MICROBIO 160 1st EditionExam# 4 Study Guide Lectures: 2 - 8Lecture 2(January 23)1. What was the purpose of the Meat and Maggot Experiment and what did it disprove? The purpose of the Meat and Maggot experiment is to disprove that dirty rags don’t turn into mice. Francesco Redi challenged the idea of Spontaneous Generation when he performed the Meat and Maggot Experiment. Spontaneous generation is the production of living organisms from nonliving matter. It disproved spontaneous generation for larger animals. Spontaneous generation was disproved by showing that maggots arose from meat only when flies laid eggs. 2. What does Koch’s Postulate prove?In 1876, a microbe was proven to cause disease. Robert Koch proved that Bacillus Anthraces caused anthrax. Koch’s Postulate is a set of rules for the assignment of a microbe as the cause of a disease (isolated the cause of anthrax, showed to be a bacterium)-The pathogen (bacteria) must be present in all diseased individuals—Pathogen is isolated from the host with the disease and grown in a pure culture –The diseased individual must cause the disease when inoculated into a healthy, susceptible pathogen host—The pathogen must be re-isolated and shown to be the same as the originally inoculated pathogen (must recover and go back to normal when separated) Lecture 3(January 26)1. What is the purpose of the cell cycle checkpoints?Cells have checkpoints to regulate the cell cycle— set of questions— if any answers to the questions are no, the cell cycle pauses until there are enough changes that the answer becomes a yes— if yes isn’t possible, the cell can exit the cycle or begin apoptosis (process of programmed cell death) The purpose of the cell cycle checkpoints are to make sure the cell has done everything and is ready to divide.2. How does Protein Production work?Deoxyribonucleic acid is transcribed into Ribonucleic acid, which is then translated into amino acids (proteins)- RNA Polymerase: the protein enzyme that makes mRNA from DNA; Ribosomes: RNA leaves the nucleus and joins the ribosomes which translate into amino acids3. What are the Nucleic Acid Bases?DNA Bases: T—A, C—G ; RNA Bases: U—A, C—G –DNA reads, synthesizes, and proofreads: Bases have assignments A—G, C—G, if they don’t go to the correct one then it will more than likely change to the correct oneLecture 4(January 30)1. What is the difference between Innate Immunity and Adaptive Immunity?Innate Immunity: these components are always “TURNED ON” and are not antigen specific (Phagocytes (Macrophages) eat things)Adaptive Immunity: these components are “TURNED ON” in response to specific antigens (Adaptive system can take two weeks to turn on (highly specific); Adaptive system recognizes the antigens, innate doesn’t)Lecture 5(February 4)1. What are the major types of tissue growth?Hypertrophy: increase in cell size, normal organization; Hyperplasia: increase in cell number, normal organization; Dysplasia: disorganized growth; Neoplasia: disorganized growth, net increase in number of dividing cellsLecture 6(February 6)1. Cancer cells vs. Normal cells?Cancer Cells:Become independent of external growth factors; Loose density dependent growth inhibition;Gain anchorage independent growth; Have limitless replicative potential (immortality); Stimulate sustained angiogenesis (developing blood vessels); Able to escape apoptosis; Can invade nearby tissue and metastasize Normal Cell:Dependent on growth factor signals in order to divide; Don’t adhere to each other (don’t make proteins)— independent growth; Can divide about 20 times then then go through apoptosis (cancer cells divide indefinitely) 2. What is the Density Dependent Inhibition of Growth:Experiment: Normal cells in a flask in liquid medium—cells only grow to a certain density if they are normal cells Normal and cancer cells will attach to the surface, Both will start dividing –Normal cells stop diving when they reach the bottom and come in contact with their neighbor because they signal each other “Don’t grow over me” (organized) ; Cancer cells do not stop— they continue dividing and ignore the signals from other cells (disorganized) –Cancer has lost its density dependent growth inhibition 3. What is Anchorage Dependent Growth?Anchorage Independent Growth: Cells need to be attached to a surface in order to grow well— if they cant make attachments to a surface or other cells, they undergo apoptosis; Cancer cells don’t need to attach to a surface or to neighbors; Cancer cells have achieved anchorage independent growth 1. What are telomeres? Telomeres: short pieces of DNA that protect chromosome ends; Do not code for protein, Are responsible for limiting the number of times a cell can divide --Because of this a cell can only divide about 20 times then their telomeres become too short; Cancer cells gain the ability to keep dividing constantly Lecture 7(February 11)1. How do antibodies stimulate cell killing?Antibodies that stimulate cell killing: These antibodies function by targeting proteins on the surface of cancer cells—The antibodies themselves mark the cancer cell for destruction by the immune system - Rituxan: specifically recognizes CD 20 proteinso Doesn’t distinguish between cancerous and noncancerous cells— it’ll cause the killing of all B cells in the system—Allows the normal ones to come back Lecture 8(February 13)1.What are the 3 gene families? Mutations can be activated by 3 gene families: DNA repair genes, Tumor suppressors, andOncogenes 2. What is Vasculogenesis?Vasculogenesis: the development of new blood vessels when there are no pre- existing ones; Undifferentiated cells that grow blood vessels on their own; Endothelial precursor cells (angioblasts) migrate and differentiate in response to local cues (such as growth factors) to form new blood vessels; Has immature cells (angioblasts) become angiogenesis 3. What is Angiogenesis?Angiogenesis: the development of new blood vessels from pre-existing ones; Mature endothelial cells lining the blood vessels start to divide in response to local cues to form new blood vessels; Cells keep dividing— causing them to grow out towards the cancer - Has mature cells Lecture 11 (February 23)1. What is the difference between Sensitivity and Specificity? Sensitivity is the percent of people with a specific cancer that actually have that cancer detected by a test—If a test is not sensitive, there will
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