Lecture 23: Carbon Fixation-C3 Metabolism

Question 1

rubisco

Answer 1

catalyzes reaction between Ribulose 1,5-bisphosphate (RuBP) and CO2 or O2

Question 2

dual function of rubisco

Answer 2

carboxylation and oxygenation

Question 3

does rubisco have an ability to discriminate between O2 and CO2

Answer 3

it does not discriminate well between O2 and CO2

Question 4

Hexadecameric form (form 1) of rubisco in plants

Answer 4

8 large subunits and 8 small subunits (found in plants and most cyanobacteria)

Question 5

how do plants overcome the catalytic efficiency of rubisco

Answer 5

they make a lot (50% of soluble leaf protein can be Rubisco)

Question 6

large subunit of rubisco is encoded by a single gene in the ______ genome

Answer 6

chloroplast

Question 7

small subunit of rubisco is encoded by a single gene in the ______ genome

Answer 7

nuclear

Question 8

what activates rubisco

Answer 8

rubisco activase

Question 9

what are required for the rubisco holoenzyme assembly

Answer 9

chaperones

Question 10

how is the activity of Rubisco regulated

Answer 10

the transcription, assembly, and inhibition of rubisco

Question 11

revisable inhibition of rubisco activity

Answer 11

a lysine (K) in the active site of Rubisco must be carbamylated for rubisco activity

Question 12

what does Rubisco-mediated carboxylation of RuBP yield

Answer 12

2 molecules of 3-PGA

Question 13

what does rubisco-mediated oxygenation of RuBP yield

Answer 13

1 molecule of 3-PGA and 1 or 2-PG

Question 14

the calvin cycle is ________

Answer 14

autocatalytic