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60 Cards in this Set
- Front
- Back
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Which type of organism belongs to prokaryotes |
Bacteria |
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Penicillin was called a “miracle drug” because it doesn’t harm human cells. Why doesn’t it?
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Human do not have cell wall. Penicillin only target and disrupt bacterial cell wall
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The universal entity for all prokaryote?
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No nucleus and no membrane-bound cell organelles
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What is the difference between eukaryotes and prokaryotes? |
prokaryotes: no nucleus no membrane bound organelle. Eukaryotes nucleus membrane bound organelles |
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What are structure of the prokaryotic cell |
Appedages-flagellum,fimbriae,pilus Cell envelope: Glycocalyx, cell wall, cell membrane Internal structure: Nucleoid, cytoplasm, ribosome, plasmid,granule, actin cytoskeleton Endospore |
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What is a flagellum and function |
a tail like appendage confer motility and guide bacteria in response to external stimulus |
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What are the 2 stimuli for the flagellum |
chemical stimuli-chemotaxis light stimuli-phototaxis |
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What is the Fimbriae and function |
small bristle-like fiber -enable cells to attach to each other to objects |
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What is the Pilus and function |
an elongate rigid tubular projection involved in mating process |
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What are the types of flagellum |
monotrichous:single at one end Lophotrichous: small branches at one end Amphitrichous: single or branchesat both end Peritrichous: all around the cell surface |
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What makes up the bacterial cell envelope |
Glycocalyx: out most Cell wall:middle layer Cell membrane: most inside layer |
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Which cell structure of the bac. cell wall would prevent the cells from rupturing if bacteria living in salty seawater were displaced to a freshwater environment?
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Peptidoglycan which is the brown region
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What are the types of Glycocalyx |
Slime layer: a loose glycocalyx capsule: a Firm glycocalyx |
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What are the functions of the glycocalyx |
Protect cells from dehydration and nutrient loss – Avoid phagocytosis by white blood cells – Attachment - formation of biofilms
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What is the function of capsule from virulent standpoint?
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Avoid phagocytosis
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What are some Pathogenic Bacteria |
-Bacillus anthracis (cause of anthrax)
• Haemophilus influenzae (cause of meningitis) • Streptococcus pneunoniae (cause of pneumonia) -have capsules |
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What is the peptidoglycan |
is primary component – Unique macromolecule composed of carbohydrate
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What is function of Peptidoglycan |
Determine the shape of bacteria – Keep a bacterium from burst
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What is the difference between gram positive and negative |
Gram-positive: thick peptidoglycan, teichoicacids Gram negative: Thin peptidoglycan outer membrane |
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What is the gram stain |
Differential stain that distinguishes cells with a gram-positive cell wall from those with a gramnegative cell wall
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What to stains do we see? |
Gram-positive - retain crystal violet and stain purple –
Gram-negative - lose crystal violet and stain red from safranin counterstain |
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Why is the gram stain so important |
• Important basis of bacterial classification and identification
• Practical aid in diagnosing infection and guiding drug treatment – E.g. Penicillin G for gram-positive and streptomycin for gram-negative bacteria |
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Do all have cell walls |
Some bacterial groups lack typical cell wall structure
– E.g. Mycobacterium and Nocardia: acid-fast bacteria with mycolic acid cell wall – E.g. Mycoplasma: have no cell wall – E.g. Archaea: no peptidoglycan in the cell wall |
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What is important about mycoplasma |
lack cell walls sterols in plasma membrane smallest known bacteria that can grow outside of host can pass through bacterial filters |
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What is mycoplasma pneumoniae? |
the most important medical species which causes atypical pneumonia
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Why are mycoplasmas resistant to antibiotics that interfere with bacterial cell wall synthesis?
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because mycoplasmas do not have cell wall.
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What is Acid-Fast bacteria |
have mycolic acid in the cell wall
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What is Archaea |
have no peptidoglycan in the cell wall
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What do mycoplasma lack |
a cell wall |
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Antibiotic isoniazid inhibits synthesis of mycolic acid component of cell wall in bacteria. This antibiotic must be effective to against
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, because acid-fast bacteria contain mycolic acid in the cell wall
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What makes up the plasma membrane |
Phospholipid bilayer
• Peripheral proteins • Integral proteins • Transport proteins |
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What is the function of the cell membrane |
Energy reaction - ATP production
• Nutrient processing - transport • Synthesis - enzyme systems located in the membrane |
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What makes up the internal structures |
Cytoplasm
• Nucleoid • Ribosomes • Mesosomes • Granules/Inclusions • Plasmids • Actin cytoskeleton |
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What makes up the cell Cytoplasm |
dense gelatinous solution of sugars, amino acids, and salts – 70-80% water
-serves as solvent |
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What makes up the prokaryotic ribosome |
50s+30s subunit important in protien sythesis |
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What makes up the Mesosomes and its function |
The cell membrane extends inwardly into coiled sacs
Function: increase internal surface area for membrane activity |
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What are the Granules and inclusion and their function |
Intracellular storage bodies
Function: support bacterial requirement when environmental source of nutrients becomes depleted |
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What are nucleoids and their function |
DNA not enclosed by a nuclear membrane
Function:source of genetic information |
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What are chromosomes |
Single, circular, double-stranded DNA molecule that contains all the genetic information required by a cell
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How many chromosome does bacterium have?
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one |
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Bacterial chromosome is in diploid or haploid state?
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haploid |
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What is a plasmid |
Acircular, tiny extrachromosomal DNA which are not essential for growth and metabolism
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What is the function of the plasmid |
1) sources of genetic information, 2) confer protective traits, 3) vehicle for genetic engineering
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What are bacterial endospores? |
Dormant bodies formed when exposed to adverse environmental conditions
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What are bacterial endospores function? |
protection of genetic material during extreme or harsh conditions
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What are endospores |
the hardest of all life forms |
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What is the purpose to form endospore
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to resist adverse environment
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What are Actin cytoskeletons |
Fine protein fibers within cells that contribute to structure and support
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What are the different shapes of bacterias |
Coccus,basillus, spirrllum, irregular |
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Similarities between Archaea and bacteria?
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– Both have cell wall – both have no nucleus and membrane bind organelle
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Differences betweenArchaea and bacteria?
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– Cell wall of archaea lack peptidoglycan – Archaea often live in extreme conditions
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What are the major taxonomic groups |
• Division I-Gram-negative bacteria • Division II-Grampositive bacteria • Division III-Bacteria lacking cell wall • Division IV - Archaebacteria: with atypical compounds in the cell wall (no peptidoglycan) and membrane, |
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What are species? |
a collection of bacterial cells which share an overall similar pattern of traits in contrast to other bacteria whose pattern differs significantly
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What is a strain or variety |
a culture derived from a single parent that differs in structure or metabolism from other cultures of that species
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What is a type |
a subspecies that can show differences in antigenic makeup (serotype) , susceptibility to bacterial viruses (phage type) and in pathogenicity (pathotype)
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These are smallest bacteria which used to be considered as viruses because they can pass through bacterial filters except ?
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Escherichia
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Which cell organelles most closely resembles a prokaryotic cell
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chloroplast & mitochondria
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What is genus ricketsias and its characteristics |
typhus & spotted fever
1. tiny size 2.obligate pracite 3.require alternative hhost |
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What is genus Chlamydias and its characteristics |
atypical pnuemonia 1.tiny size 2. obligae parasite 3.no need alternate host |
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What is genus mycoplasmas and its characteristics |
atypicl pnuemonia 1.tiny size 2. not obligate parasite 3. lack cell wall |
