Chapter 3 Microbiology LS
The outside layer of the outer membrane Gram-negative bacteria is made up of ___________, which contains both lipid A and O antigen.
lipopolysaccharides
Which of the following are found in Gram-negative cells but no Gram-positive cells?
outer membrane
____ is the most thoroughly studied group of antibiotics that prevent the cross linking of adjacent glycan chains in peptidoglycan
penicillin
Flagella
propel the cell with a whip-like motion or thrash back and forth to pull the cell forward.
________ power, also known as resolution, is the ability to show detail in an enlarged image.
resolving
Compared to sporulation, the process of germination is ______.
shorter
Hypotonic
the less concentrated solution
hypotonic
the less concentrated solution.
Which process involving endospores takes longer?
- sporulation
What does selectively permeable mean?
allows passage of only certain substances
The cell wall is part of a bacterium's
cell envelope
Which cell structure provides strength and rigidity to a cell?
cell wall
The gram stain is an example of a ________ stain because it separates bacteria based on their cell wall structure.
differential
Which of the following describes the functions of the cytoplasmic membrane?
- a barrier between the interior and exterior of a cell.
Bacterial cell components are medically relevant because they___________.
- can be used to help identify a bacterium causing an infectious disease. -are potential targets for antibacterial medications used to treat infectious diseases.
The prokaryotic cell envelope consists of which of the following?
- cytoplasmic membrane -cell wall -capsule ( if present)
From a bacterium's perspective, what are the advantages of endospore formation?
- endospores are highly resistant to radiation and heat. - the endospore provides protection in dry conditions. -the endospore is more resistant to disinfectants.
Differential stains include_________.
- gram stain , acid fast stain
Meiosis
- haploid daughter cells are generated from a diploid parent cell.
Which of the following describes how penicillin affects peptidoglycan?
- interferes with the synthesis of peptidoglycan -inhibits enzymes that make peptidoglycan -prevents cross-linking of adjacent glycan chains.
Which of the following describes how penicillin affects peptidoglycan?
- interferes with the synthesis peptidoglycan -prevents cross-linking of adjacent glycan chains -inhibits enzymes that makes peptidoglycan
Compared to a typical prokaryotic cell, a eukaryotic cell is generally much __________.
- more complex - larger
Which of the following are found in Gram-negative cells but not Gram-positive cells?
- outer membrane
A coccus is a bacterium that has a ______ shape, whereas a road ( or bacillus) is a bacterium that has a ______ shape.
- spherical; cylindrical
What is involved in making a smear?
- spreading a thin film of suspended cells on glass slide. -air drying a liquid that has been placed on a glass slide.
Hypertonic
- the more concentrated solution.
Bacterial cell components are medically relevant because they_______.
-are potential targets for antibacterial medication used to treat infectious diseases -can be used to help identify a bacterium causing an infectious disease.
The two most common examples of endospore-forming genera are ___________ and _____________.
-clostridium, bacillus.
A colorless microorganism against a colorless background is difficult to see in a bright-field a microscope because of the low _______.
-contrast
Which of the following are groupings of cells resulting from the division process?
-cubical packets -diplococci -chains -grape-like-clusters
Which structure separates the inside of a cell form the outside?
-cytoplasmic membrane
Lipopolysaccharide ( LPS) is sometimes referred to as ______.
-endotoxin
The _________ stain technique allows a microbiologist to differentiate bacteria based on their cell wall composition/structures.
-gram
Which of the following describes how penicillin affects peptidoglycan?
-inhibits enzymes that make peptidoglycan -interferes with the synthesis of peptidoglycan -prevents cross-linking of adjacent glycan chains
Cilia
-move in synchrony to move a cell forward or to propel surrounding material along a cell .
The most significant difference between eukaryotic and prokaryotic cells is the presence or absence of a membrane-bound _______, which contains the genetic material
-nucleus
The most significant structural difference between eukaryotic and prokaryotic cells in the presence or absence of a membrane-bound __________. Which contains the genetic material.
