1. Bell work – 3 minutes Pick a science word and write the definition.
Chapter 8

2. PROTEIN SYNTHESIS p. 12 & 13 RS

3. I can describe how a protein is synthesized.
Learning target
I can describe how a protein is synthesized.
Today I am…
Actively engaged in lecture of protein synthesis.
So that I’ll be able to…
understand how important protein synthesis is to life.
I’ll know I’ve got it when…
Complete all notes and homework.

4. DNA DNA contains genes, sequences of nucleotide bases
These Genes code for polypeptides (proteins)
Proteins are used to build cells and do much of the work inside cells

5. Genes & Proteins
Proteins are made of amino acids linked together by peptide bonds
20 different amino acids exist

6. Amino Acid Structure

7. Polypeptides
Amino acid chains are called polypeptides

8. DNA Begins the Process DNA is found inside the nucleus
Proteins, however, are made in the cytoplasm of cells by organelles called ribosomes
Ribosomes may be free in the cytosol or attached to the surface of rough ER

9. Starting with DNA DNA ‘s code must be copied and taken to the cytosol
In the cytoplasm, this code must be read so amino acids can be assembled to make polypeptides (proteins)
This process is called PROTEIN SYNTHESIS

10. RNA is the BLUEPRINT of the Master Plan
Roles of RNA and DNA
DNA is the MASTER PLAN
RNA is the BLUEPRINT of the Master Plan

11. RNA Differs from DNA RNA contains the base uracil (U)
RNA has a sugar ribose
DNA has a sugar deoxyribose
RNA contains the base uracil (U)
DNA has thymine (T)
RNA molecule is single-stranded
DNA is double-stranded

12. Structure of RNA
Like DNA, RNA is a polymer of nucleotides. In an RNA nucleotide, the sugar ribose is attached to a phosphate molecule and to a base, either G, U, A, or C. Notice that in RNA, the base uracil replaces thymine as one of the pyrimidine bases. RNA is single-stranded, whereas DNA is double-stranded.

13. Three Types of RNA .
Messenger RNA (mRNA) copies DNA’s code & carries the genetic information to the ribosomes
Ribosomal RNA (rRNA), along with protein, makes up the ribosomes
Transfer RNA (tRNA) transfers amino acids to the ribosomes where proteins are synthesized

14. Messenger RNA Long Straight chain of Nucleotides Made in the Nucleus
Copies DNA & leaves through nuclear pores
Contains the Nitrogen Bases A, G, C, U ( no T )

15. Messenger RNA (mRNA) Carries the information for a specific protein
Made up of 500 to 1000 nucleotides long
Sequence of 3 bases called codon
AUG – methionine or start codon
UAA, UAG, or UGA – stop codons

16. Ribosomal RNA (rRNA)
rRNA is a single strand 100 to 3000 nucleotides long
Globular in shape
Made inside the nucleus of a cell
Associates with proteins to form ribosomes
Site of protein Synthesis

17. The Genetic Code A codon designates an amino acid
An amino acid may have more than one codon
There are 20 amino acids, but 64 possible codons
Some codons tell the ribosome to stop translating

18. The Genetic Code
Use the code by reading from the center to the outside
Example: AUG codes for Methionine

19. Remember the Complementary Bases
On DNA:
A-T
C-G
On RNA:
A-U

20. Transfer RNA (tRNA) Clover-leaf shape
Single stranded molecule with attachment site at one end for an amino acid
Opposite end has three nucleotide bases called the anticodon

21. Transfer RNA
amino acid
attachment site U A C
anticodon

22. Codons and Anticodons
The 3 bases of an anticodon are complementary to the 3 bases of a codon
Example: Codon ACU
Anticodon UGA
UGA
ACU

23. Protein Synthesis Video
We will watch this in class!
Worksheet will be taped on p. 13 LS

24. 3 types of RNA p. 12 LS
Draw a picture to help you remember what the job of each RNA does during protein synthesis.
Next to the picture write which RNA is represented.