MICRO 290 - Ch. 3
Which of the following is NOT a component of bacterial flagella? A) flagellin B) basal body C) tubulin D) filament E) hook
C) tubulin Section: External Structure of Bacterial Cells
The glycocalyx of a eukaryotic cell performs all of the following functions EXCEPT A) protection against dehydration. B) anchoring cells to each other. C) cellular recognition and communication. D) transfer of genetic material between cells. E) strengthening the cell surface.
D) transfer of genetic material between cells. Section: External Structure of Eukaryotic Cells
________ may have pili.
Bacteria Section: External Structure of Eukaryotic Cells
Endocytosis and exocytosis are means of transport used by
eukaryotes Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Using a microscope, you observe an amoeba moving toward a food source. This is an example of
responsiveness Section: Processes of Life
Which of the following organisms is a prokaryote?
archaea Section: Prokaryotic and Eukaryotic Cells: An Overview
The cytoplasmic membranes of ________ may contain branched hydrocarbons.
archaeal cells Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
The flagella of archaea are similar to bacterial flagella but differ in that they
are driven by ATP hydrolysis. Section: External Structure of Archaea
Some ________ use group translocation as a means of transport.
bacteria Section: Bacterial Cytoplasmic Membranes
Cytoplasmic membranes of ________ are composed of unbranched phospholipids.
bacteria and eukaryotes Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
The process illustrated in Figure 3.6 occurs in (eukaryotic/bacterial/archaeal) cells.
bacterial Section: Bacterial Cytoplasmic Membranes
A (capsule/slime layer/matrix) is a type of glycocalyx that is firmly attached to the cell.
capsule Section: External Structure of Bacterial Cells
Some bacteria have an outer layer called a ________ which allows them to adhere to surfaces and contributes to their ability to cause disease.
capsule Section: External Structure of Bacterial Cells
Some bacteria have a water-soluble outer slime layer composed of
carbohydrate Section: External Structure of Bacterial Cells
The cell walls of eukaryotes are typically composed of (carbohydrates/peptidoglycan/glycoproteins).
carbohydrates Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
What is the function of the cellular structure indicated by "m" in Figure 3.3?
cell movement and mitosis Section: Cytoplasm of Eukaryotes
Which of the following is a nonmembranous organelle found only in eukaryotic cells?
centriole Section: Cytoplasm of Eukaryotes
Short, hairlike structures used only by eukaryotic cells for movement are called
cilia Section: Cytoplasm of Eukaryotes
The "run" in bacterial motility is the result of (clockwise/counterclockwise/whiplike) rotation of the flagella.
counterclockwise Section: External Structure of Bacterial Cells
Which of the following is part of the structure of the mitochondria of a eukaryotic cell?
cristae Section: Cytoplasm of Eukaryotes
The bacterial ________ maintains the DNA in a specific location and facilitates the process of bacterial cell division.
cytoskeleton Section: Cytoplasm of Bacteria
Lipid-soluble molecules would be expected to cross the cytoplasmic membrane by which of the following processes?
diffusion Section: Bacterial Cytoplasmic Membranes
Membrane rafts are found in the cytoplasmic membranes of
eukaryotes only. Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Cholesterols are typically found in ________ cytoplasmic membranes.
eukaryotic Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
The accumulation of glucose 6-phosphate inside a bacterial cell via phosphorylation of glucose is an example of
group translocation. Section: Bacterial Cytoplasmic Membranes
Fibrous structures with three "arms" some archaea use for attachment to surfaces are (fimbriae/hami/pili).
hami Section: External Structure of Archaea
In a(n) (hypertonic/isotonic/hypotonic) solution, an animal cell can gain so much water that it may burst.
hypotonic Section: Bacterial Cytoplasmic Membranes
The cells illustrated in Figure 3.1 are in a(n) ________ environment.
hypotonic Section: Bacterial Cytoplasmic Membranes
Bacterial ________ are sites of metabolite storage.
inclusions Section: Cytoplasm of Bacteria
The reserve deposits of starch or other compounds found in many prokaryotic cells are called (vacuoles/inclusions/nucleoid).
inclusions Section: Cytoplasm of Bacteria
Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival?
