DNA

Nucleic Acids-DNA and RNA

DNA-Deoxyribonucleic Acid 

RNA-Ribonucleic Acid

The structure of a nucleotide: What DNA/RNA are composed up of-

*A phosphate group

*A pentose sugar (5 carbon atoms)

*A nitrogen-containing organic base 

DNA:

Phosphate group-Pentose sugar-5 carbon atoms-Organic bases include: A,T,C,G

RNA:

Phosphate group-Pentose sugar-5 carbon atoms-Organic bases include:A,U,C,G

Thymine is replaced by Uracil

A,T always pair (or in RNA A,U)

C,G always pair exact identical copies of one another

DNA-Structure and function summarised:

Sugar-phosphate backbone-Makes molecule more stable

DNA coils into double helix-More compact,therefore lots of info can be stored in small space

Sequence of bases-Allows it to carry coded info for making proteins for living organisms

Very long-To store lots of information

Complementary base pairing-Allows molecule to replicate itself accurately

Double helix-Makes DNA stable,as base pairs on inside,therefore less likely to get damaged

Bases held together by 'weak' hydrogen bonds-Allows molecule to 'unzip' (separate) easily during semi-conservative replication

2 DNA strands form a twisted 'ladder' called a 'double helix'

RNA usually stays single stranded,but DNA and RNA can form a 'hybrid' (something made by combining 2 different elements)

Example question:

If you have 23% adenine,how much G,C,T woul you have in your DNA?
A=23%

T must also =23%

23+23=46

100-46=54%

54 divide by 2…