DNA to Proteins

Unraveling DNA *The structure of DNA allows it to hold information *The order of the bases is the code that carries the information *A gene is a string or group of nucleotides that give the cell information on how to make a protein. *Humans have over 30,000 genes

Genes Make Proteins DNA code is read like a book – from one end to the other and in one direction. Bases form the alphabet of the code Groups of 3 bases code for an amino acid A long string of amino acids makes a protein Each gene is a set of instructions for making a protein

Proteins Make YOU! Proteins are all through cells and make the differences you see in organisms. Proteins are chemical triggers and messengers for cell processes. An organism may have thousands for genes that code for thousands of proteins

Help from RNA RNA (ribonucleic acid) is a molecule in all living things and helps make proteins RNA helps change DNA code into a protein RNA has one strand. DNA has 2 strands RNA does not have thymine. It has uracil (U) instead.

How to make a Protein Step 1 – DNA unzips. Step 2 – RNA makes a copy of one side of the DNA where a gene is located. This mirror copy of DNA is called messenger RNA or mRNA This is called transcription

What Does the Code Say? Step 3 – RNA leaves the nucleus and goes to the cytoplasm. It is fed through a ribosome The bases on the mRNA strand are matched by another type of RNA called transfer RNA or tRNA. Every group of 3 bases on mRNA codes for 1 amino acid

A Chain of Amino Acids = Protein Molecules of tRNA deliver amino acids from the cytoplasm to the ribosome and add them to a growing protein. Usually one protein is produced for each gene

Changes in Genes A mutation is a change in the base code of a gene. A base can be deleted (left out), inserted (stuck in) or substituted (changed place). Mutations happen often and can either make no change, an improved trait or a harmful trait.

Mutation Examples

How Mutations Happen Mutagens are any substance that can cause a mutation like UV radiation, x rays, or cigarette smoke Examples of mutations are cystic fibrosis, sickle cell anemia, & hemophilia If mutations happen in sex cells, then the mutation can be passed on to the next generation.