Aqueous chemistry

Question 1

Example of a coupled reaction (ΔG)

Answer 1

peptide bond formation to ATP hydrolysis
photosynthesis
cellular respiration
Anything redox

Question 2

Strongest bond in aqueous environments

Answer 2

Covalent bonds > ionic interactions
Due to dielectric constants being lower when in water vs in a vacuum.
Eg. salt breaking apart in water.

Question 3

Liquid water flickering

Answer 3

2-3 bonds per molecule that change in pattern rapidly rather than being fixed such as in ice (four bonds per molecule).

Question 4

Amorphous ice

Answer 4

Quickly lower temp under high pressure, no lattice formation, dense!!

Question 5

Water as a solvent

Answer 5

Water becomes more ordered - loses entropy, but this is overcome by the enthalpic interactions and gain in entropy of salt during dissolution.

Question 6

Why non-polar molecules HATE water

Answer 6

Non favourable interactions (dipole-induced dipole), water cannot H-bond with the lipid meaning it has reduced mobility and lower entropy.

Question 7

Hydrophobic effect

Answer 7

Clathrate is immobile due to low entropy of water next to the lipid. But if the lipid is aggregated, there is lower surface area of the lipid-water interface - there are more free water molecules (increasing entropy - more favourable).

Question 8

Cell compartmentalisation

Answer 8

Fatty acid tail interact with eachother to minimise unfavourable contact - different shaped lipids give different compartments.

Question 9

Detergent michelle lipid shape

Answer 9

cone

Question 10

Lipid bilayer lipid shaped

Answer 10

Cylindrical