Bacteria Flashcards
All bacteria have a ____ ____ which is a thin sheet of lipid and proteins surrounding the cytoplasm
Cell (cytoplasmic) membrane
All bacteria have a _____, which is composed of condensed DNA molecules. All bacteria also have ____, composed of protein and RNA. All bacteria also have a _____, a water based solution filling the entire cell.
Nucleoid or bacterial chromosome
Ribosomes
Cytoplasm
____ is a layer of protein used for protection and attachment. ____ are fine hairlike bristles extending from cell surface that help with adhesion. Not all bacteria have these features
S layer
Fimbriae
Gram negative bacteria cells have an ____ membrane.
Outer
A ____ is a double stranded DNA circle containing extra genes in some bacteria
Plasmid
A _____ is an appendage used for drawing another bacterium close in order to transfer DNA to it
Pilus
______ do not have internal membrane bound organelles. They do share some basic structures in common with eukaryotes including cytoplasm, cytoplasmic membrane, ribosomes, and usually a cell wall.
Prokaryotes (bacteria)
In eukaryotic cells only ____ have a cell wall.
Plants
The ____ is a membrane bound structure that contains the chromosomes and eukaryotic cells. The _____ is the aggregated mass of DNA that constitutes the chromosome of bacteria and Archaea
Nucleus
Nucleoid
______ are circular extra chromosomal genetic elements that are not essential for growth. They often carry drug resistant genes.
Plasmids
Cytoplasmic membranes of bacteria are composed of ____ similar to eukaryotic cells. The proteins involved in ____ synthesis are found in bedded in the membrane of bacteria.
Phospholipids
ATP
____ ____ in the membrane is a site of many proteins that participate in transport, bioenergetics and chemotaxis
Protein anchor
Another function of bacterial membrane is ___ ____. It serves as a site of generation and use of the proton motive force.
Energy conservation
Many bacterial cell walls are made of _____. Peptide bonds and glucosidic binds hold this structure together
Peptidoglycan
Peptidoglycan consists of strands of alternating repeats of ____ and _____ with the latter cross-linked between strands by peptides.
N-acetylglucosamine
N- acetylmuramic acid
Each peptidoglycan, repeating subunits is composed of four amino acids: ____, _____, ____ , ____. and two N-acetyl glucose like sugars
L alanine
D alanine
D glutamic acid
Lysine
Here is a unit of peptidoglycan:
It is linked left to right using ____ bonds and linked top to bottom using ____ bonds.
Glycosidic
Peptide
This picture is showing:
Glycosidic bonds between sugars G and
M. And peptide bonds between amino acids
Bacteria are constantly breaking down and remaking ____ in the cell wall because they are consonantly replicating. Drugs commonly target the cell wall of bacteria like penicillin
Peptidoglycan
_____ is a sugar protein rich area that gets secreted out onto the surface of a cell. If it is loosely associated with the cell, we call it a ___ ___.
Capsule
Slime layer
Capsules and slime layers form _____, where cells form a dense mat bound together by sticky extra cellular deposits. Additional microbes are attached to develop in film and create a mature community with complex function
Biofilm
What are the important encapsulated bacteria?
Encapsulated bacteria can avoid our ___ system.
Immune
What are the four structures that all cellular life have in common? What are the functions of those structures?
What is a plasmid?
Describe the structure of the cell wall of bacteria. What is it composed of? How is it constructed?
Classifying bacteria by morphology
_____ improves contrast. Examples of common stains are methylene, blue, saffron, and crystal violet. Dyes generally carry a ____ charge.
Staining
Positive
A ____ is prepared by spreading culture in a thin film over a slide, and allowing it to dry
Smear
____ ____ is when you pass the slide through a flame to ensure the bacteria will stick on the slide while staining
Heat fixing
When viewing a slide under a microscope a drop of ___ should be placed on the slide and examined with ____ objective lens
Oil
100x
The oil ensure that the ____ moves through the glass continues to to move through a substance that has the same refraction as glass to capture as much light as possible
Light
This is showing
Cocci in chains
Gram staining is a differential stain. Bacteria can be divided into three major groups: ____, ____, and ____
Gram-positive
Gram-negative
On stainable
What is this picture showing
Gram-positive cocci bacteria
Gram-negative rod bacteria
Both gram-positive and gram-negative bacteria have a ____ ___ but they differ in structure. Gram ____ cell walls tend to be very thick. ____ acid is only found in gram positive cell walls
Cell wall
Teichoic acid
This is showing
Gram positive cell wall under a microscope, it appears very smooth
Gram negative cell walls have a ___ layer of Peptidoglycan. The crystal violet dye is unable to crystallize in the peptidoglycan of a gram-negative bacteria due to the ____ membrane.
Thin
Outer
Outer
The ____ is the space between the end of the cytoplasmic membrane to the start of the outer membrane
Periplasm
_______ is a component of gram-negative cell walls that contain Lipid A, which is a toxin to other cells. Lipid a is called a _____.
