2.3.1 - Nucleic Acids

Question 1

What are nucleic acids?

Answer 1

Polymers made of many nucleotide building blocks linked together by phosphodiester bonds

Nucleic acids include DNA and RNA

Question 2

What are the two forms of nucleic acid?

Answer 2

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA)

DNA is primarily located in the nucleus, while RNA is mainly in the cytoplasm

Question 3

What are the components of a nucleotide?

Answer 3

• A phosphate group
• A pentose sugar
• An organic base

The pentose sugar is deoxyribose in DNA and ribose in RNA

Question 4

What are the two groups of organic bases in nucleic acids?

Answer 4

• Purines
• Pyrimidines

Purines include adenine and guanine; pyrimidines include thymine, cytosine, and uracil

Question 5

What is the direction of reading a DNA sequence?

Answer 5

5′ to 3′ direction

This directionality is due to the structure of phosphodiester bonds

Question 6

What type of bond forms between nucleotides in nucleic acids?

Answer 6

Phosphodiester bonds

Formed by a condensation reaction between the –OH groups of nucleotides

Question 7

What is the structure of DNA?

Answer 7

A double helix made from two antiparallel nucleotide strands

The sides are sugar-phosphate backbones, and the rungs are base pairs

Question 8

What is complementary base pairing in DNA?

Answer 8

• Adenine pairs with thymine (two hydrogen bonds)
• Guanine pairs with cytosine (three hydrogen bonds)

This pairing is crucial for the stability of the DNA structure

Question 9

What is RNA?

Answer 9

A single polynucleotide made from nucleotides containing ribose sugar

RNA is shorter and usually single-stranded compared to DNA

Question 10

What are the types of RNA?

Answer 10

• mRNA (messenger RNA)
• tRNA (transfer RNA)
• rRNA (ribosomal RNA)

Each type has a specific role in protein synthesis

Question 11

What is the role of mRNA?

Answer 11

Transfers the code for proteins from DNA to ribosomes

It acts as a messenger for protein synthesis

Question 12

What is the function of tRNA?

Answer 12

Carries amino acids to the ribosome for protein assembly

tRNA has an anticodon and an amino acid attachment site

Question 13

What is the role of rRNA?

Answer 13

Forms part of the ribosome, aiding in bonding amino acids

rRNA is essential for the translation process

Question 14

What happens to mRNA after protein synthesis?

Answer 14

It is hydrolyzed by enzymes in the cytoplasm

This process ensures the regulation of protein synthesis

Question 15

What is the significance of DNA replication?

Answer 15

Ensures that genetic information is passed on accurately

This is vital for maintaining the integrity of genetic information across generations