Higher Plant Respiration and Its Relationships to Photosynthesis
73
4.2 Pathways and Controls of Respiration
Respiration is composed of glycolysis, the oxidative pentose phosphate
network, the TeA cycle, mitochondrial electron transport, oxidative phosphorylation, and related reactions. (Photorespiration is distinguished from
respiration, although the two may interact in photosynthesizing cells.) In
general, the pathways (Figs. 4.2 and 4.3) and control of respiration are similar
among higher plants and other organisms, indicating the conservation of the
Starch
Fructose
Glucose
UTP -:-j t-:- ATP -:-j
UDP - •• - ADP - .
F-6-P _
G-6-P
PPj~ I.- ATP
Pj ~t-ADP
DiHOAcP r F-1,6-P
*
2
Gly-3-P
NAD+-J.-Pj
NADH--t
1,3-DiPGA
I GLYCOLYSIS I
NADP+
NADPH
H 2 0
~-"" ... GL-6-P ---L.. 6-PG
r NADP+
CO 2 ....... , - NADPH
Ru-S-P
xU-S~P I
GIY-3-rR_S_p
Su-7-P
ADP~
ATP-t
Pyruvate --+-----------,
3-PGA
t
H 2 0
+-ATP
~
f-:- ADP
2-PGA •
• PEP
H+
,------,,--"'E:----_ Pyruvate
NADH
2
NAD+;t\0
~H"~ Malate .w. OAA acetyl-CoA
~-+------/
~
' - - - - - I CoA-SH
.-H 2 0
_
~
Fumarate
fTcAl Citrate
t....FADH2 I£:!£!:!.J
t
f- FAD
Isocitrate
Succinate
NAD+;t
v-:: CoA-SH NADH CO
rAt:: :.J ;Ar 'j'"' '
Succinyl-CoA
a-KG
Malate
vacuole
CO 2
mitochondrion