Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

a-level biology > 2.1.4 Enzymes and Chromatography > Flashcards

2.1.4 Enzymes and Chromatography Flashcards

You may prefer our related Brainscape-certified flashcards:
AP® Biology flashcards
1
Q

types of metabolic reactions

A

anabolic and catabolic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

anabolic reaction

A

building up/synthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

catabolic reaction

A

breaking down/degradative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

examples of anabolic reactions

A

protein synthesis, photosynthesis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

examples of catabolic reactions

A

respiration, digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

general enzyme equation

A

enzyme + substrate <-> enzyme substrate complex <-> enzyme product complex <-> enzyme + products

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

biological catalyst

A

biological - proteins used in metabolism

catalyst - a chemical that speeds up rate of reaction, lowering the activation energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

residues directly involved in enzyme action

A

contact residues and catalytic residues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

contact residues

A

bind to the substrate, determines specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

catalytic residues

A

act on the bonds within the substrate that are broken by enzyme action

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

types of inhibitors

A

competitive and non-competitive

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

denatured enzymes

A

permanent change in tertiary and secondary structure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

types of cofactors

A

prosthetic groups, inorganic ions, coenzymes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

factors that denature enzymes

A

high temperatures or extreme pH

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

cofactor

A

any substance which is essential for efficient functioning of an enzyme

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

types of cofactors

A

prosthetic group
inorganic ions
coenzymes - organic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

features of a prosthetic group

A

non-protein part of an enzyme, very tightly bound on a permanent basis (usually metal ions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

examples of prosthetic group

A

haem group (Fe2+)
zinc (Zn2+) - carbonic anhydrase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

features of inorganic ions

A

not permanently bound but may bind temporarily to an enzyme or substrate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

example of an inorganic ion

A

Cl- for amylase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

features of coenzyme

A

often vitamins, bind to active site temporarily or at the same time as the substrate, carry chemical groups between enzymes eg. e-

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

examples of coenzyme

A

NAD, FAD, both derived from vitamin B, involved in respiration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

metabolic pathways

A

series of consecutive reactions, every step catalysed by a specific enzyme that produces a specific product

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

intracellular enzymes

A

catalyse reactions inside the cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

example of intracellular enzyme

A

catalase: breaks down hydrogen peroxide into water and oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

primary structure of an enzyme

A

sequence of amino acids joined by peptide bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

secondary structure of an enzyme

A

folding of the amino acid chain into alpha helices or beta-pleated sheets held together by hydrogen bonds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

tertiary stucture of an enzyme

A

3D folding of secondary structure into a specific shape held together by hydrogen bonds, hydrophobic/hydrophilic interactions, ionic bonds, disulfide bonds

29
Q

quarternary structure of an enzyme

A

occurs in proteins that have more than one polypeptide chain working together as a functional macromolecule

30
Q

respiratory enzymes

A

responsible for the breakdown of glucose and the formation of ATP

31
Q

extracellular enzymes

A

catalyse reactions outside the cell

32
Q

phosphorylases

A

act in cytoplasm
add phosphate groups
e.g. glucose is phosphorylated to keep in cell + makes it more reactive

33
Q

decarboxylases

A

act in matrix of mitochondria
removes carbon dioxide

34
Q

dehydrogenases

A

act in matrix of mitochondria
removes hydrogen

35
Q

digestive enzymes

A

carbohydrase - e.g. amylase
protease - e.g. pepsin
lipase - e.g. lipase

36
Q

carbohydrase substrate molecule

A

carbohydrates
starch

37
Q

protease substrate molecule

A

protein

38
Q

lipase substrate molecule

A

lipids

39
Q

bonds that carbohydrases break

A

glycosidic bonds

40
Q

bonds that proteases break

A

peptide bonds

41
Q

bonds that lipases break

A

ester bonds

42
Q

site of production and action of carbohydrases

A

salivary glands
mouth

43
Q

site of production and action of proteases

A

stomach

44
Q

site of production and action of lipases

A

produced in pancreas
act in small intestine

45
Q

lock and key hypothesis

A
  1. substrate arrives + randomly collides with the active site
  2. substrate fits into the active site - complementary binding, forms temporary bonds
  3. products leave the active site
46
Q

what does the induced fit model suggest

A

the presence of the substrate induces a shape change in the active site fo the enzyme
gives a good fit

