Morphology – Flashcards
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Unlock answersWhat are the three major morphological froms of bacteria? And describe their shape? |
Cocci-sphere Bacilli-rods Curved or spiral forms |
What are the types of cocci and describe each? |
Diplococci are pairs of cocci Streptococci-are chains of cocci Staphlococci-irregular clusters of cocci |
What are the different types of bacilli? |
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Name curved or spiral forms of bacteria |
Vibros-curved rods Spirilla-s haped Sprioochetes-sprial forms Leptospira-tightly wound spiral forms Borrelia-very tight wound sprial forms |
What is a virulence factor that promotes attachment to the host tissue and allows colonization? |
FIMBRIAE/PILI |
What can be used as serologic markers termed the H Antigen? |
Flagella |
What does the GRAM (+) Bacterial cell wall consist of? |
Consists of polymers such as NAM (N-acetylmuramic) and NAG( N-acetylglucosamine)with a 1,4 Beta Bond.They have other polymers attached to the peptidoglycan which are teichoic acids and lipoteichoic acids. |
What do teichoic acids and lipteichoic acids do? |
They bind to specific receptors on the cells and play a role in anchoring sites to the cytoplasmic membrane. Techoic acids are only found in the Gram (+) cell wall and comprise major antigens. |
What can act as a virulence factor that promites spread of infection and attachement? |
Flagella. |
What is a slime layer? |
Glycocalyx is a polysaccharide coating that covers bacteria and allows them to adhere to the oral mucosa, teeth, heart valves and catheters. |
What does the Gram (-) bacteria cell wall consist of? |
Its a bilayer that consist of phospholipids, proteins and lipoploysaccharide.It has a monolayer of peptidoglycan. |
What do you call th rod shaped protein structures that Streptococcus crista contains? What are they important for? |
Fibrils-They are distributed over the cell in a patchy way. They are important for host colonization and the formation of biofilms. Important as receptors as well. |
What are the structures that are involved in the conjugation of Gram (-) bacteria? |
Pili |
What structure is in a sheath and and are attached to and wound around the long axis of the cell? |
Periplasmic Flagella. |
What is a protein on the outer membrane of the Gram (-) bacteria? |
Porins |
What is Lipopolysacchirde? |
It is found in all Gram (-) bacteria. It is composed of Lipid A, core polysaccharide, and O- specific polysacchride. It causes fever and shock. |
When a cell is in a slime layer, what is the discrete encasement? |
Capsule. |
What kind of structure do Spirochetes have that cause them to have a twisting motion? |
periplasmic flagella |
What are some hairlike filaments that occur over the entire cell? |
Fimbriae/Pili |
What is the Glycocalyx?What is its serological designation? |
It is a slime layer that increases the virulence of pathogens by building a resistance to phagocytosis, adhere and develop biofilms, and help protect them from antibiotics. The K-Antigen |
What do E-Coli contain on the cell surface? |
Fimbraie/Pili |
What is a Gram Stain? |
Gram (+) and Gram (-) are stained with CV and I. The Gram (+) bacteria traps the CV and I with dehydration and reduces porosity with ethanol. The thin peptidoglycan wall of the Gram (-) loses the CV and I and when safranin (a red colored dye) is applied the Gram + is purple and the Gram - is pink/red. |
Neisseria meningitidis and Staphylococcus aureus is Gram + or Gram -? |
Staphylococcus is Gram + and Neisseria meningitidis is Gram -. |
What is the periplasmic gel ? |
Area between the outer membrane and inner plasma membrane of the Gram - bacteria where hydrolytic enzymes and binding proteins are held that are involved in transport and chemotactic receptor activities. |
What act as virulence factors in the pathogensis of diesease? |
Hydrolytic Enzymes and exotoxins in the cytoplasmic memebrane. |
What are endospore resistant to? |
disinfectants, antibiotics, and dyes. They can withstand heat, poor nutrient supply and water. |
How are nucleoids attached to the cytoplasmic membrane? |
Via Mesosomes. |
What is a single diffuse chromosome ? |
Nucleoid |
Why can transcription and translation occur at the ribosome simultaneously? |
Because there is no nuclear membrane |
What is a mesosome? |
Invagination of the cytoplasmic membrane and is attached to the nuceloid. |
What does the nucleoid lack? |
A nuclear membrane and histone proteins. |
What % of RNA and protein does the ribosome contain? |
%30 protein %70 RNA |
What is an extra choromosomal DNA that is resistant to antibodies? |
Plasmid. |
What protects the Endspore from toxic environments? |
Spore coat of keratin like protein. |
What do call nutrient reserves that include polysaccharids, lipids or phosphates? |
Cytoplasmic granules (inclusions) |
What are some diseases caused by spore forming bacteria? |
Anthrax Botulisim Tetanus Gas Gangrene |
What do spirochetes use for movement? |
Axial Filament. |
Where is energy and proteins synthesized? |
Nucleoid |
What is a spore bearing bacilli? |
Clostridium tetani |
What is a capsulated and flagellated bacillus? |
E coli |
What is the size of bacteria? |
.2-5 um. |
A have ribosomes B possess Golgi apparatus C have their genetic material organized in the cytoplasm D reproduce by binary fission only E do not have introns in their Mrna * TRUE OR FALE Prokaryotes are different from eukaryotes in that prokaryotes: |
A. F B. F C. T D. T E. T |
What kind of bacteria is pili mainly found on? |
E Coli |
Bacterial capsule: A mediates adhesion to surfaces B hinders the action of phagocytes C helps in identification D is antigenic E in all species is made up of polysaccharides
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What bacteria has the ability to produce extracellular polysaccharides (slime layer) in the presence of dietry sugars such as sucrose? |
Streptococcus mutans. |
What is the cell wall of bacteria made up of? |
Peptidoglycan |
What mediates the adhesion of bacteria to human tissues or prosthesis? |
The capsule |
What determines the serological type in the bacterium? |
By the antigenic differences of the sugars in the polysaccharide. |
A cytoplasmic membrane B ribosomes C cytoplasmic inclusions D spores E nucleoid F fimbriae G flagella 1. associated with oxidative phosphorylation 2. mediates cell motility 3. a source of stored energy 4. protein synthesis 5. enables survival under harsh environmental conditions 6. mediates host attachment 7. enables selective transfer of molecule in and out of the cell 8. resembles a single chromosome
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A 1 and 7 B 4 C 3 D 5 E 8 F 6 G 2
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