microbiology chapter 4
The lipid portion of lipopolysaccharide (LPS) is also known as
endotoxin
____________ possess DNA enclosed in a nucleus and membrane-bound organelles whereas ____________ cells do not encase their DNA or organelles in a membrane.
eukaryotes bacterial
which is NOT a factor in endospore formation?
excess moisture
The _________ is a polysaccharide protective coating outside of the bacterial cell wall that is called either a capsule or slime layer based on its structure
glycocalyx
Lipopolysaccharide is a component of the cell membrane of which cell type?
gram-negative
which of the following have the thickest layer of peptidoglycan in the cell wall?
gram-positive bacteria
Cytoplasmic _________________, such as granules or vesicles, can store organic and inorganic nutrients and even gases or magnetic iron oxides
inclusions
A nucleoid, inclusions and cytoskeleton are _______________ structures found in bacteria
internal
Which type of microscopy is most commonly used in college laboratories to view bacterial cells?
light
LPS is the abbreviation for
lipopolysaccharide
The outer membrane of a gram-negative cell contains:
lipoproteins lipopolysaccharide
cell breaking or rupturing is known as cell
lysis
The __________ bacteria have no cell wall, but have a cytoplasmic membrane that is stabilized by sterols.
mycoplasma
only gram- _________ bacteria possess an outer membrane
negative
Gram- __________ cell walls are thinner than gram- _______________ cell walls, providing them with relatively greater flexibility and sensitivity to lysis
negative, positive
Bacteria possess ______ chromosome(s)
one
The phospholipid barrier surrounding the peptidoglycan layer in gram-negative bacteria is called the _______ membrane.
outer
Capsules protect against bacteria against immune cells known as
phagocytes
Small proteinaceous appendages in gram-negative bacteria that function in DNA exchange are called conjugation
pili
A ___________ is an extrachromosomal piece of DNA that contains genes not essential for cell growth.
plasmid
What are porins?
protein channels that span the outer membrane
The site of protein synthesis in the cell, known as the _________, is composed of rRNA and protein
ribosome
the cell membrane is a ________ permeable barrier of the cell
selectively
Some bacteria are covered with a loose shield called a ______ _______ that protects the cell from dehydration and loss of nutrients
slime layer
A coccus is a ____-shaped bacterial cell
spherical
the helical structure of a ________________ is more rigid than the spring-shaped form of a spirochete.
spirillum
A ___________ is a flexible, spiral-shaped bacterium with periplasmic flagella
spirochete
The depletion of nutrients is a stimulus for ___________ in bacteria
sporulation
Research shows that attractant molecules inhibit movements called _________, while repellents cause them to occur more often
tumbles
A curved rod (comma-shaped bacterium) is specifically described as a
vibrio
The bacterial cell shape illustrated in this figure is (3 comma shape)
vibrio
The glycocalyx is important in the ability of bacteria to cause infection because it
-Allows for the formation of biofilms -Allows the bacteria to adhere well to medical devices -Helps the bacteria evade immune defenses
The bacterial ribosome is a _____________ S ribosome
70
What is the difference between a true nucleus and a nucleoid?
A true nucleus is surrounded by a membrane whereas nucleoid is not
Which of the following are functions of the glycocalyx
Adherence Protection
Function of fimbriae
Adhesion
A cell membrane, ribosomes, chromosome(s), and cytoplasm are found in _______ bacterial cells
All
Which is true regarding all bacterial cells?
All lack a nucleus
What does selectively permeable mean?
Allows the passage of some materials, but not all materials move through freely.
Which of the following are types of flagellar arrangements with more than one flagellum?
Amphitrichous Peritrichous Lophotrichous
Which of the following are medically relevant endospore-producing genera?
Bacillus Clostridium
Diseases caused by endospore-forming bacteria
Botulism Tetanus Anthrax
Two types of glycocalyx in bacteria are:
Capsules Slime layer
Two main components of the cell envelope in most bacteria are the:
Cell membrane Cell wall
What cell structure is designed to provide shape, support and resistance to osmotic pressure?
Cell wall
Choose the characteristics that are distinguishable between eukaryotes and bacteria/archaea
Cell wall composition Presence of organelles
The prefix "staphylo-" is used to indicate that the cells are arranged in:
Clusters
What internal structure contributes to cell shape and division?
Cytoskeleton
Which of the following describes cocci in pairs?
Diplococci
Which is NOT a factor in endospore formation?
Excess moisture
The glycocalyx, fimbriae, flagella, and pili are all examples of ______ structures found in some bacteria.
