Question

1. What is NOT TRUE regarding a phospholipid bilayer?

A. The two leaflets of the bilayer are identical.

B. It takes energy to flip one phospholipid from one side to the other

C. In animal cells cholesterol is inserted into the bilayer

D. The bilayer can contain more than one type of phospholipid.

2. New membrane is made and assembled in the ___ and delivered to the plasma membrane in vesicles derived from the _.

A. Cytosol; ER

B. Cytosol; Golgi

C. ER; Golgi

D. Nucleus; ER

3. The human gene contains 25,000 to 30,000 coding regions for genes. Not all of these have been characterized. What secondary structure would you expect to find in a potential transmembrane protein?

A. Beta sheet with hydrophobic R-groups

B. Alpha helical with hydrophobic R-groups

C. Random coil with mixture of R-groups

D. Alpha helical with hydrophilic R-groups.

Answer 1

Answer 1

Option A is correct i.e " The two leaflets of the bilayer are identical".

Explanation

The lipid bilayer is asymmeteric in nature means two lipid leaflets is different from one another with respect to lipid composition, proteins presence or absence.

Answer 2

Option C is correct i.e " ER; Golgi".

Explanation

Golgi receive the proteins from the ER and then translocates in the form of vesicles from golgi to plasma membrane.

Answer 3

Option B is correct i.e " Alpha helical with hydrophobic R-groups".

Explanation

Proteins that span the membrane is mainly found to exhibits alpha helical motif and the amino acid are mainly of non-polar or hydrophobic type.