C4 and CAM plants

Question 1

CAM stands for

Answer 1

crassulacean acid metabolism

Question 2

how does heat affect photosynthesis

Answer 2

RuBisCO changes shape slightly to have a higher affinity for oxygen rather than CO2, this causes there to not be enough carbons in the calvin cycle to prooduce glucose and the cycle doesn’t get fully regenerated, RuBisCO still sometimes bind to carbon, so it just reduces the efficiency of the production of glucose

Question 3

what is it called when RuBisCO uses oxygen in the calvin cycle

Answer 3

photorespiration

Question 4

how do C4 plants diiffer in structure

Answer 4

they contain bundle sheath cells which arre usually found away from the stomata and lack grana

Question 5

what occurs in c4 photosynthesis

Answer 5

carbon dioxide enters and combines with a molecule called PEP, this is converted by pep carboxylase to form malate, malate moves throughh tthe plasmodesmata and enters the bundle sheath cell where its broken down into pyruvate and CO2 , the CO2 moves to the chloroplast where in undergoes the light independent stage

Question 6

pyruvate

Answer 6

moves back into the orginigal cell to create PEP so the cycle can be repeated, is a 3 carbon molecule

Question 7

how do the cells in the mesophyll and sheath bundle differ

Answer 7

mesophyll doesn’t contain RuBisCO, so where the light dependent stage occurs, sheath bundle cells doesn’t conatin many grana so undergo the light independent sttage, also less permeable to gas

Question 8

PEP

Answer 8

3 carbon molecule

Question 9

malate

Answer 9

4 carbon molecule

Question 10

adaptation of photosynthesis in CAM

Answer 10

adaptation for plants in arid environments, keep the stomata closed during the day to avoid water loss, stomata is open during the night, absorbing the carbon dioxide and storing in as malate in its large vacuole, light dpendent stage occurs during the day where malate is broken down to form carbon

Question 11

what are the negatives of CAM and C4 plants

Answer 11

c3 photosynthesis is much more efficient, howver some plants are able to switch between two , doing C3 photosynthesis when there is plenty of water avaliable

Question 12

examples of C4 plants

Answer 12

maize, sugarcane and ssorghum, most efficient in hot sunny climates

Question 13

example of C3 plants

Answer 13

rice, barley, wheat, soybean, most efficient in cool, wet climates

Question 14

examples of CAM plants

Answer 14

pinapple, aloe, succulents and orchids, most efficient in arid ennnvironments such as deserts