External
True or False: Bacterial endospores are reproductive structures
False
Which appendage(s) provide motility?
Flagellum Axial filaments
Which structures are possessed by a majority (but not all) of bacterial cells?
Glycocalyx Cell wall
The _______ stain technique is a differential staining methods that allows a microbiologist to classify bacteria based on their cell wall composition/structure.
Gram
What two macromolecules make up the major components of cell membranes?
Lipids Proteins
What roles do teichoic and lipoteichoic acid play in gram-positive cells?
Maintenance of the cell wall Contribute to charge of the cell surface Enlargement during cell division
The ability to move is referred to as _________
Motility
A ____________ is a hollow, protein tube that facilitates the transfer for genetic material between bacterial cells.
Pilus
Which phrase means that a cell can have various shapes?
Pleomorphic
Proteins are synthesized on the ________________, a small spherical structure located in the cytoplasm or attached to the rough endoplasmic reticulum (RER)
Ribosome
Which cellular structure is responsible for synthesizing protein?
Ribosome
Which organelle's small and large subunits are composed of rRNA and protein?
Ribosome
Which structures are possessed by ALL bacteria?
Ribosomes Chromosomes Cell membrane
A bacillus is a _____ -shaped bacterial cell.
Rod
_______ are counterclockwise rotations by flagella that propel a cell forward, whereas _________ are clockwise....
Runs, tumbles
Which term refers to the discharge of metabolic product to the extracellular environment?
Secretion
Which structural differences are found in gram-positive cells but not in gram-negative cells?
Single lipid-based membrane Teichoic acid.
What are the three most common shapes of bacterial cells?
Spirillum Coccus Bacillus
____________ is the process of endospore formation.
Sporulation
Bacterial endospores are involved in
Survival
Which of the following are terms that represent cocci in groups?
Tetrads Staphylococci Streptococci
Which of the following makes bacteria and archaea different from eukaryotes
They lack a nucleus
Which of the following describes the primary "function" of the cell membrane?
a barrier btwn the internal and external contents of the cell
The _____________-__________ stain technique would be used to discover mycobacterium tuberculosis in a sputum sample.
acid-fast
What is the glycocalyx?
an extracellular coating that provides protection to the cell.
Plasmids typically carry ______ genes.
antibiotic resistance nonessential
The main function of fimbriae is _________ to cells and other surfaces
attachment
A(n) ____________________- filament is a periplasmic flagellum found in some spirochete bacteria/
axial
Twisting or flexing of spirochete bacteria is attributed to its:
axial filaments
A term that best describes the morphology of the cells seen here is
bacilli
The proper term for a rod-shaped bacterial cell is a
bacillus
Cylindrical bacterial cells are called ___________, whereas spherical bacterial cells are called ________________.
bacillus coccus
The three most common shapes of bacterial cells are known as _______ , _______ and spirillum/spirochete bacteria. Use technical term.
bacillus, cocci
Peptidoglycans are components of the cell walls in ______________
bacteria
The ___________________ is the name given to a structure external to and bound tightly to the cell wall that is made of polysaccharides and proteins and contributes to the pathogenicity of the organism
capsules
The prefix "strepto-" is used to indicate that the cells are arranged in:
chains
During __________, bacterial cells move by flagellar motion in response to chemical signals
chemotaxis
To move towards a chemical attractant by flagellar motion is referred to as positive
chemotaxis
The hereditary material of a bacterial cell is a (normally) single circular strand of DNA known as the bacterial __________, which is aggregated in the nucleoid
chromosome
A spherically-shaped bacterial cell is termed a
coccus
The bacterial cell shape illustrated in this figure is a: (two circles)
coccus
The genetic exchange of material through pili is termed
conjugation
The internal gelatinous matrix of a cell, mostly composed of water, is referred to as
cytoplasm
The intracellular gelatinous solution is referred to as:
cytoplasm
In bacteria, sporulation is the process of _______ formation
endospore
Which of these statements indicate ways that the cell envelope contributes to functional differences between bacterial cells?
-Cell wall components interact with human tissue and cause disease -Different drugs are often requires to kill gram-negative cells -The outer membrane in gram-negative cells makes them more resistant to control methods.
The functions of the cell wall include:
-Maintaining the shape of the bacterium -Preventing destruction with changes in osmotic pressure.
what are the advantages of endospore formation?
-Protection in dry conditions. -More resistant to antimicrobial agents. -Resistant to radiation and heat.