Photosynthesis

Question 1

Chloroplast Structure

Answer 1

Has an inner and outer membrane, also contains thylakoid membranes, stack of those is grana, inside the grana is the lumen, and outside the thylakoid membranes is the stroma

Question 2

Chlorophyll

Answer 2

Absorbs the upper end of the visible spectrum of light

Question 3

Carotenoids

Answer 3

Absorb the lower end of the visible light spectrum

Question 4

Z scheme

Answer 4

Shows the energy of the electrons as photosynthesis occurs

Question 5

During high light levels…

Answer 5

High energry e- can hurt the cell, e- will be moved to an alternative pathway, e- from PS1 are redirected from ferredoxin back into the ETC

Question 6

Antioxidants

Answer 6

Can neutralize reactive oxygen species that form when there is low NADP+ and CO2 reduction can’t keep up

Question 7

Xanophylls

Answer 7

pigments that slow the formaiton of reactive oxygen by reducing excess light energy, by converting it to heat

Question 8

Carboxylation

Answer 8

CO2 is absorbed from the air and is addded to 5C ribulose by rubisco. The 6C is broken down into 2 3C molecules.

Question 9

Rubisco

Answer 9

Very slow enzyme, and must be produced at very high amounts in a cell. Most abundant enzyme on Earth. Sacrifices speed to select for CO2 instead of O2.

Question 10

Reduction

Answer 10

3PGA is reduced, high energy e- are transferred to the compound, for every 6 of these compounds produced, only one can be taken out of the calvin cycle

Question 11

Regeneration

Answer 11

The 5C molecule is regenerated, this is 12 of the 15 steps of the calvin cycle

Question 12

Cost of calvin cycle

Answer 12

3 NADPH and 3 ATP are needed for each CO2 incorporated into the calvin cycle by rubisco

Question 13

Photorespiration

Answer 13

When rubsico adds O2 instead of CO2 to RuBP, resulting in one molecules with 3C and one molecule with only 2C

Question 14

C3 plants

Answer 14

cooler weather plants

Question 15

C4 plants

Answer 15

Originate in tropics, more efficient at converting energy to carbs. Have an addition cycle before calvin cycle.

Question 16

C4 Cycle

Answer 16

Occurs in mesophyll cells, makes a 4C molecule that feeds into calvin cycle, can give up a C to CO2 for calvin cycle and regenerate the 3C PEP. Limits the damaging effects of photorespiration by spatially separating fixation and calvin cycle

Question 17

Stomata

Answer 17

Gas exchange occurs, consists of two guard cells. Usually opened during the day and closed at night. On hot dry days, leaf cells lose a lot of water to evaporation.

Question 18

CAM Plants

Answer 18

Desert plants, stomata are closed during the day and open at night. Carbon fixation and the calvin cycle are separated in time and space