Lecture 1: Intro/ Review

Question 1

Give a basic definition of the following:

• cell
• genes
• evolution

Answer 1

• cell: basic unit of life
• genes: basic unit of heredity
• evolution: propels creation and extinction of species

Question 2

What are the fundamental characteristics of life? (5)

Answer 2

life is

• cellular
• replicates
• processes information
• requires energy
• evolves

Question 3

What are the 3 levels of biological organisation? (3)

Answer 3

• cell to ecosystem
• sub-cellular components
• biosphere

Question 4

Briefly explain the following bonds and order them in terms of strongest to weakest:

• covalent bonds
• ionic bonds
• hydrogen bonds
• van der waals

Answer 4

• covalent bonds: electrons are shared between species
• ionic bonds: electrons are donated during bonding
• hydrogen bonds: Hydrogen is bonded to an electronegative atom (polar bonds)
• strength: covalent, ionic, hydrogen
• van der waals: not really a bond but a FORCE dependent on distance between atoms or molecules

Question 5

Explain the difference between polar and non polar molecules

Answer 5

• elecrons in a non polar molecule are shared evenly and/or bonds are symmetrical; atoms have the same electronegativity; this is the opposite case for polar molecules

Question 6

Explain the difference between hydrophilic and hydrophobic molecules. What sort of molecules are hydrophobic and hydrophilic?

Answer 6

• hydrophilic molecules interact well with water; example: polar molecules dissolve in water
• hydrophobic molecules do not interact well with water; example: non polar molecules do not dissolve in water

Question 7

Explain the difference between a protonated and deprotonated molecule

Answer 7

• protonated molecule: has an added proton (hydrogen molecule)
• deprotonated molecule: has a removed proton (hydrogen molecule)