Photosynthesis

Question 1

Chloroplast

Answer 1

Organelle that does photosynthesis

Question 2

Mesophyll

Answer 2

Palisade & Spongy Mesophyll

Question 3

Epidermis

Answer 3

• Protects
• Has a waxy layer to retain water (cuticle)

Question 4

Stomata

Answer 4

• Pore in epidermis
• In underside of leaf to allow for gas exchange

Question 5

Guard Cells

Answer 5

• On each side of stoma
• Opens/closes by filling w/H2O

Question 6

Spongy Mesophyll

Answer 6

Creates airspace for diffusion/transpiration

Question 7

Palisade Mesophyll

Answer 7

Made of parenchyma to collect light

Question 8

Photons

Answer 8

Individual nrg packets w/specific amount of nrg depending on wavelength

Question 9

Pigment

Answer 9

Molecules that absorb specific colours of light

Question 10

Photosystem

Answer 10

• Grp of chlorophyll, proteins
• Embedded in thylakoid membrane

Question 11

When lights hit the antenna complex

Answer 11

• It funnels the energy to the reaction center chlorophyll
• e- becomes excited, raised to a higher nrg lvl
• e- passes onto electron accepting molecule

Question 12

Photosystem 2/P680

Answer 12

1. Absorbs photon
2. e- leaves to accepter, then to ETC
3. Pulls e- from H2O to replace from z enzyme
4. O2 released, H go into lumen

Question 13

Photolysis

Answer 13

Z enzyme splits 2 H2O molecules into O2 & e-

Question 14

P680 ETC

Answer 14

1. e- move along ETC
2. H+ is pumped into lumen
3. Photosystem 1/P700 takes e-

Question 15

Photosystem 1/P700

Answer 15

1. e- is excited again
2. Passed onto ETC
3. Final e- acceptor is NADP+ reductase

Question 16

Chemiosmosis happens

Answer 16

Stroma to lumen

Question 17

Photophosphorylation

Answer 17

Photons use to drive phosphorylation

Question 18

Calvin Cycle Stages & Purpose

Answer 18

• To make glucose from CO2

1. Carbon Fixation
2. Reduction Reactions
3. Regeneration of RuBP

Question 19

Carbon Fixation

Answer 19

1. 3 CO2 attaches to 3 RuBP by rubisco
2. The 6 carbon molecule immediately breaks down into 3 carbon molecules called PGA (6)

Question 20

Reduction Reactions

Answer 20

1. ATP added to PGA
2. NADPH gives 2 e-
3. G3P is made

Question 21

Regeneration of RuBP

Answer 21

1. 5 G3P turns into 3 RuBP using 3 ATP
2. Last G3P combines w/another G3P to make glucose

Question 22

For a glucose molecule

Answer 22

18 ATP, 12 NADPH consumed

Question 23

Possibilities for G3P

Answer 23

• Creates sucrose
• Starch, cellulose
• Oils
• Amino acids w/nitrogen

Question 24

Noncyclic Photophosphorylation

Answer 24

• z scheme
• H2O → P680 → ETC→
  P700 → P700 → NADPH

Question 25

Cyclic Photophosphorylation

Answer 25

e- in P700 is cycled back by ferrdoxin to b6f complex (electron carrier) to move more H+ across gradient

Question 26

Cyclic Photophosphorylation Pathway

Answer 26

P700 → ETC P700 → Ferredoxin → b6f complex → P700

Question 27

Photorespiration

Answer 27

- O2 binds w/rubisco instead of CO2, reducing efficiency - O2 competitive inhibitor

Question 28

C3 Photosynthesis Chracteristics

Answer 28

- Around 25 degrees - 3% efficient

Question 29

Photorespiration happens because

Answer 29

Temps rise, closing the stomata, which increases O2 accumulation/photoresp

Question 30

C4 Plants Adapt by

Answer 30

- Using PEP carboxylase to make 4C molecules - Using mesophyll w/no rubisco - Bundle sheath cells w/rubisco & calvin cycle

Question 31

C4 Photosynthesis

Answer 31

1. CO2 fixed to PEP (3C) by PEP carbozylase to make oxaloacetate 2. Oxolacetate turns to malate 3. It decarboxylates and 3C goes back to be turned into PEP

Question 32

Decarboxylated

Answer 32

CO2 removed

Question 33

Bundle Sheath Characteristics

Answer 33

- Impermeable to O2 and CO2 (malate helps move CO2) - Decreases photorespiration

Question 34

CAM Plants Adapt by

Answer 34

- Opening stomata at night to collect CO2, storing as malate in vacuole - Closing stomata in the day, & doing photosynthesis w/reserves