Resolution is a measure of the clarity of the image; t is the minimum distance two points can be separated and still be distinguished as two points. 2. The development of electron microscopes has further opened our window on the cell and its organelles. What is considered a major disadvantage of electron microscopes? The methods used to prepare the specimen kill the cells. 3. Study the electron micrographs in your text. Describe the different types of images obtained from: scanning electron microscopy (SEEM): Answers may vary, but should describe the 3-D component of the specimen image. Remission electron microscopy (TEM) Answers may vary, but should mention that this type of microscopy rifles a thin section of a specimen, resulting in various views of the cells prepared. 4. In cell fractionation, whole cells are broken up in a blender, and this slurry is centrifuged several times. Each time, smaller and smaller cell parts are isolated. This will isolate different organelles and allow study of their biochemical activities. Which organelles are the smallest ones isolated in this procedure? Ribosome Concept 6. 2 Eukaryotic cells have internal membranes that compartmentalize their functions 5.
Which two domains consist of prokaryotic cells? Bacteria and Archie 6. A major preference between prokaryotic and eukaryotic cells is the location of their DNA. Describe this difference. In a eukaryotic cell, most of the DNA is in an organelle called the nucleus, which is bounded by a double membrane. In a prokaryotic cell, the DNA is concentrated in a region that is not membrane enclosed, called a nucleoli. Copyright 2011 Pearson Education, Inc. -1- 7. On the sketch of a prokaryotic cell, label each of these features and give its function or description.
See page 98 in your text for the labeled figure. Cell wall: rigid structure outside the plasma membrane plasma membrane: membrane enclosing the hotplates bacterial chromosome: carries genes in the form of DNA nucleoli: region where the cell’s DNA is located (not enclosed by a membrane) cytoplasm: interior of cell flagella: locomotion organelles of some bacteria Why are cells so small? Explain the relationship of surface area to volume. Cells are small because a high surface-to-volume ratio facilitates the exchange of materials between a cell and its environment.
As a cell (or any other object) increases in size, its volume grows proportionally more than its surface area. (Area is proportional to a linear dimension cubed. ) Thus, a smaller object has a greater ratio of surface area to illume. 9. What are microvolt? How do these structures relate to the function of intestinal cells? Microvolt are long, thin projections from the cell surface, which increase surface area without an appreciable increase in volume. A sufficiently high ratio of surface area to volume is especially important in cells that exchange a lot of materials with their surroundings, such as intestinal cells.
Concept 6. 3 The eukaryotic cell’s genetic instructions are housed in the nucleus and carried out by the ribosome 10. In the following figure, label the nuclear envelope, nuclear pores, and pore complex. See page 103 of your text for the labeled figure. 11 . Describe the nuclear envelope. How many layers is it? What connects the layers? The nuclear envelope encloses the nucleus, separating its contents from the cytoplasm. The nuclear envelope is a double membrane, meaning that there are two lipid players. The nuclear lamina, a entitle array of protein filaments, connects the layers of the nuclear envelope. 12.
What is the nuclear lamina? Nuclear matrix? The nuclear lamina is the entitle array of protein filaments that maintains the shape of the nucleus by mechanically supporting the nuclear envelope. The nuclear matrix is a ramekin of protein fibers extending throughout the nuclear interior. The nuclear matrix and nuclear lamina may help organize the genetic material so it functions efficiently. Copyright 2011 Pearson Education, Inc. -2- 13. Found within the nucleus are the chromosomes. They are made of chromatin. What are the two components of chromatin? When do the thin chromatin fibers condense to become distinct chromosomes?
Chromatin is composed of proteins and DNA. Chromatin fibers condense to become distinct chromosomes as a cell prepares to divide. 14. When are the nucleoli visible? What are assembled here? Nucleoli are visible in a impounding nucleus and in cells active in protein synthesis. Within the nucleoli, proteins imported trot the cytoplasm are assembled Witt RNA into large and Sam subunits of ribosome. 15. What is the function of ribosome? What are their two components? Ribosome are the cellular components that carry out protein synthesis. Their two components are a large subunit and a small subunit. 16.
Ribosome in any type of organism are all the same, but we distinguish between two types of ribosome based on where they are found and the destination of the protein product made. Complete this chart to demonstrate this concept. Location Suspended in the costly Product Type of Ribosome Free ribosome Bound ribosome Proteins that function within the costly Attached to the outside of the Proteins for insertion into endoplasmic reticulum or membranes nuclear envelope Concept 6. 4 The endometrial system regulates protein traffic and performs metabolic functions in the cell 17. List all the structures of the endometrial system.