isotonic Section: Bacterial Cytoplasmic Membranes
The smooth endoplasmic reticulum is the site of (protein/lipid/carbohydrate) synthesis.
lipid Section: Cytoplasm of Eukaryotes
A higher concentration of solutes corresponds to a (higher/lower) concentration of water in a given solution.
lower Section: Bacterial Cytoplasmic Membranes
Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria?
mycolic acid Section: Bacterial Cell Walls
The semiliquid matrix of the nucleus is called the (cytoplasm/nucleoid/nucleoplasm).
nucleoplasm Section: Cytoplasm of Eukaryotes
Eukaryotic cells use a process known as (pinocytosis/phagocytosis/exocytosis) to obtain liquids from their environment.
pinocytosis Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
What is the function of the cellular structure indicated by "c" in Figure 3.2?
protect from dehydration only Section: External Structure of Bacterial Cells
A(n) (symport/antiport/uniport) is a carrier protein that transports two substances in the same direction across a membrane.
symport Section: Bacterial Cytoplasmic Membranes
Lipid A is a component of
the outer membrane of Gram-negative bacteria. Section: Bacterial Cell Walls
Chloroplasts differ from mitochondria in that the former have
thylakoids Section: Cytoplasm of Eukaryotes
A structural molecule found in eukaryotic cytoskeletons, flagella, cilia, and centrioles is (flagellin/tubulin/fibrin).
tubulin Section: Cytoplasm of Eukaryotes
The presence of a cell (wall/membrane) enables bacterial and plant cells to resist the effects of hypotonic solutions.
wall Section: Bacterial Cytoplasmic Membranes
Bacterial cell walls that are resistant to drying contain
waxes Section: Bacterial Cell Walls
True/False The presence of a glycocalyx contributes to bacteria's ability to cause disease.
True Section: External Structure of Bacterial Cells
The cell walls of some ________ are composed of minerals such as calcium carbonate.
algae Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Endospores survive a variety of harsh conditions in part because of the presence of
dipicolinic acid. Section: Cytoplasm of Bacteria
Most antibacterial drugs disrupt or destroy bacterial cellular characteristics that are different from those of eukaryotic cells or that may not even be present in eukaryotic cells, an idea termed 'selective toxicity'. List and describe at least three cellular features of bacteria that could be targeted to inhibit or kill a bacterial pathogen.
1. Cell wall: The cell wall of almost all bacteria contains peptidoglycan, a molecule absent in eukaryotic cell walls. Gram-negative cell walls contain unique molecules such as lipopolysaccharide and structures such as porins, which are not present in eukaryotic cells. Additionally, human cells do not have a cell wall at all. 2. Ribosomes: Bacterial ribosomes have a 70S structure, whereas eukaryotic ribosomes have an 80S structure. This difference is enough to allow some drugs to preferentially affect bacterial ribosomes while leaving eukaryotic ribosomes unharmed. 3. Cellular appendages: Although both prokaryotic and eukaryotic cells can have flagella, the two types of cells use structurally different types of flagella. Furthermore, many bacteria have fimbriae and pili, which are not found on eukaryotic cells. 4. Cell membrane: Most cells use a phospholipid bilayer with inserted proteins as a cell membrane; however, bacterial cell membranes may contain hopanoids, which are absent in eukaryotic cell membranes. Section: Cytoplasm of Eukaryotes
Which of the following statements concerning conjugation pili is FALSE? A) Pili are longer than fimbriae and flagella. B) Pili facilitate the transfer of DNA among bacterial cells. C) Pili are long, hollow tubules. D) Not all bacteria have pili. E) A bacterial cell will usually have only one or two pili.
A) Pili are longer than fimbriae and flagella. Section: External Structure of Bacterial Cells
Which of the following statements concerning the characteristics of life is FALSE? A) reproduction is defined as an increase in the size of an organism. B) viruses have some, but not all, of the characteristics of living things. C) organisms may not exhibit all of the characteristics of life at all times. D) reproduction can occur asexually or sexually in living things. E) living things store metabolic energy in the form of chemicals such as ATP.
