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.