1. DNA to PROTEIN
2 step process of transcription and translation

2. Protein Synthesis: >Transcription & Translation
DNA contains all the information for your traits – in the form of genes
These genes are blueprints and need to remain safe – kept inside the nucleus
Copies can be made through – a messenger
Form proteins (polymers) from the building blocks – amino acids (monomers)

3. Genotype  Phenotype (genetic) (observable)
DNA mRNA tRNA PROTEIN
Transcription Translation

4. Transcription – making mRNA from DNA in the nucleus
mRNA – stands for messenger RNA
it is the copy of the DNA message for making a protein
Occurs in the nucleus only

5. Transcription Section 12-3 RNA polymerase DNA RNA
Adenine (DNA and RNA)
Cystosine (DNA and RNA)
Guanine(DNA and RNA)
Thymine (DNA only)
Uracil (RNA only)
RNA polymerase
DNA
RNA

6. Transcription (Steps)
DNA
RNA A U T C G
DNA “unzips” – helicases separate DNA molecule
Free-floating RNA w/in the nucleus attach to complementary DNA base pairs
Covalent bonds form b/w sugar-phosphate backbone
mRNA is released
DNA zips back up

7. mRNA Transcribes DNA message and carries it to ribosomes
RNA polymerase is the enzyme that matches up the base pairs
No T (thymine) so when it reads the nucleotide A on DNA it matches it with U (Uracil).
CLICK ON PICTURE FOR ANIMATION ON TRANSCRIPTION

8. Translation – using mRNA and tRNA to make proteins
Ribosomes are the site of protein synthesis
Click here to see mRNA and tRNA work together at that ribosome to build a protein
mRNA base
codon
tRNA base
anticodon A U C G

9. Codon = 3 mRNA nucleotides (bases) Anti-codon = 3 tRNA nucleotides (bases)

10. 3 bases code for 1 specific amino acid

12. Bring amino acids to ribosome
Concept Map
Section 12-3
RNA
can be
Messenger RNA
Ribosomal RNA
Transfer RNA
also called
which functions to
also called
which functions to
also called
which functions to
mRNA
Carry instructions
rRNA
Combine
with proteins
tRNA
Bring amino acids to ribosome
from to
to make up
DNA
Ribosome
Ribosomes

13. Review – by now you should know…
structure of DNA
How DNA replicates
Differences b/w DNA & RNA
Steps of Transcription & Translation
Parts of tRNA
3 types of RNA

15. Translation Section 12-3 mRNA Go to Section: Nucleus Messenger RNA
Messenger RNA is transcribed in the nucleus.
mRNA
Phenylalanine
Lysine
Methionine
tRNA
Ribosome
mRNA
Start codon
Go to Section:

17. Mutation – permanent change in DNA
Important:
source of new variation important for evolution.
Causes:
viruses, high temps, chemicals, radiation
Germ-cell Mutations
Somatic-cell
Mutations
Occurs in gametes
Occurs in body cells
Don’t affect organism, but affects offspring
Affects organism itself
Ex: skin cancer, leukemia

18. 2 categories of mutations
1) Gene mutations – may involve large segments of DNA or a single nucleotide
2) Chromosome mutations – either changes in the structure of a chromosome or loss or gain of an entire chromosome

19. Gene Mutations (large segments or a single nucleotide)
Point mutations: change in 1 nitrogen base
*Can do 1 of 3 things*
Change a.a. being coded for the protein
Change a.a. to a start and stop codon
Not change the a.a. or the protein at all
Example: sickle cell anemia

20. Gene Mutations (large segments or a single nucleotide)
Frameshift mutation: addition or deletion of a nitrogen base
Changes EVERY triplet & a.a. after the insertion or deletion of a nitrogen base
More severe since more a.a. are affected

23. Chromosomal Mutations
Section 12-4
Deletion
Insertion/
Duplication
Inversion
Translocation

24. Chromosome mutations – either changes in the structure of a chromosome or loss or gain of an entire chromosome
Inversion: chromosome segment breaks off and then reattaches in reverse orientation to the same chr
Translocation: chr segment breaks off and attaches to different chr
Causes sterility in plants

25. Chromosome mutations – either changes in the structure of a chromosome or loss or gain of an entire chromosome
Deletion: loss of a piece of chr due to chr breakage
Nondisjunction: a pair of homologous chr or single chr fails to separate during meiosis
2 kinds of gametes result
1) trisomy (extra chr…3 homologous chr’s )
Down Syndrome (trisomy 21)
2) monosomy (missing a chr…1 homologous chr instead of 2)
Ex: Turner’s Syndrome (X monosomy)

26. Nondisjunction-Chromosome mutation

27. Nondisjunction – Chr mutation