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Flashcards in Biochemistry Deck (73)
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1

The most strong type of bond is...

LOVE
jks, covalent bonds

2

Electronegativity is...

The attractive force that an atomic nucleus exerts on electrons

3

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

4

Reducing agents are themselves oxidised. True/False?

True

5

First law of thermodynamics?

Energy is neither created or destroyed

6

Second law of thermodynamics?

When energy is converted to another form, some of it is lost (never 100% efficient)

7

∆G = the change in free energy = ?

∆H - T∆S
∆G°' + RTln([C][D]/[A][B])

8

Exergonic reactions are where...

Products have less free energy than the reactants
∆G is -ve
Reaction can occur spontaneously

9

Endergonic reactions are where...

Products have greater free energy than the reactants
∆G is +ve
Reaction cannot occur spontaneously

10

The difference between normal standard conditions and biochemical standard conditions is...

pH = 7

11

At equilibrium ∆G = 0. This is characteristic of readily reversible reactions. True/False?

True

12

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

13

Amino acids are subdivided into 4 groups, which are?

Non-polar hydrophobic
Polar uncharged
Acidic (-COOH)
Basic (-NH)

14

The N-terminal of a peptide chain is -ve. True/False?

False
It is +ve due to NH3

15

The C-terminal of a peptide chain is -ve. True/False?

True due to COO-

16

A zwitterion has which type of charge?

None! No net charge

17

Ka = acid dissociation constant = ?

[H+][A-]/[HA]

18

pH = measurement of how many H+ in a solution = ?

-log10[H+]

19

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-]

20

Primary protein structure describes...

The specific sequence of amino acids in a chain

21

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

22

Tertiary protein structure describes...

The arrangement of the chain in space and forces stabilising the structure

23

Quaternary protein structure describes...

Association of non-protein groups to the chain
e.g. haemoglobin, myoglobin

24

What is the central dogma?

DNA is transcribed to RNA, which is translated into protein

25

A nucleoside has...

5C sugar + organic base

26

A nucleotide has...

5C sugar + organic base + phosphate group(s)

27

Pol II synthesises only stable RNA. True/False?

False
Pol II synthesises all RNA. Pol I and III synthesise only stable RNA

28

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

29

Enzymes can affect the equilibrium position of a reaction. True/False?

False

30

How do enzymes lower the activation energy of a reaction?

Bind to and stablise the transition state and provide alternative reaction pathways