b1.2 what happens in a cell

Question 1

what is the body made up of ?

Answer 1

organs

Question 2

what are organs made up of ?

Answer 2

cells

Question 3

what does each cell contain ?

Answer 3

nucleus

Question 4

what does the nucleus contain ?

Answer 4

chromosomes

Question 5

what are chromosomes made up of ?

Answer 5

molecules called DNA

Question 6

what does DNA stand for ?

Answer 6

deoxyribonucleic acid

Question 7

what do the DNA molecules look like ?

Answer 7

twisted ladder consisting of two strands

Question 8

what is the spiral shapes called ?

Answer 8

double helix

Question 9

what are the four bases ?

Answer 9

adenine(A)
thymine(T)
cytosine(C)
guanine(G)

Question 10

what can A pair with ?

Answer 10

T

Question 11

what can T pair with ?

Answer 11

A

Question 12

what can C pair with ?

Answer 12

G

Question 13

what can G pair with ?

Answer 13

c

Question 14

what are the sides of the DNA molecules made up of ?

Answer 14

a phosphate-sugar backbone

Question 15

what is the centre of a DNA made up of ?

Answer 15

the 4 bases

Question 16

what is a gene ?

Answer 16

the length of DNA that gives the instructions for the making of a certain protein

Question 17

what is an enzyme?

Answer 17

a protein that acts as biological catalyst

Question 18

what is a catalyst?

Answer 18

substances that speed up a chemical reaction without being used up in the reaction

Question 19

what is an active site?

Answer 19

the part of the enzyme that the substrate fits into

Question 20

what is protein?

Answer 20

molecules made up of long chains of amino acids joined by peptide links

Question 21

what happens first to the substrate?

Answer 21

it binds to the active site on the enzyme

Question 22

what happens when the substrate binds to the active site on the enzyme?

Answer 22

an enzyme-substrate complex is formed

Question 23

what happens when an enzyme-substrate complex is formed?

Answer 23

a chemical reaction takes place which makes products

Question 24

what happens after a chemical reaction takes place?

Answer 24

the products are release from the active site

Question 25

can the enzymes be used again?

Answer 25

yes

Question 26

what are enzymes effected by?

Answer 26

temperature and PH

Question 27

what happens if the temperature in an enzyme becomes too high?

Answer 27

the active site starts to change shape

Question 28

EXAM QUESTION-
describe the shape of the graph( 3 marks)
IN BOOK YR9

Answer 28

-between 0-40 degrees an increase in temperature increases enzyme activity
-at 40 degrees optimum rate of activity increases
-after 40 degrees enzyme activity decreases

Question 29

EXAM QUESTION-
explain the shape of the graph(3 marks)
IN BOOK YR9

Answer 29

-more kinetic energy—> more enzyme substrate complexes formed—> faster rate of reaction

-as enzymes denature active site no longer fits substrate

Question 30

PAST EXAM QUESTION-
describe the shape of the graph(2 marks)
IN BOOK YR9

Answer 30

-at a Ph of 3 for pepsin the rate of activity increases
-after a PH of 8 for trypsin thee enzyme activity decreases

Question 31

PAST EXAM QUESTION-
explain the shape of the graph(3 marks)
IN BOOK YR9

Answer 31

• the shape of the graph for trypsin is like that after a PH of 8 because the substrate can no longer fits the active site
  -outside the optimum PH the enzyme denatures