Cell+essays

1. Phospholipids are a critical component of the cell membrane. The cell membrane is selectively permeable, allowing only certain substances in and out, and in certain amounts. a. Describe why phospholipids are important components of cell membranes, based on their strucure and properties b. Explain why proteins are an important component of hte cell membrane, based on their structure adn properties

2. Prokaryotic and eukaryotic cells are physiologically different in many ways, but both represent functional collections of living matter a. It has been theorized that the organelles of eukaryotic cells evolved from porkaryotes living symbiotically within a large cell. Compare and contrast the structure of the prokaryotic cell with eukaryotic cell organielles, and make an argument for or against this theory. b. trace the path of a protein in a eukaryotic cell from its formation to its excretion from the cell

3. Explain whether you would use a light microscope, a transmission electron microscope (TEM) or a scanning electron microscope (SEM) to perform each of the following tasks and explain why: examining fine structural details with cell organelles, observing how a cell changes shape as it moves, studying tiny bumps on the cell surface, filming changes in the shape of the nucleus as a cell prepares to divide

4. Imagine a cell shaped like a cube. 5 micrometers on each side. (cells are not perfect cubes, but this assumption simplifies the questions.) What is the surface area of the cell, in micrometers2? What is its volume in micrometers3? What is the ratio of surface are to volume for this cell? (Sketches may help). Now imagine a second cell, this one 10 micrometers on each side. What are its surface area, volume, and surface to volume ratio? Compare the surface-to-volume ratios of the two cell. How is this comparison significant to the functioning of cells? How could the surface-to-volume ratio of the larger cell be increased?

5. An enzyme (a type of protein) called salivary amylase is manufactured in the cells of your salivary glands and secretes as part of saliva. Explain how these parts of the cell cooperate to produce and secrete salivary amylase: transport vesicles, rough ER, plasma membrane, nucleus, Golgi apparatus, ribosomes.

6.A poison that acts specifically on mitochondria was found to interfere with the movement of cilia, slow down protein synthesis, reduce the frequency of cell division, and slow down the manufacture of lipids. Explain how one chemical could affect so many different cell activities.

7.When you work harder, your muscle cells work harder and increase in size. How might various organelles in a muscle cell increase in size, number, or activity to respong to the challenge of an increased workload?

8.Compare and contrast the characteristics of prokaryotic and eukaryotic cells.

9.Living cells are highly organized and regulated. a.Describe the structure to the plasma membrane b.Explain how the plasma membrane contributes to the regulation of the cell