anatomy lab
the bold stars are new paragraphs since it kinda all merged together....
**In this lab, there are eight main concepts that one must understand. We must remember that the plasma membrane is selectively permeable. This means that for some substances, it is permeable or allowing, but with other substances it can be impermeable and not let that particular substance through the membrane. Permeable substances must be non polar, uncharged molecules such as water, carbon dioxide, and steroids. Impermeable substances include ions, charged molecules, and polar substances. Although there are some exceptions to the permeability; if a substance is small enough, they can pass through the plasma membrane. This occurs because membrane consisting of phospholipids and glycolipids move about small openings that are formed allowing even polar molecules such as water and urea across the membrane (Tortora 63).
**Diffusion is the second concept that one needs to know during this lab. Diffusion occurs by the mixing of ions and molecules at random by kinetic energy or energy of motion. In diffusion, there are solutes and solvents. A solute is the substance being dissolved and a solvent is the substance doing the dissolving. Particles move down their concentration gradients, meaning that if they are in an area of high concentration they will diffuse to an area of less concentration. This occurs until the equilibrium is reached. Equilibrium is achieved when the concentrations are equal but there is still continuous movement of particles (Tortora 65).
**The quickness of diffusion across the plasma membrane is determined by five factors. The steepness of the concentration gradient plays a big role. If the difference is larger between the two sides of the membrane then diffusion will occur at faster rate. The same applies to charged particles and the electrochemical gradient (Tortora 65). Temperature is another factor. The higher the temperature, the faster diffusion will occur (Tortora 66). The mass of a particle can also determine the rate of diffusion. A large particle will take longer to diffuse than a smaller one (Tortora 66). Surface area to diffuse across can make diffusion occur faster too by allowing more particles in (Tortora 66). The last factor to determine the rate of diffusion is the distance that a particle must go to cross the membrane. The longer the distance, the longer diffusion will take to occur (Tortora 66).
**Osmosis is the third concept. Osmosis is the net movement of a solvent through a selectively permeable membrane. The solvent in most cases is water. Like most solvents, water will move from an area of high concentration to an area of low concentration. During osmosis, water molecules by either moving through the lipid bilayer, or by moving through aquaporins that are proteins in the membrane functioning as water channels (Tortora 66).
**The fourth concept is osmotic pressure. This is the pressure used to stop the movement of water across a membrane only permeable to water into a solution containing solutes. There is a direct relationship between the solute’s concentration and the osmotic pressure. An example of this is that when a solute’s concentration is high, the osmotic pressure will also be high. Osmotic pressure can also be applied to the volume of the cell. The pressure from the external environment and the internal environment are usually the same and help to control the volume of the cell by keeping it regular (Tortora 67).
**The fifth concept of the lab is tonicity. Tonicity is described by Gerard J. Tortora as, “a measure of the solution’s ability to change the volume of cells by altering their water content” (67). For a cell to maintain its normal shape, it must be in an isotonic solution. An isotonic solution is the sixth concept. Isotonic solutions occur when the solvent concentration and the solute concentration are the same in the internal environment and the external environment (Tortora 67).
**The last two concepts that we must understand are hypotonic and hypertonic solutions. Hypo, meaning low, has a smaller concentration of solutes and a higher concentration of water. Hyper, meaning greater, has a high solute concentration and a low water concentration (Tortora 67).
this is for mark... the intro all done for ya and cited.. the last two parts of it kinda suck but it was the best i could do to explain them. ill get the rest of the discussion to you tonight hopfully. :)
**In this lab, there are eight main concepts that one must understand. We must remember that the plasma membrane is selectively permeable. This means that for some substances, it is permeable or allowing, but with other substances it can be impermeable and not let that particular substance through the membrane. Permeable substances must be non polar, uncharged molecules such as water, carbon dioxide, and steroids. Impermeable substances include ions, charged molecules, and polar substances. Although there are some exceptions to the permeability; if a substance is small enough, they can pass through the plasma membrane. This occurs because membrane consisting of phospholipids and glycolipids move about small openings that are formed allowing even polar molecules such as water and urea across the membrane (Tortora 63).
**Diffusion is the second concept that one needs to know during this lab. Diffusion occurs by the mixing of ions and molecules at random by kinetic energy or energy of motion. In diffusion, there are solutes and solvents. A solute is the substance being dissolved and a solvent is the substance doing the dissolving. Particles move down their concentration gradients, meaning that if they are in an area of high concentration they will diffuse to an area of less concentration. This occurs until the equilibrium is reached. Equilibrium is achieved when the concentrations are equal but there is still continuous movement of particles (Tortora 65).
**The quickness of diffusion across the plasma membrane is determined by five factors. The steepness of the concentration gradient plays a big role. If the difference is larger between the two sides of the membrane then diffusion will occur at faster rate. The same applies to charged particles and the electrochemical gradient (Tortora 65). Temperature is another factor. The higher the temperature, the faster diffusion will occur (Tortora 66). The mass of a particle can also determine the rate of diffusion. A large particle will take longer to diffuse than a smaller one (Tortora 66). Surface area to diffuse across can make diffusion occur faster too by allowing more particles in (Tortora 66). The last factor to determine the rate of diffusion is the distance that a particle must go to cross the membrane. The longer the distance, the longer diffusion will take to occur (Tortora 66).
**Osmosis is the third concept. Osmosis is the net movement of a solvent through a selectively permeable membrane. The solvent in most cases is water. Like most solvents, water will move from an area of high concentration to an area of low concentration. During osmosis, water molecules by either moving through the lipid bilayer, or by moving through aquaporins that are proteins in the membrane functioning as water channels (Tortora 66).
**The fourth concept is osmotic pressure. This is the pressure used to stop the movement of water across a membrane only permeable to water into a solution containing solutes. There is a direct relationship between the solute’s concentration and the osmotic pressure. An example of this is that when a solute’s concentration is high, the osmotic pressure will also be high. Osmotic pressure can also be applied to the volume of the cell. The pressure from the external environment and the internal environment are usually the same and help to control the volume of the cell by keeping it regular (Tortora 67).
**The fifth concept of the lab is tonicity. Tonicity is described by Gerard J. Tortora as, “a measure of the solution’s ability to change the volume of cells by altering their water content” (67). For a cell to maintain its normal shape, it must be in an isotonic solution. An isotonic solution is the sixth concept. Isotonic solutions occur when the solvent concentration and the solute concentration are the same in the internal environment and the external environment (Tortora 67).
**The last two concepts that we must understand are hypotonic and hypertonic solutions. Hypo, meaning low, has a smaller concentration of solutes and a higher concentration of water. Hyper, meaning greater, has a high solute concentration and a low water concentration (Tortora 67).
this is for mark... the intro all done for ya and cited.. the last two parts of it kinda suck but it was the best i could do to explain them. ill get the rest of the discussion to you tonight hopfully. :)