A) reproduction is defined as an increase in the size of an organism. Section: Processes of Life
The endosymbiotic theory does NOT provide an explanation for A) the two membranes of the nuclear envelope. B) the presence of ribosomes in mitochondria. C) the presence of DNA in chloroplasts. D) the cristae in mitochondria. E) the double membrane of chloroplasts.
A) the two membranes of the nuclear envelope. Section: Cytoplasm of Eukaryotes
Which of the following statements concerning osmosis is FALSE? A) Osmosis requires a selectively permeable membrane. B) During osmosis, water crosses to the side of the membrane with a lower solute concentration. C) Cells placed in hypotonic solutions will gain water. D) Crenation results when blood cells are placed in a hypertonic solution. E) Osmosis stops when the system reaches equilibrium.
B) During osmosis, water crosses to the side of the membrane with a lower solute concentration. Section: Bacterial Cytoplasmic Membranes
Which of the following is paired incorrectly? A) plants; cellulose cell wall B) algae; glycocalyx C) bacteria; peptidoglycan cell wall D) fungi; polysaccharide cell wall E) archaea; protein cell wall
B) algae; glycocalyx Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Which of the following never have cell walls? A) algae B) animal cells C) archaea D) bacteria E) fungi
B) animal cells Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Which of the following is NOT a characteristic of all living things? A) metabolism B) motility C) growth D) reproduction E) responsiveness
B) motility Section: Processes of Life
Compare and contrast archaea and bacteria, with particular attention to the features that lead to their placement in separate taxa.
Bacterial cell walls are composed of peptidoglycan, whereas archaeal cell walls are composed of a variety of carbohydrate forms but never peptidoglycan. The flagella of the two groups of prokaryotes have several differences, including size, manner of assembly, and function. Although both have fimbriae, archaea have a distinctive attachment structure called a hamus that is somewhat like a barbed grappling hook. Bacterial cytoplasmic membranes may contain hopanoids, archaeal cytoplasmic membranes do not. The ribosomes of archaea and bacteria are of similar size, but some ribosomal components of archaea are more like those of eukaryotic ribosomes than those of bacteria. RNA metabolism in the two prokaryotic groups differs, and the archaeal genetic code is more like that of eukaryotes than that of bacteria. Archaeal phospholipids are different from bacterial and eukaryotic phospholipids in that the glycerol is a stereoisomer, the linkages are ether instead of ester between hydrocarbon chains and glycerol, the hydrocarbon chains are isoprene chains rather than fatty acids, which are branched rather than linear, as the fatty acids are. Section: Cytoplasm of Archaea
Both mitochondria and chloroplasts have inner membranes with much greater surface area than their outer membranes. Discuss the contribution of the extensive inner membranes to the roles of these organelles.
Both organelles use metabolic processes embedded in lipid membranes to produce cellular energy. The cristae of mitochondria produce ATP. The thylakoids of chloroplasts are the site of light energy capture and conversion to cellular energy. The extensive surface area of the folded inner membranes allows both organelles to produce much more energy than would otherwise be possible. Section: Cytoplasm of Eukaryotes
Which of the following statements concerning endocytosis is TRUE? A) This process occurs in both prokaryotes and eukaryotes. B) Phagocytosis is a type of endocytosis in which liquids are brought into the cell. C) Endocytosis produces a structure called a food vesicle. D) Waste products and secretions are exported from the cell during endocytosis. E) Endocytosis is a form of passive transport.
C) Endocytosis produces a structure called a food vesicle. Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Which of the following is NOT a function of the eukaryotic cytoskeleton? A) anchors organelles B) gives shape to the cell C) packages cellular secretions D) performs endocytosis E) aids in contraction of the cell
C) packages cellular secretions Section: Cytoplasm of Eukaryotes
What types of molecules may NOT need transport proteins to be able to cross cytoplasmic membranes? A) large molecules B) ions C) small hydrophobic molecules D) small hydrophilic molecules E) nothing crosses cytoplasmic membranes without transport proteins
C) small hydrophobic molecules Section: Bacterial Cytoplasmic Membranes
Which of the following prokaryotic cells contain an outer membrane?
Gram-negative bacteria only Section: Archaeal Cell Walls and Cytoplasmic Membranes
Which of the following may have cell walls containing teichoic acids?