-nucleus
Neisseria gonorrhoeae is a diplococcus. This indicates that the bacteria occur as ________>
-pairs of cells
Which eukaryotes have cell wall?
-plant - fungal
A __________ is a circular DNA molecule that is similar than the chromosome and typically encodes non-essential characteristics that can be advantages to a cell.
-plasmids
Which term means that a cell can have various shapes?
-pleomorphic
In microcopy, immersion oil is important when using the 100x lens because it________.
-prevents the image from looking fuzzy -has nearly the same refractive index as glass.
The environment in which bacteria and archaea normally live are very dilute ( hypotonic.) As a result of osmosis, their cytoplasmic membrane therefore_________.
-pushes up against the rigid cell wall.
A cytoplasmic membrane protein that faces the outside of a cell often binds a specific ligand, thereby function as ________ for that ligand.
-receptor
Compounds that interfere with the synthesis or structural integrity of peptidoglycan can __________.
-result in bursting of a bacterial cell.
Compounds that interfere with the synthesis or structural integrity of peptidoglycan can _________.
-result in bursting of bacterial cell
In prokaryotic cells, proteins are synthesized by__________.
-ribosomes
The cytoplasmic membrane is a _________ permeable barrier of the cell.
-selectively
Molecules that pass freely through a lipid bilayer can move across the cytoplasmic, membrane by _____________ diffusion.
-simple
Why are cells sometimes difficult to see in a wet mount?
-some are transparent - some move quickly
Cells of which bacterial genus typically occur in grape-like clusters?
-staphylococcus
If a cell has more than enough of a carbon source, but not enough nitrogen, then that cell might use the carbon source to produce.
-storage granules.
Which type of electron microscope would be used to observe the final details of cells structure?
-transmission
True or false: Although eukaryotic flagella and cilia appear to project out of the cell, they are covered by extensions of the cytoplasmic membrane.
-true
Mitosis
-two diploid daughter cells are generated from a diploid parent cell . -
The maximum resolving power of the best light microscope is approximately____________.
0.2um
In microscopy, immersion oil must be used for viewing a specimen using with which lens?
100x
True or false: Injecting lipopolysaccharide ( LPS) into an animal causes symptoms characteristic of infections by live bacteria.
TRUE
Penicillin interferes with the synthesis of peptidoglycan and lysozyme degrades peptidoglycan. Based on this information, you can conclude that penicillin and lysozyme may result in bursting ( lysing) of which type of cells.
bacteria
A distinct and gelatinous layer surrounding a cell is called a ________.
capsule
lipid raft
cholesterol-rich region where many viruses enter or exit cells
The bacterial cell illustrated in this figure is a ________.
coccus
Long protein structures responsible for most types of prokaryotic motility are called _______ flagella.
flagella
__________ involves applying colored chemicals ( dyes) to specimens so that they can be better visualized.
staining
__________ involves applying colored chemicals colored chemicals (dyes) to specimens so that they can better visualized.
staining
Cholesterol
sterol in animal cells
ergosterol
sterol in fungal cells that is a target for anti-fungal medication
isotonic
solution that is equal in concentration
istonic
solution that is equal in concentration.
Endospores ___________.
-are common in soil, and can therefore be found nearly anywhere. -can germinate to produce vegetative cells, which can then multiply. - are very resistant to damaging conditions, including high heat, toxic chemicals, UV light.
hypertonic
more concentrated solution.
Which term is used exclusively to describe water's movement across a selectively permeable membrane?
osmosis
A gel-like substance called ______ fills the region between the cytoplasmic membrane and the outer membrane in Gram-negative bacteria
periplasm
The cytoplasmic membrane of prokaryotes is composed of a _______ with proteins.
phospholipid
In contrast to an endospore, a typical multiplying cell is called a(n)__________ cell.
vegetative cell
Which of the following would you expect to be the shortest cell type?
vibrio
Unlike a stained specimen, living moving cells can be observed using a _______mount
wet