B5 - enzyme

Question 1

define enzymes

Answer 1

protein that is involved in all metabolic reactions where they function as biological catalysts

Question 2

define catalyst

Answer 2

a substance which increases rate of reaction without being used up in the reaction

Question 3

why are enzymes biological catalysts

Answer 3

they’re made in cells

Question 4

define substrate

Answer 4

molecule which an enzyme acts on

Question 5

what is the lock and key hypothesis

Answer 5

analogy used to show reaction involving enzymes and substrate

Question 6

what is the lock

Answer 6

active site of enzyme

Question 6

7 properties of enzymes

Answer 6

-made of protein
-function as biological catalysts
-re-usable
-active site is specific
-can break down or join substrates
-sensitive to temp. changes
-sensitive to pH changes

Question 7

what is the key

Answer 7

substrate

Question 7

what does the substrate do to the enzyme

Answer 7

they bind together

Question 8

what are complementary

Answer 8

active site and substrate

Question 9

what are each enzymes (activities sites) to substrate

Answer 9

specific

Question 10

what do enzymes do

Answer 10

-maintain rate of all metabolic reactions
-at rate that can sustain life

Question 11

what is it called when enzyme and substrate binds together

Answer 11

enzyme- substrate complex

Question 12

what breaks down hydrogen peroxide

Answer 12

-catalase

Question 12

what happens to the substrate after it binds with the enzyme

Answer 12

-it is a products
-diffuses from the active site
-either joined tgt or broken

Question 13

what is hydrogen peroxide broken down into

Answer 13

• hydrogen peroxide -> water and oxygen
  (2H2O + O2)

Question 14

what causes oxygen gas to foam

Answer 14

liquid detergent

Question 15

where are enzymes written in a reaction

Answer 15

on top of arrow

Question 16

3 hazards of experimenting catalase enzyme reaction

Answer 16

-cutting food
- H2O2 is irritant to skin
- H2O2 gets in eyes

Question 17

3 control measures of experimenting catalase enzyme reaction

Answer 17

-cutting food downwards on a tile
-wash it off, avoid skin contact
-wear googles

Question 18

which side of the table and graph is the independent variable in

Answer 18

-left of table
-x- axis

Question 19

what is the optimum temperature in humans for most enzymes

Answer 19

37 C

Question 20

what is the optimum temperature in plants for most enzymes

Answer 20

-around 25C

Question 21

what can be said about the optimum temp/ pH level of each enzymes

Answer 21

-enzymes have different optimum temp./ pH levels

Question 22

define optimum temp

Answer 22

temp where enzyme activity is highest

Question 23

describe the relationship between rate of reaction and temp

Answer 23

-as temp increases until optimum temp, rate of reaction increases -after the optimum temp, the rate of reaction decreases

Question 24

explain why rate of reaction increases as temp increase until optimum temp

Answer 24

-more temp -more KE in substrate and enzyme -molecular motion of substrate and enzyme more -more successful collisions -more products are formed -increased rate of reaction

Question 25

when does an enzyme denature

Answer 25

temp past optimum temp

Question 26

explain why rate of reaction decreases as temp increase after optimum temp

Answer 26

-molecular motion of enzyme increases so much that it denatures permanently -bonds that stabilise enzyme's structure are changed -active site changes shape- no longer complementary to substrate -enzyme cannot function -less products -decrease rate of reaction

Question 26

is denaturing irreversible

Answer 26

yes

Question 27

define KE

Answer 27

-random movement energy by enzyme and substrate -heat increases this

Question 28

define successful collisions

Answer 28

-when enzyme and substrate bump into each other with sufficient energy for chemical reaction to take place

Question 29

define denatured

Answer 29

-when enzyme's active site changes shape permanently so that itis not complementary to substrate -caused by high temp and extreme pH

Question 30

3 hazards of experimenting catalase enzyme reaction in pH levels

Answer 30

-cutting hazard -corrosive/ caustic/ irritant substance -allergies

Question 31

what is pH a measure of

Answer 31

acidity

Question 31

3 control measures of experimenting catalase enzyme reaction in pH levels

Answer 31

-cut down onto a tile -wear googles, avoid skin contact -use tweezer to pick food up

Question 32

here is pH 2, pH7.5, pH9 found in the body

Answer 32

pH2- stomach pH7.5- mouth pH9- small intestine

Question 33

are enzymes living things

Answer 33

no, they are organic chemicals made by living things

Question 34

how many amino acids are enzymes made from

Answer 34

22 diff. natural occurring

Question 35

define anabolic enzymes

Answer 35

enzymes that join substrate to form product

Question 36

define catabolic enzymes

Answer 36

enzymes that break substrate to form product

Question 37

does the concentration of enzyme stay the same and why

Answer 37

yes because it is not used up

Question 38

note: when drawing line of best fit, make sure there is a peak btw 2 of the most active points