Top1-Ch1-ThingsMissed

Question 1

What is Biochemistry

Answer 1

is the study of the chemical processes in living organisms. It deals with the structure and function of cellular components such as proteins, carbohydrates, lipids, nucleic acids and other biomolecules.’

Question 2

What are the limits to cell size?

Answer 2

Upper limit of cell set by rate of diffusion- ratio surface area to volume

Hence if cell size is too large, it will not have enough surface area to diffuse substances (eg. O2) into all parts of it

A is r² while volume is r³

Question 3

Prokaryotic V Eukaryotic

Answer 3

Prokaryotic:

• Small (generally 1-10 µm)
• Single cell organism (usually)
• Nucleoid- no membrane, cytoplasmic DNA
• Low DNA content
• Cytoplasmic DNA plasmids
• No membrane bound organelles

Eukaryotic:

• Larger (generally 5-100 µm)
• Single or multicellular organism
• Nucleus with nuclear envelope, DNA condensed into nucleus
• High DNA content
• No cytoplasmic DNA plasmids
• Organelles: eg. Golgi, ER, mitochondria, peroxisomes

Question 4

Animal cell picture from slides

Answer 4

Question 5

Macromolecules are held together by covalent or non-covalent bonds? Name the bonds.

Answer 5

non-covalent bonds

• Hydrogen bonds – between polar groups
• Ionic interactions – between charged groups
• Hydrophobic interactions (non-polar groups in aqueous solution)
• Van der Waals interactions (very close proximity, ≈ “exact fit”)

Question 6

Name four classes of macromolecules

Answer 6

1. Proteins - amino acids
2. Lipids - fatty acids, glycerol
3. Polysaccharides (carbohydrates) - sugars
4. Nucleic acids (DNA, RNA) - nucleotides

In general, polymers are large molecules formed by stringing together smaller compounds or monomers.