1. Warm Up 11/28/16
Explain the process of transcription and translation. Be sure to include base pairing rules when going from DNA to RNA and RNA to RNA.

2. What do all three of following pictures have in common?

4. Let’s discuss DNA like a sentence…
The fat cat ate the wee rat.
If this sentence represents a strand of DNA, what does each word represent?
codon
What does each letter represent?
A nitrogen base

5. Mutations
When you hear about mutations, you may think about some teenage mutant ninja turtles or growing an extra arm, but the word mutate just means to change.
Where do these mutations occur?

6. NUCLEOTIDE
CANNOT
CAN

7. Let’s look at what happens when we change the sentence/DNA.

8. Insertion (Point Mutation)
The fat cat ate the wee rat.
The fab tca tat eth ewe era t.
What changed?
Description: Is a mutation in which an extra base pairs are inserted into a new place in the DNA strand.
How would this type of change affect the protein?
Significance: As a result, the protein may not function properly, and the impact may lead to a genetic disorder.
ADDED
What changed: There was a “b” inserted between the “at” of “fat”.
How would this type of change affect the protein: Again, it changes everything else remaining, so it will likely make the protein shorter or ineffective.

9. Substitution (Point Mutation)
The fat cat ate the wee rat.
The fat cat ate the wet rat.
What changed?
Letter “e” changed to “t”
What does this represent?
Description: Substitution – is a mutation that exchanges one base for another.
How would this type of change affect the protein?
Significance: It MAY change the function of the protein, but not always. This impact is minimal.
SWITCHED WITH
ANOTHER
What changed: The letter “e” changed to “t”.
What does this represent: It represents a substitution of a single nucleotide in a codon.
How would this type of change affect the protein: It may change one amino acid in the protein, or it may not change anything; depending upon the specific nucleotide change. For example, if AAA becomes AAG, they both still code for the same amino acid (phenylalanine).

10. Deletion (Point Mutation)
The fat cat ate the wee rat.
The fat cat att hew eer at.
What changed?
Some of the letter were deleted.
What does this represent?
Description: a portion of the DNA code is deleted (causing all the remaining codons to move over)
How would this type of change affect the protein?
Significance: Deletions of larger portions of a chromosome often lead to genetic disorders (muscular dystrophy)
DELETED
What changed: The “e” in “ate” was deleted. This caused all the letters to shift and changed all of the remaining codons.
This represents a deletion of a nucleotide that causes a change in all the remaining triplets/codons.
How would this type of change affect the protein: Because all of the remaining codons are changed, it may shorten the protein or make it ineffective.

11. Effects of Mutations NO
DIFFERENT
STOP
CODON
DIFFERENT

12. Warm up 11/29
Complete your DNA Mutations Practice Sheet from yesterday. To finish, you must begin AS SOON AS you enter the room.
I will be collecting these for a grade!!!

13. You determine the TYPE of Mutation (insertion, deletion, or substitution) and the EFFECT of this mutation ( silent, missense, nonsense, frameshift)
Original:
DNA: GTA AAC ATA GGA CTT CTT
mRNA: CAU UUG UAU CCU GAA GAA
Amino acid: his leu tyr pro glu glu
Mutated:
DNA: GTA AAC ATA GGA CAT CTT
mRNA: CAU UUG UAU CCU GUA GAA
Amino acid: his leu tyr pro val glu

14. You determine the TYPE of Mutation (insertion, deletion, or substitution) and the EFFECT of this mutation ( silent, missense, nonsense, frameshift)
Original:
DNA: GTA AAC ATA GGA CTT CTT
mRNA: CAU UUG UAU CCU GAA GAA
Amino acid:  his leu tyr pro glu glu
Mutated:
DNA: GTA AAC ATA GGA CTC TT
mRNA: CAU UUG UAU CCU GUG Amino acid: his leu tyr pro val

15. Effects of Mutations
These last example of deletion was a frameshift mutation.
What’s the difference between a point mutation and frameshift mutation? Which has the most significant impact on the protein? Why?
Point mutation only changes one single point/nucleotide in the DNA sequence, therefore may have a minimal impact.
Frameshift mutation changes the entire remaining codon’s in the DNA sequence, therefore the DNA strand will have a larger impact.

16. Chromosomal Mutations: Deletion
Description: A portion of the chromosome is deleted
How would this type of change affect the protein?
Significance: Deletions of larger portions of a chromosome often lead to genetic disorders (muscular dystrophy).
This graphic represents a chromosome level deletion mutation. A portion of the chromosome is deleted. Deletions of larger portions of a chromosome often lead to genetic disorders (ex: Duchenne Muscular Dystrophy, Cri du chat syndrome, and Spinal Muscular Atrophy) and some deletions may be fatal. (Note to students the difference between a base sequence deletion when just one or a few nucleotides are deleted vs. a chromosomal deletion in which a large portion of a chromosome is deleted.)

17. Chromosomal Mutations: Translocation
Description: Rearrangement of chromosomal sections with non-homologous chromosomes
How would this type of change affect the protein?
Significance: destroying the gene’s function; alterations in gene expression or creation of a hybrid gene (ex. Leukemia).
This graphic represents a chromosome level translocation mutation. This is the rearrangement of chromosomal sections with non-homologous chromosomes. Possible affects include: destroying the gene’s function; alterations in gene expression (ex. Burkitt’s Lymphoma) or creation of a hybrid gene (ex. Chronic Myelogenous Leukemia).

18. Chromosomal Mutations: Insertion/Duplication
Description: Part of the chromosome was duplicated.
How would this type of change affect the protein?
Significance: This may result in no noticeable change; however, it is also how some cancers spread.
This graphic represents a chromosome level duplication mutation. A portion of the chromosome is duplicated. This may result in no noticeable change; however, it is also how some cancers spread.

19. Chromosomal Mutations: Inversion
 ACT-TGC-AGG
ACT-CGT-GGA
Description: Part of the chromosome order is reversed
Significance: This type of change may result in an ineffective protein.
What changed: The last portion of the sentence was completely inverted (reversed).
How would this affect the protein: It will invert the amino acid sequence so it may result in an ineffective protein.

20. Mutation Impact
The impact of a mutation on an individual also depends on where and when it occurs. If there was a mutation in the DNA of a zygote, how would that impact the individual? Birth defects can develop How might a mutation in a skin cell affect an individual? Develop skin cancer.

21. Mutations Practice