DOC PREVIEW
WKU BIO 207C - Microbial Genetics
Type Lecture Note
Pages 8

This preview shows page 1-2-3 out of 8 pages.

Save
View full document
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
View full document
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience
Premium Document
Do you want full access? Go Premium and unlock all 8 pages.
Access to all documents
Download any document
Ad free experience

Unformatted text preview:

BIO 207c 1st Edition Lecture 5Chapter 8 Microbial GeneticsIntroduction to GeneticsI. Genetics- the study of inheritancea. Includes:i. Passing of traits down from one generation to anotherii. Transmission of traits from parent to offspringiii. Expression and variation of traitsiv. Structure and function of the genetic materialv. How genetic material changesNature of Genetic MaterialI. Genomea. Sum total of genetic material in an organismb. Most of it exists as chromosomesc. Some in the form of plasmidsd. Composed of DNAe. Viruses can have either DNA or RNAII. Chromosomesa. Discrete structure composed of DNA molecule and proteinsb. Prokaryotic chromosomesc. Singular and circulard. Humans have 46III. Genea. Segment of DNA that codes for a specific proteini. Types of genes1. Structural- code for proteins2. Those that code for RNA to be used in protein production: DNA – RNA – protein 3. Regulatory – control gene expressionIV. Genotypea. Actual genetic makeup of the organismV. Phenotypea. Expression of traitsb. All organisms have more genes in their genotype than are expressedc. Environment plays a role in genes that are expressedDNA CodeI. DNA is composed of nucleotides (basic unit of its structure) proteins and DNA are both polymersa. Each nucleotide consists of:i. Phosphate (stored in metachromatic granules)ii. Deoxyribose sugariii. Nitrogenous base1. Adenine2. Thymine3. Guanine4. Cytosineb. Nucleotides bond to each otheri. Sugars and phosphates come together to form the backbone of the moleculeii. Bases are off to the side and will bond with other bases in whatis called “complementary” pairingiii. This creates the double strandedness of DNA1. Adenine bonds to thymine2. Cytosine bonds to guanineSignificance of DNA StructureI. How can such a simple molecule have such complex results?II. There is almost endless variation that can be found in the sequence of the basesIII. Sequence of bases is what’s important-will determine the traits of the organisma. SUGAR-PHOSPHATE BACKBONE IS NOT IMPORTANTDNA ReplicationI. When reproducing, organisms must maintain their genetic integritya. For cells, this means that the daughter cells created must contain the same amount and type of genetic material as the mother celli. This is accomplished by DNA replication1. In this process, the DNA molecule makes an exact copy of itself2. DNA molecule unzips3. Enzymes separate the strands from each other4. Each strand serves as a template (pattern) to produce a new strand of DNA5. Involves free nucleotides and complementary base pairing6. At end, have 2 molecules of DNA that are identical to each other7. Cell can now divide with 1 molecule of DNA going into each new daughter cellii. Daughter cells are identical to mother cellTranscription and TranslationI. Central dogma of biologya. Information flows from DNA to RNA to protein********II. Transcription- production of RNA from a DNA templateIII. Translation- production of protein from an RNA templateIV. DNA does NOT change to RNA – it is used to make RNA TranscriptionI. At first, looks like replicationa. DNA molecule unwinds, unzipsb. But only 1 strand of DNA is used to make RNA (the cell knows which strand to use)i. RNA is similar to DNA with the following differences:1. Single stranded2. Contains uracil instead of thymine3. Contains ribose instead of deoxyriboseRNAI. Different types of RNAa. Messenger RNAi. RNA produced from DNA templateb. Transfer RNAi. Used to bring amino acids into place to make the protein coded for by DNAc. Ribosomal RNAi. Used to make ribosomesii. Site of protein synthesis1. Used to make proteinsTranslationI. Messenger RNA is read in groups of 3 bases-codona. Each codon represents an amino acidi. Some codons code for the same amino acidii. Start and stop codonsII. Transfer RNA is grouped in threesa. Called anticodoni. Each triplet is attached to an amino acidii. mRNA and tRNA bond to each otheriii. This brings the amino acid into the proper place in the proteiniv. This continues until the protein is completeDNA RecombinationI. Event where one bacterium donates DNA to another (pili transfer the genetic material) a. End up with new strains of bacteriai. Provides genes for drug resistance, increased virulence, new metabolic capabilities (virulence – greater ability to cause disease) (new metabolic capabilities are – toxin production)II. Plasmidsa. Pieces of DNA separate from the chromosomeb. Can replicate independently of the chromosomec. Found in many bacteriai. Not all of them have them but a lot doRegulation of Protein SynthesisI. Genes can be turned on or offII. If they are on it means that a protein is being producedIII. If they are off a protein is not being producedIV. 80% of genes are turned on all the time (80% is true of mostly all organisms are they are needed for survival)V. The remaining 20% are turned on and off as needed (ex: some cancer genes are never turned on and you never get that kind of cancer)VI. Genes control whether or not genes are expressedVII. In bacteria, this is the operon (in prokaryotes ONLY)a. Parts of the operoni. Regulator (or regulatory gene)1. Codes for the repressor proteinii. Promoter region (transcription is occurring) 1. Interacts with RNA polymeraseiii. Operator region1. Interacts with the repressor proteiniv. Structural gene1. Codes for the actual proteinVIII. Basics to rememberIX. If RNA polymerase occupies the promoter region the gene is turned on (this initiates transcription)X. If repressor protein occupies the operator region the gene is turned offXI. Presence of the repressor protein at the operator region blocks RNA polymerase from occupying the promoter regionTypes of OperonsI. 2 types of operonsa. Inducible operon-i. Involves an inducerii. Must start an eventb. Repressible operon-i. Involves a repressorii. Must stop an eventII. Inducible operona. Have an active repressor protein-can occupy the operator regionb. The inducer inactivates the repressor proteinc. Repressor protein cannot occupy the operator regiond. This allows RNA polymerase to occupy the promoter regione. Gene is turned on (protein produced)i. ***what happens if the inducer is taken away? YOU TURN THE GENE OFF***III. Repressible operona. Have an inactive repressor protein-cannot occupy the operator regionb. Repressor activates the repressor protein (repressor protein is made by regulatory gene)c. Repressor protein occupies the operator regiond. RNA polymerase cannot occupy the promoter


View Full Document

WKU BIO 207C - Microbial Genetics

Type: Lecture Note
Pages: 8
Download Microbial Genetics
Our administrator received your request to download this document. We will send you the file to your email shortly.
Loading Unlocking...
Login

Join to view Microbial Genetics and access 3M+ class-specific study document.

or
We will never post anything without your permission.
Don't have an account?
Sign Up

Join to view Microbial Genetics 2 2 and access 3M+ class-specific study document.

or

By creating an account you agree to our Privacy Policy and Terms Of Use

Already a member?