× Didn't find what you were looking for? Ask a question
Top Posters
Since Sunday
w
5
a
3
j
2
a
2
t
2
u
2
r
2
j
2
j
2
l
2
d
2
y
2
Home Q & A Board Biology-Related Homework Help Zoology and Botany (Moderator: ehd123)
New Topic  
colleen colleen
wrote...
Valued Member
Posts: 17076
Rep: 251 1
12 years ago
Rubisco is an important enzyme in the Calvin cycle. It catalyzes the addition of carbon dioxide and water to ribulose-1,5-bisphosphate, which then forms two molecules of 3-phosphoglycerate. Rubisco acts as a carboxylase and is essential for carbon fixation. 

a.   Rubisco has an additional function. It can also function as an oxygenase. Why is this a problem for plants?
b.   Rubisco has a much lower affinity for oxygen than for carbon dioxide. Why is the oxygenase activity still a problem for plants? 
c.   What is (are) the product(s) of the reaction when rubisco acts as an oxygenase?
d.   How does the plant deal with the product of the oxygenase reaction?
e.   The oxygenase activity of rubisco is particularly a problem for plants in arid environments. Can you explain why?
f.   What strategies do plants in arid environments use to deal with this problem? 
Read 6816 times
1 Reply
Sunshine ☀ ☼

Related Topics

Replies
wrote...
#1
12 years ago
a.   If rubisco functioned solely as an oxygenase, carbon fixation would cease.
b.   The earth's atmosphere contains much higher concentrations of oxygen.
c.   Phosphoglycolate and 3-phosphoglycerate are the products rather than two molecules of 3-phosphoglycerate. 
d.   The glycolate pathway is used to transform phosphoglycolate into 3-phosphoglycerate.
e.   Higher temperatures decrease carbon dioxide solubility relative to oxygen solubility. These plants close their stomata to reduce water loss. This will further reduce the concentrations of carbon dioxide in the leaf. 
f.   C4 plants confine rubisco to cells containing high carbon dioxide levels. CAM plants only open their stomata at night. 
~Live well, laugh often, and love with all of your heart!~
New Topic      
Quick Reply
Explore
Post your homework questions and get free online help from our incredible volunteers
  1661 People Browsing
 139 Signed Up Today
Start New Topic Take the Tour CoursesNew Study Tools Topics Trending Browse by Textbook
Live Chat
Related Images
  
 121
  
 292
  
 360