Chapter 6: nucleic acids and protein synthesis

Question 1

what are nucleotides made up of?

Answer 1

• nitrogen-containing base
• pentose sugar
• phosphate group

Question 2

name the two purine bases

Answer 2

adenine

guanine

Question 3

name the three pyrimidine bases

Answer 3

thymine
uracil
cytosin

Question 4

what three things make up the structure of a molecule of ATP?

Answer 4

adenine
ribose
three phosphate groups

Question 5

how are polynucleotides arranged?

Answer 5

-covalent bonds link the 5’-carbon and 3’-carbon of sugar molecules together

Question 6

how are the two polypeptide bonds held together?

Answer 6

with hydrogen bonds

Question 7

DNA has a … structure

Answer 7

double helix

Question 8

RNA has a … structure

Answer 8

single strand

Question 9

what is the name for the process in which a DNA molecule is copied?

Answer 9

semi-conservative replication

Question 10

during DNA replication, what activates the free nucleotides?

Answer 10

the two extra phosphate groups

Question 11

during DNA replication, how are the new nucleotides linked together?

Answer 11

using covalent bonds

Question 12

what is a gene?

Answer 12

a sequence of nucleotides that forms part of a DNA molecule

Question 13

what is a gene mutation?

Answer 13

a change in the sequence of nucleotides that may result in an altered polypeptide

Question 14

during transcription, what bonds the sugar phosphate groups together?

Answer 14

RNA polymerase

Question 15

what is the function of RNA polymerase during transcription?

Answer 15

it bonds together the sugar-phosphate groups of RNA nucleotides during transcription

Question 16

describe the structure of a tRNA molecule

Answer 16

one end has a site where an amino acid can bind to

the other end has 3 unpaired bases

Question 17

what is always the first codon that is translated?

Answer 17

AUG (complementary anticodon from the tRNA is therefore always UAC)

Question 18

what bond is formed between two amino acids?

Answer 18

a peptide bond

Question 19

which enzyme catalyses the formation of a peptide bond?

Answer 19

peptidl transferase

Question 20

name the three stop codons

Answer 20

UAA, UAC and UGA

Question 21

where does the mRNA bind to on the ribosome

Answer 21

the small subunit

Question 22

what is mRNA involved with?

Answer 22

translation