Module 3.Activity 2.Investigating Membranes PDF

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Module 3 Activity 2 Assignment Course Work General Biology...

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BIOS1010 General Biology Green______________ Module 3 Activity 2

Name __________Lucy

Investigating Membranes Cell Defense: The Plasma Membrane Investigate how a membrane works and how diffusion occurs using the app Cell Defense: The Plasma Membrane or go to Bioman Biology: The Fun Place to Learn Biology! Click on Cells and the Cell Defense: The Plasma Membrane. In either case, start by choosing Start a New Game. 1. Start with Build a Membrane and investigate the parts of a membrane. For the following membrane components, describe their structure and function: a. Phospholipids – Made up of a phosphate head and two fatty acid tails. Makes a phospholipid bilayer, surrounds and protects internal cell components. b. Cholesterol- Essential for making the cell membrane and cell structures, vital for synthesis of hormones, vitamin d, and other substances. Helps stabilize and has direct effects on the membrane to ensure it isn’t too fluid nor too solid.

c. Channel Protein- A special arrangement of amino acids embedded in the cell membrane, provides hydrophilic passageway for water and small polar ions. Allows ions and water to flow freely from one side of a membrane to another. d. Carrier Protein- Made up of 20 different amino acid chains, each protein has a specific role. Defines specific shape and function of the protein and allows chemicals to cross the membrane against a concentration gradient or when the phospholipid bilayer is impermeable to a chemical. e. Carbohydrates- Able to decipher that yoru cells are your own cells and are not bacteria, viruses, or a foreign cell attacking the body. Cells have different membrane carbohydrates if they do different jobs, carbohydrates also function as fuel molecules.

What are some substances that pass through the membrane easily?

Oxygen, water, and carbon dioxide

What are some substances that need help passing through the membrane? Charged ions and sugar 2. Complete the membrane structure challenge to help you review what you have just learned. 3. After completing the diffusion challenge, define diffusion, including what will diffuse and in what direction. Diffusion is the movement of particles from a area of higher concentration to an area of lower concentration. The mechanism of molecules spreading from where they are more concentrated to where they are less concentrated is a form of passive transport.

4. After completing the Energy and Transport Challenge, answer the following questions: a. Under what conditions would facilitate diffusion be used? When the solute can move from regions of higher to lower concentration, relying on the protein carrier to pass through the membrane. b. Under what conditions would active transport be used? Moving against a gradient to move substances against a concentration or electrochemical gradient, a cell must use the energy. Maintains the right concentration of the ions and molecules in living cells. c. In which type of transport is energy used? What is this energy? Used in active transport, used to move substances against a concentration or electrochemical gradient. 5. After completing the osmosis challenge, define the following:

a. Osmosis- diffusion of water through a semipermeable membrane down a concentration gradient b. Hypertonic- solution that has higher concentration of solutes than another solution c. Hypotonic- solution that has lower concentration of solutes than another solution d. Isotonic- when two solutions have the same concentration of a solute. 6. When you are done, take a screen shot and attach to this assignment....