2. Cell Chemistry & Cell Components
Introduction to the Cytoskeleton
- Multiple ChoiceWhich of the following structures is found in animal cells but not in plant cells?1685views
- Multiple ChoiceCilia and flagella move due to the interaction of the cytoskeleton with which of the following?2133views
- Multiple ChoiceBasal bodies are most closely associated with which of the following cell components?1872views
- Textbook Question
What effect would the hypothetical poison of question 3 have on other functions of the cell? Explain.
356views - Textbook QuestionHow does the hydrolysis of ATP result in the movement of a motor protein along a cytoskeletal filament?1338views
- Textbook QuestionDescribe two different ways in which cilia can function in organisms.1579views
- Textbook QuestionThe eukaryotic cytoskeleton is a highly dynamic network of filaments and motor proteins. Which of the following correctly describe activities of these cytoskeletal components? Select True or False for each statement.T/FMyosin motors walk toward the plus ends of intermediate filaments.T/FDynein motors are responsible for the whip-like movement of eukaryotic flagella.T/FKinesin motors move vesicles along tracks toward the microtubule-organizing center.T/FActin filaments are required for cytoplasmic streaming.1496views
- Textbook QuestionGeorge Palade's research group used the pulse–chase assay to elucidate the secretory pathway in pancreatic cells. If they had instead performed this assay on muscle cells, where would you expect the labeled proteins to end up during the chase? (Muscle cells consist primarily of actin and myosin filaments and have high energy demands for muscle contraction.)1349views
- Textbook QuestionCilia are found on cells in almost every organ of the human body, and the malfunction of cilia is involved in several human disorders. During embryological development, for example, cilia generate a leftward flow of fluid that initiates the left-right organization of the body organs. Some individuals with primary ciliary dyskinesia exhibit a condition (situs inversus) in which internal organs such as the heart are on the wrong side of the body. Explain why this reversed arrangement may be a symptom of PCD.2033views
- Textbook QuestionThe figure below illustrates the results they observed as the chromosomes moved toward the opposite poles of the cell. Describe these results. What would you conclude about where the microtubules depolymerize from comparing the length of the microtubules on either side of the mark? How could the experimenters determine whether this is the mechanism of chromosome movement in all cells?1349views
- Textbook QuestionMicrotubules often produce movement through their interaction with motor proteins. But in some cases, microtubules move cell components when the length of the microtubule changes. Through a series of experiments, researchers determined that microtubules grow and shorten as tubulin proteins are added or removed from their ends. Other experiments showed that microtubules make up the spindle apparatus that 'pulls' chromosomes toward opposite ends (poles) of a dividing cell. The figures below describe a clever experiment done in 1987 to determine whether a spindle microtubule shortens (depolymerizes) at the end holding a chromosome or at the pole end of a dividing cell. Experimenters labeled the microtubules of a dividing cell from a pig kidney with a yellow fluorescent dye. As shown on the left half of the diagram below, they then marked a region halfway along the microtubules by using a laser to eliminate the fluorescence from that region. They did not mark the other side of the spindle (right side of the figure).1731views
- Textbook Question
Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.
Actin filaments combine with myosin motor proteins to provide the cell with mechanical strength.
382views - Textbook Question
Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.
The cilia found on sperm cells propel the cells through a liquid medium.
413views - Textbook Question
Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.
Microtubules are hollow tubes that align organelles and shuttle them to their proper places in the cell.
416views - Textbook Question
Mark the following statements about the cytoskeleton as true or false. If a statement is false, correct it to make a true statement.
Intermediate filaments are ropelike structures composed of tubulin proteins.
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