Photosynthesis Flashcards
(33 cards)
Define autotrophs
Organisms that produce their own food from inorganic substances
Define heterotrophs
Organisms that obtain food by consuming other organisms
What are producers?
Organisms that produce organic compounds from carbon dioxide through photosynthesis
Define photoautotrophs
Autotrophs that use light energy to convert carbon dioxide and water into glucose
Describe the structure of chloroplasts
Chloroplasts have an outer membrane, inner membrane, thylakoids, and stroma
Where in a leaf are chloroplasts most concentrated?
In the mesophyll layer
Where is most light energy converted to chemical energy in chloroplasts?
In the thylakoid membranes
What are photosynthetic pigments?
Molecules that absorb light energy for photosynthesis
List the main photosynthetic pigments
- Chlorophyll a
- Chlorophyll b
- Carotenoids
Why are plants green?
They reflect green wavelengths of light and absorb other wavelengths
What happens to leaf colors in the fall?
Chlorophyll breaks down, revealing other pigments
How do plants produce oxygen?
Through the process of photosynthesis, specifically during the light reactions
Where does most of a plant’s mass come from?
From carbon dioxide absorbed from the air
What role do redox reactions play in photosynthesis?
They involve the transfer of electrons, crucial for energy conversion
Compare the reactants of light reactions and the Calvin cycle
Light reactions use water and light; Calvin cycle uses ATP and NADPH
What do photosystems do?
Capture solar energy and initiate electron transport
What is generated during light reactions?
- ATP
- NADPH
- Oxygen
What is photophosphorylation?
The process of generating ATP from ADP and inorganic phosphate using light energy
Describe the Calvin cycle
A series of reactions that convert carbon dioxide into glucose using ATP and NADPH
What are the reactants of the Calvin cycle?
- Carbon dioxide
- ATP
- NADPH
What are the products of the Calvin cycle?
- Glucose
- ADP
- NADP+
What is the function of ADP+P and NADP+ after the Calvin cycle?
They return to the light reactions to be recharged
What is a limiting factor in photosynthesis?
Any condition that restricts the rate of photosynthesis
How does photorespiration affect photosynthesis?
It reduces the efficiency of photosynthesis by consuming oxygen and releasing carbon dioxide
