Biology Flashcards
(32 cards)
What pigment gives plants their green color?
Chlorophyll
Chlorophyll is crucial for photosynthesis as it captures light energy.
What is the process called in which plants convert light energy into chemical energy?
Photosynthesis
Photosynthesis synthesizes glucose and other organic molecules.
Who proposed that plants convert light energy from the Sun into chemical energy in 1845?
Julius von Mayer
This proposal was based on accumulating scientific knowledge about photosynthesis.
What general equation for photosynthesis was proposed by Cornelis van Niel?
CO2 + 2 H2A + Light energy → CH2O + A2 + H2O
A2 can be oxygen or sulfur, depending on the organism.
What are the two types of autotrophs mentioned?
- Photoautotrophs
- Chemoautotrophs
Photoautotrophs use light for energy; chemoautotrophs derive energy from chemical reactions.
Where does photosynthesis primarily occur in plants?
In the chloroplasts
Chloroplasts contain chlorophyll and are essential for photosynthesis.
What is produced during the light reactions of photosynthesis?
- O2
- ATP
- NADPH
These products are essential for the Calvin cycle.
What is the role of the thylakoid membrane in photosynthesis?
It hosts the light reactions
The light reactions convert light energy into chemical energy.
What is the term for a molecule that absorbs light energy?
Pigment
Pigments are critical for capturing light in photosynthesis.
What are the two types of chlorophyll found in green plants?
- Chlorophyll a
- Chlorophyll b
Both types are involved in the photosynthetic process.
What happens during the process of photophosphorylation?
ATP is synthesized using an H+ electrochemical gradient
This process is similar to oxidative phosphorylation in mitochondria.
What enzyme catalyzes the carbon fixation step in the Calvin cycle?
RuBP carboxylase/oxygenase (rubisco)
Rubisco is essential for incorporating CO2 into organic molecules.
What is the product of the Calvin cycle that is used to make glucose?
Glyceraldehyde-3-phosphate (G3P)
G3P is a three-carbon carbohydrate that serves as a precursor to glucose.
What are the phases of the Calvin cycle?
- Carbon fixation
- Reduction and carbohydrate production
- Regeneration of RuBP
Each phase plays a crucial role in synthesizing carbohydrates.
What is photorespiration?
A process that uses O2 and liberates CO2
Photorespiration occurs when RuBP reacts with O2 instead of CO2.
True or False: The Calvin cycle directly produces glucose.
False
The Calvin cycle produces G3P, which is then used to synthesize glucose.
What is the Z scheme in photosynthesis?
A model describing the light reactions involving two photoactivation events
The Z scheme illustrates energy changes of electrons during photosynthesis.
Fill in the blank: The light reactions of photosynthesis produce _______ as a byproduct.
O2
O2 is produced from the oxidation of water during the light reactions.
What are the primary products of the light-dependent reactions of photosynthesis?
ATP, NADPH, and O2
What does the Calvin cycle use to synthesize carbohydrates?
ATP and NADPH
What is the initial reaction in photorespiration?
RuBP + O2 → 3PG + Phosphoglycolate
What is produced when phosphoglycolate is processed?
Organic molecule + CO2
True or False: Photorespiration is beneficial for plant growth.
False
