Microbiology with Diseases by Taxonomy, 5/E

Microbiology with Diseases by Taxonomy, 5e (Bauman) Chapter 3 Cell Structure and Function 3.1 Multiple Choice Questions 1) Using a microscope, you observe an amoeba moving toward a food source. This is an example of A) reproduction. B) cellular structure. C) metabolism. D) growth. E) responsiveness. Answer: E Bloom's Taxonomy: Comprehension Section: Processes of Life Learning Outcome: 3.1 2) Which of the following is NOT a component of bacterial flagella? A) flagellin B) basal body C) tubulin D) filament E) hook Answer: C Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.5 3) 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. Answer: A Bloom's Taxonomy: Comprehension Section: Processes of Life Learning Outcome: 3.1 4) Protein synthesis occurs in the A) nucleus. B) ribosome. C) inclusion. D) cytoskeleton. E) periplasmic space. Answer: B Bloom's Taxonomy: Knowledge Section: Cytoplasm of Bacteria Learning Outcome: 3.21 5) Which of the following bacterial cell structures plays an important role in the creation of biofilms? A) glycocalyces B) flagella C) fimbriae D) pili E) both fimbriae and glycocalyces Answer: E Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.3, 3.7 6) Which of the following organisms is a prokaryote? A) algae B) archaea C) fungus D) protozoa E) both archaea and protozoa Answer: B Bloom's Taxonomy: Knowledge Section: Prokaryotic and Eukaryotic Cells: An Overview Learning Outcome: 3.2 7) Which of the following is NOT a characteristic of all living things? A) metabolism B) motility C) growth D) reproduction E) responsiveness Answer: B Bloom's Taxonomy: Knowledge Section: Processes of Life Learning Outcome: 3.1 8) Some bacteria have a water-soluble outer slime layer composed of A) carbohydrate. B) lipid. C) peptidoglycan. D) protein. E) lipoteichoic acid. Answer: A Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.3 9) 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. Answer: A Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.7 10) Which of the following may be a component of bacterial cell walls? A) carrageenan B) lipoteichoic acids C) mycolic acid D) tubulin E) both lipoteichoic and mycolic acids Answer: E Bloom's Taxonomy: Comprehension Section: Bacterial Cell Walls Learning Outcome: 3.11 11) Bacterial cell walls that are resistant to drying contain A) carbohydrates. B) amino acids. C) lipopolysaccharide. D) tubulin. E) waxes. Answer: E Bloom's Taxonomy: Comprehension Section: Bacterial Cell Walls Learning Outcome: 3.11 12) Lipid A is a component of A) lipopolysaccharides. B) plant cell walls. C) cytoplasmic membranes. D) mycolic acid. E) bacterial glycocalyces. Answer: A Bloom's Taxonomy: Comprehension Section: Bacterial Cell Walls Learning Outcome: 3.12 13) Bacteria of the genus Mycoplasma lack cell walls. What sort of environment do they require for survival? A) low temperature B) hypotonic C) isotonic D) hypertonic E) a biofilm Answer: C Bloom's Taxonomy: Analysis Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.17 14) Lipid-soluble molecules would be expected to cross the cytoplasmic membrane by which of the following processes? A) osmosis B) facilitated diffusion C) diffusion D) active transport E) group translocation Answer: C Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 15) ATP is expended in which of the following processes? A) facilitated diffusion B) diffusion C) group translocation D) active transport E) both active transport and group translocation Answer: E Bloom's Taxonomy: Comprehension Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 16) 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. Answer: B Bloom's Taxonomy: Application Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.17 17) Endospores survive a variety of harsh conditions in part because of the presence of A) mycolic acid. B) lipopolysaccharide. C) hopanoids. D) dipicolinic acid. E) glycoproteins. Answer: D Bloom's Taxonomy: Application Section: Cytoplasm of Bacteria Learning Outcome: 3.20 18) Bacterial ________ are sites of metabolite storage. A) nucleoids B) vacuoles C) inclusions D) pili E) periplasm Answer: C Bloom's Taxonomy: Knowledge Section: Cytoplasm of Bacteria Learning Outcome: 3.19 19) Which of the following is unique to archaea? A) hypotonic B) hypertonic C) isotonic D) fluid mosaic E) passive Answer: C Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.17 20) The cells illustrated in Figure 3.1 are in a(n) ________ environment. A) hypotonic B) hypertonic C) isotonic D) fluid mosaic E) passive Answer: A Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.17 21) The bacterial ________ facilitates the process of bacterial cell division. A) nucleoid B) inclusion C) pilus D) cytoskeleton E) fimbriae Answer: A Bloom's Taxonomy: Comprehension Section: Cytoplasm of Bacteria Learning Outcome: 3.21 22) Bacterial ribosomes are composed of several polypeptides and A) three RNA molecules in two subunits. B) three RNA molecules in three subunits. C) two RNA molecules in two subunits. D) two RNA molecules in a single complex. E) one large RNA molecule in a single complex. Answer: A Bloom's Taxonomy: Comprehension Section: Cytoplasm of Bacteria Learning Outcome: 3.21 23) 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. Answer: D Bloom's Taxonomy: Application Section: External Structure of Eukaryotic Cells Learning Outcome: 3.30 24) Which of the following is classified as a nonmembranous organelle of eukaryotic cells? A) endoplasmic reticulum B) Golgi body C) mitochondrion D) centriole E) peroxisome Answer: D Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.39 25) Which of the following is part of the structure of the mitochondria of a eukaryotic cell? A) cilia B) cristae C) thylakoids D) inclusions E) nucleolus Answer: B Bloom's Taxonomy: Knowledge Section: Cytoplasm of Eukaryotes Learning Outcome: 3.43 26) 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. Answer: D Bloom's Taxonomy: Application Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 27) Short, hairlike structures used only by eukaryotic cells for movement are called A) pili. B) flagella. C) fimbriae. D) pseudopodia. E) cilia. Answer: E Bloom's Taxonomy: Knowledge Section: Cytoplasm of Eukaryotes Learning Outcome: 3.37 28) Chloroplasts differ from mitochondria in that the former have A) DNA. B) two lipid bilayers. C) 70S ribosomes. D) thylakoids. E) cristae. Answer: D Bloom's Taxonomy: Application Section: Cytoplasm of Eukaryotes Learning Outcome: 3.43 29) 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 Answer: B Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 30) Which of the following eukaryotic processes involve pseudopodia? A) endocytosis B) exocytosis C) amoeboid action D) both amoeboid action and endocytosis E) both endocytosis and exocytosis Answer: D Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.33 31) 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 Answer: C Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.39 32) The accumulation of glucose 6-phosphate inside a bacterial cell via phosphorylation of glucose is an example of A) facilitated diffusion. B) group translocation. C) osmosis. D) plasmolysis. E) diffusion. Answer: B Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 33) 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 Answer: C Bloom's Taxonomy: Application Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.15 34) Which of the following processes requires a carrier protein? A) diffusion only B) facilitated diffusion only C) active transport only D) endocytosis only E) both facilitated diffusion and active transport Answer: E Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.16 35) Which of the following chemical substances contributes to the unique characteristics of acid-fast bacteria? A) N-acetylglucosamine B) peptidoglycan C) lipoteichoic acid D) endotoxin E) mycolic acid Answer: E Bloom's Taxonomy: Application Section: Bacterial Cell Walls Learning Outcome: 3.11 36) The cytoplasmic membranes of ________ contain unbranched phospholipids and proteins. A) archaeal cells B) bacterial cells C) eukaryotic cells D) both bacterial and eukaryotic cells E) archaeal, bacterial, and eukaryotic cells Answer: D Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 37) Membrane rafts are found in the cytoplasmic membranes of A) archaea only. B) bacteria only. C) eukaryotes only. D) both archaea and bacteria. E) both archaea and eukaryotes. Answer: C Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 38) Endocytosis and exocytosis are means of transport used by A) bacteria. B) eukaryotes. C) archaea. D) all prokaryotes. E) nothing; no cells use both processes. Answer: B Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.32 39) Some ________ use group translocation as a means of transport. A) eukaryotes B) bacteria C) archaea D) protozoa E) eukaryotes and prokaryotes Answer: B Bloom's Taxonomy: Comprehension Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 