photosynthesis

Question 1

what is the general balanced equation for photosynthesis

Answer 1

6CO2 + 6H2O –> C6H1206 + 6O2

Question 2

is photosynthesis endergonic or exergonic? explain

Answer 2

photosynthesis is an endergonic reaction, as it requires input of energy to synthesize carbohydrate.

Question 3

what is the main function of the CO2 in photosynthesis

Answer 3

enters the calvin cycle and is added to ribulose 1,5- bisphosphate and CO2 is converted into C-containing organic compounds (ex. glucose)

Question 4

what is the main function of H2O in photosynthesis

Answer 4

provides electrons for P680 to send them through the antenna complex to the ETC and H+ ions enter the lumen to create a proton gradient

H2O gets split by P680

Question 5

where does the O2 molecule come from during photosynthesis

Answer 5

it comes from P680 spliting two water molecules

2 splittings makes 1 oxygen molecule

Question 6

transpiration

Answer 6

the process by which plants give off water vapor (evaporates) through the stomata in their leaves.

Question 7

stomata

Answer 7

regulates gas exchange between the plant and environment and control of water loss

Question 8

how, when and why do stomatas open

Answer 8

when K+ ions diffuse into guard cells, water moves in by osmosis, guard cells swell, and the stoma opens
- when open there is some water loss
- to enable controlled gas exchange

(turgid)

Question 9

how, when and why do stomatas close

Answer 9

when K+ ions diffuse out of guard cells, water moves out by osmosis, guard cells become flaccid, and the stoma closes
- when the plant is at risk of losing too much water, the stomata remain closed

(flaccid)