Mutations

Understand what mutations are Understand how they occur Analyze the different types of mutations Understand how mutations affect amino acid

sequences and proteins

Objective

Central Dogma DNA is transcribed into RNA, RNA is translated

into proteins 3 nitrogenous bases give us a codon One codon codes for a specific amino acid

ie. AUG codes for “start” and Methionine Peptide bonds hold amino acids together Amino acids give us proteins!

What we know so far!

If the DNA in the cells inside your entire body

were lined up end to end, they would stretch around the Earth and Jupiter 60 times in distance!

Many mechanisms were developed to protect DNA from change within the cell but mutations still happens

Any change in the DNA sequence is called a mutation!

What is a mutation?

Mutations can affect the reproductive cells of an

organism. Changes the sequence of the nucleotides within a

gene (sperm or egg cell) If this cell takes part in fertilization, the altered

gene becomes part of the genetic make-up. Can result in a new trait or a protein that doesn’t

work correctly. May (few times) have a positive effect

Mutation may make organism faster, stronger, and better to survive in environment.

Basis of evolutionary theory

Powerful radiation could cause DNA in a non-

reproductive cell to change. This mutation would not be passed on, but

could cause problems for the individual. Impaired function of the cell

ie. Stomach acid, skin cells When a cell divides, the mutation will carry on.

Mutations in Body Cells

Some mutations can affect the genes that

control cell division! Rapid division and growth (result) This mutation is known better as cancer.

(uncontrolled division of cells) ie. UV radiation in sunlight can change the

DNA in skin cells ; cells produce rapidly, causing skin cancer.

Cancer is a mutation!

Point Mutation

A change in a single base pair in DNA.

Types of Mutations

The first point mutation did not result in a change in the protein.The second point mutation caused a change in the protein. This was a stop codonThe third point mutation coded for a different protein as well.

THE DOG BIT THE CATTHE DOG BIT THE CAR..the meaning of the sentence changed due to that one change in a word…point mutations!

Frameshift Mutation

When a single base is added or deleted from DNA

Types of Mutations

THE DOG BIT THE CATTHE DOB ITT HEC AT

The G was deleted from the sentence resulting in a scrambled sentence; frameshift mutation.

THE DOG BIT THE CATTHE DOG BBI TTH ECA TThe B was added to the sentence resulting in a scrambled sentence; frameshift mutation.

Changes sequence

in nitrogenous bases

May cause change in amino acid

sequence

Different amino acids sequence may code for

different proteins that intended.

Function of cell may be altered

Phenotype (physical

appearance) of trait may be

altered.

Why mutations Matter!

Chemicals

Asbestos was used to insulate buildings Known to cause lung cancer an disease

UV Rays

Cause of Mutations

What is a mutation? What different types of mutations are there? Can you describe them? Why do mutations matter?

Knowledge Check