MICRB 106 1st Edition Exam 1 Study Guide Lectures 1 5 Lecture 1 August 26 Microbes What is Microbiology Describe the features that all living things possess known as the basis of life How do macromolecules play a role in microbes Understand the domains of microbes and their similarities differences Understand Microbial genetics and what they tell us about the microbes we study today Describe the various ways microbes gain energy from the environment Know important people in association with microbes and disease Microbiology The study of microorganisms also referred to as microbes consisting of bacteria archaeons eukaryotes and viruses Basis of Life Features shared by all living organisms Metabolism is chemical reactions that use energy and nutrients from environment to form new biological materials Growth is an increase in the mass of biological materials Reproduction is the production of new copies of the organism Genetic variation evolution allows changes within a population by natural selection throughout multiple generations Response to environmental stimuli allows for adaptation to environment with genetic physiological constraints Homeostasis is the regulation of a cell s internal environment Macromolecules in Microbes Polypeptides are enzymes that catalyze chemical reactions inside cell and provide materials for cellular structure Nucleic acids are informational DNA provides instructions for reproduction of cells while RNA provides production of proteins structural and catalytic functions within a cell Lipids form membrane boundaries around cell that restricts materials from getting in or out of the cell Polysaccharides are sugar molecules that provide structure and serves to store energy glycogen and starch Polypeptides and polysaccharides are both found in the lipid bilayer of an organism s plasma membrane that separates the inside of the cell from the outside environment Domains of microbes Microbes were first categorized into Prokaryotes or Eukaryotes based off of whether or not they had a nucleus However Carl Woese discovered the third domain of microbes through DNA sequencing which compared ribosomal RNA genes between different organisms Woese s discoveries led to three domains Archaea Bacteria and Eukarya Archaea Bacteria and Eukarya have many similarities and differences however one major difference between all three domains would be their RNA polymerases which were used to classify these organisms Polymerase Chain Reaction PCR is used to examine these DNA sequences Viruses are not considered a domain because they are not alive and do not replicate unless they are within a host cell but are still studied because they are too small to be seen with the human eye Microbial genetics The first macromolecules were synthesized from an atmosphere with very little oxygen available in it Microbes have been projected to be around for the past 3 5 billion years Miller and Urey s experiment demonstrated the idea behind the beginning of the first macromolecules First macromolecules needed genetic information biochemical reactions to occur through catalysis and an early version of a plasma membrane RNA ribosomes or enzymes provided the catalysis of reactions while also storing genetic information A micelle was the formation of an early plasma membrane made up of a single lipid layer Eventually cells used DNA instead of RNA to store genetic information because it is more reliable stable due to its second copy of the genetic information Eukaryotes are described to have appeared from the endosymbiotic theory which consists of prokaryotes engulfing other cells for food purposes which resulted in the first eukaryote Mitochondria are microbes that had been engulfed that were capable of using oxygen for a respiratory process of producing energy Chloroplasts were also engulfed that could turn carbon dioxide into organic molecules using energy from the sun photosynthesis RNA s activity in modern cells proves its importance in the first microorganisms DNA is transcribed into messenger RNA mRNA to be translated into proteins used by the cell Microbial genetics allows us to understand the changes and effects of mutations in DNA and helps us compare genomes between domains Benefits for humans include production of human insulin using E coli cells first done by Genentech in 1978 How Microbes get Energy If a microbe is a heterotroph it ingests preformed organic molecules for energy If they are autotrophs microbes produce their own organic molecules Once microbes get organic molecules they break them down to get ATP or chemical energy One process is fermentation which does not need oxygen but does not produce nearly as much ATP Another process is aerobic respiration where oxygen is used to produce ATP and produces much more of it Glycolysis is also a source of energy where Glucose is converted into pyruvate to get ATP molecules This process can use either fermentation or aerobic respiration Microbes and disease Louis Pasteur disproved spontaneous generation theory by separating microbes from a broth by boiling and sanitizing the broth Once microbes extracted from broth the broth continued to remain sterile until it once again came into contact with microbes Robert Koch discovered that Bacillus anthracis and Mycobacterium tuberculosis caused anthrax and tuberculosis and created vaccinations to prevent cattle ranchers and sheep herders from losing money due to these two diseases infecting their animals Lecture 2 August 28 Bacteria Chapter 2 Understand the different morphologies shapes of Bacteria Know the cytoplasm of bacteria cells What internal structures organize bacteria cells What are the structural and function properties of the cell envelope What structures are on the surface of bacterial cells and how do they allow the cell to interact with the environment How are bacteria named and categorized Morphology of Bacteria Bacteria have many different shapes that include spherical cocci rod shaped bacilla curved rods vibrios and spirals spirilla Pleiomorphic bacteria have no protein inside cells to give a certain shape Bacteria cells grow multicellular organizations that form hyphae mycelia and trichomes Hyphae are filaments branched off from c ells that where nutrients and signals may be passed from cell to cell Mycelia are networks groups of 3 of hyphae Trichomes are smooth chains of cells that are unbranched from the cell that allows for nutrients and signals to pass between cells Bacteria