Question

What is NOT a reason for why lipids don't dissolve well in water?

Select one:

a. Lipids are rich in carbon atoms.

b. Lipids are low in oxygen atoms.

c. Lipids are essentially non-polar molecules.

d. Most all the atoms that make up lipid molecules have about the same electronegativity.

e. Lipids are hydrophobic.

In DNA, the type of bonds found in the nucleotides that join the sugar to the phosphates are?

Select one:

a. ionic bonds

b. covalent bonds

c. H-bonds

d. peptide bonds

Answer 1

Question 1

The correct answer is option c - Lipids are essentially non polar molecules

Explanation: Lipids are non polar molecules and whereas water is a polar molecule. Polar molecules dissolves in polar solvents and non polar molecules dissolve in non polar solvents. So, being non polar, lipids does not dissolve in water molecule which is a polar compound.

Question 2

The correct answer is option b - Covalent bond

Explanation: Sugars and phosphate together form the backbone of DNA and they remain attached to ech other by phosphodiester bond. This is a covalent bond that is formed between  carbon 4 of sugar and a CH₂ group attached to the phosphate group.