MICROBIOLOGY AN INTRODUCTION 13TH EDITION TORTORA 2023

Microbes (Microorganisms) Minute living things individually too small to be seen w/ unaided eye. Includes bacteria, protozoa, microscopic algae, archaea, fungi, multicellular animal parasites What constitutes something living? The 9 levels of an organism 9 levels of organization AMM-OCT-OOO Atom, molecule, macromolecule, organelle, cell- the lowest level of living, tissue, organ, organ system, organism Cell is the lowest level of organization that can perform all activities required for life Cells must have 3 things to be living 1 is cell membrane 2 is genetic material, 3 is cytoplasm which is energy and machinery for metabolism The cell theory states that all organisms are made of cells; cells are the most basic unit of life; and all cells come from preexisting cells Basic characteristics of life metabolism, responsiveness to the environment, movement, growth, reproduction Microorganisms include Prions, viruses, bacteria, archaea, protozoa, algae, fungi, helminths, Prions infectious protein particles that do not have a genome eg mad cow disease=CJD CJD (Creutzfeldt-Jakob disease) rare fatal encephalopathy caused by a prion Mad cow disease Virus A tiny, nonliving particle that invades and then reproduces inside a living cell. No genetic material, no cytoplasm Bacteria single-celled organisms that lack a nucleus; prokaryotic but has a cell membrane. Has genetic material floating around, no nucleus only a nucleoid Nucleoid A non-membrane-bounded region in a prokaryotic cell where the DNA is concentrated. prokaryotic cell that does not have a nucleus or other membrane-bound organelles., single chromosome that is circular with no ends, cellular division by binary fusion, Ribosome size is smaller only 70s, site of protein synthesis is smaller Eukaryotic cells possessing a nuclear membrane and other membrane-bound organelles. True nucleus, multiple chromosomes and linear with ends, and Has organelles like ER, Mitochondria, cellular division is mitosis Bigger ribosome 80s, site of bigger protein synthesis 2 theories of how life comes about 1, spontaneous generations and 2. Biogenesis Biogenesis Theory states that cells can only arise from pre-existing cells