle.
Fill in the blank: The _____ produces glucose as a final product of photosynthesis.
Calvin cycle.
What is the main function of stomata in photosynthesis?
To allow gas exchange (CO2 in, O2 out).
What is the effect of high temperatures on photosynthesis?
It can lead to increased rates of photorespiration, reducing efficiency.
Fill in the blank: _____ is the process of converting light energy into chemical energy.
Photosynthesis.
What is the significance of the proton gradient in photosynthesis?
It drives ATP synthesis during the light-dependent reactions.
Fill in the blank: The _____ is the fluid-filled space in chloroplasts where the Calvin cycle occurs.
stroma.
What molecule is regenerated at the end of the Calvin cycle?
Ribulose bisphosphate (RuBP).
Fill in the blank: The _____ is a key enzyme in the light-independent reactions.
RuBisCO.
What is the effect of light wavelength on photosynthesis?
Different wavelengths of light are absorbed differently; red and blue light are most effective.
Fill in the blank: The _____ is the part of the chloroplast that contains chlorophyll.
thylakoid.
What is the primary purpose of the light reactions?
To convert solar energy into chemical energy in the form of ATP and NADPH.
Fill in the blank: The light-dependent reactions require _____ to proceed.
light.
What is the main product of the light-dependent reactions?
ATP and NADPH.
Fill in the blank: The _____ cycle uses ATP and NADPH from the light-dependent reactions.
Calvin.
What is the significance of chlorophyll a and b?
They absorb light at different wavelengths, optimizing energy capture.
Fill in the blank: The _____ cycle occurs in the stroma of chloroplasts.
Calvin.
Which molecule is the final product of the Calvin cycle that can be used to form glucose?
G3P (glyceraldehyde-3-phosphate).
