Module 2: Topic 2:3: Nucleotides and Nucleic Acids.

Question 1

What elements do Nucleotides consist of?

Answer 1

Carbon

Hydrogen.

Oxygen.

Nitrogen.

Phosphorus.

Question 2

What are nucleotides made from?

Answer 2

It is made from a pentose sugar , a nitrogenous base and a phosphate group

Question 3

What are nucleotides monomers of?

Answer 3

They are monomers of RNA and DNA.

(DNA & RNA are both types of nucleic acids)

Question 4

What are RNA and DNA used for?

Answer 4

DNA is used to store genetic information - The instructions for an organism to grow and develop.

RNA is used to make proteins from the instructions in DNA.

(They are both found in living things.)

Question 5

What does RNA and DNA stand for?

Answer 5

DNA = Deoxyribonucleic acid.

RNA = Ribonucleic acid.

Question 6

What are the 4 Nitrogenous bases for DNA?

Answer 6

Adenine, Thymine, Guanine, Cytosine.

Question 7

What are the 4 Nitrogenous bases for RNA.

Answer 7

Adenine, Uracil, Guanine, Cytosine.

Question 7

What are the two types of Bases in RNA and DNA?

Answer 7

Purines and Pyrimidines.

Question 7

What is the difference between Purines and Pyrimidines?

Answer 7

Purines contain 2 Carbon to Nitrogen rings joined together.

Whereas Pyrimidines contain only 1 Carbon to Nitrogen rings.

Question 8

Which Nitrogenous bases belong to Purines?

Answer 8

Adenine and Guanine.

They form 3 hydrogen bonds with each other.

Question 8

Which Nitrogenous bases belong to pyrimidines?

Answer 8

Cytosine and Thymine.

They form 2 hydrogen bonds with each other.

Uracil (RNA only)

Question 9

Explain the Polynucleotide structure?

Answer 9

Nucleotides join together to form Polynucleotides.

The nucleotides join up between the Phosphate group of one nucleotide and the sugar of another nucleotide via a condensation reaction.

Question 10

What is a Phosphodiester bond?

Answer 10

It is a covalent bond that forms when Nucleotides join together to form polynucleotides.

Polynucleotides can be broken down into nucleotides again by breaking the Phosphodiester bonds using hydrolysis reactions.

Question 11

Explain the sugar- phosphate backbone.

Answer 11

The chains of sugars and phosphates is known as the sugar- phosphate backbone.

It consists of a phosphate group and two ester bonds.

Question 12

Describe the structure of DNA.

Answer 12

DNA is composed of 2 polynucleotide strands joined together to form a double helix shape.

The two strands are anti-parallel as they have the sequence running in opposite directions.

Question 13

What are the differences between RNA and DNA?

Answer 13

DNA is found in chromosomes in the nucleus whereas RNA is found in the cytoplasm.

DNA is an extremely long molecule whereas RNA is a relatively short molecule.

DNA has the pentose sugar called deoxyribose (one less oxygen atom) whereas RNA has the pentose sugar Ribose.

DNA has hydrogen bonds between the two complementary strands .

RNA contains Uracil instead of thymine.

Question 14

What are Phosphorylated nucleotides and give examples.

Answer 14

To phosphorylate a nucleotide, you add one or more phosphate groups to it.

ADP and ATP are examples of phosphorylated nucleotides.

Question 15

What are the structures for ADP and ATP?

Answer 15

ADP stands for adenosine diphosphate and it contains the base adenine, the sugar ribose and two phosphate groups.

The structure for ATP consists of ribose sugar and adenosine (base) attached to 3 phosphate groups.

Question 16

Explain how ATP is used in Respiration.

Answer 16

Plants and animal cells release energy from glucose- this is called respiration.

A cell cannot get its energy directly from glucose , so in respiration, the energy released from glucose is used