Biology: C4 and CAM Plants

Question 1

Wasteful pathway that competes with the Calvin cycle.

Answer 1

Photorespiration

Question 2

It begins when rubisco acts on oxygen instead of carbon dioxide.

Answer 2

Photorespiration

Question 3

C3 Plants stand for:

Answer 3

Carbon 3 Plants

Question 4

C4 Plants stand for:

Answer 4

Carbon 4 Plants

Question 5

CAM Plants stand for:

Answer 5

Crassulacean Acid Metabolism

Question 6

A problem for plants that sometimes requires trade-offs with other metabolic processes, especially photosynthesis.

Answer 6

Dehydration

Question 7

On hot, dry days, plants close ________.

Answer 7

stomata

Question 8

Plants closing stomata during hot days conserves ___________ but also limit __________.

Answer 8

water; photosynthesis

Question 9

The closing of stomata reduces access to _________ and causes _______ to build up.

Answer 9

CO2; O2

Question 10

What does photorespiration consumes and what does it release?

Answer 10

Consumes O2 and organic fuel.
Releases CO2 without producing ATP or sugar.

Question 11

Normal photosynthesis only happens in the (a) __________. But, in the process/recycling of glycolate, photorespiration may also go through (b) _________ and __________.

Answer 11

a. Chloroplast
b. Peroxisome and Mitochondrion

Question 12

Photorespiration limits the damaging products of ___________ that build up in the absence of the Calvin cycle

Answer 12

light reactions

(it acts a protective mechanism)

Question 13

In many plants, photorespiration is a problem because on a hot, dry day it can drain as much as ____ of the carbon fixed/resourced by the Calvin cycle.

Answer 13

50%

Question 14

Some plants were able to minimize the cost of Photorespiration like the _______________.

Answer 14

C4 Plants and CAM Plants

Question 15

C4 plants minimize the cost of photorespiration by incorporating CO2 into ___________ in the ___________.

Answer 15

four-carbon compounds; mesophyll cells

Question 16

C4 Plants. The initial carbon fixation requires the enzyme ___________.

This has higher affinity for CO2 than rubisco even when CO2 has low concentrations.

Answer 16

PEP carboxylase

Question 17

What does PEP carboxylase stands for:

Answer 17

phosphoenolpyruvate carboxylase

Question 18

C4 Plants. As malate, the 4-c compounds are exported to _______________ where they release CO2 that is then used in the Calvin cycle.

Answer 18

bundle-sheath cells

Question 19

Some plants, including succulents, use ____________ to fix carbon.

Answer 19

Crassulacean Acid Metabolism (CAM)

Question 20

a. CAM plants open their stomata __________, incorporating CO2 into organic acids. (taking in CO2)
b. Stomata close __________, and CO2 is released from organic acids and used in the Calvin cycle. (photosynthesis)

Answer 20

a. at night
b. during the day

Question 21

Difference of C4 Plants and CAM Plants in terms of separation of steps:

Answer 21

C4 Plants: Spatial Separation
CAM Plants: Temporal Separation

Question 22

Examples of C3 Plants:

Answer 22

Rice, Wheat, Barley, Oats, Beans, Lettuce, Spinnach

Question 23

Examples of C4 Plants:

Answer 23

Corn, Sugarcane, Switchgrass, Millets, Tumbleweed, Sunflower

Question 24

Examples of CAM Plants:

Answer 24

Aloe Vera, Cacti, Pineapple, Jade Plant, Orchids