Download missense mutations

Mutation
Monday
Cystic Fibrosis
• http://www.youtube.com/watch?v=FMAOEO
mLoUE
Work time!
• Work alone for 15 minutes to complete the
worksheet
• I will then give you 5 minutes to share with a
partner, until then, no talking
Point Mutations
• Point mutations are single-base changes in a
gene’s DNA sequence.
• These include:
-missense mutations
-nonsense mutations
-silent mutations
Point Mutations: missense mutation
• Missense mutations result in a single amino
acid change within a protein.
• This DOES change the resulting protein.
THE DOG BIT THE CAT
THE DOG BIT THE CAR
Point Mutations: nonsense mutation
• Nonsense mutations create a premature stop
codon, causing the protein to be shortened.
• This DOES change the resulting protein.
THE DOG BIT THE CAT
THE DOG BIT
TAC TTC AAA CCC CGT ATC ATT
AUG AAG UUU GGG GCA UAG UAA
Met - Lys - Phe - Gly - Ala - stop-STP
Point Mutations: silent mutation
• Silent mutations change the DNA sequence,
but not the amino acid sequence.
• This DOES NOT change the resulting protein,
and has no effect on an organism.
THE DOG BIT THE CAT
THE DOG BIT THE KAT
TAC TTC AAA CCA CGT AAC ATT
AUG AAG UUU GGU GCA UUG UAA
Met - Lys - Phe - Gly - Ala - Leu STP
Frameshift Mutations
• Frameshift mutations result from the insertion
or deletion of one or more bases into or from
the DNA sequence.
• This alters the grouping of nucleotides into
three-base codons, causing a shift in the
“reading frame” during translation.
• The resulting protein is usually nonfunctional.
Frameshift Mutation
• Insert a D
THE DOG BIT THE CAT
THE DDO GBI TTH ECA
• Delete a D
THE DOG BIT THE CAT
THE OGB ITT HEC ATS
What Causes Mutations?
•
•
Many mutations are due to mistakes made in
replication, or transcription.
Mutagens are things that can cause a change
in DNA sequences. All of these mutagens can
damage your DNA:
• UV light
• radiation
• exposure to chemicals
Practice
• RNA seq. 1: AUU GAG CCA UUA GAA CUA
• RNA seq. 2: AUU GAG CCA UUA GAG CUA
• What kind of mutation is this?
Give me 5!
• 5 random students will be picked
• I will explain what they must share with the
class
Tuesday
• Nature isn’t always perfect!
• What happens when a MISTAKE is made in
DNA Replication or RNA Transcription?
Mutants!
Pros and Cons of Mutations
•
PRO: mutations are the source of genetic
variability in a species!
•
CON: mutations can disrupt normal
biological activity, resulting in a genetic
disorder or cancer.
Nothing is perfect….
• Cells can make mistakes in replicating or
transcribing their own DNA
• Mutations are changes in the genetic material
(from a Latin word meaning “to change”)
Time to work!
• Not all diseases will be completely harmful
and you will have to create a PowerPoint
presentation about the disease and the
mutation type you select from the Ziploc bag
• What to address:
– Mutation type
– Disease characteristics
– Benefits if from having the disease
– Where is the disease most common in the world?
• You must e-mail me your presentation for a
grade: [email protected]
• Make sure you have all your member’s names
Wednesday
• Pamphlet Guide Topics:
– Name of Disease
– Type of mutation
– Effect on the individual
– Characteristics of mutation
– Ways to manage Disease
– Is there a cure?
Assessment Time!
• 10 minutes for a short 7 question quiz