47
Q

the induced fit model

A
  1. initial complementary binding of substrate and active site
  2. temporary bonds form
  3. conformation in the enzyme structure - enzyme changes shape
  4. catalytic R groups interact with substrate and reaction occurs
  5. products are released
48
Q

activation energy

A

the minimum amount of energy required to reach the transition state of a reaction

49
Q

how do enzymes lower activation energy

A

catalytic R groups may donate or accept e-, forms bonds with substrate - helps substrate reach transition state
enzyme may create a particular environment by enclosing substrate
on binding, bonds in substrate may be strained - helps molecules reach transition state
enzymes orientate molecules so reacting bonds are closer to each other

50
Q

factors that affect the rate of enzyme controlled reactions

A

enzyme concentration
substrate concentration
temperature
pH

51
Q

effect of enzyme concentration on rate

A

increasing enzyme conc. increases rate
more active sites are available
increased frequency of successful collisions (enzyme + substrate)
increased number of enzyme - substrate complexes
more products formed per second
increased initial rate

52
Q

effect of enzyme concentration, limited substrate, on rate

A

graph flattens/plateaus
substrate is a limiting factor
if enzyme conc. increased further, rate would not increase
not all active sites are occupied by substrate
VMax is reached

53
Q

effect of substrate concentration on rate

A

increasing substrate conc. increases rate
increased frequency of successful collisions
increased number of enzyme - substrate complexes
more products formed per second
increased initial rate

54
Q

effect of substrate concentration, fixed enzyme concentration, on rate

A

rate plateaus
rate is prevented from increasing further
enzyme reached its VMax
every active site is occupied

55
Q

effect of low temperature on rate

A

enzyme is unactivated
less KE = move slowly and not frequently
low frequency of successful collisions
less product formed per second
low initial rate

56
Q

effect of increasing tempertaure on rate

A

KE increases = move quicker, more frequently
increased frequency of successful collisions
more enzyme - substrate complexes
increased initial rate

57
Q

effect of optimum temperature on rate

A

enzyme reaches VMax
highest initial rate

58
Q

effect of temperature above optimum temp on rate

A

initally enzyme begins to change shape = decreased frequency of successful collisions
more vibrations = more H/ionic bonds broken
loss of secondary and tertiary structure
active site changes shape = no longer complementary
no enzyme - substrate complexes formed
enzyme is denatured = function cannot be restored

59
Q

effect of small changes of pH on rate

A

decrease rates
shape of active site is disrupted, not denatured

60
Q

effect of extreme changes from optimum pH on rate

A

enzyme is denatured
rate = 0

61
Q

effect of extreme low pH on rate

A

acids = H+ donors
H+ ions attracted to negatively charged parts of molecule
excess H+ interferes with hydrogen/ionic bonds - can cause secondary and teritary structure to unravel
active site changes shape
substrate molecule no longer complementary

62
Q

buffer

A

a solution which resists changes in pH when small amounts of acids or alkalis are added

63
Q

enzyme inhibitors

A

reduce the rate of enzyme controlled reactions
have an effect on the enzyme
may block the active site, change active site shape, stop it from catalysing the reaction

64
Q

competitive inhibitors

A

similar shape to substrate
binds to active site of an enzyme = enzyme - inhibitor complex
competes with substrate for active site
prevents the substrate from binding
mostly reversible

65
Q

example of competitive inhibitor

A

statins = competitive inhibitor of enzyme HMG-coA reductase (makes cholesterol in liver)
treates people with coronary heart disease - reduces fatty deposits in arteries

66
Q

non-competitive inhibitor

A

binds to allosteric site
no structural similarity to substrate
binding causes active site shape to distort - comfromational change in tertiary structure = substrate no longer complementary to active site

67
Q

example of non-competitive inhibitor

A

cyanide is a non-competitive inhibitor of respiratory enzyme (cytochrome oxidase)
prevents the formation of ATP

68
Q

reversible inhibitors

A

most competitive inhibitors do not bind permanently
removal of inihibitor from a reaction mixture leaves enzyme molecule unaffected

69
Q

irreversible inhibitors

A

most non-competitive inhibitors bind permanently to enzyme molecules
any molecules bound by inhibitor are inactivated

a-level biology (26 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions