DNA

Question 1

What is the full name of DNA? How does the sugar differ?

Answer 1

deoxyribonucleic acid

the sugar is deoxyribose - a sugar with one fewer oxygen atoms than ribose

Question 2

What are the different bases that DNA nucleotides contain? What are the two groups of bases?

Answer 2

pyrimidines:
thymine (T)
cytosine (C)

purines:
adenine (A)
guanine (G)

Question 3

How do the different groups of bases differ?

Answer 3

pyrimidines are smaller bases and contain a single carbon ring structure

purines contain a double carbon ring structure

Question 4

What does it mean that DNA has a double helix structure?

Answer 4

DNA is made up of two strands of polynucleotides coiled into a helix, known as the DNA double helix

Question 5

How is the double helix held together?

Answer 5

held together by hydrogen bonds between the bases, much like the rungs of a ladder.

Question 6

What does it mean that the strands run antiparallel?

Answer 6

each strand has a phosphate group (5’ ) at one end and a hydroxyl group (3’) at the other end

the two parallel strands are arranged so that they run in opposite direction

they are said to be antiparallel

Question 7

What does the term complementary base pairing mean?

Answer 7

A and T are always able to form h bonds are join to eachother

C and G form three h bonds and so also only bind to eachother

primidine always binds to a larger purine base

Question 8

Why is it important for primidine to only bind to purine?

Answer 8

this arrangements maintains a constant distance between the DNA ‘backbones’, resulting in parallel polynucleotide chain

Question 9

What determines the genetic infomation of an organism and forms the code?

Answer 9

the sequence of bases

Question 10

Which are the pyrimidines and which are the purines?

Answer 10

pyrimidines are T and C

purines are A and G