Question | Answer |
Eukaryotic cells have a N______ and membrane enclosed organelles. | Nucleus |
Membrane organelles are present in Eukaryotic cells are present in: | • Animals
• Plants
• Fungi
• Protozoa |
Bacteria and Archaea are called: | Prokaryotic cells |
Prokaryotic cells do not have: | a nucleus or membrane-enclosed
organelles |
Prokaryotic cells are Differentiation by: | • Morphology
• Cell wall structure
• Nutritional requirements
• Biochemical activities
• Source of energy
• Sequence of genetic material
• Size |
The typical size of a Prokaryotic cell is | – 0.2 to 2.0 um in diameter
– 2.0 to 8.0 um in length |
Most common shapes of bacteria cells are: | Coccus
Cocobacillus
Vibrio
Bacillus
Sprillium
Sprirochete |
Most common shapes of Bacteria cells are: | Coccus
Cocobacillus
Vibrio
Bacillus
Sprillium
Sprirochete |
Chains (prefix strepto) are: | Divide into one plane |
Diplococci | Divided into one plane |
Tetrads are divided : | into two planes |
Sarcinae are divided: | into three planes |
Staphylococci are divided into: | Divide in multiple planes |
Staphylococcus aureus are resistant to _____. | Methicillin-resistant |
Structures external to the
bacterial cell wall are: | • Glycocalyx
• Flagella
• Axial filaments
• Fimbriae and pili |
Glycocalyx is composed of a ______coat | sugar |
Glycocalyx can have a C______or S_____ L____. | Capsule (firm) or slime layer (loose) |
Made of polysaccharides in most bacteria, and
polypeptides in a few bacteria | Glycocalyx |
Glycocalyx main function is to: | • Inhibits phagocytosis
• Attachment to host and environmental surfaces
• Protects against desiccation (dehydration) (outside
environment) |
Bacterial slime in our
food? | Xanthomonas campestris |
Xanthomonas campestris | • Source of the polysaccharide xanthan gum
• Stable at high temperatures
• 1% in water thickens it significantly |
Xanthomonas campestris in foods is used to : | – Emulsifing and stabilizing agent in
salad dressings, ice creams, |
Xanthomonas campestris in the industry is used to : | – Thickening agent (oil industry)
• Drilling “mud” |
Some Biofilm health effects of medical implants are are: | -Catheters
– Heart valves
– Prostheses
– Contact lenses |
Biofilm health effects also include | tooth decay and gingivitis |
Flagella are: | Long filamentous appendagesand are made of the protein flagellin |
Flagella are the bacteria motility. Positve | towards |
Flagella are the bacteria motility. Negative | Away |
T/F Some bacteria lack flagella | true |
Monotrichous | one flagellum |
Atrichous | no flagellum |
Operation of Flagella if it moves counterclockwise : | it runs |
Operation of Flagella if it moves clockwise: | it tumbles |
Axial filaments are present in? | Present in spirochette cells |
Axial filaments are present in? | Present in spirochette cells |
Adapted to viscous fluids and wrap around the cell? | Axial Filaments |
Two types of Axial Filaments are? | Treponema pallidum and – Borrelia burgdorferi |
Treponema pallidum is: | Syphilis |
Borrelia burgdorferi is: | Lyme disease |
Axial filaments are present in? | Present in spirochette cells |
Adapted to viscous fluids and wrap around the cell? | Axial Filaments |
Two types of Axial Filaments are? | Treponema pallidum and – Borrelia burgdorferi |
Treponema pallidum is: | Syphilis |
Borrelia burgdorferi is: | Lyme disease |
Other forms of bacterial motility include: | • Motility over low-water content surfaces
• Gliding motility (smooth)
• Mediated by specialized projections |
Twitching (grappling) motility (jerky)
– Extends adheres contracts | Mediated by specialized projections (pili) or pilus |
Pseudomonas aeruginosa moves by: | twitching |
Fimbriae: | Made of pilin
– Short thin appendages some bacteria
(about 1,000/cell)
• Help cells to adhere to surfaces and to
one another
• Virulence (attachment) factor |
E coli are attached to the intestinal mucosa by: | fimbriae |
Sex pilus are present in gram_____. | negative bacteria |
Sex pilus are made of: | Made of pilin protein |
Sex pilus bridges related bacteria and: | performs a DNA transfer (conjugation) |
The Cell envelope is | All structural
layers covering
the cytoplasm |
The cell wall: | Protects the cell from high internal osmotic
pressure
– Lattice formed by peptidoglycan (murein)
• Strong elastic sac
– Present in most bacteria |
The cell wall is present in all bacteria. T/F | False (the cell wall is present in most bacteria) |
Lattice formed by peptidoglycan (murein)
• Strong elastic sac | cell wall |
Peptidoglycan is a: | Repeating disaccharides crosslinked by
polypeptides |
Gram-positive cells have | Teichoic acids and
lipoteichoic acids |
Teichoic acids and
lipoteichoic acids | -Stability of
peptidoglycans
– Cell division
– Attachment to
surfaces |
Gram-negative cells have | – Lipoprotein-lipopolysaccharide-phospholipid
-A thin poorly-organized peptidoglycan layer
-Outer membrane |
The Outer membrane in
Gram-negative cells : | – Protects against phagocytosis
– Porins
• Transport of small hydrophilic molecules
–Sugar and some amino acids
– Barrier to many substances
• Penicillin
• Lysozyme |
Unique to Gramnegative
cells: | Periplasmic space |
Periplasmic space (periplasm) | • Area between the “two
membranes”
– Contains the cell wall
(peptidoglycans)
– Abundance of digestive
enzymes and selective
transport proteins |
Atypical bacterial cells | Mycoplasma bacteria lack cell walls
Cell membrane contains sterols |
Has a Highly impermeable wax coat
–Mycolic acid: | Mycobacterium tuberculosis (acid fast bacteria) atypical |
– Cell wall contains pseudomurein instead of
murein (peptidoglycans) | Archaea |