Nucleic acids and DNA replication

Question 1

DNA makes RNA, RNA makes protein

Answer 1

Central Dogma

Question 2

What are the components of a nucleotide?

Answer 2

Phosphate group
pentose sugar
N base (A-T/U, C-G)

Question 3

How do nucleotides differ between DNA and RNA?

Answer 3

DNA is Double Stranded; RNA is single stranded

Pentose: DNA has H on 2’-C=deoxyribose; RNA has OH group on 2’ carbon = ribose (less stable than DNA)

N base: DNA uses A-T, C-G; RNA uses A-U, C-G

Question 4

How are nucleotides connected to form DNA?

Answer 4

Phosphodiester bonds create backbone of nucleic acid by joining 3’ end of one nucleotide to the 5’ end of the next nucleotide
Double stranded/antparellel with H bonded base pairs.

Question 5

How are nucleotides connected to form RNA?

Answer 5

Phosphodiester bonds in in (sugar) backbone

-OH group (2’-C) interferes with double strand, hence why RNA is single stranded.

Question 6

When is DNA replication used?

Answer 6

cell division

Question 7

What is the process of DNA replication?

Answer 7

-Helicase unwinds DNA (breaks H bonds between pairs)
-DNA polymerase reads (3’ - 5’) and matches template strand (5’ - 3’)
-creates two identical DNA double helices: (semiconservative) one original strand, one daughter strand

Question 8

What is the difference between leading and lagging strands?

Answer 8

leading strand is continuous

lagging strand is made in pieces, Okazaki fragments and must be ligated (DNA ligase)