3.1.5.1 STRUCTURE OF DNA AND RNA

Question 1

Structure vs function of DNA:

Answer 1

• Very stable- passes fro, generation to generation without changing
• two strands- hydrogen bonds allow the strands to be separated so code can be read and copied for DNA replication and protein synthesis
• large- carries a lot of information
• code protected (base pairs)

Question 2

How are DNA + RNA formed (steps):

Answer 2

• single nucleotide- mononucleotide, pentose sugar, nitrogenous base and a phosphate group joined together by a condensation reaction
• deoxyribose sugar and phosphate group of another is the site of how two nucleotides join together
• condensation reaction
• phosphodiester bond
• forms a dinucleotide
• eventually forms a polynucleotide (DNA/ RNA)

Question 3

What makes up DNA?

Answer 3

Phosphate group, deoxyribose sugar, nitrogenous base

Question 4

Differences between DNA and RNA:

Answer 4

• DNA has thymine, RNA has uracil
• DNA is double stranded, RNA is single stranded
• DNA has deoxyribose sugar, RNA has ribose sugar
• DNA is long, RNA is short

Question 5

COMPARE AND CONTRAST DNA VS CELLULOSE (5 MARKS):

Answer 5

• DNA has phosphodiester bonds, cellulose has glycosidic bonds
• both have hydrogen bonds joining strands together
• DNA’s monomers are DNA nucleotides, cellulose has beta- glucose
• Cellulose is found in plants, DNA is found in all eukaryotic cells
• cellulose is a carb, DNA is a polynucleotide
• both are polymers

Question 6

What does DNA hold?

Answer 6

Genetic information

Question 7

What does RNA transfer?

Answer 7

Genetic information from DNA to ribosomes

Question 8

What are ribosomes formed from?

Answer 8

RNA and proteins

Question 9

DNA and RNA are polymers of..

Answer 9

Nucleotides

Question 10

What is each nucleotide formed from?

Answer 10

Phosphate group, pentose sugar, nitrogenous base

Question 11

Components of a DNA nucleotide:

Answer 11

Phosphate group, deoxyribose sugar, adenine/cytosine/guanine/thymine

Question 12

Components of a RNA nucleotide:

Answer 12

Phosphate group, ribose sugar, adenine, cytosine, guanine, uracil

Question 13

What is formed from a condensation reaction?

Answer 13

A phosphodiester bond

Question 14

Structure of a DNA molecule:

Answer 14

• double helix
• two polynucleotide chains
• held together by hydrogen bonds
• between complementary base pairs

Question 15

Structure of an RNA molecule:

Answer 15

Relatively short polynucleotide chains