The Function of DNA

DNA Sequence The DNA sequence is the order the nitrogenous bases are attached DNA stores information by its sequence Much like a computer stores information in a sequence of 1’s and 0’s This sequence determines how the cell will function.

DNA Sequence This sequence is used to make proteins Proteins carry out all of the functions of the cell DNA makes proteins so this is how it controls the cell

How DNA Makes Proteins Every 3 nucleotides tells the cell what amino acid to use These amino acids hook to each other Eventually, the DNA tells the cell to stop adding amino acids The section of DNA that makes 1 protein is called a gene

The Genetic Code is what amino acid goes with each 3 nucleotide sequence Which amino acid does the code CAA pick? What protein would be made from the DNA sequence AACGATGACTCAGGC? The Genetic Code

Genes Genes are sections of DNA that make proteins These genes are passed down when a living thing reproduces This means the offspring (children) will make the same proteins as the parent

Genes to Proteins DNA makes genes Genes create proteins The types of proteins determine how the cell will function This is how DNA controls the function of the cell. DNA is a recipe for all of the proteins in the cell

Alleles Although genes determine how our cells function, they can also determine our traits Traits – characteristics or living things Example – your eye colour is a trait Traits are determined by alleles Alleles are a group of genes that are located on the same area on a chromosome

Alleles Since living things have 2 of each chromosomes, they have 2 of each allele How these alleles interact determines what a living things traits are.

Dominant vs Recessive Alleles There are 2 types of alleles. Dominant and Recessive. Dominant alleles mask (cover) the presence of other alleles. Recessive alleles can only be seen if a living thing has 2 recessive alleles

Genotype Bb BB bb The alleles of an organism are called its genotype It is the Genetic Type = Genotype We show the alleles with letters Dominant alleles are represented with capital letters Recessive alleles are represented with lowercase letters Bb BB bb Dominant and Recessive Allele 2 Dominant Alleles 2 Recessive Alleles

Phenotype Genotype Bb BB bb Phenotype The trait shown is called the phenotype It is the physical type = phenotype The phenotype is determined by the genotype Genotype Phenotype Bb BB bb Brown Eyes Brown Eyes Blue Eyes

Mutations Sometimes a cell will make a mistake and change a nucleotide in the DNA This change is called a mutation Mutations can be neutral, harmful, and rarely beneficial This depends on the change to the protein made

Cancer Cancer is typically caused by a mutation in the DNA This make the cell function so differently that it will only have the information to copy itself and reproduce This process happens more quickly and builds a large mass of improperly functioning cells

Viruses Viruses hijack the processes of transcription and translation to do their work Viruses are a protein that contains DNA or RNA Viruses find a way to get their DNA or RNA into a cell The cell reads it and makes the protein it codes for That protein, is a new virus! This process continues and releases viruses which then infect more cells

Genetic Engineering Genetic engineering is changing the genome (code) in a living thing. This is done by taking a section of DNA that codes for a protein you want. It is then put into a new cell’s DNA. The organism made from this cell will have this gene and make this protein.