Transcript Mutations
5.4: Genes, DNA, and Proteins 7.1.a Students know cells function similarly in all living organisms. The Genetic Code • Proteins help to determine the size, shape, color, and other traits • DNA is made up of 4 nitrogen bases: adenine, thymine, guanine, cytosine • Gene- a section of DNA which has the information to code for a protein • Bases are genes in a specific order • Each gene is located at a specific place on the chromosome • Chromosome contains thousands of genes The DNA Code • Chromosomes are inside the nucleus, made of DNA, and contain thousands of genes • The sequence of bases in a gene forms a code telling what protein to produce How Cells Make Proteins • Key concept: “During protein synthesis, the cell uses information from a gene on a chromosome to produce a specific protein.” • Messenger RNA- copies the coded message from the DNA in the nucleus, and carries the message to the ribosome in the cytoplasm • RNA is similar to DNA but different • RNA is 1 strand DNA has of 2 strands • RNA has Uracil DNA has Thymine • RNA has a different sugar molecule • Transfer RNA- carries amino acids to the ribosome and adds them to the growing protein Mutations • Mutation- any change in the gene or chromosome, it can be harmful or helpful • If a mutation happens in the sex cell the mutation might be passed onto an offspring • If a mutation happens in a body cell, like a skin cell, it will not be passed on • A mutation is harmful if it reduces the organisms chance for survival and reproduction • A mutation is helpful if it improves an organism’s chance for survival and reproduction Mutations • Key Concept: “Mutations can cause a cell to produce an incorrect protein during protein synthesis. As a result, the organism’s trait, or phenotype, may be different from what it normally would have been.” • There are different kinds of mutations Section 4: Genes, DNA, and Proteins What forms the genetic code? How does a cell produce proteins? How can mutations affect an organism?