Chapter 3 Microbiology

Responsiveness

Cells engaging in taxis are exhibiting which of the following basic processes of life?

Hypertonic

Crenation, the shriveling of cells due to loss of water, occurs when cells are placed in what kind of solution?

Facilitated diffusion

Passive transport of molecules across the cell membrane that requires specific channel proteins is called __________.

*False*: Exocytosis is a process to export substances from the cell.

Phagocytosis is a process that allows a cell to release wastes.

Mycobacterium

The bacterial genus __________ is named for the presence of mycolic acid in its cell walls.

Lose Water

A cell in a hypertonic solution will __________.

Centrosome

A special region of the eukaryotic cytoplasm, called the __________, plays a role in mitosis and cytokinesis.

Bacterial flagella move in a wave motion, whereas eukaryotic flagella rotate 360

All of the following are differences between bacterial flagella and eukaryotic flagella EXCEPT that __________.

Archaeal flagella rotate from the flow of hydrogen ions across a membrane

All of the following statements are true of archaeal flagella EXCEPT that __________.

*True*: Glycocalyces can be found in bacterial, archaeal, and eukaryotic cells.

All types of cells have glycocalyx.

Endospores

Bacteria in the genera Bacillus and Clostridium can create __________ in order to survive harsh conditions.

*True*: Many endospore-forming bacteria produce toxins.

Endospores are a concern to healthcare workers because they are resistant to treatments that inhibit other microbes.

*True*: In eukaryotic cells, the flagellum is technically within the cell and is covered by an extension of the cytoplasmic membrane.

Eukaryotic flagella, unlike the flagella of prokaryotes, are enclosed within the cytoplasmic membrane.

Archaea

Hami are proteinaceous structures found in which of the following?

*True*: A tumble is a disorganized type of movement made in the presence of unfavorable stimuli; a bacterium would decrease its tumbles and increase its runs in the presence of favorable stimuli.

In the presence of a favorable stimulus, a bacterium will increase the number of runs and decrease the number of tumbles it performs.

Chloroplast

Light-harvesting organelles found in all photosynthetic eukaryotes are called __________.

*False*: Inclusions are deposits placed throughout the cytosol of bacteria. Ribosomes, on the other hand, are used for protein synthesis.

Magnetobacteria contain the mineral magnetite in large ribosomes spread throughout the bacterial cytoplasm.

*False*: By definition, membrane rafts are areas of the membrane that contain lipids and proteins that do not flow independently like much of the rest of the membrane's components. These rafts are used for various important cell functions, such as cell signaling and protein sorting.

Membrane rafts are used by eukaryotic cells to make their membranes more fluid and flexible.

*False*: Eukaryotic ribosomes are larger than those of prokaryotes.

Since all cells use their ribosomes to produce proteins, the ribosomes of eukaryotic cells are identical to those of prokaryotic cells.

Endoflagella

Spirochetes have a special kind of flagella called __________.

*True*: Sterols are characteristic components of eukaryotic membranes and are used primarily to keep the membranes fluid at lower temperatures.

Sterols, found in eukaryotic cytoplasmic membranes, make these membranes stronger at high temperatures and more fluid at low temperatures.

Glycocalyx

The __________ is a sticky, gelatinous substance that helps keep many prokaryotic cells from drying out.

Cytoskeleton

The __________ is an internal network of fibers that gives most cells their shape.

*True*: Archaeal cytoplasmic membrane lipids contain ether linkages instead of the ester linkages common in bacterial cytoplasmic membrane lipids, making them stronger in more extreme environments.

The ability of the archaea to live in extreme environments is due in part to their cytoplasmic membrane composition.

Lipopolysaccharide

The bacterial cell walls of Gram-negative bacteria have a thin layer of peptidoglycan and an outer membrane composed of __________ and proteins.

*False*: Capsules are well-organized, fairly rigid structures; slime layers are loose and water soluble.

The capsule found in some bacterial cells is a loose, water-soluble structure.

Osmosis

The diffusion of water across a semipermeable membrane is the process called __________.

Mitochondria and Chloroplast

The endosymbiotic theory is one possible explanation for the origin of which of the following organelles?

Enzymes

The eukaryotic cytoskeleton is composed of all of the following EXCEPT __________.

Nucleoid

The genetic material of a bacterial cell is contained within a region called the __________.

To enhance destruction of the microbe by immune cells

The glycocalyx of microbial cells has all of the following functions EXCEPT __________.

Endoflagella

The structures that permit bacteria such as Treponema pallidum to "corkscrew" through a medium are called __________.

Metabolism

The sum of a cell's catabolic, anabolic, and exchange chemical reactions is called __________.

*False*: Lipid A is found only in Gram-negative bacteria, not Gram-positive bacteria.

When Gram-positive bacteria die, a large amount of lipid A can be released into the immediate environment.

peptidoglycan

Which of the following components of the bacterial cell wall is found in varying amounts in both Gram-positive and Gram-negative cells?

animal cell: silica

Which of the following eukaryotic cell wall types is INCORRECTLY matched?

Pili

Which of the following has NOT yet been discovered in the archaea?

All of the listed responses are characteristics of endospores.

Which of the following is NOT a characteristic of endospores?

Lipid A

Which of the following is NOT a component of peptidoglycan?

Lipopolysaccharide (LPS)

Which of the following is NOT a component of peptidoglycan?

Movement toward chemicals or light

Which of the following is NOT a primary function of fimbriae?

Flagellin is a molecule found only in eukaryotic flagella.

Which of the following is a FALSE statement concerning flagella?

Small, lipid-soluble molecules

Which of the following kinds of molecules would be expected to cross the cytoplasmic membrane by diffusion alone?

endoplasmic reticulum: exocytosis and secretion

Which of the following membrane-bound organelles is INCORRECTLY paired with its primary function?

Rough endoplasmic reticulum

Which of the following organelles is involved in producing and transporting proteins throughout the cell?

Peroxisome

Which of the following organelles is involved in the degradation of toxic molecules?

Ribosomes

Which of the following organelles is present in both prokaryotic and eukaryotic cells?

DNA

Which of the following would NOT be found in an inclusion?

Endocytosis

__________ is the process by which large molecules or extracellular fluids are brought into a eukaryotic cell through manipulation of the cytoplasmic membrane.