Microbiology Ch. 3
Order by
60 terms
Terms | Definitions |
|---|---|
 Living Organisms | 1. growth 2. reproduction 3. responsiveness 4. metabolism. |
| Prokaryotic cells Have | 1. Ribosome 4.Inclusions 2. Cytoplasm 5.Cell wall 3. Flagellum 6. Nucleoid |
| Cell wall | Prevents osmotic lysis and gives shape Made of peptidoglycan (only in bacteria) |
| All cells have | 1. Ribosomes 4.DNA=genetic material 2. Cell membrane 3. Cytoplasm |
| Prokaryotic cell structure | a) Bacteria and archea i) lack nuclei (membrane bound organelles) ii) binary fission |
| Eukaryotic cell structure | i) lack cell wall ii) Cytoskeleton iii) mitosis |
| Glycocalyx | -composed of polysacharides, polypeptides or both -survive and cause disease -sticky allow bacteria to adhere to other cells -has moisture to prevent cell from drying out -May hide a cell - unrecognized by the immune system |
| Slime layer | loose, water soluble glycocalyx |
| Capsule | A glycocalyx when repeating units of organic chemicals attached to the cell surface |
| Flagella | A cell's motility, long structures that extend beyond the surface of a cell and its glycocalyx and propel the cell through its environment |
| Flagella Composed of | 1. a long, thin filament 2. a hook 3. a basal body |
| Flagella Motility/Functions | Chemotaxis- Motile through sensing chemicals If chemical compound is nutrient, Acts as attractant If compound is toxic, Acts as repellent Flagella rotation responsible for run and tumble movement of bacteria |
| Gram + Flagella | Peptidoglycan layer (cell wall) Rod Protein Rings Cytoplasmic membrane |
| Gram - Flagella | Basal Body Cytoplasmic membrane Cell wall (outer membrane and Peptidoglycan layer) |
| Basal Body | Outer protein rings Inner protein rings Rod Integral protein |
| Fimbriae | sticky, bristlelike projections, to adhere to one another and to substances in the environment. Shorter than flagella |
| Fimbriae Function | used to move across a substrate or toward another bacterium via a process similar to pulling an object with a rope |
| pilus | A special type of fimbria. Also called conjugation pilus. Pili are longer than other fimbriae and usually shorter than flagella. |
| conjugation pilus | mediate the transfer of DNA from one cell to the other via a process termed conjugation |
| Bacterial Cell Wall | Gram - and Gram + Alternating series of NAG and NAM which is the backbone of the peptidoglycan (found only in bacteria) Chains are attached by cross-bridges of 4 amino acid |
| Gram + cell wall | thick layer Teichoic Acid: covalently linked to lipids forming lipoteichoic acid (anchors the peptidoglycan to the cytoplasmic membrane) |
| Gram - cell wall | Thin layer of peptidoglycan -Periplasmic space (chemical reactions occur) -Porin (integral proteins that regulates what comes in/out of the periplasmic space) -Inner leaflet-phospholipids + proteins -Outer-lipopolysaccharide (LPS) |
| Transport Across Plasma membrane | 1. Simple diffusion 2. Facilitated Diffusion 3. Osmosis 4. Active Transport 5. Group Trans-location |
| Passive Transport | diffusion, facilitated diffusion, and osmosis |
| Simple Diffusion | High to low concentration |
| Facilitated Diffusion | proteins act as channels or carriers to allow certain molecules to diffuse down their concentration gradients into or out of the cell. High to low |
| Osmosis | diffusion of water across a selectively permeable membrane, across a membrane that is permeable to water molecules, but not to solutes that are present, such as proteins, amino acids, salts, or glucose. Continues until equilibrium is reached, water goes into cell and cell wall keeps it from bursting |
| Hypertonic | solution has a lower concentration of water; a higher concentration of solutes . Water will move out, a cell will lose water and shrivel |
| Hypotonic | As water moves into the cell, water pressure against its cytoplasmic membrane increases, and the cell expands. |