40) Cholesterols are typically found in ________ cytoplasmic membranes. A) eukaryotic B) bacterial C) archaeal D) prokaryotic E) both eukaryotic and prokaryotic Answer: A Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 41) The cell walls of some ________ are composed of minerals such as calcium carbonate. A) archaea B) bacteria C) algae D) fungi E) bacteria and fungi Answer: C Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 42) Cytoplasmic membranes of ________ are composed of unbranched phospholipids. A) bacteria B) eukaryotes C) archaea D) prokaryotes E) bacteria and eukaryotes Answer: E Bloom's Taxonomy: Knowledge Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 43) Some members of ________ have hami. A) archaea B) bacteria C) eukaryotes D) archaea and bacteria E) bacteria and eukaryotes Answer: A Bloom's Taxonomy: Knowledge Section: External Structures of Archaea Learning Outcome: 3.26 44) ________ may have pili. A) Eukaryotes B) Archaea C) Bacteria D) Prokaryotes E) Both eukaryotes and bacteria Answer: C Bloom's Taxonomy: Knowledge Section: External Structures of Eukaryotic Cells Learning Outcome: 3.7, 3.30 45) Which of the following never have cell walls? A) algae B) animal cells C) archaea D) bacteria E) fungi Answer: B Bloom's Taxonomy: Knowledge Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.31 46) Which of the following may have cell walls containing teichoic acids? A) Gram-negative bacteria only B) Gram-positive bacteria only C) archaea D) both Gram-positive and Gram-negative bacteria E) all prokaryotes Answer: B Bloom's Taxonomy: Comprehension Section: Archaeal Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.11, 3.27 47) What is the function of the cellular structure indicated by "c" in Figure 3.2? A) provide shape only B) attach to surfaces only C) protect from dehydration only D) attach to surfaces and protect from dehydration E) serve as carbohydrate storage Answer: D Bloom's Taxonomy: Knowledge Section: External Structures of Bacterial Cells Learning Outcome: 3.3 48) Which of the following have a periplasmic space? A) Gram-negative bacteria only B) Gram-positive bacteria only C) both Gram-positive and Gram-negative bacteria D) archaea E) eukaryotes Answer: A Bloom's Taxonomy: Knowledge Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.12 49) Which of the following prokaryotic cells contain an outer membrane? A) Gram-negative bacteria only B) Gram-positive bacteria only C) both Gram-positive and Gram-negative bacteria D) archaea E) all prokaryotes Answer: A Bloom's Taxonomy: Comprehension Section: Archaeal Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.12 50) What is the function of the cellular structure indicated by "m" in Figure 3.3? A) ATP synthesis B) protein synthesis C) synthesis of lipids D) packaging of materials for export E) cell movement and mitosis Answer: E Bloom's Taxonomy: Knowledge Section: Cytoplasm of Eukaryotes Learning Outcome: 3.39 3.2 True/False Questions 1) Chloroplasts use light energy to produce ATP and carbohydrates. Answer: TRUE Bloom's Taxonomy: Knowledge Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 2) Peroxisomes contain enzymes used to digest nutrients that have been brought into the cell through phagocytosis. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 3) Bacterial protein synthesis can begin before the reading of the gene is complete. Answer: TRUE Bloom's Taxonomy: Knowledge Section: Prokaryotic and Eukaryotic Cells: An Overview Learning Outcome: 3.2 4) Archaeal cytoplasmic membranes are composed of unbranched phospholipids. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Archaeal Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.28 5) The processes illustrated in Figure 3.4 do not require energy input. Answer: TRUE Bloom's Taxonomy: Comprehension Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 6) Eukaryotic ribosomes are composed of 50S and 30S subunits. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.39 7) Lysosomes result from the endocytosis of food particles by eukaryotic cells. