1. DNA, RNA and Protein Synthesis
Chapter 11

2. Phenomenon: DNA = instructions
A fullblood Belgian Blue bull showing the double muscling phenotype. (due to mutation in myostatin gene)
Genetically engineered fish (Changing their DNA makes them fluorescent)

3. DNA Structure DNA is a chain of Nucleotides 3 parts of a Nucleotide:
sugar (deoxyribose)
Phosphate
nitrogen base -
4 possible bases:
Adenine
Guanine
Thymine
Cytosine

4. Structure of DNA (continued)
The DOUBLE HELIX (looks like a twisted ladder)
Double Stranded–
2 sugar/ phosphate backbones
rungs = nitrogen base pairs
hydrogen bonds between complementary nitrogen bases
complementary= will bond together
A is complementary to T,
G is complementary to C
Base-pairing rules (see above)
The number and sequence of the nitrogen bases determines the CODE of the genes in the DNA!

5. Bonus: Easy Way to Remember base pairs
Apple – Tree
Car – Garage

6. Video
Personal DNA Testing!
Very Good! Show toward end of unit (discusses genome, mutations etc.)
S:\Biology\Protein Synthesis\Videos\Genetics
Bill Nye Greatest Genetic Discoveries. Can be started around here (about 1 hr.)

7. DNA making copies of itself is called DNA REPLICATION
Replication is SEMI-CONSERVATIVE.
Steps of DNA replication are controlled by enzymes.
Animation F:\Desktop\animations from bio powerpoints\Chapter 11 BDOL IC

8. DNA Replication Animations

9. Enzymes of Replication
3 of the main enzymes are:
Helicase: untwists and unzips the DNA
DNA polymerase: adds new nucleotides and connects them to build up a new strand (follows base-pairing rules!)
Ligase: Joins DNA fragments together

10. Think!
1. When in a cell’s life cycle will replication of DNA need to occur? Explain.
2. You began as a single cell and now you are made of trillions of cells. Explain why DNA replication was necessary for this process of growth to occur.

11. Background info for Protein Synthesis…
DNA is important because it is the instructions for how to make proteins!
But…
DNA can’t make proteins by itself!
RNA is needed!

12. RNA Structure of RNA nucleotide sugar= ribose phosphate
nitrogen base (instead of thymine, RNA has Uracil).
Uracil is complementary to Adenine (it replaces Thymine)
Single stranded

13. RNA Function of RNA accomplish protein synthesis
Why?--DNA is trapped in the nucleus but protein synthesis happens at ribosomes located in cytoplasm.

14. Three Types of RNA
Messenger RNA (mRNA) is used to take the message from DNA to the ribosome
Ribosomal RNA (rRNA) attaches to mRNA and helps assemble proteins
Transfer RNA (tRNA) transfers (brings) amino acids to mRNA so that they can be attached to make a protein

15. Compare and Contrast DNA and RNA in the following table
# strands
sugar
Nitrogen bases
function

16. Protein Synthesis 11.2 From DNA to PROTEIN
I. The Purpose of DNA: DNA is used to make RNA which is used to make proteins!!
DNA--> RNA--> Proteins
A. One DNA molecule has many GENES on it!
B. Gene—segment of DNA molecule that codes for a specific protein.

17. Protein Synthesis Step 1: Transcription
Transcription Animation C:\Documents and Settings\BBAUGHMAN\Desktop\bio powerpoints\Chapter 11 BDOL IC
II. TRANSCRIPTION
A. Transcription is the synthesis of mRNA using the code of a gene (DNA) as a template (pattern).

18. Single stranded mRNA leaves the nucleus and goes to the ribosome.
Transcription Steps:
the gene is located
RNA Polymerase unzips DNA and attaches RNA nucleotides following base pairing rules.
Single stranded mRNA leaves the nucleus and goes to the ribosome.
Animation

19. Protein Synthesis Step 2: Translation
Translation (Converting the “language” of mRNA to the language of proteins.)
Codon= triplet of nitrogen bases on mRNA
Each codon codes for one specific amino acid
Note: amino acids are the building blocks of proteins
This code is universal- it applies to all organisms!

22. Translation continued…
The order of codons determines the order of amino acids found in the protein.
mRNA is ‘read’ along its codons
this occurs at the ribosome
tRNA has anticodons that are complementary to specific codons
Each tRNA can only bind one amino acid
tRNA transfers or transports the amino acids to the ribosome where they are attached (in order) to make a polypeptide chain.
Translation Animation C:\Documents and Settings\BBAUGHMAN\Desktop\bio powerpoints\Chapter 11 BDOL IC
Analogy of Transcription through translation (RNAi explained)
RNAi on YouTube

23. Good Summary animation

24. MUTATIONS! Any CHANGE in the DNA sequence is a mutation!
Mutations are caused by mutagens!

25. Point mutation (substitution)—change in a single base pair of DNA
Types of mutations
Point mutation (substitution)—change in a single base pair of DNA
May change one amino acid in protein
Animation:

26. frameshift mutation—deletion or addition of a single base pair
frameshift mutation—deletion or addition of a single base pair.—Causes every codon after the mutation to be different!!

27. Chromosomal Mutations

28. Great Videos (also good intro to human genome project)
Mutation Video:
Very Good! Show toward end of unit (discusses genome, mutations etc.)