Problem 1. (2 points off for each 3 wrong)
Problem 2
Problem 3
Complex I
NADH:ubiquinone oxidoreductase
net rxn: NADH + 5H+N +Q6QH2 + NAD+ + 4H+P
Mass : 850 kD in 42 polypepides, FMN prosthetic groups and FeS centers
Complex II
Succinate dehydrogenase complex
net rxn: Succinate +Q 6Fumarate + QH2
(Book usually shows as FAD and FADH2 but these are bound to the
enzyme so they cannot leave. In reality the reducing equivalents are
passed to ubiquinone QH2)
Mass 140 kD in 5 polyptptides, FAD prosthetic group and FeS centers in proteins
Complex III
Cytochrome bc1 complex or ubiquinone:cytochrome c oxidoreductase
net rxn: QH2 + 2Cyt c1(ox) +2H+N 6Q + 2Cyt c1(ox) + 4H+P
Actually 2 reactions:
QH2 + Cyt c1(ox) 6Q@- + 2H+P + Cyt c1(ox)
QH2 +Q@- +2H+N + Cyt c1(ox) 6QH2 + 2H+P + Cyt c1(ox)
Mass 250 kDa in 11 polypeptides, Heme and FeS groups involved
Complex IV
Cytochrome oxidase
net rxn: 4 Cyt c1(ox) + 8H+N +O2 64 Cyt c1(ox) + 4H+P + 2H2O
Mass 160 kD in 13 polypeptides, Hemes and CuA and CuB involved
ATP Synthase
net rxn: ADP + Pi + 3H+P 6ATP + 3H+N
F1 "3$3(*, the ATP syntase
FO ab2c10-12 The proton transporter
proton transport down its chemiosmotic gradient is mechanically linked to
changing conformations in the F1 subunit to make the enzyme first bind ADP and PI
then fuse these into ATP then kick the ATP out of the active site
4. I was looking for a diagram like figure 5-11 from your text, or the following reactions
Glycogen + phosphate 6 Glucose-1-P (enzyme is phosphorylase)
Glucose-1-P 6Glucose-6-P (Enzyme is phosphoglucomutase)
Fructose + ATP 6Frustose-6-phosphate (Enzyme is hexokinase)
Galactose 6UDP-Galactose 6UDP-Glucose6Glucose-1-P6 Glucose-6-P
Mannose + ATP 6Mannose-6-Phosphate (Hexokinase)
Mannose-6-P 6Fructose-6-P (phosphomannose isomerse)
5. I was looking for a diagram like figure 16-6 from your text, but instead of pyruvate,
insert "-ketoglutarate
There are three enzymes in the complex, E1, E2, and E3
The E1 structure for pyruvate and "-ketoglutarate are structurally similar, but the
sequences are different
the E2 complexes are similar
the E3 complexes are almost identical
Overall Mech
6. The way NADH equivalents in the cytoplasm get into the mitochondria is through the
Malate-Aspartate Shuttle. In the cytosol the NADH is used to reduce oxaloacetate to
malate, then the malate is transported to the mitochondira where the reverse reaction
occurs, and the H that started on cytosol NADH gets placed on mitochondiral NADH
Then there are other steps involving glutamate, "-ketoglutarate and aspartate that are
used to keep the net amount of oxaloacetate in the mitochondria from increasing.
The bottom line from this shuttle system is that the reducing equivalents from the
NADH are moved into the mitochondira without physically transporting the NADH into
the mitochondria. Thus the 13C label that stays in the NADH molecule cannot get into
the mitochondira, but the 3H labeled H atoms are transferred to Malate, and malate is
transferred into the mitochondira where the tritium label now appears in the matrix.