| Active transport | Molecules more against the concentration gradient. Low to high. Energy required (ATP or proton motive force) |
| Group Translocation | Active process, occurs in some bact. Substance being transported is chemically changed. |
| cytoplasm of Bacteria | cytosol, inclusions, ribosomes, and in many cells, a cytoskeleton |
| Cytoplasmic Membrane | Structure is a lipid bilayer with embedded proteins Integral and peripheral proteins Bilayer consists of two opposing leaflets Leaflets composed of phospholipids |
| Cytoplasmic membrane functions | Selective permeability Maintain concentration gradients Energy transformations |
| Cytoplasm | Cytoplasm is the gel-like substance inside the plasma membrane. |
| Cytoplasm Internal Structures | 1. Chromosome: Resides in cytoplasm in nucleoid space 2. Plasmid 3. Ribosome- Involved in protein synthesis, composed of large and small subunits |
| prokaryotic ribosomal subunits | Large = 30S Small = 50S Total = 70S Larger than eukaryotic ribosomes 40S, 60S, 80S Difference often used as target for antimicrobials |
| Plasmid | Extrachromosoma, Independently replicating Encode characteristic, Potentially enhances survival Antimicrobial resistance |
| Cytoplasm contains | 1. cytosol 2. ribosomes 3. inclusions 4. cytoskeleton 5. endospores |
| Cytosol | -liquid portion of cytoplasm, mostly water, but contains dissolved and suspended substances (ions, carbohydrates, proteins (mostly enzymes), lipids, and wastes) -contains the cell's DNA in a region called the nucleoid. -a distinctive feature of prokaryotes is lack of a phospholipid membrane surrounding this DNA. |
| inclusions | Deposits, are often found within bacterial cytosol. Rarely, a cell surrounds its inclusions with a polypeptide membrane. Inclusions may include reserve deposits of lipids, starch, or compounds containing nitrogen, phosphate, or sulfur. |
| Endospores | durability and potential pathogenicity constitute a defensive strategy against hostile or unfavorable conditions. |
| Endospores used for survival | 1. Dormant cell types- remain dormant for 100 years 2. Resistant to damaging conditions- Heat, desiccation, chemicals, UV light 3. Vegetative cell |
| Vegetative Cell | vegetative cell transforms itself into an endospore only when one or more nutrients (such as carbon or nitrogen) are in limited supply |
| Vegetative cell produced through germination | -Germination occurs after exposure to heat or chemicals -Germination not a source of reproduction |
| Endospore structure | coat, outer membrane, cortex, germ cell wall, inner membrane, core |
| Endospore formation | Complex, ordered sequence called sporulation |
| Sporulation | Bacteria sense starvation and begin sporulation Growth stops, DNA duplicated, Cell splits Cell splits unevenly, Peptidoglycan between membranes forms core wall and cortex, Mother cell proteins produce spore coat, Mother cell degrades and releases endospore |
| Spherical | Cocci (coccus) |
| Rod | Bacillus |
| Spiral | Spirochaeles |
| Prefix | 1. Diplo - pairs 2. Staphylo - clusters (divides in several planes at random) 3. Strephto - chains (cell divides in one plane) |
| Packets | cell divides in two or more planes, perpendicular to one another |
| Vibrio | Spiral, comma shaped |
| Spirillum | Semi-wavey |
| Spirochete | Really wavey |
| Other shapes | square, star, appendage, filamentous |
| phototaxis | Movement in response to a stimulus is termed taxis. The stimulus is light |
| Acid fast bacteria | Gram-positive cells that contain large amounts of waxy lipids. |
| mycoplasma | lack cell walls entirely. In the past, these bacteria were often mistaken for viruses because of their small size and lack of walls. However, they do have other features of prokaryotic cells, such as prokaryotic ribosomes |
First Time Here?
Welcome to Quizlet, a fun, free place to study. Try these flashcards, find others to study, or make your own.