Chapter 4

The molecule primarily responsible for the strength and stability of the bacterial cell wall is

peptidoglycan.

Ribosomes function primarily to

synthesize proteins.

Prokaryotic cells have no nucleus or membrane-bound organelles?

True

What best describes Pleomorphism?

Variation in cell shape and size within a single species

The best understood bacterial cytoskeletons are composed primarily of

actin.

The bacterial flagellum moves

by rotation that is powered by the proton motive force.

True or False: Cyanobacteria are of interest (and are named for) their ability to degrade areas contaminated with cyanide.

False

match the cell arrangement to the statement that most accurately describes that arrangement and how it was formed in order to test your understanding of the arrangements of bacteria.

1. This arrangement is formed when a coccus divides on a single plane and the two daughter cells remain attached. - diplococci 2. This arrangement is formed when a coccus divides on perpendicular planes and results in four cocci being attached as a cluster of cells. - tetrad 3. This arrangement is formed when bacilli that are attached end to end fold back on each other to form rows of side-by-side cells. - palisades arrangement 4. This arrangement is formed when two rod-shaped bacteria divide on the transverse plane and do not separate. - diplobacilli 5. This arrangement is formed when rod-shaped bacteria divide multiple times on their transverse planes and do not separate therefore the cells continue to be attached to each other. - streptobacilli

order the following choices (1 being the smallest to 4 being the largest) to test your understanding of the size ranges of bacteria in comparison to other organisms.

1. a typical virus 2. rickettsias and chlamydias 3. typical bacteria 4. human red blood cell

Match the cell component with its role in the cell.

1. chromosome - The structure which contains the essential DNA of the cell. 2. plasmid - The structure which contains the nonessential DNA of the cell. 3. ribosome - Composed of RNA and protein, this structure synthesizes new proteins. 4. cytoskeleton - This structure is a network of protein polymers that helps stabilize the shape of the cell from within. 5. inclusion bodies - This structure stores nutrients during periods of ample resources to compensate for times when nutrients are scarce. 6. granules - This structure stores inorganic compounds, such as sulfur and polyphosphate.

order the following choices to reflect the generalized anatomy of bacterial cells with "1" being the innermost cell component and "4" being the outermost cell component.

1. cytoplasmic matrix 2. cell membrane 3. cell wall 4. glycocalyx

match the appendages to the description that most accurately describes their function to distinguish among the types of external cell appendages.

1. flagella - composed of a filament, hook and basal body, these cell appendages provide movement to the cell 2. axial filaments - these long, coiled threads provide movement to spirochetes

match to cell component with the statement that most accurately describes it to test your understanding of glycocalyx, the different forms and their most important functions.

1. glycocalyx - this is the general term which describes all the various coatings covering the surface of the cell 2. slime layer - this loosely attached, thin mucoid layer protects the cell from drying out or losing nutrients 3. capsule - this layer of polysaccharides and/or proteins is tightly bound to the cell and contributes to the cell's pathogenicity

match the cell types with the statements that most accurately describe them to test your understanding of cell walls and wall-free cells.

1. gram-positive cells - cells which contain a thick layer of peptidoglycan and teichoic acids 2. gram-negative cells - cells which contain both an inner and outer membrane as well as a thin layer of peptidoglyan 3. acid-fast cells - cells which contain a thick layer of mycolic acid or cord factor 4. mycoplasms - cells which lack a cell wall with peptidoglycan but contain sterols to strengthen their cell membrane

match the type of extremophile with the description of its preferred environment to test your understanding of archaeal adaptations.

1. halophile - an organism that lives in an environment that contains high amounts of salt such as the Dead Sea 2. hyperthermophile - an organism that lives in extremely hot temperatures such as the hot springs of Yellowstone National Park 3. methanogen - an organism that lives in anaerobic environments and converts carbon dioxide and hydrogen into methane 4. psychrophile - an organism that lives in very cold conditions, including temperatures below freezing

match the technologies with the statements that most accurately describe them to test your understanding of the methods and characteristics used in classifying bacteria.

1. morphology - these tests use cell shape and Gram reaction to classify organisms 2. bacterial physiology/biochemistry - these tests use the presence or absence of biochemical processes and enzymes to group organisms 3. serological analysis - these tests use antibody reactions to identify an organism or to determine relatedness 4. genetic techniques - these tests use DNA to determine the identity of an organism

match the terms related to flagella with the statement that most accurately describe them to test your understanding of the attachment patterns of bacterial flagella.

1. polar - this type of flagella can be found at either or both ends of a cell 2. monotrichous - this pattern has one flagellum attached at one end of the cell 3. lophotrichous - this pattern has groups of flagella all originating from the same point on the cell 4. amphitrichous - this pattern has flagella at both poles of the cell 5. peritrichous - this pattern consists of flagella randomly distributed around the cell

match the cell components with the type of cell where it is found. If the component is found in both gram-positive and gram-negative cells, select "both gram-positive and gram-negative cells"

1. teichoic acid - gram-positive cells 2. lipopolysaccharide; outer membrane - gram-negative cells 3. peptidoglycan; cell membrane - both gram-positive and gram-negative cells

What is the primary role of Fimbriae?

Adhesion to other cells and surfaces

What is the primary role of Pili?

Allows for conjugation

What best characterizes endospores?

Dormant, tough, and non-reproductive structure produced by certain gram (+) bacteria

Classification systems are used to organize bacterial pathogens by the type of disease or infection each causes.

False

Which of the following explains why archaeons are extremophiles?

They are ancient, primitive organisms that adapt well to extreme conditions because they have retained characteristics of the cells that first evolved when Earth's conditions were far more extreme.

The two groups of obligate intracellular bacteria are the ________, usually spread by contact, and the ________, usually transmitted by the bites of arthropods.

chlamydias; rickettsias

Excess nutrients that the cell may store for later use may be found within

cytoplasmic granules.

Other than maintaining the shape of the cell, what is the primary function of the cell wall, and which component contributes most to this function?

maintaining strength; peptidoglycan

Bacterial species are defined in a fundamentally different way than mammalian species are. This is because

mammals reproduce sexually while bacteria reproduce asexually.

Of the photosynthetic bacteria, cyanobacteria produce ______ as a product of photosynthesis but the green and purple sulfur bacteria do not produce this substance.

oxygen

A taxonomical outline of bacterial species based on shared evolutionary histories would be described as a

phylogenetic system.

The cell membrane is composed of _____________.

proteins dispersed throughout a phospholipid bilayer

Choose the answer that best completes this statement's blanks in the correct order. When all the flagella on a cell rotate in a counterclockwise fashion, the cell is propelled forward in a movement known as a ____, but when the flagella reverse direction, the cell stops and changes course in an action known as a ____.

run; tumble

The _______ level of bacterial organisms refers to a group of organisms that all share the same traits while the subspecies level refers to the variation or differences of individual cells within that group.

species

The primary function of the cell membrane is

to regulate the transport of molecules in and out of the cell.