Mutations Errors in DNA

What happens when your DNA is damaged? Ted Ed video https://ed.ted.com/lessons/what-happens-when-your-dna-is- damaged-monica-menesini Amoeba Sisters – Mutations https://www.youtube.com/watch?v=GieZ3pk9YVo

What happens when DNA does not replicate properly? Ribosomes assemble different amino acids in a specific order to make a specific protein, according to the DNA’s instructions. If the DNA has been changed in some way, the sequence becomes altered and no longer has the correct code for that protein. That protein may not get made, cellular functions may not be carried out.

What is a Mutation? Any change in an organisms DNA.

What can cause a mutation? Mistakes can occur during DNA Replication Eg. The wrong nucleotide can be added 2. Environmental Factors: UV light Cigarette smoke Chemicals Factors that cause mutations are called mutagens

Are mutations harmful? Mutations can be classified as either: Harmful (Negative) Beneficial (Positive) Neutral (neither harmful nor beneficial) Build up of mutations can lead to cancer – multiple hit (smoker, alcolholic, working with chemicals)

Negative mutations Genetic diseases are caused by harmful mutations. Eg: Sickle cell anemia is a condition resulting from a single gene mutation causing a person’s red blood cells to be “sickle- shaped” instead of the normal disc shape. The new shape prevents RBCs from carrying oxygen well and also may clog vessels A single gene mutation can be very harmful

Sickle Cell Anemia

Positive Mutations Positive mutations are beneficial to the organism Eg. Plants carry a mutated gene that protects them from certain diseases. Some people have a mutated gene that produced a special kind of protein that prevents them from getting infected with HIV.

Neutral Mutations Organism neither benefits nor is harmed Spirit Bears have a mutated gene that makes their fur white instead of black

Can Mutations be fixed? When a mistake occurs in DNA replication, DNA has its own repair mechanism that will often repair the damage before it is fully replicated. If the mistake is NOT corrected, all future DNA strands from that cell will contain that mistake. This may result in a particular protein never being made. This can lead to genetic diseases The healthy gene must first attach to a chromosome witin a patiet’s cells. Thentee gene needs to make the correct ype and mount f protein.

HW: Cancer Handout Read p53-55 Answer mutations WS

Can Mutations be fixed? When a mistake occurs in DNA replication, DNA has its own repair mechanism that will often repair the damage before it is fully replicated. If the mistake is NOT corrected, all future DNA strands from that cell will contain that mistake. Some mutations can be treated with drugs or surgery. Gene Therapy – researchers replace a mutated gene with a healthy copy of the gene. The healthy gene must first attach to a chromosome within a patient’s cells. Then the gene needs to make the correct type and amount of protein. potential to eliminate and prevent hereditary diseases such as cystic fibrosis and hemophilia and its use as a possible cure for heart disease, AIDS, and cancer, gene therapy is a potential medical miracle- worker. The helathy gene must first attach to a chromosome witin a patiet’s cells. Thentee gene needs to make the correct ype and mount f protein.