Crash Course! Introduction to Molecular Biology 1 chromosome = 1 DNA molecule Major Functions- DNA Stores genetic information! Expresses genetic information when needed. Replicates. Doesnt do any other important cellular functions. Major Functions- RNA Middle Man. DNAs messenger boy. Part-time building material. Most of a cell (excluding the water) is protein. DOES THIS MAKE SENSE?? Major Functions- Proteins They execute nearly all cell functions. They are a major building material. They are enzymes, motors, receptors, hormones, antibodies, cables, etc. Central Dogma What is a gene? A gene is a stretch of DNA that contains the information to produce a particular product (usually a protein). A gene produces a particular product (usually a protein). Transfer RNA (tRNA) Ribosomal RNA (rRNA) Messenger RNA (mRNA) PROTEIN Transcription: The enzyme RNA polymerase unwinds and copies: The mRNA and the DNA are base-pairing. One strand is involved in transcription. Next- Translation How an mRNA produces a protein Fig. 9-3, p. 214 DNA Transcription mRNA Translation Polypeptide Nucleus Cytoplasm Cell The genetic code is a triplet code. Transfer RNA Met How many different codons are there?? Eukaryotic Gene Structure Eukaryotic gene detail: What is a mutation? Explain why this mutation is different. It is a synonymous mutation. SNPs are not mutations. Mutations are rare. Mutations are random. SNPs are ancient differences and common. Almost all common SNPs have only two alleles. Many SNPs lie in the intergenic regions (between the genes) or in introns. Is the study of SNPs important? SNPs may influence your susceptibility to a wide variety of diseases. At least that is what some people think! The End