Nucleic Acids

Question 1

What is a nucleic acid?

Answer 1

Large molecules in the nucleus. 2 types, DNA(DeoxyRiboNucleicAcid, RNA(RiboNucleicAcid)

Question 2

What is a nucleotide made of?

Answer 2

-A pentose monosaccharide
-A phosphate group(acidic and negatively charged)
-A nitrogenous base

Question 3

What are pyrimidines?

Answer 3

-Thymine and cytosine.
-Smaller bases, SINGLE carbon ring structure

Question 4

What are Purines?

Answer 4

-Adenine and guanine.
-Larger bases, DOUBLE carbon ring structure

Question 5

What are the complimentary base pairings?

Answer 5

Adenine and Thymine, 2 hydrogen bonds
Cytosine and guanine, 3 hydrogen bonds

-This arrangement between a purine and pyrimidines results in a constant distance between the DNA backbones

(means there’s always equal amounts of A+T and C+G)

Question 6

How does genetic information leave the nucleus?

Answer 6

-DNA is too large to leave the nucleus. So a single gene is transferred into mRNA(polymer of nucleotide monomers)

Question 7

How is RNA different to DNA?

Answer 7

RNA pentose sugar=ribose
DNA pentose sugar=deoxyribose

Thymine base is replaced with Uracil, a pyrimidine that forms 2 hydrogen bonds with adenine.

Question 8

What do RNA molecules do?

Answer 8

Leave nucleus with single gene.

Central in protein synthesis, after their phosphodiester bonds are hydrolysed, releases RNA nucleotides to be reused.

Question 9

What are the 5 steps in the DNA extraction practical?

Answer 9

1.Grind sample with mortar and pestle, breaks down cell wall.

2.Mix sample with detergent, breaks down cell memb which releases cell contents into the solution

3.Add salt to break H+ bonds between water and DNA molecules

4.Add protease enzyme, breaks down histones

5.Add a layer of ice cold ethanol, collect the white DNA strands with a glass rod.