AP Biology 2006-2007

Nucleic acids

AP Biology 2006-2007

Nucleic Acids

AP Biologyproteinsproteins

DNADNA

Nucleic Acids Function:

Stores all genetic material of an organism

In the form of genesProvides the blueprint for building

proteins DNA RNA proteins

transfers informationblueprint for new cellsblueprint for next generation

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AA

A

A

TC

G

CG

TG

C

T

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Nucleic Acids Examples:

RNA (ribonucleic acid) 3 forms serving different functions in building protiens:

mRNA – carries the blueprint to build proteins tRNA – carries amino acid to build proteins rRNA – assists the ribosome to build protein

DNA (deoxyribonucleic acid) Spiraled double helix Stores the organism’s entire genome (all genetic

information)

RNA

DNA

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Nucleotides Are the monomers of nucleic

acids Has 3 parts:

nitrogen base 5 (pentose) carbon sugar

Sugar in RNA is ribose Sugar in DNA is deoxyribose

phosphate (PO4) group

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Types of nucleotides 2 types of nucleotides

different nitrogen bases purines

double ring N base adenine (A) guanine (G)

pyrimidines single ring N base cytosine (C) thymine (T) uracil (U)

Purine = AGPure silver!

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Nucleic polymer Backbone

sugar to PO4 bond phosphodiester bond

new base added to sugar of previous base

polymer grows in one direction N bases hang off the

sugar-phosphate backbone

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Pairing of nucleotides Nucleotides bond between

DNA strands H bonds purine :: pyrimidine A :: T

2 H bonds G :: C

3 H bonds

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DNA molecule Double helix

H bonds between bases join the 2 strands A :: T C :: G

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double helix 1st proposed as structure of DNA in 1953 by James Watson & Francis Crick