Chapter+3+Cell+Structure+NLL

//**Chapter 3. Cell Structure.**//

1. What does the cell theory state? All living things are made of cells. Cells are the basic units of structure and function in living things. All cells come from the reproduction of existing cells.

2. Why are cells so tiny? The small size of cells is explained by considering the surface area-to-volume ratio of cells. Once a hen’s egg is fertilized and starts metabolizing, it divides repeatedly without growth. Cell division restores the amount of surface area needed for adequate exchange of materials. Also important is the decrease in the distance a substance must travel to reach a destination, when a cell is small compared with one that is large.

3. What are the three main parts of a eukaryotic cell? The three main parts of a Eurokaryotic cells are the Cell Membrane, Organelles, and Nucleus.

4. Explain how the eukaryotic cell gained mitochondria and chloroplasts. As some of the organelles in eukaryotic cells are raised by engulfing prokaryotic cells, it gives the eukaryotic cell a mitochondrion and chloroplast.

5. What are glycoproteins, and what functions do proteins, including glycoproteins, have in the plasma membrane? Glycoproteins are short chains of sugars attached to the outer surface of some protein and lipid molecules. Glycoproteins helped mark it as belonging to a particular individual and account for why people have blood types. They act as a receptor for a chemical messenger, such as a hormone. Proteins form channels in which certain substances can enter cells. Others are enzymes that catalyze reactions.

6. What is endocytosis and exocytose, and how do they occur? They are both processes that occur in the plasma membrane. During endocytosis, a portion of the plasma membrane invaginates, or forms, a pouch to envelope a substance and fluid. During exocytosis, a vesicle fuses with the plasma membrane as secretion occurs.

7. The nucleus, ribosome’s, and rough endoplasmic reticulum make what contribution to protein synthesis? They all help determine a cell’s specificity.

8. The endoplasmic reticulum and the Golgi apparatus make what contribution to the processing of proteins? The Golgi apparatus modifies the proteins and lipids received and it helps detoxify drugs. Attached ribosome’s may be secreted from the cell of become part of the plasma membrane. It produces testosterone. It also forms transport vesicles in which large molecules are transported to other parts of the cell.

9. What is the function of smooth endoplasmic reticulum and liposome’s? Smooth endoplasmic reticulum synthesizes the phospholipids that occur in membranes and has various other functions depending on the particular cell. Lysosomes help digest things into simpler subunits that then enter the cytoplasm.

10. What is the function of the mitochondria? The main function of the mitochondrion is the production of energy, in the form of adenosine triphosphate (ATP). The cell uses this energy to perform the specific work necessary for cell survival and function.