Lipopolysaccharide (LPS)
Endotoxin
What is this showing
Gram negative cell wall under a microscope, appear more rough
Bacteria that do not Gram stain well are classified. _____ means too thin to be visualized. ____ means the cell wall has high lipid content. _____ means there is no cell wall (it dissolves in dye)
Leptospira
Mycobacteria
Mycoplasma
These are all examples of….
Bacteria that lack the classic Peptidoglycan cell wall and can not be stained as well
_____ stain binds to the phosphate groups of DNA in AT rich sections also used to visualize chromosomes of cells. Used to visualize chlamydia, borrelia, rickettsia
Giemsa
______ stain is used for mycobacteria and Norcardia. It uses carbofuchsin and heat to make the organisms retain the dye even after the application of acid alcohol.
Acid-fast
What is the difference between a simple staining procedure and a differential staining procedure?
Compare gram-positive cell walls to gram-negative cell walls
Name reasons why a bacterial cell would not be stainable
____ ____ is bacteria cell division. Steps are cell _____, ____ formation, and cell _____.
Binary fission
Elongation
Septum
Separation
Bacteria cells grow _____, which is best seen by plotting the number of cells over time.
Exponentially
Exponential growth plays in to pathways of _____. They can colonize and grow very rapidly
Infection
The most common portals of entry include your ____, ____ tract, and ____ tract.
Skin
GI
Respiratory
Wounds in your ____ can be an entry point for bacteria. _____ that cause skin rashes usually enter at other sites of the body and then spread systemically
Skin
Viruses
Pathogens can reside in ingested ___ or ___ and infect the GI tract
Food
Water
_____ is a commonly inhaled pathogen that causes a sore throat
Streptococcal
______ transmitted infections account for 4% of all infections worldwide. They mainly infect the urogenital tract
Sexually
Some pathogen such as ____ can cross the placenta and enter the umbilical vein. The common infections of fetus and neonate are grouped together in a unified cluster known by the acronym _____, this stands for: ________
Syphilis
TORCH: toxoplasmosis, other diseases, rubella, cytomegalovirus, and herpes simplex
Pathogens use _____, ______, or _____ to attach themselves to the host
Fimbriae
Capsules
Spikes
_____ ____ are virulence factors that help pathogens cause an infection. The most aggressive strategy involves bacteria that kill ____.
Antiphagocytic factors
Phagocytes
Species of strep and staph both produce ____ substances that are toxic to white blood cells
Leukocidins
Some bacteria have adapted to survive ____ phagocytes after ingestion
Inside
_____ _____ are secreted by pathogens they break down and damage tissues, dissolve the host defense barriers, and promote the spread of microbes to deeper tissue
Extracellular enzymes
_____ are classified by target, organ system, mechanism of production and biological function
Toxins
______ can deliver toxins into a cell
Injectosome
____ produces at least three different types of toxins (enterotoxin, endotoxin, and cytotoxin)
Salmonella
A _____ is a type of virulence factor and is a iron scavenging protein
Siderophores
______ inhibits host cell protein synthesis. Functions within the G.I. tract.
Cytotoxin (enterotoxin)
_____ inhibits, compliment, binding and antibodies function also used for adherence
Capsule
_____ is used for motility adherence and inhibiting phagocyte killing
Flagellum
_____ inhibits phagocyte killing
O antigen
_____ is derived from LPS in the outer membrane
Endotoxin
_____ are secreted into the environment by the pathogen
Exotoxin
_____ exotoxin causes cell lysis. It creates an ____ ____ in the cytoplasmic membrane on the target cell that allows for influx and efflux of material
Cytolytic
Alpha pore
Some cytolytic exotoxins directly target red blood cells. They are called _____. (Alpha, beta, gamma)
Hemolysins
_____ hemolytic bacteria produce a cytolytic exotoxin that damage red blood cells and spill out their contents, and those contents become oxidized, forming a brownish green color in the Petri dish
Alpha
_____ hemolytic bacteria produce cytolytic exotoxins that completely destroy red blood cells.
Beta
_____ hemolytic bacteria do not produce toxins against red blood cells.
Gamma
____ toxins have an active part and the binder part. An example is the A will phosphorylate _____ , translation is stoped and cell dies
AB
EF2
____ is an exotoxin that specifically affects the nervous system. Example is _____ it blocks the release of acetylcholine, the cell is no longer able to control muscle movement
Neurotoxin
Botulism
______ is a neurotoxin that binds to inhibitory interneurons, preventing release of lysing. This prevents the muscle from being able to relax.
Tetanus
_______ is an exotoxin that functions by forcing a T helper cell to bind to a macrophage or B cell. This causes inflammation, activates a lot T helper cells and produces a ____ ____ which can be lethal
Superantigen
Cytokine storm
______ is the most common example of an endotoxin. It produces Lipid A. this is not an exotoxin because it is not being secreted.
LPS
What is this showing?
LPS.
_____ can target specific cells and are generally destroyed by heat, generally only need low doses. They don’t always cause fevers.
Exotoxin
_____ are usually part of the cell itself, it gets released in high concentrations which caused general physiological factors, such as fever malaise aches. Not easily destroyed by heat.
Endotoxin
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