Nucleic Acids and Protein Synthesis

Question 1

What is a nucleotide?

Answer 1

a nucleotide is the monomer that makes up nucleic acids, made of a pentose sugar, a phosphate group, and a nitrogen base

Question 2

What is the structure of the nucleotide ATP?

Answer 2

adenine + 3 phosphates

Question 3

What is the structure of an RNA nucleotide?

Answer 3

ribose sugar, phosphate, and adenine, guanine, cytosine, or uracil

Question 4

What is the structure of a DNA nucleotide?

Answer 4

deoxyribose sugar, phosphate, and adenine, guanine, cytosine, thymine

Question 5

What are the nitrogen bases?

Answer 5

adenine, guanine, cytosine, thymine, uracil

Question 6

What are purines?

Answer 6

adenine, guanine

Question 7

What are pyrimidines?

Answer 7

cytosine, thymine, uracil

Question 8

What is base pairing?

Answer 8

hydrogen bonding between nitrogen bases

Question 9

What is the structure of purines?

Answer 9

double ring structure

Question 10

What is the structure of pyrimidines?

Answer 10

single ring structure

Question 11

What is the type of replication by which DNA replicates?

Answer 11

semi-conservative replication

Question 12

What is the process of DNA replication?

Answer 12

double helix unwinds, hydrogen bonds between complementary bases break, free nucleotides attach to their complementary bases on the template strand, adjacent phosphodiester bonds are formed by DNA polymerase

Question 13

What is a gene?

Answer 13

code for a polypeptide made of nucleotides on part of dna

Question 14

What is a gene mutation?

Answer 14

a change in the base sequence of a DNA molecule, which replicates

Question 15

What is the nucleotide sequence that causes the different alleles of B globin causing sickle cell anaemia?

Answer 15

cat instead of ctt, coded by the Hbs allele of the gene, two copies of the Hbs allele result in sickle cell anaemia

Question 16

How are polypeptides made?

Answer 16

transcription and translation

Question 17

How do nucleotides join?

Answer 17

by forming phosphodiester bonds in condensation reactions

Question 18

What is the structure of a DNA molecule?

Answer 18

double helix, two polynucleotides joined by hydrogen bonding between complementary bases, 3’ and 5’ ends

Question 19

What are gene mutations caused by?

Answer 19

mutagenic agents such as chemicals and radiation

Question 20

What is transcription?

Answer 20

in transcription, mRNA is made in the nucleus
DNA uncoils, free nucleotides pair with the antisense strand, forming mRNA, which moves out of the nucleus through a nuclear pore

Question 21

What is translation?

Answer 21

in translation, mRNA attaches to a ribosome in the cytoplasm, tRNA, carrying an amino acid on one end, attaches its anticodon to the first codon on mRNA, another tRNA binds to the second codon, the amino acids join by peptidyl transferase and the tRNA leave, the process is repeated until a stop codon in reached.

Question 22

Why is base pairing important?

Answer 22

complementary base pairing allows exact replication of DNA, which allows semi-conservative replication and ensures genetic continuity

Question 23

How do nucleotides code for amino acid sequences?

Answer 23

each group of three nucleotides (a codon), codes for one amino acid, which decides the sequences of amino acids in a polypeptide