Nuclear envelope Endoplasmic reticulum Googol apparatus Lossless Vesicles Vacuoles Plasma membrane 18. The endoplasmic reticulum (ERE) makes up more than half the total membrane system in many eukaryotic cells. Use this sketch to explain the lumen, transport vesicles, and the difference between smooth and rough ERE. See page 104 of your text for the labeled figure. Copyright 2011 Pearson Education, Inc. -3- The ERE lumen is the cavity, or cistern’s space. Because the ERE membrane is continuous within the nuclear envelope, the space between the two membranes of the envelope is continuous with the lumen of the ERE.
Transport vesicles bud off from a region of the rough ERE called transitional ERE and travel to the Googol apparatus and other destinations. Smooth ERE is so named because its outer surface lacks ribosome. Rough ERE is studded with ribosome on the outer surface of the membrane and thus appears rough through the electron microscope. 19. 1 . 2. 3. 20. List and describe three major functions of the smooth ERE. Synthesis of lipids: Enzymes of the smooth ERE are important in the synthesis of lipids, including oils, phosphoric, and steroids.
Detoxification of drugs and poisons: Detoxification usually involves adding hydroxyl groups to drug molecules, making them more soluble and easier to flush from the body. Storage of calcium ions: In muscle cells, the smooth ERE membrane pumps calcium ions from the costly into the ERE lumen. Why does alcohol abuse increase tolerance to other drugs such as barbiturates? Barbiturates, alcohol, and many other drugs induce the proliferation of smooth ERE and its associated detoxification enzymes, thus increasing the rate of detoxification.
This, in turn, increases the tolerance to drugs, meaning that higher doses are required to achieve a particular effect, such as sedation. 21 . The rough ERE is studded with ribosome. As proteins are synthesized, they are threaded into the lumen of the rough ERE. Some of these proteins have carbohydrates attached to them in the ERE to form globetrotting. What does the ERE then do with these secretors proteins? After secretors proteins are formed, the ERE membrane keeps them separate from proteins that are produced by free ribosome and that will remain in the costly.
Secretors proteins depart from the ERE wrapped in the membranes of vesicles that bud like bubbles from a specialized region called transitional ERE. 22. Besides packaging secretors proteins into transport vesicles, what is another major function of the rough ERE? The rough ERE grows membrane proteins and phosphoric for the cell by adding them to its own membrane. The ERE membrane expands, and portions of it are rearranged in the form of transport vesicles to other components of the endometrial system. 23. The transport vesicles formed from the rough ERE fuse with the Googol apparatus.
Use this sketch to label the cistern of the Googol apparatus, and its CICS and trans faces. Describe what happens to a transport vesicle and its contents when it arrives at the Googol apparatus. See page 106 of your text for the labeled figure. Copyright 2011 Pearson Education, Inc. -4- 24. What is a lissome? What do they contain? What is the pH range inside a lissome? A lissome is a membranous sac of hydrolysis enzymes that an animal cell uses to gets (hydrology) macromolecules. The pH range inside a lissome is acidic. 25. One function of lossless is intracellular digestion of particles engulfed by phagocytes.
Describe this process of digestion. What human cells carry out phagocytes? Amoebas and many other protests eat by engulfing smaller organisms or food particles, a process called phagocytes. The food vacuole formed in this way then fuses with a lissome, whose enzymes digest the food. Digestion products, including simple sugars, amino acids, and other monomers, pass into the costly and become nutrients for the cell. Some of the human cells that carry out phagocytes re macrophages, a type of white blood cell that helps defend the body by engulfing and destroying bacteria and other invaders. 6. A second function of lossless is to recycle cellular components in a process called autopsy. Describe this process. During autopsy, a damaged organelle or small amount of costly becomes surrounded by a double membrane, and a lissome fuses with the outer membrane tot this vesicle. The Allyson enzymes dismantle the enclosed material, and t organic monomers are returned to the costly for reuse. With the help of the lossless, the cell community renews itself. A human liver cell, for example, recycles half of its macromolecules each week. 27.
