polynucleotides

Question 1

what do nucleotides join together to form

Answer 1

polynucleotides

Question 2

where does the bond occur between two nucleotides

Answer 2

the phosphate group of one nucleotide and the sugar of the next nucleotide

Question 3

what is the name of the bond formed between two nucleotides

Answer 3

phosphodiester bond

Question 4

what is the chain of sugars and phosphates known as

Answer 4

sugar-phosphate backbone

Question 5

what reaction forms polynucleotides

Answer 5

condensation

Question 6

what reaction breaks polynucleotides

Answer 6

hydrolysis

Question 7

how are the two polynucleotide strands in DNA joined together

Answer 7

hydrogen bonding between bases

Question 8

what is complementary base pairing

Answer 8

each base can only join with one particular base

Question 9

what does adenine always pair with

Answer 9

thymine (DNA)
uracil (RNA)

Question 10

what does cytosine always pair with

Answer 10

guanine

Question 11

how many hydrogen bonds form between A and T

Answer 11

two

Question 12

how many hydrogen bonds form between C and G

Answer 12

three

Question 13

how does the double helix get its shape

Answer 13

two antiparallel polynucleotide strands twist together

Question 14

what reaction purifies DNA

Answer 14

precipitation

Question 15

what is the first stage in purifying DNA

Answer 15

break up the cells in your sample using a blender

Question 16

what solution do you add to the broken cells

Answer 16

detergent, salt and distilled water

Question 17

what is the purpose of adding detergent to the broken cells

Answer 17

breaks down the cell membrane

Question 18

what is the purpose of adding salt to the broken cells

Answer 18

binds to DNA causing it to clump together

Question 19

where should this solution be stored

Answer 19

in a water bath at roughly 60*

Question 20

why does the solution need to be in a hot water bath

Answer 20

prevent enzymes from working correctly and breaking down the DNA

Question 21

what must you do after leaving the solution in a hot water bath

Answer 21

place in an ice water bath to cool the mixture down

Question 22

after the mixture is cool, what must happen

Answer 22

filter and transfer to a clean boiling tube

Question 23

what enzyme needs to be added to the mixture

Answer 23

protease enzyme
RNase enzyme

Question 24

what is the purpose of the protease enzyme

Answer 24

break down proteins in the mixture such as proteins bound to DNA and RNA

Question 25

after adding the enzymes, what has to be added to the mixture

Answer 25

ethanol

Question 26

what does ethanol do to the mixture

Answer 26

forms a layer ontop of the mixture

Question 27

what is the final step in purifying DNA

Answer 27

leave it for a few minutes after adding ethanol and a white precipitate will appear

Question 28

what is the role of DNA helicase in DNA replication

Answer 28

breaks the hydrogen bonds between the base pairs on the polynucleotide strands

Question 29

what happens after DNA helicase breaks the hydrogen bonds

Answer 29

helix unzips to form two single strands

Question 30

what does each original strand of DNA act as

Answer 30

a template for the new strand

Question 31

what happens to the free floating nucleotides

Answer 31

join to the exposed bases on the original DNA strand by complementary base pairing

Question 32

what enzyme joins the nucleotides of the new strand

Answer 32

DNA polymerase via hydrogen bonds

Question 33

what forms after DNA polymerase joins the nucleotides

Answer 33

the sugar-phosphate backbone

Question 34

why is DNA replication called semi conservative replication

Answer 34

each new DNA molecule contains one strand from the original DNA and one new strand

Question 35

why does DNA replication have to be accurate

Answer 35

ensures genetic information is conserved