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 8) The presence of a glycocalyx contributes to bacteria's ability to cause disease. Answer: TRUE Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.3 9) Chromatin is composed of DNA and special packaging proteins called hopanoids. Answer: FALSE Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 10) The short structures on the surface of the cell in Figure 3.5 are pili. Answer: FALSE Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.7 3.3 Short Answer Questions 1) In a(n) (hypertonic/isotonic/hypotonic) solution, an animal cell can gain so much water that it may burst. Answer: hypotonic Bloom's Taxonomy: Comprehension Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 2) The presence of a cell (wall/membrane) enables bacterial and plant cells to resist the effects of hypotonic solutions. Answer: wall Bloom's Taxonomy: Comprehension Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 3) A higher concentration of solutes corresponds to a (higher/lower) concentration of water in a given solution. Answer: lower Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.17 4) A(n) (symport/antiport/uniport) is a carrier protein that transports two substances in the same direction across a membrane. Answer: symport Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 5) The "run" in bacterial motility is the result of (clockwise/counterclockwise/whiplike) rotation of the flagella. Answer: counterclockwise Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.5 6) The reserve deposits of starch or other compounds found in many prokaryotic cells are called (vacuoles/inclusions/nucleoid). Answer: inclusions Bloom's Taxonomy: Comprehension Section: Cytoplasm of Bacteria Learning Outcome: 3.19 7) Eukaryotic cells use a process known as (pinocytosis/phagocytosis/exocytosis) to obtain liquids from their environment. Answer: pinocytosis Bloom's Taxonomy: Comprehension Section: Eukaryotic Cell Walls and Cytoplasmic Membranes Learning Outcome: 3.32 8) Fragments of (LPS/NAM/NAG) released from Gram-negative bacteria into the bloodstream produce fever and shock. Answer: LPS Bloom's Taxonomy: Comprehension Section: Bacterial Cell Walls Learning Outcome: 3.12 9) The smooth endoplasmic reticulum is the site of (protein/lipid/carbohydrate) synthesis. Answer: lipid Bloom's Taxonomy: Knowledge Section: Cytoplasm of Eukaryotes Learning Outcome: 3.39 10) Fibrous structures with three "arms" some archaea use for attachment to surfaces are (fimbriae/hami/pili). Answer: hami Bloom's Taxonomy: Knowledge Section: External Structures of Archaea Learning Outcome: 3.26 11) A (capsule/slime layer/matrix) is a type of glycocalyx that is firmly attached to the cell. Answer: capsule Bloom's Taxonomy: Comprehension Section: External Structures of Bacterial Cells Learning Outcome: 3.4 12) Golgi bodies are examples of a (membranous/non-membranous/cellular) organelle. Answer: membranous Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 13) The semiliquid matrix of the nucleus is called the (cytoplasm/nucleoid/nucleoplasm). Answer: nucleoplasm Bloom's Taxonomy: Comprehension Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 14) A structural molecule found in eukaryotic cytoskeletons, flagella, cilia, and centrioles is (flagellin/tubulin/fibrin). Answer: tubulin Bloom's Taxonomy: Application Section: Cytoplasm of Eukaryotes Learning Outcome: 3.41 15) The process illustrated in Figure 3.6 occurs in (eukaryotic/bacterial/archaeal) cells. Answer: bacterial Bloom's Taxonomy: Knowledge Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.16 3.4 Essay Questions 1) Compare and contrast the characteristics of prokaryotic and eukaryotic cells. Answer: 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. Bloom's Taxonomy: Application Section: Prokaryotic and Eukaryotic Cells: An Overview Learning Outcome: 3.2 2) Compare and contrast archaea and bacteria, with particular attention to the features that lead to their placement in separate taxa. Answer: 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. Bloom's Taxonomy: Analysis Section: Cytoplasm of Archaea Learning Outcome: 3.24, 3.25, 3.26, 3.27, 3.28, 3.29 3) 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. Answer: 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. Bloom's Taxonomy: Analysis Section: Cytoplasm of Eukaryotes Learning Outcome: 3.31, 3.34, 3.36, 3.40 4) 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. Answer: 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. Bloom's Taxonomy: Application Section: Cytoplasm of Eukaryotes Learning Outcome: 3.42 5) Describe how the structure of the bacterial cytoplasmic membrane relates to its function of selective permeability. Answer: 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. Bloom's Taxonomy: Application Section: Bacterial Cytoplasmic Membranes Learning Outcome: 3.15