1. Protein synthesis: TRANSCRIPTION & TRANSLATION

2. PROTEIN SYNTHESIS:
DNA -> DNA
DNA -> RNA
RNA -> Protein

3. Types of RNA Transfer RNA (tRNA) Ribosomal RNA (rRNA)
picks up amino acid in cytoplasm and carries them to the ribosome
tRNA has ANTI-CODONS
Ribosomal RNA (rRNA)
- found in ribosome
- associates with proteins to form ribosomes in the cytoplasm
Messenger RNA (mRNA)
carries nucleotide sequence from nucleus to ribosome
mRNA has CODONS

4. T-RNA AND M-RNA
CODONS (in mRNA) and ANTI-CODONS (in tRNA) work together to make protein during TRANSLATION
Remember: proteins are also called polypeptides!
tRNA

5. TRANSCRIPTION: DNA produces RNA Genetic code is transferred to mRNA
Occurs in the nucleus
Genetic code is transferred to mRNA

6. A segment of DNA separates: one segment serves as a pattern for RNA
RNA Polymerase adds nucleotides to the template DNA strand.
(Remember: no “T” in RNA, only “U”, A-U, G-C)

7. A genetic code for a protein in DNA is copied into the mRNA
A genetic code is made of “CODONs” in mRNA
Each codon is made of 3 nitrogen bases
Each codon codes for an AMINO ACID

8. TRANSLATION:
PROTEIN SYNTHESIS!
Occurs in ribosomes in cytoplasm or RER

9. 1. The mRNA leaves the nucleus and enters the cytoplasm
Steps of Translation:
1. The mRNA leaves the nucleus and enters the cytoplasm
2. Ribosomes attach to the mRNA
3. tRNA picks up free amino acids in the cell and carries them to the ribosome
4. The anti-codon in tRNA matches the codon in mRNA and start adding amino acids to a growing protein
The bonds between
amino acids are
peptide bonds!!
Translation animation

10. TRANSLATION OF GENETIC CODE IN
MESSENGER RNA INTO
PROTEINS
INSTRUCTIONAL VIDEO

11. DNA sequence: AAT CGC ATC mRNA sequence: UUA GCG UAG CODONS:
YOU CAN FIND THE AMINO ACID SEQUENCE OF A PROTEIN USING THE CODONS IN M-RNA AND A CODON TABLE!
Example:
DNA sequence: AAT CGC ATC
mRNA sequence: UUA GCG UAG
CODONS:
UUA = Leucine amino acid
GCG= Alanine
UAG = Stop amino acid
AMINO ACID/PROTEIN SEQUENCE:
LEU- ALA – STOP
**THERE ARE ONLY 20 AMINO ACIDS, BUT MILLION
S OF PROTEINS: IT’S THE COMBINATION OF
THOSE AMINO ACIDS THAT WILL GENERATE
MILLIONS OF PROTEINS!**

12. CODON WHEEL