BIOL 100 Lecture Notes - Lecture 9: Genetic Variation, Frameshift Mutation, Missense Mutation
Document Summary
Genetic code shows that mrna codons correspond to amino acid. Language of genes is nearly universal among all organisms. Human genes are inserted to bacteria and bacteria will translate/ transcribe genes. Universality of genetic code shows that early acquisition of genes and common descent. Mutation: change in cell"s dna sequence- changes the instruction of genes. Mutation rate is very low (1/109 nucleotides per generation of protein synthesis), natural phenomenon. Most common mutation is point mutation- changes to one nucleotide base pair of a gene- substitutions and. Substitutions- e. g. single base substitution in a gene that causes blood cells to form abnormally, sickle cell. Insertion or deletion of one or two nucleotides changes every codon downstream. Insertion or deletion of three nucleotides (codon) won"t affect the other codons. Usually very disastrous and almost leads to nonfunctional proteins. Silent mutation- change in gene sequence but no change in amino acid. Missense mutation- change in gene sequence changes amino acid product.
