Worksheet 2

Worksheet 2- Brittani Wright 1. a) Define a cell. A cell is the basic unit of life b) What is a unicellular organism? An organism that consists of only one cell c) Can a cell be multicellular? No because a cell is the smallest unit of life, cells can however join together to start forming something else 2. a) What is a difference between prokaryotic and eukaryotic cells? b) What is one significant similarity? Prokaryotic cells do not have a neucleus and Eukaryotic cells do have a nucleus. One similarity is that both are covered by a cell membrane and contain RNA as well as require energy 3. Which type of microscopy provides a 3d view of the surface of an object? Scanning electron microscope 4. Would you find proteins inside cells or cells inside proteins? (Choose one answer.) Protein inside cells 5. Which type of molecule travels through an aquaporin? Small, lipid-soluble molecules 6. Explain the basic organization (main components) of a plasma membrane. Include at least 4 distinct parts in your description. A plasma membrane is composed of a phospholipid bilayer in which proteins are embedded. The hydrophilic heads of phospholipids are a part of the outside surface and the inside surface of the membrance. The hydrophobic tails make up the interior of the membrane. The plasma membrane is asymmetrical. Carbohydrate chains are attached to the outside surface, and cytoskeleton filaments are attached to the inside surface. Cholesterol lends support to the membrane. 7. Osmosis is the net movement ofwater across a semipermeable membrane from an area of higher concentration to an area of lower concentration. 8. What would happen if an intravenous solution was hypertonic to blood? Water leaves the red blood cells and they shrink 9. Why are the proteins that are involved in active transport often called pumps? Because energy is used to move substances against their concentration gradients. 10. What is an organelle? Small