Download - mRNA to Protein
mRNA to ProteinThanks to Ms. Dozier and Ms. Kimball for many of these
slides!
3 Types of RNA•mRNA (messenger):
Brings info from DNA in
nucleus to ribosome in
cytoplasm
•tRNA (transfer):
associates three RNA
bases (codon) with
amino acid
•rRNA (ribosomal): part
of ribosomal machinery
Protein
•A protein is a polymer
•Monomers are called Amino Acids (AAs)
•AAs are held together by peptide bonds, so a protein is also called a polypeptide
•20 types of AAs
•Protein function is determined by the order and number of AAs
Amino
Acids•Each amino acid
has same
backbone
•Different “R”
groups
Protein Structure
•After the AAs are
strung together they
are folded into a 3-D
shape
•Must be folded to do
a job
•Unfolded proteins
called “denatured”
Protein Function
•Used for:
ocellular structure
omovement
odefense
otransport
ocommunication
•Enzymes are proteins that speed up chemical
reactions
How are proteins made?
•Now that we know a little more about
proteins and why they’re important, let’s
continue looking at how they are made!
•We’ve looked at the first part of protein
synthesis. What was it called?
2 Parts of Protein
Synthesis
1.Transcription
2.Translation
Translation (Part 2 of Protein Synthesis)•mRNA travels from nucleus to
cytoplasm and attaches to ribosome
•Ribosome "decodes" mRNA sequence
•Each 3 nucleotide mRNA section is a codon that codes for an amino acid (AA)
•Transfer RNAs (tRNAs) then transport the amino acids to polypeptide chain (each tRNA anticodon corresponds to an mRNA codon)
Codons•Series of 3 nucleotides
which codes for a specific amino acid.
•64 codons code for 20 amino acids.
o1 codon can code for ONE amino acid ONLY
oBut…
oSeveral codons can code for the same amino acid
Codons
•One start codon- AUG
oAlso codes for
Methionine (Met)
•3 stop codons
oUAA, UAG, UGA
Practice
•Use your Codon
Table and list the
amino acids in your
notes that each
codon codes for.
Amino Acid:
m
Protein Synthesis
•Translate this DNA sequence to mRNA,
tRNA, and then AAs in your notes:
•: TAC TGC ATA CTG GGC ATC
•: AUG ACG UAU GAC CCG UAG
•: UAC UGC AUA CUG GGC AUC
•:start Thr Tyr Asp Pro Stop
DNA
mRNA
AAs
tRNA
Use mRNA codon