Question 1

Which part(s) of the atom are shared during covalent bond formation?

Accepted Answer

Electrons in the outermost shell

Question 2

If an atom loses an electron, what will be its overall charge?

Accepted Answer

Positive

Question 3

Which of the following molecules contains polar covalent bonds?

Accepted Answer

H$$_2CO$$ ($$C=O$$ and $$C-H)$$

Question 4

When boiling water, which type of bond is primarily broken?

Accepted Answer

Hydrogen bonds

Question 5

Why does water have a high surface tension?

Accepted Answer

Because of hydrogen bonds between water molecules

Question 6

Which of the following molecules is most soluble in water?

Accepted Answer

CH$$_3CH$_2OH ($$ethanol)

Question 7

What is the definition of pH?

Accepted Answer

$$pH = -\log_{10}[H^+]$$

Question 8

A solution has a pH of 3. Which statement is true?

Accepted Answer

It has more $$H^+$$ ions than pure water

Question 9

Which property of water is most directly responsible for capillary action in plants?

Accepted Answer

Hydrogen bonding leading to adhesion and cohesion

Question 10

In nucleic acids, what is the significance of the 5' and 3' carbon positions on the sugar?

Accepted Answer

They are the sites where phosphate groups and new nucleotides attach, giving directionality to the polymer

Question 11

Which of the following is true about the backbone of DNA and RNA?

Accepted Answer

It is composed of alternating phosphate and sugar groups

Question 12

What type of bond forms between the hydrogen in adenine and the oxygen in thymine?

Accepted Answer

Hydrogen bond

Question 13

Which statement best explains why DNA strands are antiparallel?

Accepted Answer

Base pairing requires the 5' to 3' direction of one strand to be opposite to the other

Question 14

If a viral DNA is 35% guanine, what percent is adenine?

Accepted Answer

15%

Question 15

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose, RNA contains ribose

Question 16

Why do hydrophobic molecules cluster together in water?

Accepted Answer

Because water molecules exclude them due to their inability to form hydrogen bonds

Question 17

Which statement about hydrogen bonds is correct?

Accepted Answer

Hydrogen bonds require less energy to break than covalent bonds

Question 18

What happens to the phosphate group of a nucleotide in water?

Accepted Answer

It loses hydrogen atoms but keeps their electrons, making the nucleotide acidic

Question 19

Which of the following is a direct consequence of hydrogen bonding in biological macromolecules?

Accepted Answer

3D structure and stability of DNA and RNA

Question 20

If you wanted to convert a DNA sequence to an RNA sequence for origami, what would you need to change?

Accepted Answer

Replace all thymine (T) with uracil (U)

Water, Chemistry of Life, and Nucleic Acids: Study Notes

Study Guide - Practice Questions