Transcript ProSyn

The Pathway to Protein
• RNA – single stranded
– Uracil instead of thymine
– Ribose instead of deoxyribose
– Shorter than DNA
– Folds to form some double-stranded regions
(A-U, C-G)
Types of RNA
• Messenger
RNA – carries
DNA’s
message
Ribosomal RNA – makes up
ribosomes
Transfer RNA
– transfers
amino acids to
a growing
protein
Transcription – in the nucleus
• Building mRNA
– Must have the same info as DNA
– Match the letters in the gene (A-U, C-G)
mRNA leaves the nucleus
Translation – in cytoplasm
• mRNA is
grabbed by a
ribosome
• Matching tRNA
docks
• Amino acids
bond
Genetic Code
• Each 3-nucleotide sequence in mRNA =
codon
– Codes for one particular amino acid (there are
20) or the STOP signal
• tRNA has anticodon (complementary to
codon)
– each tRNA holds one particular amino acid