More biological molecules: DNA and RNA

Question 1

What does DNA stand for

Answer 1

Deoxyribonucleic acid

Question 2

What does RNA stand for

Answer 2

Ribonucleic acid

Question 3

What are nucleic acids

AND

Name two main ones

Answer 3

*Polymers of nucleotides

*DNA and RNA

Question 4

State what monomer DNA and RNA derive from

Answer 4

Nucleotides

Question 5

Name the three components of nucleotides

Answer 5

• A pentose sugar
• A phosphate group
• A nitrogen-containing organic base

Question 6

State the function of DNA

Answer 6

• Stores genetic information containing all instructions needed to grow and develop

Question 7

State the function of RNA

Answer 7

• Transfers genetic information from the DNA to the ribosomes which reads RNA to make polypeptides through translation

Question 8

State what is formed when many nucleotide condense

Answer 8

Polynucleotides

Question 9

State what parts of the nucleotides join together via a condensation reaction

Answer 9

A phosphate group of one nucleotide and the sugar of another

Question 10

What bond forms when a condensation reaction occurs between two nucleotides

Answer 10

A phosphodiester bond

Question 11

Define the sugar-phosphate backbone

Answer 11

The chain of phosphates and sugars in a polynucleotide

Question 12

State how many carbons a pentose sugar have

Answer 12

Five

Question 13

Name the features making up DNA’s structure

Answer 13

• Double helix structure (two separate stands which wind around each other forming a spiral)
• Long and coiled up very tightly

Question 14

Describe the benefit of DNA being tightly coiled

Answer 14

It means it is compact making it optimal for storage as they can easily fit in the cell

Question 15

State the four possible bases for a DNA nucleotide

Answer 15

• Adenine (A)
• Thymine (T)
• Cytosine (C)
• Guanine (G)

Question 16

Define complementary base pairing

Answer 16

Two polynucleotide strands joining together by hydrogen bonds between another specific base

Question 17

Describe how two polynucleotide chains (forming a DNA molecule) is held together

Answer 17

They are held together by hydrogen bonds between specific complementary base pairs

Question 18

State what adenine (A) always pairs with

Answer 18

Thymine (T)

Question 19

State what guanine (G) always pairs with

Answer 19

Cytosine (C)

Question 20

State how many hydrogen bonds form between adenine (A) and thymine (T) during complementary base pairing

Answer 20

Two hydrogen bonds

Question 21

State how many hydrogen bonds form between guanine (G) and cytosine (C) during complementary base pairing

Answer 21

Three hydrogen bonds

Question 22

When polynucleotide strands join together through complementary bade pairing what directions do they run in

Answer 22

Opposite directions (antiparallel) to each other

Question 23

How many antiparallel strands twist to form a DNA double helix

Answer 23

Two

Question 24

What are the possible bases in RNA

Answer 24

• Adenine (A)
• Uracil (U) - Replaces thymine as a base
• Cytosine (C)
• Guanine (G)

Question 25

State what pentose sugar is found in DNA

Answer 25

Deoxyribose sugar

Question 26

State what pentose sugar is found in RNA

Answer 26

Ribose sugar

Question 27

Compare the shape of DNA to RNA

Answer 27

DNA is double stranded - twisted into a double helix and held together by hydrogen bonds
WHILST
RNA is single stranded

Question 28

Compare the size of DNA to RNA

Answer 28

DNA is long WHILST RNA is relatively short

Question 29

State why scientists doubted DNA could carry the genetic code

Answer 29

Because DNA had a relatively simple genetic code