Question

Imagine a new type of cell was discovered on Mars in an organism growing in benzene, a nonpolar liquid. The cell had a lipid bilayer made of phospholipids, but its structure was very different from that of our cell membranes.What might be characteristic features of the phospholipid head groups?1) The phospholipid head groups would likely bind to each other with covalent bonds that would pack well and not be bulky.2) The phospholipid head groups would likely have equal numbers of positively and negatively charged groups that would pack well and not be bulky.3) The phospholipid head groups would likely have equal numbers of hydroxyl and amino groups that would pack well and not be bulky.4) The phospholipid head groups would likely bind to each other with hydrogen bonding that would pack well and not be bulky.

Answer 1

Answer:

2) The phospholipid head groups would likely have equal numbers of positively and negatively charged groups that would pack well and not be bulky.

Explanation:

Benzene contains aromatic groups making it non-polar while the phopholipid head contains the negatively charged phosphate group making it polar. These molecules would repel each other forcing the phopholipid head to be in the inner membrane forming. The hydrophobic non-polar phospholipid tail would form hydrophobic bonds with benzene. The phospholipid head would likely have equal numbers of positively and negatively charged groups that would allow them to form ion-ion interactions helping them pack well and not be bulky. If the heads were still negatively charged they would likely repel each other and be disordered.