(impermeable; freely permeable; selectively permeable)

Transcription

1 BIOL 2457 CHAPTER 3 Part 1 SI 1 1. A is the basic structure of life. 2. The gelatinous inside of the cell is called the. 3. Name the structure that increases the cell s surface area? 4. Name the structure that moves materials across the cell s surface. 5. Name the structures that give support to the cell and move structures within the cell. 6. The plasma membrane is described as a model because it moves and has many structures floating in it. 7. Name some functions of cell proteins. 8. In diffusion, molecules move from an area of concentration to an area of concentration. (high or low) In diffusion, movement is. (active or passive) 9. Osmosis is a special type of diffusion in which the molecule that moves is. In osmosis, movement is. (active or passive) 10. Diffusing molecules (including water) move across a membrane that is (impermeable; freely permeable; selectively permeable) 11. Compare concentration of solute (and water) in the cell with the concentration of solute (and water) outside the cell in the following solutions: isotonic hypertonic hypotonic 12. What happens to cells placed in the following solutions? isotonic hypertonic hypotonic 13. Explain simple diffusion across a plasma membrane 14. Explain facilitated diffusion across a plasma membrane 15. Name 3 things that will affect simple diffusion; indicate what speeds up diffusion for each.

2 BIOL 2457 CHAPTER 3 Part 1 SI Movement of molecules across a membrane from an area of low concentration to an area of high concentration is called. Does this process require energy? 17. Give an example of transport against a concentration gradient. 18. Define resting membrane potential 19. What is the polarity of the resting membrane potential? 20. List and explain the 3 types of endocytosis. 21. Explain exocytosis. 22. Do endocytosis and exocytosis require energy? 23. Give 3 reasons why cells are small. 24. Match the cell structures with their functions. Cell membrane A. Modifies and packages proteins Cytosol B. Protein synthesis Cytoskeleton C. Gel-like substance; holds organelles Microvilli D. Contains genetic information Cilia/flagella E. Increase surface area Centrioles F. Digests damaged organelles and pathogens Ribosomes G. Structure, support, movement Mitochondria H. Makes ribosome subunits Rough endoplasmic reticulum I. Selective permeability Smooth endoplasmic reticulum J. Makes ATP Golgi apparatus K. Carbohydrate and lipid synthesis Lysosomes L. Move cell or substances across cell Peroxisomes M. Neutralize toxic compounds Nucleus N. Move chromosomes during cell division Nucleolus O. Modifies and packages substances secreted 25. Explain the endosymbiotic theory of origin of mitochondria.

3 BIOL 2457 CHAPTER 3 Part 1 SI Define the Central Dogma 27. What types of RNA are made by DNA? 28. Contrast DNA and RNA DNA RNA Number of strands Sugar Bases 29. Most of the time, DNA is found in the nucleus as long thin strands called. During cell division, these strands condense into. 30. Segments of DNA that code for proteins are called. Segments of DNA that do not code for anything (junk DNA) are called. 31. Name 3 things that can cause mutations in DNA.

4 BIOL 2457 CHAPTER 3 Part 1 - Answers SI 4 1. cell 2. cytoplasm 3. microvilli 4. cilia 5. cytoskeleton microtubules, intermediate filaments, microfilaments 6. Fluid-Mosaic 7. attachment; cell recognition; enzymes; receptors; carrier proteins; channels 8. high; low; passive 9. water; passive 10. selectively permeable 11. isotonic concentration of solutes and water is the same inside and outside the cell (cell is isotonic to its environment) hypertonic concentration of solutes in the environment is greater than the concentration of solutes inside the cell; concentration of water in the environment is less than concentration of water inside the cell. (cell is hypotonic to its environment) hypotonic concentration of solutes in the environment is less than the concentration of solutes inside the cell; concentration of water in the environment is greater than concentration of water inside the cell. (cell is hypertonic to its environment) 12. isotonic water moves in and out of cell at same rate hypertonic water leaves cell; cell shrinks crenation hypotonic water enters cell; cell swells, and maybe bursts hemolysis 13. lipid soluble molecules move through phospholipid bilayer; water soluble molecules and ions move through channel proteins 14. large molecules bind to receptor site on integral protein; protein changes shape and moves molecule across membrane 15. size of concentration gradient; large gradient thickness of membrane; thin membrane temperature; warmer temperature 16. active transport; yes 17. sodium-potassium pump; (3 Na + out and 2 K + in) 18. balance between pos/neg charges inside membrane and pos/neg charges outside membrane 19. negative inside; positive outside 20. phagocytosis; cell takes in solid substances pinocytosis; cell takes in liquid substances receptor-mediated endocytosis; cell takes in specific substances 21. movement of substance out of cell 22. yes 23. need a large surface area to maintain homeostasis; small size is quickly moved; small cells easily isolated 24. I, C, G, E, L, N, B, J, A, K, O, F, M, D, H 25. Mitochondria have double membrane because anaerobic organism engulfed aerobic organism that had developed ability to use oxygen; lived symbiotically because organism could now use aerobic and anaerobic processes. 26. DNA makes RNA makes products/protein

5 BIOL 2457 CHAPTER 3 Part 1 - Answers SI messenger RNA (mrna); ribosomal RNA (rrna); transfer RNA (trna) 28. DNA RNA Number of strands Double strand Single strand Sugar Deoxyribose Ribose Bases A, T, C, G A, U, C, G 29. chromatin; chromosomes 30. exons; introns 31. chemicals; UV radiation; viruses