Transcript What is DNA
DNA stands for: D: Deoxyribose N: Nucleic A: Acid DNA is too small to see, but under a microscope it looks like a twisted up ladder! Every living thing has DNA. That means that you have something in common with a zebra, a tree, a mushroom and a beetle!!!! DEOXYRIBONUCLEIC ACID STORES AND PASSES ON GENETIC INFORMATION FROM ONE GENERATION TO ANOTHER . Nucleotides • Consist of a five-carbon sugar • Phosphate Group • Nitrogenous base Polynucleotides • Nucleotide monomers are linked into long chains – These chains are called polynucleotides, or DNA strands – A sugar-phosphate backbone joins them together Backbone Nucleotide Bases (a) DNA strand Figure 3.26a Two strands of DNA join together to form a double helix Base pair Figure 3.26b (b) Double helix REPLICATION MAKING ANEW COPY OF DNA Why cells need to copy DNA? TYPES OF REPLICATION How big is the Human Genome? • Contains over 3 billion base pairs • One meter long when fully streched • Size of 6 billion genomes, one from each person on earth = 1 meter long human hair • 150000 times under • electron micrograph What is a Gene? One Gene One Protein Over 100,000 genes reside in the human genome • Each gene (DNA sequence) contains the genetic code of a protein (amino acid sequence) • Gene to protein transcription translation From DNA to Protein • Transcription – Copies and splices a gene (single strand of DNA sequence) into an mRNA sequence • Translation – Converts mRNA into a protein (string of amino acids) • Promoter – tells the cell when to turn on the gene and how much transcription will occur