Fixation pathways

Question 1

3 Carbon dioxide fixation pathways

Answer 1

Calvin cycle
Reductive (reverse) TCA
3-hydroxypropionate bi-cycle

Question 2

What uses Calvin cycle for carbon dioxide fixation

Answer 2

Aerobes, facultative anaerobes, chloroplasts

Question 3

What uses Reductive (reverse) TCA for carbon dioxide fixation

Answer 3

Green sulfur bacteria, anaerobes, archaea (parts of pathway)

Question 4

What uses 3-hydroxypropionate bi-cycle for carbon dioxide fixation

Answer 4

Green nonsulfur bacteria

Question 5

Three different CARBON fixation pathways in archaea

Answer 5

Reductive acetyl-CoA pathway (Wood-Ljungdahl pathway) Widespread in Archaea
3-hydroxypropionate/4-hydroxybutyrate (HP/HB) cycle
Dicarboxylate/4-hydroxybutyrate (DC/HB) cycle

Question 6

Comparison of Archaeal CO2-fixation pathways to Calvin-Benson cycle

Answer 6

look at table 20.1 or page 15 top slide

Question 7

Archaeons are not known to incorporate (fix) carbon dioxide.

Answer 7

False

Question 8

The electrons used in carbon fixation by chloroplasts ultimately come from …
A.	Atmospheric oxygen
B.	Atmospheric carbon dioxide
C.	Water
D.	Glyceraldehyde 3-phosphate

Answer 8

water