1. Section 4 Protein Synthesis
Chapter 10
Section 4 Protein Synthesis

2. What is the importance of synthesizing protein?
Our hair, skin, nails, muscle fibers, and enzymes are made of protein.
Proteins protect us from infections and allow our blood to carry oxygen.

3. Protein Synthesis
Forming proteins based on information in DNA and carried out by RNA
Proteins are made in the organelles called ribosome.

4. RNA is the second type of nucleic acid Differences between DNA and RNA
Double-stranded
Thymine nitrogen base, not uracil
Sugar; dexoyribose
Longer
Single-stranded
Uracil nitrogen base, not thymine
Sugar; ribose
Shorter
*3 types of RNA

5. Types of RNA: mRNA (Messenger RNA)
Transcribes instructions from DNA in the nucleus
tRNA
(transfer RNA)
Transfers amino acids to the ribosome to make a protein
rRNA
(ribosomal RNA)
Makes up the ribosomes

6. 1st step- Transcription This occurs in the nucleus
The process of making an mRNA strand using the DNA in the nucleus as a template

7. Steps of transcription:
RNA polymerase attaches to DNA causing the DNA strands to unwind and separate
RNA polymerase adds free nucleotide s to one side of the DNA molecule
If DNA reads…
GGCTATACGTAC
What would the mRNA read?
3) RNA polymerase reaches a termination signal to stop transcription and RNA and DNA are released from the polymerase

8. 2nd Step Translation This occurs in the ribosome.
Translation involves putting together amino acids according to the base sequence of mRNA transcribed from DNA

9. The Genetic Code
-the term for the rules that relate how a sequence of nitrogen bases in nucleotides corresponds to a particular amino acid,
Every 3 letters of mRNA is called a codon.

10. Each codon “codes” for a certain amino acid Ex. GGU CUA

11. tRNA
-has a 3-letter anti-codon on one end and is attached to an amino acid on the other
-brings the amino acid to the ribosome where it is attached to another amino acid by a peptide bond to form a polypeptide