Energy transfer in and between organisms - PHOTOSYNTHESIS Flashcards
1
Q
Why is ATP useful?
A
- Releases small, manageable amounts of energy
- Easily broken down so energy can be released quickly
- Can transfer energy by transferring a phosphate
2
Q
How are the leaves adapted for photosynthesis?
A
- Large SA: absorbs as much sunlight as possible
- Arrangement of leaves on the plant: minimises overlapping to avoid one leaf shadowing the other
- Thin: most light absorbed and short diffusion distance for gases
- Transparent cuticle and epidermis: allows light to pass through
- Long, narrow palisade mesophyll cells, packed with chloroplastsP: maximum sunlight capture
- Lots of stomata for GE: short diffusion pathway from mesophyll cells
- Stomata open and close depending on situations (light intensity)
- Air spaces: spongy mesophyll layer, rapid diffusion of gases
- Xylem brings water to the leaves, phloem takes sugar away
3
Q
Which part of the chloroplast does the light dependent reaction occur?
A
Grana
4
Q
Where does photolysis occur?
A
Grana - inside the thylakoid membrane
5
Q
State the 3 products of photolysis
A
- Protons
- Electrons
- Oxygen
6
Q
How is light energy used during the light-dependent reaction?
A
- Excites electrons
- Electrons move along ETC, releasing energy
- Energy used to form ATP from ADP and Pi
- Photolysis of water into protons, electrons and O2
- NADP reduced by electrons
7
Q
Describe the role of the ETC in the light dependent revision
A
- ETC accepts excited electrons from chlorophyll
- Electrons lose energy along chain
- ATP produced from ADP and Pi
- Reduced NADP formed, when electrons from ETC and H+ from photolysis combine with NADP
8
Q
What is the role of chlorophyll in the light dependent reaction?
A
- Absorbs light
- Loses electrons
- Accept electrons from water
9
Q
What is the function of a chloroplast?
A
- Absorbs light energy
- For photosynthesis
- Produces carbohydrates
10
Q
Where is rubisco found?
A
Stroma of chloroplast
11
Q
Where does the Calvin cycle occur?
A
Stroma of chloroplast
12
Q
During the light-independent reaction, carbon dioxide is converted into organic substances - describe how
A
- CO2 combines with RuBP
- Produces 2x GP
- GP reduced to triose phosphate
-> Using reduced NADP and energy from ATP - Triose phosphate converted to glucose
13
Q
Describe the light independent reaction
A
- 5C combines with CO2 to form 3C compound
-> using ATP and reduced NADP - 2 molecules of 3C compound
- All RuBP is regenerated
- 10 molecules of 3C