Gram-positive bacteria only Section: Archaeal Cell Walls and Cytoplasmic Membranes
Fragments of (LPS/NAM/NAG) released from Gram-negative bacteria into the bloodstream produce fever and shock.
LPS Section: Bacterial Cell Walls
True/False The processes illustrated in Figure 3.4 are driven by electrochemical gradients.
True Section: Bacterial Cytoplasmic Membranes
True/False Chloroplasts use light energy to produce ATP and carbohydrates.
True Section: Cytoplasm of Eukaryotes
True/False Bacterial protein synthesis can begin before the reading of the gene is complete.
True Section: Prokaryotic and Eukaryotic Cells: An Overview
Bacterial ribosomes are composed of several polypeptides and
3 RNA molecules in 2 subunits. Section: Cytoplasm of Bacteria
Which of the following statements about the endoplasmic reticulum (ER) is CORRECT? A) The rough ER is the site of lipid synthesis. B) The smooth ER has ribosomes associated with it. C) The ER is a lipid storage organelle. D) The ER is a transport system within the cytoplasm. E) The smooth ER is a site of ATP synthesis.
D) The ER is a transport system within the cytoplasm. Section: Cytoplasm of Eukaryotes
True/False Archaea are similar to bacteria in having cytoplasmic membrane that are composed of phospholipids and hopanoids.
False Section: Archaeal Cell Walls and Cytoplasmic Membranes
True/False Chromatin is composed of DNA and special packaging proteins called hopanoids.
False Section: Cytoplasm of Eukaryotes
True/False Eukaryotic ribosomes are composed of 50S and 30S subunits.
False Section: Cytoplasm of Eukaryotes
True/False Lysosomes result from the endocytosis of food particles by eukaryotic cells.
False Section: Cytoplasm of Eukaryotes
True/False Peroxisomes contain enzymes used to digest nutrients that have been brought into the cell through phagocytosis.
False Section: Cytoplasm of Eukaryotes
True/False The short structures on the surface of the cell in Figure 3.5 are pili.
False Section: External Structure of Bacterial Cells
Compare and contrast the characteristics of prokaryotic and eukaryotic cells.
Prokaryotic cells have a nucleoid, a region within the cytoplasm where the DNA is found, but this region is not surrounded by a membrane. Eukaryotic cells, however, have a true nucleus that is surrounded by a nuclear membrane. Additionally, eukaryotic cells have a variety of membranous compartments known as organelles within the cell, whereas prokaryotes do not have membranous organelles. Prokaryotic cells tend to be smaller and less structurally complex in general than eukaryotic cells. Even though the two types of cells may have various structures in common, such as cell walls and flagella, these structures can vary widely in their molecular composition. Section: Prokaryotic and Eukaryotic Cells: An Overview
Describe how the structure of the bacterial cytoplasmic membrane relates to its function of selective permeability.
The structure and function of the cytoplasmic membrane are explained in the fluid mosaic model. The cytoplasmic membranes of bacterial cells are composed of phospholipids, which create a semipermeable barrier to the cell's outer environment. The only molecules that can easily cross the membrane are small, lipid soluble molecules. Other types of molecules must use the wide variety of transport proteins embedded in the phospholipid bilayer to cross the membrane. In this way, the cell can control the concentration of both its nutrients and its waste products. The cytoplasmic membrane can also be used for energy production and for photosynthesis in prokaryotic cells. Section: Bacterial Cytoplasmic Membranes
ATP is expended in which of the following processes?
both active transport and group translocation Section: Bacterial Cytoplasmic Membranes
Which of the following processes requires a channel protein?
both facilitated diffusion and active transport Section: Eukaryotic Cell Walls and Cytoplasmic Membranes
Which of the following bacterial cell structures plays an important role in the creation of biofilms?
both fimbriae and glycocalyces Section: External Structure of Bacterial Cells
Which of the following may be a component of bacterial cell walls?
both lipoteichoic and mycolic acids Section: Bacterial Cell Walls
Which of the following contribute to the ability of archaea to survive in extreme environments?
branched hydrocarbons with ether linkages Section: Archaeal Cell Walls and Cytoplasmic Membranes
