1. In Complex III of the mitochondrial electron transport chain, residues 180–196 are found in the ____________ domain and residue 104 is found in the _________ domain. a. intermembrane space; matrix b. membrane-spanning; intermembrane space c. membrane-spanning; matrix d. intermembrane space; membrnae-spanning 2. Comparison of the Fe2S2 clusters in Complexes II and III of the mitochondrial electron transport chain reveals that ________ coordinates the iron atoms of the cofactor in Complex II, and ____________ coordinate/s the iron atoms of the cofactor in Complex III. a. cysteine; cysteine and histidine b. cysteine; cysteine c. histidine; cysteine and histidine d. cysteine; histidine Solution 1) In Complex III of the mitochondrial electron transport chain, residues 180–196 are found in the Intermembrane domain and residue 104 is found in the Matrix domain. 2) Comparison of the Fe2S2 clusters in Complexes II and III of the mitochondrial electron transport chain reveals that cysteine coordinates the iron atoms of the cofactor in Complex II, and cysteine coordinate/s the iron atoms of the cofactor in Complex III. .

1. 1. In Complex III of the mitochondrial electron transport chain, residues 180–196 are found in
the ____________ domain and residue 104 is found in the _________ domain.
a. intermembrane space; matrix
b. membrane-spanning; intermembrane space
c. membrane-spanning; matrix
d. intermembrane space; membrnae-spanning
2. Comparison of the Fe2S2 clusters in Complexes II and III of the mitochondrial electron
transport chain reveals that ________ coordinates the iron atoms of the cofactor in Complex II,
and ____________ coordinate/s the iron atoms of the cofactor in Complex III.
a. cysteine; cysteine and histidine
b. cysteine; cysteine
c. histidine; cysteine and histidine
d. cysteine; histidine
Solution
1) In Complex III of the mitochondrial electron transport chain, residues 180–196 are found in
the Intermembrane domain and residue 104 is found in the Matrix domain.
2) Comparison of the Fe2S2 clusters in Complexes II and III of the mitochondrial electron
transport chain reveals that cysteine coordinates the iron atoms of the cofactor in Complex II,
and cysteine coordinate/s the iron atoms of the cofactor in Complex III.