Molecular Biology

Question 1

What are the four basic molecules cells use to interact with each other?

Answer 1

Methyl
Hydroxyl
Carboxyl
Amino

Question 2

What are the four families of small organic molecules?

Answer 2

Sugars
Fatty acids
Amino acids
Nucleotides

Question 3

Nucleic acids are made from what?

Answer 3

Nucleotides

Question 4

Proteins are made from what?

Answer 4

Amino acids

Question 5

Polysaccharides are made from what?

Answer 5

Sugars

Question 6

What is the main function of nucleic acids?

Answer 6

Code genetic information (DNA)

Question 7

What type of bond joins polymers of nucleotides?

Answer 7

Phosphodiester bond

Question 8

What are the five main functions of proteins (also known as the “work horses of the cell”)?

Answer 8

Structure
Movement
Catalysis
Transport
Signaling

Question 9

Polymerization to form peptide bonds between amino acids is a result of what?

Answer 9

Dehydration

Question 10

Polysaccharides are polymers of _____________ joined by ____________ bonds

Answer 10

Pentose/hexose

Glycosidic bonds

Question 11

What does amphipathic mean?

Answer 11

Both hydrophilic (head) and hydrophobic (tail) groups

Question 12

How are lipids formed?

Answer 12

Esterification of acids

Question 13

What are the four aspects of the “lock and key” model of complementarity?

Answer 13

Shape
Charge
Polarity
Hydrophobicity

Question 14

Non-covalent interactions between macromolecules allows what to happen?

Answer 14

Tight, highly specific macromolecular bonding

Question 15

What are the four main types of weak, non-covalent bonding interactions?

Answer 15

Ionic bonds
van der Waals interactions
Hydrogen bonds
Hydrophobic effect

Question 16

Describe ionic bonds

The absence of what molecule increases the strength of ionic bonds?

Answer 16

Interactions between fully or partially charged groups (current between the two groups)
Absence of water increases the strength of ionic bonds

Question 17

Describe hydrogen bonds

Answer 17

Hold molecules together
Polarized molecules (such as water) can link via hydrogen bonds

Question 18

Describe van der Waals attractions

At what physical conditions are van der Waals interactions more effective?

Answer 18

Electrons are shared between adjacent nuclei
Adjacent, oppositely charged molecules come close enough to attract, with each molecule having a radius at which van der Waals forces are strongest
More effective in lower temperatures

Question 19

What is the clathrate cage seen with the hydrophobic effect?

Answer 19

A clathrate cage occurs when one molecule traps another
Aggregated states (where water population is less ordered, more entropy) are more energetically favourable

Question 20

What are the main features seen in prokaryotes that are not seen in eukaryotes?

Answer 20

Inner and outer membranes with cell wall and periplasmic space
Nucleoid instead of nucleus
Plasmid (extra chromosomal, can carry antibiotic resistance)

Question 21

What are micelles and liposomes?

Answer 21

Artificial membranes made by mixing phospholipids and water

Liposomes have a hydrophilic core and can hide hydrophilic compounds within this core

Question 22

What does self-assembly mean?

Answer 22

Can change the diameter of liposomes or plasma membranes by adding more phospholipids

Question 23

How was the plasma membrane involved in defining the first cells?

Answer 23

Phospholipid molecules in prebiotic soup assembled spontaneously
Enclosed self-replicating mixture of RNA and protein molecules