nucleic acids

Question 1

what is the monomer and polymer of a nucleic acid

Answer 1

monomer = nucleotide
polymer = polynucleotide (nucleic acid)

Question 2

what 3 components make a nucleotide ?

Answer 2

1) phosphate group
2) nitrogenous base
3) (DNA) deoxyribose sugar
(RNA) ribose sugar

Question 3

base pairs in DNA and RNA

Answer 3

DNA
Adenine-thymine
Cytosine-guanine

RNA
Adenine-uracil
Cytosine-guanine

Question 4

what happens when many nucleotides join together ?

Answer 4

through a condensation reaction a polynucleotide chain is formed
this forms a phosphodiester bond between phosphate group and 3rd carbon
covalent bond which males sugar phosphate back bone very strong

Question 5

must know

Answer 5

a nucleotide is a nitrogenous base

Question 6

a DNA molecule has a double helix structure

Answer 6

this is due to the 2 polynucleotide chains held together by many week hydrogen bonds between specific complimentary base pairings

Question 7

3 bases =

Answer 7

1 triplet

Question 8

DNA codes for ?

Answer 8

the primary structure of polypeptide chains or proteins

Question 9

DNA and RNA are important

Answer 9

information carrying molecules

Question 10

Structure of DNA

Answer 10

1- Sugar phosphate backbone which provides strength
2- larger molecules so can store lots of information
3- base sequence allows info to be stored
4- coiled so compact
5- double stranded so replication can happen semi-conservatively
6- complimentary base pair so accurate replication
7- weak hydrogen bonds for unzipping
8- many weak hydrogen bonds so stable molecule

Question 11

Compare and contrast DNA and RNA

Answer 11

DNA. - .RNA

Double stranded - single stranded
Deoxyribose - ribose
Thymine - Uracil
Has H bonds. - no H bonds

Question 12

Semi conservative replication

Answer 12

1- DNA helicase (enzyme) attached and moves along DNA molecule, unwinding the DNA and breaks H bonds between complimentary Bases

2- two strands separate

3- each strand acts as a template, free nucleotides join to exposed bases via base pair ruling

4- DNA polymerase joins adjacent nucleotides together developing new strand via condensation reaction forming a phosphodiester bond

5- semi-conservative REP ensures 1 new strand and 1 old strand and is identical to DNA

Question 13

Significance of Semi Conservative REP

Answer 13

• accurate replication occurs
• no mutations