1. Double bilayer of with imbedded, dispersed 2. Bilayer consists of, cholesterol, and glycolipids

Transcription

1 Bio Chapter 7.3 Cellular Movement Notes I. Background Information A. - a mixture in which the (molecules being ) never settle out in the (water). B. In a 25% Koolaid solution, how much water is there? C. Every living cell contains a liquid (cytoplasm) and is by a liquid (fluid that baths your cells). II. Homeostasis A. Process where the cell/organism tries to maintain a environment. 1. Examples:, blood sugar, and body fluids. B. Cells maintain homeostasis by controlling what and leaves the cell via the (plasma). 1. It is selectively (semi-) it allows molecules to move in/out of the cell III. Cell Membrane A. Structure: Model parts are not in positions, they are free to along the bilayer (sea of fat) Label: Glycoprotein, Glycolipid, Integral protein, Peripheral protein, Cholesterol 1. Double bilayer of with imbedded, dispersed 2. Bilayer consists of, cholesterol, and glycolipids

2 a. Glycolipids are lipids with bound, found in membrane b. Phospholipids have two (water hating) tails and a (water loving) head i. The center section of the lipid bilayer is, either side of the bilayer (in/out of the cell) is. ii. The regions of the protein in the bilayer are ; the regions of protein to the internal/external environment of the cell are. iii. molecules have a difference in charges; therefore attract like Na +, Ca +2, and K + 3. Draw a single phospholipid (label: head, tails, hydrophobic and hydrophilic end); Draw the phospholipd bilayer membrane. 4. Functions of Membrane Proteins molecules floating in of allow: a. i. Proteins bind to a substance and transport it across the membrane the concentration gradient ( to ) ii. Proteins form or passageways for molecules to move through the membrane down the gradient b. activity c. for signal transduction i. signaling important in normal development and ii. signaling voltage-regulated in and muscle tissue iii. signaling bind to chemically gated channel-linked receptors in nerve and muscle tissue d. Intercellular (CAM s) i. cells to the extracellular matrix

3 ii. Assist in of cells past one another iii. Rally protective cells to or infected areas e. Cell-cell identify the cell f. Attachment to and extracellular IV. Transport across the membrane A. Label Diagram B. bilayer prevents molecules (like and amino acids) from passing through the membrane. C. molecules are small enough to across the lipid bilayer. V. Processes (No required) A. - mixing of particles in a solution as a result of the particle s energy 1. More molecules move from an area of concentration to an area of concentration ( their concentration gradients) 2. It s the that in and out of the cell if it can pass through the membrane 3. The following conditions affect the of diffusion (how the solute across the membrane): a. The greater the difference in between the 2 sides of the membrane, the the rate of diffusion b. The the temperature, the the rate of diffusion c. The the size of the diffusing substance, the the rate of diffusion

4 d. An in surface area, the rate of diffusion e. diffusion distance, rate of diffusion 4. When the molecules are, equilibrium has been reached 5. Indicate the direction of solute movement by drawing an arrow in the direction of flow for each diagram B. Osmosis - Net movement (diffusion) of through a membrane from an area of water concentration to an area of water concentration 1. Water is concentrated where there is the solute concentration. 2. Water moves to solutions ( solute concentrations). 3. Only occurs if membrane is to water but not to certain 4. Indicate the direction of water movement by drawing an arrow in the direction of flow 5. how a solution affects cell a. solutions with the solute concentration as that of the cytosol (the concentration of solutes if inside and outside the cell) b. solutions having solute concentration than that of the cytosol (the concentration of solutes is greater the cell than it is ) i. In plant cells, the central vacuole water and the cells, causing wilting. ii. In animal cells, the cells also.

5 c. solutions having solute concentration than that of the cytosol (the concentration of solutes is greater the cell than it is ) ii. In plants the central vacuole and the plants are rigid (but the cell wall keeps it from ) iii. In animals the cell could (burst) unless certain organelles water out quickly! 6. Osmotic - Pressure created by osmosis (pg. 186) a. Cells are filled with, salts, proteins, and other molecules which cause a to build up on the side of the membrane (or inside the cell). b. If a cell is placed in water, water will rush into the cell causing is to and burst ( ). c. If this is true, why aren t your cells expanding and exploding right now?????? i. Our cells are bathed by, which is with the fluid in our cells. This means that the concentration inside the cell is the same as that in the. C. Facilitated Diffusion with in the make it easier for certain molecules to enter the cell 1. move their concentration gradients 2. proteins allow large molecules (like and amino acids) to cross the membrane 3. proteins provide a safe crossing for across the cell membrane a. channels can contain that can open or close depending on internal/external of the cell i. This allows the cell to when can enter/exit the cell.

6 VI. Processes - ( required ) A. Active Transport - molecules moved across from concentrations to concentrations ( up their concentration gradients) with the help of membrane 1. Types of Active Transport a. active transport hydrolysis of, phosphorylates the transport protein causing change (change of ) b. active transport use of an pump (such as the pump) indirectly to drive the transport of other i. The sodium potassium pump ( ) moves (1) 3 ions of the cell (2) 2 ions the cell (3) Since both ions are (+) the net on the inside of the plasma membrane becomes (-) (4) The in is important in the conduction of electrical (neurons) 2. Types of Transport-transport of particles and across plasma membranes a. - surrounding a substance with some of the and then, bringing it into the cell, within a ( ). i. - bringing in -like food and cells. ii. - bringing in. b. - opposite of i. contents of vesicles of the cell ii. This is a way to the cell of. iii. the membrane, so the cell doesn t. c. moving substances into,, and then out of a cell d. Vesicular moving substances from one in the cell to another e. Draw and label Endocytosis, Transcytosis and Exocytosis