Cellular Replication

Question 1

Describe the structure of DNA

Answer 1

• Base pairs
• Phosphate
• Deoxyribose
• Double stranded

Question 2

State the function of DNA

Answer 2

• Provides instructions needed for an organism to develop, survive and reproduce

Question 3

Describe the structure of RNA

Answer 3

-Bases
-Phosphate
-Ribose sugar
-Single stranded

Question 4

State the function of RNA

Answer 4

Protein synthesis

Question 5

State the three RNA types

Answer 5

Messenger RNA
Transfer RNA
Ribosomal RNA

Question 6

Why are DNA and RNA described as polymers?

Answer 6

They are made from repeating monomer units known as nucleotides to make polynucleotide chains.

Question 7

What are the 3 different units nucleotides are made from?

Answer 7

Phosphate group
Pentose sugar
Nitrogenous base

Question 8

What are the differences between RNA and DNA

Answer 8

RNA has the nucleobase uracil while DNA contains thymine

RNA contains ribose sugars whereas DNA contains deoxyribose

DNA is double stranded

Question 9

Which bond joins nucleotides in both DNA and RNA?

Answer 9

Phosphodiester bond

Question 10

What is meant by the primary structure?

Answer 10

The linear sequence of nucleotides

Question 11

What is meant by the secondary structure?

Answer 11

The base-pairing of complementary nucleotides gives the secondary structure of a nucleic acid - DNA forms a double helix

Question 12

How many hydrogen bonds between A and T?

Answer 12

2

Question 13

How many hydrogen bonds between G and C?

Answer 13

3

Question 14

What are chromosomes?

Answer 14

• Thread like structures located inside the nucleus of animals and plant cells.
• They are passed from parents to offspring

Question 15

How many chromosomes in the human body?

Answer 15

46 which are arranged into 23 pairs

Question 16

What are chromosomes made of?

Answer 16

A protein and a single molecule of DNA

Question 17

What does each section of a chromosome contain?

Answer 17

The code for the production of a particular protein called a gene.

Question 18

What is a gene?

Answer 18

A gene is the basic physical and functional unit of heredity
Genes act as instructions to make proteins.

Question 19

Describe the function of DNA Helicase.

Answer 19

They separate double stranded DNA into single strands allowing each strand to be copied
Requires energy ATP

Question 20

Describe the function of DNA polymerase

Answer 20

They add nucleotide triphosphate to a growing DNA strand in the 5’ to 3’ direction

Question 21

Describe the initiation stage of transcription.

Answer 21

1. Transcription start site
2. Promoter - directs RNA polymerase to the site
3. Transcription factors - promote RNA polymerase to start the process

Question 22

What stage comes after initiation in transcription?

Answer 22

Elongation

Question 23

Describe the termination stage of transcription.

Answer 23

Transcribing RNA polymerase releases the DNA template and the nascent RNA

Question 24

What are the major components of translation?

Answer 24

• Ribosomes
• tRNA molecules - amino acids
• mRNA molecules
• Peptidyl transferase - enzyme

Question 25

Describe the 3 sites on a ribosome.

Answer 25

1. A-site - accepts the incoming amino acid 2. P-site - peptide is made 3. E-site - holds the tRNA before it leaves the ribosome

Question 26

How many potentials codes are there for amino acids?

Answer 26

64

Question 27

How many amino acids are used for protein synthesis?

Answer 27

20

Question 28

Describe the structure of tRNA.

Answer 28

- Clover shaped -Anticodon -Amino acid attachment site

Question 29

Describe the termination stage of translation.

Answer 29

1. When a ribosome reaches a stop codon on mRNA, the A site of the ribosome accepts a protein called a release factor instead of tRNA 2. Release factor hydrolyses the bond between the tRNA in the P site and the last amino acid of the polypeptide chain. 3. The two ribosomal subunits and the other components of the assembly dissociate.