Biology: C4 and CAM Plants Flashcards
Wasteful pathway that competes with the Calvin cycle.
Photorespiration
It begins when rubisco acts on oxygen instead of carbon dioxide.
Photorespiration
C3 Plants stand for:
Carbon 3 Plants
C4 Plants stand for:
Carbon 4 Plants
CAM Plants stand for:
Crassulacean Acid Metabolism
A problem for plants that sometimes requires trade-offs with other metabolic processes, especially photosynthesis.
Dehydration
On hot, dry days, plants close ________.
stomata
Plants closing stomata during hot days conserves ___________ but also limit __________.
water; photosynthesis
The closing of stomata reduces access to _________ and causes _______ to build up.
CO2; O2
What does photorespiration consumes and what does it release?
Consumes O2 and organic fuel.
Releases CO2 without producing ATP or sugar.
Normal photosynthesis only happens in the (a) __________. But, in the process/recycling of glycolate, photorespiration may also go through (b) _________ and __________.
a. Chloroplast
b. Peroxisome and Mitochondrion
Photorespiration limits the damaging products of ___________ that build up in the absence of the Calvin cycle
light reactions
(it acts a protective mechanism)
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.
50%
Some plants were able to minimize the cost of Photorespiration like the _______________.
C4 Plants and CAM Plants
C4 plants minimize the cost of photorespiration by incorporating CO2 into ___________ in the ___________.
four-carbon compounds; mesophyll cells
C4 Plants. The initial carbon fixation requires the enzyme ___________.
This has higher affinity for CO2 than rubisco even when CO2 has low concentrations.
PEP carboxylase
What does PEP carboxylase stands for:
phosphoenolpyruvate carboxylase
C4 Plants. As malate, the 4-c compounds are exported to _______________ where they release CO2 that is then used in the Calvin cycle.
bundle-sheath cells
Some plants, including succulents, use ____________ to fix carbon.
Crassulacean Acid Metabolism (CAM)
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)
a. at night
b. during the day
Difference of C4 Plants and CAM Plants in terms of separation of steps:
C4 Plants: Spatial Separation
CAM Plants: Temporal Separation
Examples of C3 Plants:
Rice, Wheat, Barley, Oats, Beans, Lettuce, Spinnach
Examples of C4 Plants:
Corn, Sugarcane, Switchgrass, Millets, Tumbleweed, Sunflower
Examples of CAM Plants:
Aloe Vera, Cacti, Pineapple, Jade Plant, Orchids