What happens in ATA-Cash disease? Explain the role of the lossless in ATA-Cash. In ATA-Cash disease, a lipid-digesting enzyme is missing or inactive, and the brain becomes impaired by an accumulation of lipids in the cells. In ATA-Cash, the lossless lack a functioning hydrolysis enzyme normally present. 28. There are many types of vacuoles. Briefly describe: food vacuoles: Food vacuoles are formed by phagocytes. Contractile vacuoles: Contractile vacuoles pump excess water out of the cell, thereby maintaining a suitable incineration of ions and molecules inside the cell. Entrap vacuoles in plants: Central vacuoles in plants develop by the coalescence of smaller vacuoles, contained in mature plant cells. Solution inside the central vacuole, called cell sap, is the plant cell’s main repository of inorganic ions, including potassium and chloride. The central vacuole plays a major role in the growth of plant cells, which enlarge as the vacuole absorbs water, enabling the cell to become larger with a minimal investment in new cytoplasm. (give at least three functions/materials stored here) -5_ 29.
Use this figure to explain how the elements of the endometrial system function together to secrete a protein and to digest a cellular component. Label as you explain. See page 108 in your text for the labeled figure. Nuclear envelope is connected to rough ERE, which is also continuous with smooth ERE. Membranes and proteins produced by the ERE flow in the form of transport vesicles to the Googol apparatus. Googol apparatus pinches off transport vesicles and other vesicles that give rise to lossless, other types of specialized vesicles, and vacuoles.
Lissome is available for fusion with another vesicle for digestion. Transport vesicle carries proteins to plasma membrane for secretion. Plasma membrane expands by fusion of vesicles; proteins are secreted from cell. Concept 6. 5 Mitochondria and chloroplasts change energy from one form to another 30. What is an indentations? An indentations is a cell living within another cell. 31 . What is the indentations theory? Summarize three lines of evidence that support the model of endometriosis.
The indentations theory states that an early ancestor of eukaryotic cells engulfed an oxygenating nonprescription prokaryotic cell, and over the course of evolution, the cost cell and its indentations merged into a single organism, a eukaryotic cell with a mitochondria. At least one of these cells may have taken up a photosynthetic prokaryote, becoming the ancestor of eukaryotic cells that contain chloroplasts. Three lines of evidence that support the model of endometriosis: 1. Rather than being bound by a single membrane, like organelles of the endometrial system, mitochondria and typical chloroplasts have two membranes surrounding them. . Like prokaryote, mitochondria and chloroplasts contain ribosome, as well as circular DNA molecules attached to their inner membranes. . Also consistent with their probable evolutionary origins as cells, mitochondria and chloroplasts are autonomous organelles that grow and reproduce within cells. 32. Mitochondria and chloroplasts are not considered part of the endometrial system, although they are enclosed by membranes. Sketch a mitochondria here and label its outer membrane, inner membrane, inner membrane space, Cristal, matrix, and ribosome. See page 110 of your text for the labeled figure. 3. Now sketch a chloroplast and label its outer membrane, inner membrane, inner membrane space, ayatollahs, granular, and stoma. Notice that the mitochondria has two membrane compartments, while the chloroplast has three compartments. See page 1 11 of your text for the labeled figure. -6- What is the function of the mitochondria? Mitochondria are the sites of cellular respiration, the metabolic process that uses oxygen to generate TAP by extracting energy from sugars, fats, and other fuels. 35. What is the function of the chloroplasts? Chloroplasts are sites of photosynthesis.
These organelles convert solar energy to chemical energy by absorbing sunlight and using it to drive synthesis of organic compounds such as sugars from carbon dioxide ND water. Recall the relationship of structure to function. Why is the inner membrane of the mitochondria highly folded? What role do all the individual ethylated membranes serve? (Notice that you will have the same answer for both questions. ) As highly folded surfaces, the Cristal give the inner mitochondrial membrane a large surface area, thus enhancing the productivity of cellular respiration.
As in mitochondria, ethylated membranes serve to increase the surface area and thus the function of the chloroplasts. 37. Explain the important role played by promises. Promises contain enzymes hat remove hydrogen atoms from various substrates and transfer them to oxygen, thus producing hydrogen peroxide as a by-product. SUMMARY On these diagrams of plant and animal cells, label each organelle and give a brief statement of its function. See pages 100-101 of your text for the labeled figures and a brief statement of each organelle’s function. Concept 6. The cytokines is a network of fibers that organizes structures and activities in the cell 38. What is the cytokines? The cytokines is a network tot fibers extending throughout the cytoplasm . 39. What are the three roles of the cytokines? 1 . Maintenance of cell shape 2. Mechanical support 3. Cell motility (movement) both of the cell as a whole and more limited movement of parts of the cell 40. There are three main types of fibers that make up the cytokines. Name them. Misconstrues, Microorganisms, Intermediate Filaments 41 . Misconstrues are hollow rods made of a globular protein called tubing.
