Biochem principles

Question 1

what is the strongest and weakest bonds

Answer 1

covalent –> hydrophobic interactions

Question 2

when does REDOX and OILRIG mean

Answer 2

redox: when one thing is reduced another is oxidised.
OILRIG: oxidation is loss (of H), reduction is gain (of H)

Question 3

what is the first law of thermodynamic

Answer 3

energy is neither created or destroyed

Question 4

what is the 2nd law of thermodynamics

Answer 4

when energy is converted from one form to another some of it’s ability to do work is lost

Question 5

what is free energy

Answer 5

a systems ability to ‘do work)

Question 6

what is the equation for free energy

Answer 6

∆ = ∆H -T∆S

Question 7

what is entropy

Answer 7

the amount of disorder within a system,

Question 8

what is an exergonic reaction

Answer 8

free energy of the products is less than the reactants and so has a -ive value and can occur spontaneously

Question 9

what is an endergonic reaction

Answer 9

when the total free energy of the products is more than the reactants and ∆G is +ive, this requires energy to proceed

Question 10

if A + B –> C + D, what is the ∆G equation

Answer 10

∆G = ∆G + RTln([C][D]/[A][B])

Question 11

what is the bodies preferred pH

Answer 11

pH 7

Question 12

what does coupling of processes do to a endergonic reaction

Answer 12

coupling with a very -ive ∆G reaction to make an overall -∆G system

Question 13

if ∆G is close to 0 what does this mean

Answer 13

can be easily reversed

Question 14

what are the 4 types of amino acids

Answer 14

hydrophobic, polar, basic, acidic

Question 15

what is at the N-terminal and is it +ive or -Ive

Answer 15

NH2, amino group, +ive

Question 16

what is at the C-terminal ana is it +ive or -ive

Answer 16

COOH, -ive

Question 17

what is an amino acid with no overall net charger

Answer 17

zwitterions

Question 18

what is the difference between a acid and base

Answer 18

acids donate protons (H), and bases accept them

Question 19

what is the pH equation

Answer 19

pH = -log10[H+]

Question 20

what is the buffer equation

Answer 20

buffer = pka - log10[acid/base]

Question 21

what is primary structure of an amino acid

Answer 21

chain amino acids are synthesised to

Question 22

what is the secondary structure of amino acids

Answer 22

hydrogen bonds creating 3D structure: alpha helix beta sheets parallel or antiparallel

Question 23

what is the tertiary structure for proteins

Answer 23

3D shape plus additional chains

Question 24

what is the quaternary structure proteins

Answer 24

additional of subunits

Question 25

what do chaperone proteins do

Answer 25

quicken protein folding

Question 26

what can denature proteins

Answer 26

heat, extreme pH, detergents, reducing agents

Question 27

what structure is triple helix

Answer 27

collagen

Question 28

what is the central dogma

Answer 28

total DNA in genoma --> RNA --> protein

Question 29

where does transcription occur

Answer 29

nucleus

Question 30

where does transcription occur

Answer 30

nucleus

Question 31

where does translation occur

Answer 31

cytoplasm

Question 32

what is a nucleoside

Answer 32

base and sugar

Question 33

what is a nucleotide

Answer 33

base and sugar and phosphate

Question 34

what connects at the 5' end

Answer 34

phosphate

Question 35

what connects at the 3' end

Answer 35

hydroxyl

Question 36

what direction does polymerase move in and what is required for synthesis

Answer 36

5'-->3' and a primer

Question 37

what joins okazaki fragments on the lagging strand

Answer 37

ligase

Question 38

what unwinds DNA

Answer 38

helicase

Question 39

apart from synthesis DNA, what can polymerase do

Answer 39

remove incorrect DNA

Question 40

what are the differences between DNA and RNA

Answer 40

RNA has U not T, ribose not deoxyribose and is single stranded .

Question 41

what are the 3 types of RNA and what do they do

Answer 41

mRNA carries DNA replica to ribosome, tRNA carries amino acid to protein rRNA ribosomes

Question 42

what are promotors

Answer 42

specific nucleotide sequence to help initiate polymerase binding

Question 43

what is transcription elongation

Answer 43

transcription bubble moves along with polymerase, unwinding and rewinding

Question 44

what process removes introns and where does it take place

Answer 44

RNA splicing, nucleus

Question 45

what are degenerate amino acids

Answer 45

have multiple codons

Question 46

in initiation of translation what is required

Answer 46

GTP hydrolysation

Question 47

what site does a-tRNA originally bind to

Answer 47

A

Question 48

where does it move to when binding to other amino acids

Answer 48

P

Question 49

where does it leave from

Answer 49

E

Question 50

what does elongation factor (EF) do

Answer 50

brings a-tRNA to A site

Question 51

what enzyme catalysed peptide bonds between P and A amino acids

Answer 51

peptidyl transferase

Question 52

where are free ribosomes found

Answer 52

cytosol, nucleus, mitochondria

Question 53

where are bound ribosomes found

Answer 53

rough ER, golgi and membrane

Question 54

what can happen to amino acid chain after translation

Answer 54

post-translational modifications

Question 55

can enzymes change equilibrium

Answer 55

no but they change the rate it can be reached

Question 56

what do enzymes do to activation energy

Answer 56

lower it

Question 57

how do they do this

Answer 57

bind to transition state, stabilise it and provide alternative pathways

Question 58

what are cofactors

Answer 58

metal ions that assist enzymes

Question 59

what are coenzymes

Answer 59

organic molecules that assist enzymes

Question 60

what is an enzyme with a cofactor called

Answer 60

holoenzyme

Question 61

what is an enzyme without a cofactor called

Answer 61

apoenzyme

Question 62

what is an induced fit

Answer 62

when a substrate bind to active site it causes a conformational change making it fit better

Question 63

what are zymogens

Answer 63

inactive precursors of enzymes, irreversible reactions

Question 64

what is an isoenzyme

Answer 64

enzymes that catalyse same reaction but have different structures

Question 65

which enzymes phosphorylate

Answer 65

kinases

Question 66

what is vmax

Answer 66

max rate of reaction with unlimited substrate

Question 67

what is km

Answer 67

conc of substrate that gives 1/2 vmax

Question 68

in: E + S ES--> E + P. which reaction is K1, K2 and K-1

Answer 68

E + S --> ES = k1 | E + S E + P = k2

Question 69

how do you calculate km or michalis constant

Answer 69

(k-1 + k2)/ k1

Question 70

what does a low km mean

Answer 70

low amount of substrate needed (high affinity)

Question 71

in a lineweaver burk plot, what shows Km and Vmax

Answer 71

y intercept = vmax | x intercept = Km

Question 72

do enzymes change vmax

Answer 72

no only km

Question 73

in competitive inhibition (orthosteric) of an enzyme, what happens to km and Vmax

Answer 73

Km increases and Vmax stays the same

Question 74

in non-competitive (allosteric) inhibition of an enzyme, what happens to km and Vmax

Answer 74

km stays the same and Vmax changes - binds to secondary binding site

Question 75

in orthosteric inhibition what does the curve look like, does it follow M-M rules

Answer 75

hyberbola, yes

Question 76

in allosteric inhibition what does the curve look like

Answer 76

sigmoid. no

Question 77

feedback control is what type of inhibition

Answer 77

allosteric