Microbiology Test 1 Chapter 1,2,3 Questions and Answers

Microbiology Test 1 Chapter 1,2,3 Questions and Answers Microbiology The study of microorganisms and their activities Microorganism A living thing that can only be seen with the aid of a microscope. Also knows as a microbe. Somewhat is a germ - but a germ has a connotation of being harmful so this is not a great synonym The Theory of Evolution by Natural Selection States that populations of living organisms change over time due to interactions with their environment The Cell Theory of Life Proposes that all living things are made of cells The Theory of Disease States that microorganisms are often the cause of disease Koch's Postulates Modern methods by which we are able to show that a specific pathogen causes a specific disease Taxonomy The scientific process of classifying living things Domains All living things are divided into 3 major groups called these Bacteria (modern prokaryotes), Arachea (primitive prokaryotes), Eukarya (eukaryotes) The 3 domains that all living things are divided into Prokaryotes Domains Bacteria and Arachea are called these and also means that they are simple cells without a true nuclei or true organelle Eukaryotes The Domain Eukarya is called this meaning that they DO have true neclei and true organelles Viruses These are not considered to be alive, and are therefore NOT classified among the 3 domains Taxonomic Hierarchy The list of classification categories, from the largest to the smallest category, in a Domain Domain, Kingdom, Phylum, Class, Order, Family Genus, Species The order of the Domains Domain Eukarya, Kingdom Animalia, Phylum Chordata, Class Mammalia, Order Primates, Family Hominidae, Genus Homo, Species Sapiens Humans are classified as this (Eukarya) Nomenclature System of naming Linnaean System The current naming system used in Biology Binomial method In the Linnaean System we name living things using this method Genus and Species These are the only 2 domain names that are used Home Sapien Humans are called this Staphylococcus aureus round cell found in clusers and it forms yellow gold colonies in the lab Prokaryotic characteristics Do not have a neclei (DNA is not protected in a nucleus) Do not have true organelles (internal structures do not have membranes) Unicellular (although they may form simple colonies) Exhibit relatively simple structure (when compared to Eukaryotes) Possess an external cell wall that provides an extra layer of protection Size typically ranges between .5 and 5.0 (micrometers or millionths of a meter) They divide via binary fission (rather than mitosis) Domain Archaea The most ancient type of Prokaryote, tend to have the simplest structure of any known cells, contain rather unusual chemical not found in other prokaryotes, live in VERY EXTREME environments - this is known as extremepholes Domain Bacteria The modern Bacteria or least primitive form of Prokaryote, found in most environments on Earth today, cell structure is more complex than that of arachea, but simpler than that of the Eukaryote Cocci Round bacteria Bacilli Rod Shaped Spirals Spiral shaped bacteria Spirochetes Flexible spirals that are motile due to contraction of an axial filament embedded in the cell Spirilla rigid spirals, corkscrew like cells that are motile due to polar flagella Vibrous Comma shaped bacteria - related to spiral bacteria Coccobacilli Resemble elongated cocci Involution Forms Distorted bacteria - bacteria that change shape as they age, becoming swollen and distorted Gram Stain Bacteria are commonly classified this way, a special laboratory staining process causes some cells to turn bluish/purple (Gram Positive) or red (Gram Negative) Domain Eukarya All Eukaryotes are a member of this domain Eukaryotic Chacteristics They consist of cells that contain a true nuclei (meaning their genetic material is protected within the nuclei), cells have internal structures called organelles - contain some type of membrane, they are more complex than prokaryotes, may be unicellular OR multicellular, cells are much larger than most prokaryotes, cells divide via some form of mitosis Kingdom Protista Consists of a wide variety of eukaryotic orgaism that are often called protists and/or protozoa False Prokaryotes reproduce sexually True Protists can reproduce sexually True Algae rarely cause disease in humans Protozoa Members of the Kingdom Protista, unicellular, nonphotosynthetic that possess complex structural characteristics similar to animal cells, often live in soil or water, and are often referred to as parasites when they infect humans Amoebas, Flagellates, Ciliates, Sporozoa 4 Major groups of protozoa Amoebas move by using psuedopods Flagellates move by using flagella Ciliates move by using cilia Sporozoa have no mechanism for movement Viruses Extremely small nonliving particles (most are too small to be seen without an electron microscope) True Viruses are not cells and are not made of cells Host Cell A specific kind of cell that viruses must enter in order to make copies of themselves Replication The process in which a virus makes copies of itself and can be damaging or even deadly to the host cell Core and Capsid 2 major parts that Viruses always contain Core Collection of DNA or RNA, usually located in the center fo the virus Capsid A protein coat that surrounds and protects the core, made of protein subunits called capsomeres. Envelope Some viruses possess an additional layer found outside the capsid Enzyme Some viruses contain this to help them replicate it the host cell Bacteriology study of bacteria Mycology study of fungi Protozoology study of protozoa Virology study of viruses Phycology study of algae External appendages Bacterial Cell Structures obtain these Flagellum, Fimbrae, Pili External Appendages Glycocalyx The outermost layer of the cell also known as a capsule and is also a layer of carbohydrates that is secreted by the cell and that adheres to the cell surface Slime layer and a capsule 2 types of Glycocalyx Cell Wall a rigid structure found between the glycocalyx and the cell membrane, present in bacteria and some eukaryotes, consists mainly of a molecule called peptidoglycan Glycocalyx, Cell Wall, Cell Membrane Surface Layers Cytoplasm Internal Structures which are 80% water, with proteins (enzymes), carbs, lipids, necleic acids, salts nutrients, has a thick elastic consistency called a cell sap Bacterial Chromosome Single, circular, double stranded DNA molecule that is not enclosed in a membrane, sometimes called nucleoid and acts as the control center of the cell, and contains genes Plasmid Small, circular, double stranded piece of Extrachromosonal DNA. Can be transfrd from one cell to another during the process called bacterial conjugation