Nucleic acids and proteins

biomolecule

large molecule found in living cells e.g proteins, nucleic acids

condensation

process where monomers are linked together through the removal of a small molecule (often water)

condensation polymerisation

reaction where many many monomers are linked to form a polymer chain

monomer

subunit of a large molecule e.g amino acids, nucleotides

polymer

large molecule made up of many monomers e.g DNA, RNA, polypeptides

Nucleic acids

large linear polymers made of monomers called nucleotides, able to store and transport genetic information, e.g DNA, RNA

nucleotide structure

3 main units: pentose (5 carbon) sugar, negatively charged phosphate group, nitrogenous base

sugar molecule structure

sugar molecules in DNA contain one less oxygen than RNA

carbon labelling

carbons in sugar a labelled from 1’ (1 prime) to 5’. Phosphate is joined to 5’ sugar, nitrogenous base is joined to 1’ sugar, hydroxyl group joined to the 3’ sugar.

double helix structure

two seperate DNA polymers (nucleotide strands) joined by hydrogen bonds to form double helix structure

DNA structure

Nucleotides joined by condensation polymerisation, sugar and phosphate groups form sides of ladder

phosphodiester bonds

bonds between nucleotides, condensation reaction produces pyrophosphate (two phosphate groups bound together) instead of a water molecule

Nitrogenous bases

adenine, thymine, cytosine, guanine, make up rungs of ladder, held together by hydrogen bonds

Pyrimidines

cytosine, uracil and thymine. chemical structure has one ring.

Purines

adenine, guanine. chemical structure has two rings.

complementary base pairing

Adenine-thymine, cytosine-guanine. Purines bind with pyrimadines.

hydrogen bonds

adenine and thymine=double hydrogen bonds, cytosine and guanine=triple hydrogen bonds. Bond between cytosine and guanine is stronger than adenine and thymine.

base pair rule

two factors: number of hydrogen bond attraction points, length of base (pyrimidine binds to purine)

sugar phosphate backbone

has 3’ end and 5’ end, nucleotides added to 3’ end, in 5’ to 3’ direction.

antiparallel

sugar phosphate backbones of each strand run parallel in opposite directions

DNA sequence

represents segment of DNA, written using letters of nitrogenous bases. only template strand written