photosynthesis C4 and CAM

Question 1

What is the most important enzyme for an light independent stage

Answer 1

Rubisco

Question 2

Is Rubisco a teritiary or quatenary protien

Answer 2

Quataneray Protien

Question 3

What does the Rubsico ENzyme do? (role)

Answer 3

The Rubsico undergoes Carbon Fixation converts inorganic carbon dioxide gas to an organic compound called- **3-PGA*

Question 4

What does carbon fixation mean

Answer 4

The turning of inorganic carbon in organic compounds like glucose

Question 5

What is the slight problem with Rubsico in light independent reactions and why would it be bad.

Answer 5

Rubsico also can bind to oygen as an substrate which causes photorespiration leading to less glucose.

Question 6

What is photorespiration
and how it is bad

Answer 6

When oxygen binds to Rubisco and prevents the production of glucose.
1.A waste of energy
2.And essentially disrupts photosyntheisis.

Question 7

What are the two reasons for more photorespiration in hot and dry conditions

Just list the two dot points

Answer 7

1. Substrate Concentration
2. Tempreature

Question 8

Explain substrate concentration affect on photorespiration IN HOT AND dry enviorment

Answer 8

When there is high water loss, the stomata closes and stays closed, trapping all the Oxygen made from light dependant reactions and preventing carbon dioxide from entering. This increases the oygen concentration near rubisco, increasing the chance of binding with the rubsico and oxygen.

Question 9

Explain temperature affect on photorespiration IN HOT AND dry enviorment

Answer 9

A higher tempreature causes a higher affinity for rubsico to bind with Oxygen

Question 10

What type of plants are majority of plants, C3 C4 OR CAM

Answer 10

c3 plants

Question 11

What cells undergo the light independent stage in C3 plants

Answer 11

JUST the mesophyll cell

Question 12

What adaptations do C3 plants have to prevent photorespiration

Answer 12

NONE they posses no adaptations to prevent photorespiration

Question 13

What is different about the light independent stage in c4 plants compared to C3 plants

Answer 13

Inital Carbon fixation happens in the mesophyll cell, wheras the rest of the calvin cycle occys in the bundle sheath cell.

Question 14

How does seperating the light independent stage in C4 plants prevent photorespiration?

Answer 14

As there is a constant pump of C02 from the mesophyll cell to the bundle sheath cell, the calvin cycle will continue with a higher concentration than O2 for binding with RUBISCO. This is because Oxygen produced in the light dependent stage is produced and kept in the mesophyl cell, seperated from the calvin cycle stage.

Question 15

What is an example of an C4 plant?

Answer 15

Corn or weed

Question 16

What is one bad thing about C4 plants compared to c3 platns

Answer 16

C4 plants requires more energy for photosynthesis

Question 17

What does CAM plants have as an adaptation to minimise photorespiration

Answer 17

Seperates light- independent stage over time, Night and Daytime.

Question 18

What happens at night time for CAM plants

Answer 18

CAM plants open their stomata at night as it cooler and intakes carbon dioxide and converts it into malate that is stored inside the vacuoles in mesophyll cells.

Question 19

What happens at daytime for CAM plants

Answer 19

At daytime, the stomata closes to prevent water loss as it is warmer.
It then releases malate to be broken down back to carbon dioxide and be used in the Calvin Cycle

Question 20

How does CAM plants even maximise photosynthesis and minimises photorespiration

Answer 20

The controlled release of malate ensures there is a high concentration of C02 near rubisco.

Question 21

Does CAM plants take more energy than C3

Answer 21

Yes