1. How do you do the voodoo that you do so well!
Replication and RNA
How do you do the voodoo that you do so well!

2. DNA structure

5. Replication - DNA is copied
1st step - two chains separate at replication fork
2nd step - helicase enzymes break hydrogen bonds between base pairs
3rd step - DNA polymerase binds new nucleotides to existing chains
-G-C-
-A-T-
-C-G-
-T-A- -G -A -C -T
-C-
-T-
-G-
-A-
-G-
-A-
-C-
-T- C- T- G- A-

6. Nucleic Acids! There are two major kinds of nucleic acids
DNA stores all the biological information to produce the organism
RNA is able to read the message in DNA and use it to construct proteins

7. RNA - ribonucleic acid
RNA (Ribonucleic Acid) - final product of RNA is
protein

8. Differences between DNA & RNA
1. Double helix
2. Thymine
3. One Kind
4. Deoxyribose
RNA
1. Single Stranded
2. Uracil (U)
3. Three Kinds
4. Ribose

9. Transcription - making RNA from DNA
RNA Transcription - DNA provides code to make mRNA
-A-
-T-
-G-
-C- U- A- C- G-

10. How Proteins Are Made
GENE EXPRESSION
Using DNA information to make proteins

11. 2 Stages of Gene Expression
1. Transcription
a RNA copy is made from a DNA pattern
this copy is called mRNA (messenger RNA) because it carries the DNA’s message to the ribosome!!!!!!
Codons are groups of 3 bases in mRNA that translate into amino acids.

13. 2 Stages of gene expression cont’d.
2. Translation
3 different kinds of RNA work together to assemble amino acids into a protein chain.

15. The steps of protein synthesis
mRNA (messenger) leaves the nucleus and enters the cytoplasm.
2. tRNA (transfer) picks up amino acids in the cytoplasm and brings them to the ribosome.
3. rRNA (ribosomal) reads mRNA and starts making a protein.

16. PROTEIN SYNTHESIS CONT’D
4. tRNA anticodons match up with the mRNA codons.
U A C codon (mRNA)
A U G anticodon (tRNA)
5. Amino acids detach from the tRNA and attach to a growing protein chain. tRNA picks up another amino acid and begins again.

19. MUTATIONS Mistakes in the DNA code
May be helpful, harmful, or no effect
helpful mutations can sometimes be passed to offspring
caused by breaks in x-somes or parts of x-somes switching places (crossing over)
also caused by mutagens (chemicals, drugs, x-rays, smoke, pollution, viruses)

20. Types of Mutations
1. Germ Cell Mutations - mutations in sex cells; transmitted to offspring; may not be expressed for several generations. May be harmless or lethal
2. Somatic Mutations - mutations in body cells; not passed to offspring; passed to other body cells or affect cell reproduction
ex. cancer

21. Types of Mutations (con’t.)
3. Lethal mutations – cause death, often before birth

22. Chromosome Mutations
Changes in the structure of a chromosome or loss of an entire chromosome.
A. Deletions - chromosome segments break off and are lost.
B. Inversions - chromosome segments break off and turn around - usually not harmful

23. C. Addition or Substitution – a base pair is added or removed from a sequence
D. Translocations - chromosome segments break off and reattach to totally different chromosome - causes abnormalities in humans