Question

Can someone please answer all four of these MCQs? They're relatively short, Id appreciate it too! Thank you :)

1. A surface transmembrane protein, when it is in a transport vesicle has a certain topology- the extracellular domain of the protein when found in a transport vesicle would be located in the -

A) Cytoplasm
B) Lumen of vesicle
C) Must be cleaved to enter vesicle
D) Mitochondria

2. Synapses contain different classes of proteins, some of them include-
A) Neurotransmitter receptors
B) Scaffold proteins
C) DNA polymerase
D) A and B only
E) A and C only

3. The extracellular space is a ___ environment that __ disulfide bonds.
A) Reducing, maintains
B) Oxidizing, maintains
C) Reducing, prevents
D) Oxidizing, Prevents

4. Cytoplasm is a ___ environment that ____ disulfide bonds.
A) Reducing, maintains
B) Oxidizing, maintains
C) Reducing, prevents
D) Oxidizing, Prevents

Answer 1

Answer 1

Option B is correct i.e " Lumen of the vesicle".

Explanation

When surface transmembrane proteins transported in transport vesicle to membrane; its extracellular domain always faces the lumen of vesicle and the intracellular domain faces the interior of the cell or cytoplasm.

Answer 2

Option D is correct i.e " A and B only".

Explanation

Synapse contains neurotransmitter receptors and scaffold proteins; these are needed for trafficking , for passage of signal from pre- synaptic to post-synaptic neurons.

Answer 3

Option B is correct i.e " Oxidizing and maintains".

Explanation

Extracellular compartment exhibits oxidizing potential by which it promotes the disulfide bond formation by oxidizing the -SH group to -S-S- bond.

Answer 4

Option C is correct i.e " Reducing and prevents".

Explanation

Intracellular compartment or cytosol is Reducing by which it reduces the -S-S- bond to -SH and -SH groups and prevents the disulfide bond formation.