nucleic acids (DNA)

Question 1

DNA - function

Answer 1

• important information-carrying molecules
• holds genetic information

Question 2

RNA - fuc

Answer 2

• important information-carrying molecules
• transfers genetic information from DNA to the ribosomes

Question 3

ribosomes

Answer 3

they are formed from RNA and proteins

Question 4

structure of DNA

Answer 4

2 strands joined together in anti-parallel held together by hydrogen bonds between specific complementary base pairs (A-T, C-G), twisting into a double helix structure

Question 5

structure of RNA

Answer 5

single short RNA polynucleotide strand

Question 6

nucleotide - structure

Answer 6

1. a pentose sugar
2. a nitrogenous base
3. a phosphate group

Question 7

nucleotides (BLANK) make DNA or RNA which are nucleic acids (BLANK)

Answer 7

nucleotides (monomers) make DNA or RNA which are nucleic acids (polymers)

Question 8

how are DNA or RNA nucleotides joined together?

Answer 8

joined together by a condensation reaction forming a phosphodiester bond (sugar phosphate backbone)

Question 9

DNA nucleotides

Answer 9

1. deoxyribose
2. a phosphate group
3. one of the organic bases (adenine, cytosine, guanine, thymine)

Question 10

RNA nucleotides

Answer 10

1. ribose
2. a phosphate group
3. one of the organic bases (adenine, cytosine, guanine, uracil)

Question 11

double stranded - DNA structure

Answer 11

both strands can act as templates for semi-conservative replication

Question 12

weak hydrogen bonds between bases - DNA structure

Answer 12

can be unzipped for replication

Question 13

complementary base pairing - DNA structure

Answer 13

accurate replication

Question 14

many hydrogen bonds between bases - DNA structure

Answer 14

stable/ strong molecules

Question 15

double helix with sugar phosphate backbone - DNA structure

Answer 15

protect bases/ H bonds

Question 16

long molecule - DNA structure

Answer 16

stores lots of genetic information that codes for polypeptides

Question 17

double helix (coiled) - DNA structure

Answer 17

compact

Question 18

DNA replication

Answer 18

the semi-conservative replication of DNA ensures genetic continuity between generations of cells

Question 19

replication process

Answer 19

1. the DNA unwinds, then DNA helicase breaks the hydrogen bonds between the complementary base pairs
2. the double helix unwinds and separates the two strands of DNA
3. new DNA nucleotides bind to exposed bases on the DNA template strand
4. DNA polymerase catalyses the condensation reaction that joins adjacent nucleotides

Question 20

DNA helicase

Answer 20

• unwinds the DNA double helix
• ensuring the bases on both strands are exposed

Question 21

DNA polymerase

Answer 21

lining of nucleotides in the developing strands via condensation reactions forming the phosphodiester bonds

Question 22

semi-conservative DNA replication

Answer 22

DNA must be able to replicate exact copies of itself

Question 23

who suggested the idea of semi-conservative DNA replication?

Answer 23

Watson and Crick suggested the strands would separate and each produce a new helix

Question 24

who confirmed the idea of semi-conservative DNA replication?

Answer 24

confirmed by Meselson and Stahl, who grew E. coli bacteria with radioactive-labelled nitrogen