C1.3 Photosynthesis Flashcards
What is photosynthesis?
The process by which green plants, algae, and some bacteria 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 (light-independent reactions).
Where do the light-dependent reactions occur?
In the thylakoid membranes of chloroplasts.
True or False: Oxygen is a product of the light-dependent reactions.
True.
What is the primary pigment involved in photosynthesis?
Chlorophyll.
Fill in the blank: The formula for photosynthesis is ____ + ____ + light energy → ____ + ____.
6CO2 + 6H2O → C6H12O6 + 6O2.
What is the role of water in photosynthesis?
Water provides electrons and protons and is split to release oxygen during the light-dependent reactions.
What is produced in the Calvin cycle?
Glucose (C6H12O6) is produced in the Calvin cycle.
Which molecule carries energy from the light-dependent reactions to the Calvin cycle?
ATP and NADPH.
True or False: Photosynthesis occurs only during the day.
False; while light is necessary for the light-dependent reactions, the Calvin cycle can occur at any time.
What is the role of carbon dioxide in photosynthesis?
Carbon dioxide is a reactant that is fixed during the Calvin cycle to produce glucose.
How does light intensity affect the rate of photosynthesis?
Increased light intensity typically increases the rate of photosynthesis up to a certain point.
What is photolysis?
The process of splitting water molecules into oxygen, protons, and electrons using light energy.
Which organisms perform photosynthesis?
Green plants, algae, and some bacteria.
What is the function of the stomata in plants?
Stomata allow for gas exchange, enabling CO2 to enter and O2 to exit the leaf.
What are the main factors affecting the rate of photosynthesis?
Light intensity, carbon dioxide concentration, and temperature.
What is the significance of chlorophyll’s absorption spectrum?
Chlorophyll absorbs primarily blue and red light, which are most effective for photosynthesis.
Fill in the blank: The light-dependent reactions convert light energy into ____ and ____.
ATP and NADPH.
What is the main product of the Calvin cycle?
Glyceraldehyde-3-phosphate (G3P), which can be converted into glucose.
What is the role of RuBisCO in photosynthesis?
RuBisCO is the enzyme that catalyzes the fixation of carbon dioxide in the Calvin cycle.
True or False: The Calvin cycle requires light directly.
False; it does not require light directly but relies on ATP and NADPH produced in the light-dependent reactions.
What is the role of NADP+ in photosynthesis?
NADP+ acts as an electron carrier, becoming NADPH during the light-dependent reactions.
Which part of the plant is primarily involved in photosynthesis?
The leaves.
What is the role of ATP synthase in photosynthesis?
ATP synthase synthesizes ATP from ADP and inorganic phosphate during the light-dependent reactions.
How does temperature affect photosynthesis?
Higher temperatures can increase the rate of photosynthesis to a point, after which it may decrease due to enzyme denaturation.
What is a limiting factor in photosynthesis?
A condition that can restrict the rate of photosynthesis, such as low light, low CO2, or extreme temperatures.
Fill in the blank: The thylakoids are located within the ____ of chloroplasts.
stroma.
What is the end product of the light-dependent reactions?
Oxygen, ATP, and NADPH.
True or False: Photosynthesis is an endothermic reaction.
True; it absorbs energy from light.
What is the primary purpose of photosynthesis?
To convert solar energy into chemical energy stored in glucose.
What is the name of the cycle that fixes carbon dioxide into organic molecules?
Calvin cycle.
What is the role of the light-harvesting complex?
To capture and transfer light energy to the reaction center of the photosystem.
What is the role of the electron transport chain in photosynthesis?
To transfer electrons from water to NADP+, creating a proton gradient that drives ATP synthesis.
Fill in the blank: The process of converting light energy into chemical energy occurs during the ____ reactions.
light-dependent.
What are the main products of the Calvin cycle?
Glucose and other carbohydrates.
How do plants store energy produced during photosynthesis?
As starch or other carbohydrates.
What is the role of light in photosynthesis?
Light provides the energy needed to drive the photosynthetic reactions.
True or False: Only plants can perform photosynthesis.
False; some algae and bacteria also perform photosynthesis.
What is the significance of the Calvin cycle?
It converts atmospheric CO2 into organic compounds, primarily glucose.
What are the two types of chlorophyll found in plants?
Chlorophyll a and chlorophyll b.
What happens to the glucose produced during photosynthesis?
It can be used for energy, stored as starch, or converted into other organic compounds.
Fill in the blank: The light-dependent reactions produce ____ and ____ as energy carriers.
ATP and NADPH.
What is the role of rubisco in the Calvin cycle?
It catalyzes the first step of carbon fixation.
True or False: The chloroplast is the site of photosynthesis in plant cells.
True.
What is the relationship between photosynthesis and cellular respiration?
Photosynthesis produces glucose and oxygen, which are used in cellular respiration to produce ATP.
What is the significance of the proton gradient created during the light-dependent reactions?
It drives the synthesis of ATP through ATP synthase.
