Lecture 1 Flashcards
Why are cellular organisms carbon based?
Because carbon is very versatile. It can form single, double and triple bonds with ease and it can also take on many geometric shapes.
What is conformation?
Freedom of rotation around single bonds
What is configuration?
Restricted rotation due to presence of a double bond. Causes atoms to be fixed in spatial arrangement to one another and produces cis and trans isomers. Bonds would have to be broken to convert between different configurations.
What confers configuration?
Double bonds and chiral centers
What type of system are biological organisms?
Open - exchange energy and mass with environment. Total energy stays the same but entropy increases.
What 2 statements must be true of a spontaneous process?
1) the process will proceed toward the state with the lowest potential energy
2) the process will increase the entropy of the universe
What is meant my equilibrium?
The rate of product formation = the rate at which product is converted back into reactant
What does delta G_nought_prime tell us?
Which direction a reaction must go to reach equilibrium when the temp is 25C, initial concentrations of reactants and products are all 1M and pressure = 1atm
What is the sign of delta_G_nought_prime when:
1) Keq > 1
2) Keq = 1
3) Keq < 1
1) ln(Keq) when Keq > 1 is positive, thus delta G is negative, rxn proceeds forward
2) ln(Keq) when Keq = 1 is 0, this delta G is 0 and rxn is at equilibrium
3) ln(Keq) when Keq < 1 is negative, thus delta G is positive and rxn proceeds in reverse
How can unfavorable reactions be made favorable?
1) Le Cahtelier’s principle (adjust [products] and [reactants] to drive reaction in a particular direction)
2) Couple an Endergonic rxn with Exergonic rxn (ex: electron transport chain creates H+ gradient that provides the power for ATP synthesis in mitochondria)
What is the electron geometry of H2O? What is the molecular geometry?
Electron: tetrahedral
Molecular: bent
How many hydrogen bonds does water participate in as a gas? As a liquid? As a solid?
Gas = 0 Liquid = 3.4 Solid = 4
Describe the hydrophobic effect.
When a non polar, hydrophobic substance is placed in water, the water will initially order itself around each individual non polar molecule. This is entropically unfavorable because the order of many water molecules is increased, so overtime the hydrophobic molecules will aggregate together. This results in less water molecules being trapped around the hydrophobic molecule, thus increasing the disorder of the water which corresponds to an increase in entropy. The hydrophobic effect explains this process of non polar molecules aggregating together in polar solvents.
What does blowing off CO2 result in?
Increased pH (drives bicarbonate buffer system towards production of CO2 which consumes H+ in the process)
H2O + CO2 H2CO3 H+ + HCO3-
