Intro to Biochemistry

Question 1

Bonds/interactions in Biomolecules

Answer 1

• Covalent: sharing of electrons
• Ionic: attraction of opposite charges
• Hydrogen Bond: sharing of H atom
• Hydrophobic Interaction: interaction of non polar substances in presence of polar substances
• Van der Waals: interaction of electrons of non-polar substances

Question 2

1) Electronegativity

1. Phosphorylation and de-phosphorylation
2. Acylation
3. Carboxylation
4. Esterification

Answer 2

1) the attractive force that an atomic nucleus exerts on electrons within a bond
1. addition/removal of phosphoryl group
2. adding acyl group
3. adding carboxyl
4. reaction between acid (usually carboxylic acid) and alcohol

Question 3

1) Condensation

2) Hydrolysis

Answer 3

1) water removed, molecules polymerize (many repeating units)
2) water added, molecules depolymerize

Question 4

Redox

1) Oxidation states of carbon

Answer 4

• electrons transferred from one molecule to another OILRIG

1) alkane… alcohol… aldehyde… carboxylic acid… carbon dioxide

Question 5

1) Functions of Biomolecules

2) Major classes of biomolecules

Answer 5

1) info storage, structural, energy generation, energy currency/storage, recognition/communication/specificity
2) peptides, proteins, nucleic acids, lipids, carbohydrates

Question 6

Carbohydrates

Answer 6

• Monosaccharides: e.g. glucose
• Disaccharides: (2 mono joined together)
• Polysaccharides: e.g. cellulose, glycogen (Storage & Rapid Energy Conversion)

Question 7

Thermodynamics

Answer 7

(biophysical discipline, deals with if a process is energetically favourable)
1st Law: energy neither created/destroyed
2nd Law: when is energy is converted from one form to another, some energy becomes unavailable to do work

Question 8

1) Entropy (S)

Answer 8

1) free energy will tend towards an unusable state after multiple transformations

Entropy = randomness, disorder (ΔS = change in entropy)

Definition: measure of system’s thermal energy per unit temp. that is unavailable for doing useful work

Takes energy to impose order on a system

Question 9

Enthalpy (H)

Answer 9

H = heat content (ΔH = change in enthalpy)

Question 10

Change in free enenrgy = ΔG

Answer 10

ΔG = ΔH - TΔS (T is temp. in K)

Free energy change ΔG = (energy of products) - (energy of reactants)