Photosynthesis Flashcards
1
Q
What is the 1st electron donor in photosynthesis?
A
Water
2
Q
What is the ultimate electron acceptor in photosynthesis?
A
Carbon in CO₂
3
Q
What is G3P?
A
- Glyceraldehyde-3-phosphate
- Carbohydrate
- Used to make organic molecules like sucrose or starch
- Product of photosynthesis
4
Q
What is a byproduct of photosynthesis?
A
Oxygen
5
Q
Stomata
A
Small pores in leaf in which CO₂ and O₂ can enter and exit respectively
6
Q
Epidermal Cells
A
- Pavement Cells (protective layer)
- Guard Cells (control gas exchange)
- Subsidiary Cells
7
Q
Mesophyll Cells
A
- Cells in the middle of leaf
- Where photosynthesis actually occurs
8
Q
Vascular Bundles
A
Means by which organic molecules are transported to the rest of the plant
9
Q
What 2 processes make up photosynthesis?
A
- Light Reactions
- Calvin Cycle
10
Q
Thylakoids
A
Where Light Reactions occur
11
Q
Stroma
A
Where Calvin Cycle occurs
12
Q
Light Reactions
A
- Contains Photosystem I and II, Cytochrome complex
- ADP and NADP⁺ → ATP and NADPH
- Water molecules split into O₂ (byproduct), provides the protons (H⁺)
- Electrons are excited by photons and get passed down ETC by ECs
- PS II → EC → Cytochrome Complex → EC → PS I → e⁻ recycled or sent to NADP⁺ (final EC of LR)
- VERY SIMILAR TO ETC IN CELL RESP
13
Q
Calvin Cycle
A
- ATP and NADPH energy used
- CO₂ and organic molecules → new organic molecules
- ADP and NADP⁺ form (can be used again for LR)
- Phase 1: Carbon fixation - carbon dioxide and RuBP form 3-PGA; Rubisco enzyme
- Phase 2: Reduction - 3-PGA uses ATP and NADPH to form G3P, 1 of which exits the cycle to be used to form other organic molecules
- Phase 3: Regeneration - G3P + ATP forms RuBP and the cycle repeats
- Electrons lost from NADPH are accepted by CO₂, which makes carbon the final electron acceptor)
14
Q
What causes biomass gain?
A
Formation of new organic molecules
15
Q
Photosystem
A
- Protein-pigmet complexes
- They absorb light
