Study Questions List 8 major structural differences between prokaryotes and eukaryotes and/or draw a picture of each cell type that shows these differences (don’t forget to label the structures). is it important for us to… Read More »Bacterial Classification and Structure Study Questions
Capsule Gelatinous layer surrounding the bacterial cell; gives many bacterial colonies a mucoid appearance. Composed of polysaccharide (except in Bacillus anthracis) which varies among bacteria and is used in identification. 4 reasons the capsule is… Read More »Specialized Structures Outside of the Cell Wall
1. Cytoplasmic (Cell) Membrane Located just inside the peptidoglycan layer. Phospholipid bilayer similar to eukaryotic membranes, but does not contain sterols (except Mycoplasma species). Functions: transport of molecules into cell energy generation by oxidative metabolism… Read More »Cytoplasmic (Cell) Membrane, Mesosome and Cytoplasm
like a stiff “canvas sack” around the bacterial cell. maintains cell structure. is a permeability barrier to large molecules (like lysozyme) and hydrophobic molecules; also provides protection from adverse environments like the GI tract. has… Read More »Outer Membrane of Gram-negative Cells
Structure Chemical Composition Function Essential Components Cell Wall Peptidoglycan Outer membrane of Gram- negative bacteria Surface fibers of Gram- positive bacteria Sugar backbone with peptide side chains… Read More »The Structure of Bacterial Cells
Name Reason Alternative Microscopic Approach Mycobacteria (Ex. M. tuberculosis) Too much lipid in cell wall so dye cannot penetrate Acid-fast stain Treponema pallidum Too thin to see Dark-field microscopy or fluorescent antibody Mycoplasma pneumoniae No… Read More »Medically important bacteria that cannot be seen in the Gram stain
It is difficult to classify all bacteria into clear-cut categories. Various classification methods are used, depending in part, on the purpose. Nomenclature Bacteria are given 2 names (usually Latin) denoting their genus and species… Read More »Classification of Bacteria
Property Prokaryotic Bacterial Cells Eukaryotic Human Cells DNA within a nuclear membrane No Yes Number of chromosomes 1 More than 1 Mechanism of Replication Binary Fission Mitosis Presence of organelles, e.g. Golgi, mitochondria, lysosomes,… Read More »Eukaryotes vs. Prokaryotes
Learning Objectives: You should be able to: describe the major differences between eukaryotic and prokaryotic cells and explain why it is important to know the differences. use bacterial nomenclature properly. describe the phenotypic features used… Read More »Bacterial Classification and Structure