Each tubing protein is a dimmer made of two subunits. These are easily assembled and disassembled. What are four functions of misconstrues? 1 . Maintenance of cell shape 2. Cell motility 3. Chromosome movement in cell division 4. Organelle movement 42. Animal cells have a connectors that contains a pair of centurions. Plant cells do not have centurions. What is another name for commentators? What is believed to be the role of centurions? Another name for connectors is “microcircuit-organizing center. ” The centurions function as compression-resisting girders of the cytokines. 3. Describe the organization of misconstrues in a centurion. Make a sketch here that shows this arrangement in cross section. See page 114 of your text for the labeled figure. The two centurions are at right angles to each other, and each is made up of nine sets of three misconstrues. 44. Cilia and flagella are also composed of misconstrues. The arrangement of misconstrues is said to be “9 + 2. ” Make a cross- sectional sketch of a cilium here. (See Figure 6. Bib in your text. ) See page 115 of your text for the labeled figure. 45. Compare and contrast cilia and flagella.
Cilia and flagella are both microcircuit-containing extensions that project from some cells. Cilia and flagella share a common structure, each having a group of misconstrues sheathed in an extension of the plasma membrane. Flagella and cilia differ in their beating patterns. A flagellum has an undulating motion that generates force in the name direction as the flagellum’s axis, like the tail of a fish. In contrast, cilia work more like oars, with alternating power and recovery strokes generating force in a direction perpendicular to the cilium’s axis. 46.
How do motor proteins called dyne’s cause movement of cilia? What is the role of TAP in this movement? This figure might help you explain. See page 116 of your text for the labeled figure. Dyne’s are responsible for the bending and movements of the organelle. A dyne molecule performs a complex cycle of movements caused by changes in the shape of the protein, with TAP providing the energy for these changes. 47. Microorganisms are solid, and they are built from a double chain of acting. Study Figure 6. 27 in your text, and explain three examples of movements that involve microorganisms.
Copyright O 2011 Pearson Education, Inc. -8- 1 . Myosin motors in muscle cell contraction: The “walking” of myosin projections (the so-called heads) drives the parallel myosin and acting filaments past each other so that the acting filaments approach each other in the middle. This shortens the muscle cell Muscle contraction involves shortening tot many muscle cells at the same time. See also Figure 6. AAA on page 117. 2. Amoeboid movement: Interaction of acting ailments with myosin causes contraction of the cell, pulling the cell’s trailing end forward. See also Figure 6. Bib on page 117. 3.
Cytoplasm streaming in plant cells: A layer of cytoplasm cycles around the cell, moving over a carpet of parallel acting filaments. Myosin motors attached to organelles in the fluid costly may drive the streaming by interacting with the acting. See also Figure 6. ICC on page 117. 48. What are the motor proteins that move the microorganisms? Myosin 49. Intermediate filaments are bigger than microorganisms but smaller than misconstrues. They are more permanent fixtures of cells. Give two functions of intermediate filaments. Possible answers include: 1 . Maintenance of cell shape (tension-bearing elements) 2.
Anchorage of nucleus and certain other organelles 3. Formation of nuclear lamina Concept 6. 7 Extracurricular components and connections between cells help coordinate cellular activities 50. What are three functions of the cell wall? 1 . Protects the plant cell 2. Maintains its shape 3. Prevents excessive uptake of water 51 . What is the composition of the cell wall? Microfossils made of the polysaccharide cellulose are synthesized by an enzyme called cellulose syntheses and secreted to the extracurricular pace, where they become embedded in a matrix of other polysaccharides and proteins. 52.
What is the relatively thin and flexible wall secreted first by a plant cell? Primary cell wall 53. What is the middle lamellar? Where is it found? What material is it made of? The middle lamellar is a thin layer of sticky polysaccharides called pectin’s, located between the primary walls of adjacent cells. 54. Explain the deposition of a secondary cell wall. The secondary wall, often deposited in several laminated layers, has a strong and durable matrix that affords the cell protection and support. 55. On this sketch, label he primary cell wall, secondary cell wall, middle lamellar, plasma membrane, central vacuole, and bloodstream.
See page 119 of your text for the labeled figure. 56. Animal cells do not have cell walls, but they do have an extracurricular matrix (ECMA). On this figure, label the elements indicated, and give the role of each. See page 120 of your text for the labeled figure. 57. What are the intracellular Junctions between plant cells? What can pass through them? Bloodstream are the intracellular junctions between plant cells. Costly passes through the bloodstream and Joins the internal chemical environments of adjacent cells. 8. Animals cells do not have bloodstream.
