lecture 12 - protein synthesis

deoxyribonucleic acid

double stranded helix

made up of nucleotides

contains instruction to make proteins

genes

sections of DNA

each gene is a recipe for a protein

RNA

single stranded

made up of nucleotides

involved in protein synthesis

mRNA

carries code from DNA to ribosome

tRNA

tRNA - transfer amino acid to ribosome

rRNA

rRNA - component of the ribosome

proteins

made up of amino acids

function in the cell - enzymes, channels, antibodies, etc.

transcription

location:

enzyme:

process of making copy of gene in the DNA into molecule of RNA (mRNA)

inside nucleus

rRNA polymerase

DNA

RNA

TAC G

AUG C

mRNA processing

• starts as pre-mRNA

• add guanosine cap

• add poly a tail

• remove introns

ribosome

• made up of protein & rRNA

• small subunit binds to mRNA

• large subunit binds to tRNA

translation

• process of translating mRNA into protein

• outside nucleus (cytoplasm)

molecules involved in translation

• tRNA

• amino acids

• mRNA

• ribosomes

mRNA is read as triplets called

codons

mRNA

protein

AUG CCU AAG GGC UGA

Met Pro Lys Gly stop

tRNA - contains anti-codon complementary to

codons in mRNA

tRNA - anticodon determine

amino acids the tRNA will carry

codon

anticodon

AUG C

UAC G

ribosomes has three spaces

e - exit site for tRNA

p - peptide bond formation

a - amino acid brought in