Biochemistry L01 Foundations

Question 1

What are the main types of chemical bonding?

Answer 1

• Covalent
• Non-Covalent:
  - Ionic
  - Hydrogen
  - Van der Waals attractions
  - Hydrophobic Interactions, i.e. protein
  folding

Question 2

What are macromolecules?

Answer 2

Polymers (chains) of single units (monomers) linked by covalent bonds

Question 3

What are the four main molecule types in living things (list both monomers and the polymers they form)?

Answer 3

Monomers - Polymers: 
Sugars (monosaccharides) - Polysaccharides 
Fatty Acids - Fats, Lipids, Membranes
Amino Acids - Protein
Nucleotides - Nucleic Acids

Question 4

How many cells do we have and how big are they?

Answer 4

Humans have around 10^14 cells with varying sizes. Most cells in an organism have a diameter less than 30μm. White blood cells =±3μm long and nerve cells up to 1m.

Question 5

Why does the number of cells in an organism increase as the organism gets larger, but not the size of individual cells?

Answer 5

In order to allow adequate exchange of nutrients, ions, waste, gases etc, the cell needs to maintain a reasonable surface area in comparison to its volume. As the volume increases, the ratio of the surface area to volume decreases. The surface area will eventually not allow for the adequate exchange of nutrients, ions, waste or gases for the size of the cell and the cell will die. Therefore the cell needs to be small enough that the ratio of surface area to cell volume is adequate.

Question 6

What are the defining features of Prokaryotes?

Answer 6

• No nucleus
• No membrane bound organelles
• cell division by fission (not mitosis) – rapid
  growth and reproduction
• Size range: 1-10μm

Question 7

What are the defining features of Eukaryotes?

Answer 7

• Nucleus and nucleolus
• Membrane-bound organelles
• Cell division by mitosis or meiosis
• Bigger than prokaryotes
• Many are multicellular (i.e. animals and plants)

Question 8

What is a Hydroxyl group?

Answer 8

-OH

Question 9

What is a Carboxyl group?

Answer 9

-COOH

Question 10

What is a Ketone?

Answer 10

Oxygen double bonded to a carbon with two R groups.

Question 11

What is an Aldehyde?

Answer 11

Oxygen double bonded to a carbon with only one R group and one H.

Question 12

What is a Methyl group?

Answer 12

-CH3

Question 13

What is an Amino group?

Answer 13

-NH2

Question 14

What is a Sulfhydryl group?

Answer 14

-SH

Question 15

What is a disulfide group?

Answer 15

-S-S-

Question 16

What is a phosphate group?

Answer 16

Phosphate surrounded by 4 oxygens. One bond is a double bond.

Question 17

Define Life

Answer 17

Life is what distinguishes animals and plants from inorganic matter. These are the 7 characteristics of life:
M - movement
R - respiration
S - sensitivity
G - growth
R - reproduction
E - excretion
N - nutrition

Question 18

Why is carbon used so much in biological molecules?

Answer 18

Carbon is able to attach between 2-4 atoms to itself, in a variety of shapes and patterns - it has a huge number of bonding patterns available to it
It also forms very stable, and so long-lasting bonds, making molecules of life very tenacious