Biomed module 6 obj. 1-3
Card Set Information
Biomed module 6 obj. 1-3
Module 6 objective 1-3
What are the medically important microorganism (microbes) asociated with microbiology?
True or false: Prokaryotes have a membrane bound nucleus, membrane bound oranelles, and DNA that is organized into chromosomes
All living cells are clasified as ________ or _________.
What are the five kingdomes that all living organisms are divided into?
Prokaryotes belong to which kingdom?
Monera - consist of all the single celled prokaryons
What is the earths most abundant form of life?
All bactira and prokaryotic organisms
The average size of bacteria are ______ to _____ microns in diameter.
(in comparison the human red blood cell is about 7.5 microns in diametr.)
What do prokaryotes have insteadeof a nucleus?
A nuclear region called a nucleoid which is the cells chromosome.
True or False: All bacteria are prokaryotic cells
Prokaryotes have _______ _______similare to eukaryotic cells. These carry __________ essential to cell function.
Describe the prokaryotic Cell Structures
Cytoplasm- semi-fluid substance that fills inner cellular space
-primarily water with carbohydrates, lipids, and enzymes
Ribosomes- protein synthesis centers
: store molecules essentioal to cell finction
-secrete a capsule
: contributes to pathogenicity
- have plasmids
: Extachromosomal DNA important for transfer of genetic material.
What is a
and what is its function?
A protective structure that serves as a defence mechanism
Tightly bound to the cell wall
Consist of complex polysaccharide molecules that form a gel-like comering that surrounds the bacterial cell
Considered to be a major contrubutor to pathogenicity
Self-replicating extrachromosomal DNA that carry one or more pieces of genetic information
Not required to sustain life
What is a unique feature of a of the majority of prokaryotic bacterial cell walls?
A semi-rigid cell wall
What is the main function of the cell wall?
Provides shape and stability
Located in cell walls of all bacteria
It is an immense, covalenly linked molecule arranged in layers resembling multiple layers of a chain-link fence which give the cell support.
True or false: Many antibiotics target the cell wall
True. (i.e. penicillins)
The _____ _________ is present in all living cells (both prokaryotic and eukaryotic) and regulates the ________ of material in and out of the cell.
Cell membrane, transport
About half of all known bacteria possess filamentous organelles of locomotion call _________.
Are said to be
What are pili?
Tiny tube-like projections from the cells surface
Associated with adherence
Flagella and Pili are examples of what?
Why is the shape and arrangement of prokaryotic cells important?
Bacteria are characterized by their shape and size
Before specific culture information is available, physicians use loction and appearance characteristics to begin andtibiotic therapy.
What are the different kinds of prokaryotic bactirial cells and their shapes?
: oval- between a cocus and a bacillus
: comma shaped
: loosely coiled
: Tightly coiled
What are the distinctive arrangements some bacteria have?
Diplo (pair) -Diplococci (spherical, non motile bacteria)
Stepto (chain) - steptococci
staphylo (irregular cluster)- staphylococci (grapelike cluster)
Tetra (group of four)
A widely accepted means of grouping bacteria
Gram positive bacteria
Thich layer of peptidoglycan and teichoic acid causes retention of crystal violet (blue) dye
Gram negative stain
Thin layer of peptidoglycan and high lipoprotein content; releases crystal violet dye when rinsed with alcohol
The safranun (pink) counterstain is retained
What are the steps of a Gram stain ?
1. A sample is smeared on a slide and fixed with heat.
2. the slide is stained with crystal violet (purple) for 1-2 min
3. Gram's iodine is used to "fix" the crystal violet (helps to retain the stain).
4. Acetone is used to decolorize the slide
5. Stain the slide with safranin (pink).