Basics of Genetics Part 1 Introduction Cells come from existing cells the cell theory Like produces like dogs produce pups not kittens But how??????? Heredity- transmission of traits from one generation to the next Genetics- the science of heredity usually dealing with the molecular basis DNA Genetics: Study of heredity and DNA Discovered in the late 1800s (not known as genetic material yet.) (Proteins) Limited by technology Located inside nucleus of cell (also in mitochondria, chloroplast, virus and bacteria). Purpose of DNA is to code for proteins. Made up of a phosphate, sugar and nucleotide bases. Arranged in a double helix (twisted ladder). Watson and Crick (1953) II. DNA A. Structure Nucleotide Phosphate group + Sugar + Nitrogen base DNA cont. Four nucleotide bases: AdenineA always pairs w/ T Thymine GuanineG always pairs w/ C CytosineComplimentary base pairs 2-3 billion base pairs in DNA Chargraffs ratio: #A = #T and #G = #C Diagram of DNA RNA Acts as an intermediary between DNA and protein. Common in cytoplasm of the cell. Transfers code from DNA to ribosome (where protein is made). Made of phosphate, sugar and nucleotide bases. Single stranded. RNA cont. Four nucleotide bases: AdenineA always pairs w/ U Uracil (replaces thymine) GuanineG always pairs w/ C Cytosine RNA cont. Three types of RNA mRNA- (messenger) carries information from DNA to ribosome tRNA- (transfer) carries amino acids to ribosome rRNA- (ribosomal) assembles amino acids to make protein 3 Important Processes Replication: DNA making copies of itself Transcription: DNA makes RNA Translation: Protein synthesis (making proteins) Comparing DNA and RNA DNA Deoxyribose (sugar) Double stranded Thymine Located in nucleus RNA Ribose (sugar) Single stranded Uracil Found in cytoplasm 3.After amino acids have bonded, the tRNA leaves. -Continues until STOP codon -Protein synthesis is done -New protein is releasedNew protein is released DNA code TGA ______________ _______________ mRNA codon _____________ UCU_______________ tRNA anticodon`_____________ _______________________________ Amino acid ____________ ______________ tryptophan DNA code CAT ______________ _______________ mRNA codon _____________ GUU_______________ tRNA anticodon`_____________ _______________________________ Amino acid ____________ ______________ methionine Sickle Cell Anemia