more enzymes

Question 1

enzymes are..

Answer 1

macro molecules whose function is to increase the rate of reaction–> generally do this by reducing transition state energy for a reaction

Question 2

general properties of enzymes

Answer 2

catalyst - enzymes end in the state they started -specific -protein itself is not changed in reaction -fast

Question 3

catalysed reactions vs normal reactions

Answer 3

no enzyme: s–> p enzyme: E+s –> ES–> EP–> E+ P many more intermediate reactions

Question 4

catalysed reactions assume that

Answer 4

-release of product is very fast, compared to the reaction itself -reverse reaction is sufficiently slow

Question 5

how is the transition state barrier reduced? 2 ways

Answer 5

• stabilise the unfavourable intermediate
• make possible less favourable reactions

Question 6

stabilise the unfavourable intermediate

Answer 6

• charge-charge interactions
• h bonding
• protecting hydrophobic groups

Question 7

make possible less favourable reactions

Answer 7

• provide acid/base conditions
• allow oxidation.reduction
• provide a small vacuum
• provide attacking group
• provide a metal ion

Question 8

Vmax=

Answer 8

maximal rate -reveals turn over number–> also called Kcat

Question 9

Km

Answer 9

michaelmas constant -measure of catalytic efficiency

• the conc of substrate at which half the active sites are filled
• provides a measure of the substrate conc needed for significant catalysis to occur

Question 10

Km values of enzymes range widely..

Answer 10

between 10^-1 and 10^-7

Question 11

what does Km depend on..

Answer 11

the substrate and conditions such as pH

Question 12

a high Km indicates

Answer 12

weak bonding

Question 13

a low Km indicates

Answer 13

strong bonding

Question 14

a low Km indicates

Answer 14

strong bonding

Question 15

when entropy is large than Km..

Answer 15

the rate of catalysis (V) is equal to Vmax–> a function of Kcat

Question 16

Kat take sinto cosndieration..

Answer 16

the rate of catalysis and strength of the ES interaction

Question 17

M-M proves that

Answer 17

when the conc of substrate drops so does the rate

Question 18

two types of graphs which use M-M kinetics

Answer 18

Hanes woolf Line-weaver

Question 19

two types of graphs which use M-M kinetics

Answer 19

Hanes woolf Line-weaver

Question 20

important enzyme characteristics..

Answer 20

Km and Vmax

Question 21

working out the constants for a give enzyme requires..

Answer 21

several experiments

Question 22

what must the experiments provide

Answer 22

-provide the value for Vo (velocity) for a least 5 (8-10 preferable) values -these values of [s] must be both sides of Km for a good result constants of enzymes can now be calculated

Question 23

lineweaver plot

Answer 23

Question 24

hanes-woolf

Answer 24

Question 25

arrhenius equation

Answer 25

Question 26

Michaelis-Menten equation

Answer 26

Question 27

M-M graph

Answer 27

Question 28

arrhenius equation gives the relationship between

Answer 28

activation energy and the reaction rate constant