Chapter 3- Prokaryotic Structure Flashcards
What is the size range of prokaryotic cells? What is the average size of prokaryotic cells?
The average size of a prokaryote is one micron.
Prokaryote cells can be anywhere from .2 µm to 750 µm
Define pleomorphic
Normal variability of cell shapes in a single species
Define Diplo
Two
Define strepto
Chains of few to hundreds
Define staphylo
Irregular clusters
Name to genera of bacteria that are pleomorphic.
Mycoplasma pneumonia
Corynebacterium diphtheriae
What structures are associated with all bacteria?
Cell membrane, cytoplasm ribosomes nucleoid chromosome cytoskeleton.
What structures are associated with most bacteria
Cell wall
What structures are associated with some
Outer membrane, inclusions, intracellular, endospore membranes, plasmid
What are the three parts of flagella? What does flagella consist of?
The filament, the hook or sheath, and the basal body.
Describe the various possible arrangements of flagella.
Monotrichous polar arrangement: a single flagellum.
Loohotrichoud polar arrangement: with small bunches of flagella emerging from the same site.
Amphitrichous polar arrangement: flagella at both poles of the cell.
Peritrichous arrangement: flagella are dispersed randomly over the surface of the cell
What is a basal body
A stack of rings firmly anchored through the cell wall to the cell membrane and the outer membrane that holds the hook
Define chemo taxis. How does it affect bacterial movement.
A reaction in response to chemical signals.
Positive chemotaxis is movement towards a favorable chemical stimulus
Negative chemotaxis is a movement away from a repellent compound.
Describe periplasmic flagella.
Spirichettes are an unusual Wrigley mode of locomotion caused by two or more long coil thread. A periplasmic flagellum is a type of internal flagella that is enclosed in the space between the cell wall and the cell membrane.
What is the difference between fimbriae and pil?
Fimbriae are small, bristle like fibers sprouting off the surface of many bacterial cells. They contain protein. They have the tendency to stick to each other and surfaces.
Pilis are long, rigid and tubular structures made of a special protein, Pilin. They transferred DNA from one cell to another. They are only found on Graham negative bacteria. They are utilized in a mating process called conjugation
What are two types of glycocalyx.
slime layer is loosely attached to cell wall and on organized. Capsule is attached to the cell wall and is very organized.
Describe a cell wall.
Most have cell walls. An organism that does not is called Mycoplasmas. The cell wall helps determine the shape of the bacterium and provide structural support.
Describe the cell wall and a prokaryotic cell.
The cell wall is mainly meet up peptidoglycan, which is made up of glycan, sugar, teens cross-linked by sure peptide, protein, fragments
What are some similarities and differences between the cell wall of a gram-negative and gram-positive bacteria?
Both have a inner cell membrane a layer of Peotidoglycan. Graham negative bacteria have a thin layer of peptidoglycan but they also have an outer membrane layer. Gram-positive has a very thick layer of peptidoglycan.
What is LPS
Lipopolysaccharide
What is an acid fast microbe?
Some cells have walls that are composed of unique types of weapons which can cause them to have an incorrect Gram stain. The thick imparted cell wall by these lipid is responsible for a high degree of resistance to certain chemicals and dyes. Examples include mycobacterium and nocardia – tuberculosis and leprosy
Define protoplast.
A fragile cell bounded only by membrane that is highly susceptible to lysis.
Define sero-blast.
A gram-negative cell who’s peptidoglycan when disguised by lysozyme, remains intact but is Osmotically vulnerable
Define L forms.
Wall deficient forms that would ordinarily have a cell wall but somehow lost it during part of their life cycle.
Which type of bacteria is susceptible to penicillin?
Gram-positive bacteria
Discuss the structure and function of the plasma membrane
Enzymes for ATP production, chromatophores which are in foldings containing photosynthetic pigment and it is selectively permeable
Discuss hypotonic, hypertonic, isotonic
Hypotonic – having a lower osmotic pressure then a reference solution.
Hyper tonic – having a greater osmotic pressure then a reference solution.
Iso tonic – two solutions having the same osmotic pressure such that, when separated by a semi permeable membrane, there is no net movement of solvents and either direction
What types of chemicals can damage the plasma membrane?
Alcohols and detergents, polymyxin antibiotics – gram-negative
Describe the inside of the prokaryotic cell
The cytoplasm, nucleoid, plasmid, prokaryotic ribosomes, inclusions, endospores
What is the difference between chromosomal DNA and plasmid DNA
Chromosome DNA contains information regarding genetic units that are related to bacterial maintenance and growth.
Plasmid DNA does not contain information necessary for growth and maintenance.
What size is prokaryotic ribosomes?
70S
What is the process by which endospores are formed what is the purpose of calcium and dipicolinic acid in the process?
Endospores form through a process of sporulation.
What genera of bacteria can form endospores?
Bacillus, clostridium and sporosarcina
Define germinate and sporulate.
Germination is when the spore swells and then releases the vegetative cell
Sporley send is when the vegetative cell is a metabolically active and growing entity that can be induced by environmental conditions
What is the purpose of the Bergeys manuals
They are used to classify prokaryotes
Bergeys manual of systemic bacteriology
Presents a comprehensive view of prokaryotic relatedness, combining phenotypic information with our RNA sequencing information to classify prokaryotes
Bergeys manual of determinative bacteriology
Based entirely on phenotypic characteristics. It is organized and focus, categorizing bacteria by traits, commonly assayed clinical, teaching, and research labs.
What distinguishes a prokaryotic cell from a eukaryotic cell? What do both cell types have in common?
Prokaryotes don’t wind their DNA around proteins called histones; eukaryotes do. Prokaryotes have a wall structure that is unique: bacteria have dirty walls made up of peptidoglycan. Archaeal walls are tough and made up of other chemicals. Prokaryotes do not have organelles in their cytoplasm.
Prokaryotes and eukaryotes both surround nature and both can cause infectious diseases.
