Study Guide for Final - Principles of Biology | BIOL 1105, Study notes of Biology

Download Study Guide for Final - Principles of Biology | BIOL 1105 and more Study notes Biology in PDF only on Docsity! This is everything from the review session that was actually pertinent to the exam: (at least the notes that I took) CHAPTER 21 >>Cloning animals takes 2 to 3 animals:  From one animal, 2n DNA(donor nucleus) is taken to be cloned  From another animal, n egg is extracted with nucleus pulled out with a tube  2n DNA is put into n egg  Implant emerging embryo into another animal or the same animal the n egg was donated from This results in a clone of the animal where the 2n DNA was taken to be clones. >>Stem cells are cells that are grown into 2-300 cell size coming from embryonic cells with the ability to turn into any cell needed---by manipulation, specialized cells can be formed  When the embryo is less than four days old, its cells are called totipotent stem cells. This means that they have a total potential to form a human being if they were separated and individually implanted in a woman’s uterus.  After four or five days, the cells are pluripotent stem cells. These cells have the potential to form every single cell in the human body, but these cells do not hold the ability to form an entire human being.  As the pluripotent stem cells continue to divide into more cells, differentiation occurs and they become multipotent. Mulitpotent stem cells have the ability to form several types of cells, but lack the ability to form all the cells of the body. Adult stem cells are Multipotent. CHAPTER 18 >>Lytic Cycle and Lysogenic cycles were gone over by drawing the exact diagram of these cycles as shown on pages 332-33. Just be familiar with these cycles. >>Examples of Viral Structure (page 330) 1. Tobacco mosaic virus has a helical capsid with the overall shape of a rigid core. 2. Adenoviruses have a polyhedral capsid with a glycoprotein spike at each vertex. 3. Influenza viruses have an outer envelope studded with glycoprotein spikes. The genome consists of eight different RNA molecules, each wrapped in a helical capsid. 4. Bacteriophage T4, like other “T-even” phages, has a complex capsid consisting of a polyhedral head and a tail apparatus. >>There will be a question on a well-known viral structure… >>Go over the figures on the reproductive cycle of an enveloped virus on page 334 and the reproductive cycle of HIV on page 336. >>Bacterial gender determination:  A special F factor can exist either as a segment of DNA within the bacterial chromosome or as a plasmid called the F plasmid  Cells containing the F plasmid are labeled as F+ (“male”) and those lacking the F factor are known as F- (“female”)  F+ cells have the ability to form a sex pilus to replicate with F- in a process called conjugation. The “female” F- cell inherits the F factor and becomes a “male” F+ cell >>Prions are misfolded versions of normal brain proteins. When a protein contacts a normal “twin”, it may induce the normal protein to assume the abnormal shape. The resulting chain reaction may continue until prions accumulate to dangerous levels, causing cellular malfunction and eventual degeneration of the brain. …Examples include scrapie in sheep, “mad cow disease”, and Creutzfeldt-Jakob disease in humans. (page 339) >>Operons: Repressible versus Inducible (pages 347-50)  Operons are stretches of DNA required for enzyme production  An operator is placed upstream of selected genes to serve as a promoter for the RNA polymerase to bind and transcribe the genes that make polypeptides that make up enzymes for tryptophan and lactose synthesis Repressible trp operon  A regulatory gene, trpR, produces an inactive allosteric protein that serves as a repressor only when tryptophan is present  When present, tryptophan binds to the allosteric site of the repressor protein acting as a corepressor which makes it active, thus binding to the operator in effect shutting it off which blocks the attachment of the RNA polymerase *The main focus of this whole thing is that the cell produces tryptophan when there is no tryptophan present. When the tryptophan is present, a small piece of the tryptophan binds to the repressor making it active. This active repressor does its job of repressing and binds to the operator which blocks the RNA from attaching. Inducible lac operon  Is stimulated when a specific molecule interacts with a regulatory protein  A regulatory gene, lacI, produces an allosteric protein which is an active repressor which binds to the operator which inhibits the production  Allolactose, an isomer of lactose, binds to the repressor and inactivates it  This induces the production of metabolic enzymes to break down lactose *The main focus of this is to understand that the repressor is already active upon its creation unlike with the trp operon. An isomer on lactose is required to induce the process. >>Transposons are a piece of DNA that can move from one location to another in a cell’s genome. (Go over figures on pages 345-46)