3.1.5.1 nucleic acid structure

Question 1

what is the function of DNA?

Answer 1

the storage of genetic information.

Question 2

what is DNA a polymer of?

Answer 2

nucleotides

Question 3

how are nucleotides formed?

Answer 3

condensation reaction

Question 4

what is the structure of nucleotides?

Answer 4

• phosphate group.
• nitrogenous base.
• pentose deoxyribsose sugar.

Question 5

what are the nitrogenous bases of DNA?

Answer 5

• adenine.
• thymine.
• guanine.
• cytocine.

Question 6

what are the base pairing rules in DNA?

Answer 6

• adenine binds to thymine forming two hydrogen bonds.
• cytosine binds to guanine forming three hydrogen bonds.

Question 7

what is the structure of DNA?

Answer 7

• polymer of nucleotides.
• DNA sugar-phosphate backbone.
• antiparallel.
• held together by hydrogen bonds.
• phosphodiester bonds connect the nucleotides.

Question 8

what forms between nucleotides in DNA?

Answer 8

phopshodiester bonds, formed by condensation reactions.

Question 9

what is the function of the sugar-phosphate backbone?

Answer 9

• protects the sequence of bases, which contain genetic information.
• creates a stable molecule.
• makes sure code remains unchanged, so mutations are rare so we have consistent codes to produce fundamental proteins.

Question 10

what is the purpose and function of the strands being held together by hydrogen bonds?

Answer 10

• so they can easily separate for transcription and translation.

Question 11

what is the purpose and function of DNA being an extremely large molecule?

Answer 11

• so it can store large amounts of information.

Question 12

what is the function of the base pairs within the sugar-phosphate backbone?

Answer 12

• protects bases from reactive chemicals that might cause mutations.

Question 13

what’s the function of base pairing?

Answer 13

• allows DNA replication to produce two identical copies.

Question 14

what shape does DNA take?

Answer 14

DNA coils to form a double helix.

Question 15

what is the function of RNA?

Answer 15

the transfer of genetic information from DNA to ribosomes.

Question 16

what is RNA a polymer of?

Answer 16

RNA nucleotides are formed by condensation reactions, which forms phosphodiester bonds.

Question 17

what is the structure of RNA nucleotides?

Answer 17

• phosphate group.
• pentose ribose sugar.
• nitrogenous bases (adenine, URACIL, guanine and cytocine).

Question 18

what is the structure of RNA?

Answer 18

• single-stranded.
• relatively short in comparison to DNA.

Question 19

use of mRNA:

Answer 19

transfers genetic information from DNA to ribosomes.

Question 20

use of tRNA:

Answer 20

transfers specific amino acids to ribosome to form a polypeptide: anticodon pairs with a complementary codon on the mRNA.

Question 21

what are ribosomes formed from?

Answer 21

rRNA and proteins.

Question 22

what’s the structure of tRNA?

Answer 22

• clover leaf shape.
• hydrogen bonding in structure.
• single anticodon.

Question 23

what’s the structure of mRNA?

Answer 23

• linear.
• no hydrogen bonding.
• mainly anticodons.

Question 24

what is the structure of a chromosome in a eukaryotic cell?

Answer 24

• linear.
• DNA is associated with histone protein.
• more than one per cell.

Question 25

what is the structure of a chromosome in a prokaryotic cell?

Answer 25

• circular.
• not associated with histone proteins.
• only one per cell.