Flashcards in Biochemistry Deck (73)
The most strong type of bond is...
jks, covalent bonds
The attractive force that an atomic nucleus exerts on electrons
EN carbon is greater than EN hydrogen. Which is reduced?
Carbon has a greater attractive force for electrons, so it gains electrons, therefore it is reduced and hydrogen is oxidised
Reducing agents are themselves oxidised. True/False?
First law of thermodynamics?
Energy is neither created or destroyed
Second law of thermodynamics?
When energy is converted to another form, some of it is lost (never 100% efficient)
∆G = the change in free energy = ?
∆H - T∆S
∆G°' + RTln([C][D]/[A][B])
Exergonic reactions are where...
Products have less free energy than the reactants
∆G is -ve
Reaction can occur spontaneously
Endergonic reactions are where...
Products have greater free energy than the reactants
∆G is +ve
Reaction cannot occur spontaneously
The difference between normal standard conditions and biochemical standard conditions is...
pH = 7
At equilibrium ∆G = 0. This is characteristic of readily reversible reactions. True/False?
Reaction spontaneity can be achieved by...
Changing concn of reactants/products
Coupling with highly favourable processes (e.g. with hydrolysis of ATP)
Both of the above help ∆G become -ve
Amino acids are subdivided into 4 groups, which are?
The N-terminal of a peptide chain is -ve. True/False?
It is +ve due to NH3
The C-terminal of a peptide chain is -ve. True/False?
True due to COO-
A zwitterion has which type of charge?
None! No net charge
Ka = acid dissociation constant = ?
pH = measurement of how many H+ in a solution = ?
Henderson Hasselbach Equation connects Ka of a weak acid with the pH of a solution containing this acid. The equation is...
pH = pKa + log[A-]/[HA]
pKa - pH = log[HA]/[A-]
Primary protein structure describes...
The specific sequence of amino acids in a chain
Secondary protein structure describes...
The hydrogen-bonded 3D arrangement of the chain
α-helix (one peptide chain spiralled; right-handed)
B-stranded-sheet or B-pleated-sheet
Tertiary protein structure describes...
The arrangement of the chain in space and forces stabilising the structure
Quaternary protein structure describes...
Association of non-protein groups to the chain
e.g. haemoglobin, myoglobin
What is the central dogma?
DNA is transcribed to RNA, which is translated into protein
A nucleoside has...
5C sugar + organic base
A nucleotide has...
5C sugar + organic base + phosphate group(s)
Pol II synthesises only stable RNA. True/False?
Pol II synthesises all RNA. Pol I and III synthesise only stable RNA
DNA polymerase has 3 important characteristics
Can only add to existing nucleic acids
Cannot start synthesis on its own
Requires an RNA primer to start replication
Enzymes can affect the equilibrium position of a reaction. True/False?