BSC 181 1st Edition Lecture 7Outline of Last Lecture I. Different Types of AcidsII. Membrane Proteins/Plasma MembraneIII. Functions of Cell MembraneIV. Membrane JunctionsOutline of Current Lecture II. Passive Membrane TransportIII. ToxicityIV. Active Membrane TransportV. Our Cells OrganellesCurrent LecturePassive Membrane Transport: Passive means that the cell does not need to waste any energy on getting something to pass through the membrane. There are four different types of passive membrane transport. The cell will decide which type to use depending on what molecule is trying to get passage through the membrane. There is Simple Diffusion, Carrier-mediated Facilitated Diffusion,Channel-Mediated Facilitated Diffusion, and Osmosis. Page 69 in our book gives really good visuals for these processes. Keep in mind that facilitated diffusion can monitor how often they are active as well as how many particles they allow pass through. Diffusion: a movement of high concentration to low concentration.Simple Diffusion: This truly is the simplest way of diffusion. This is when non polar molecules and lipid soluble (fat soluble) molecules simply pass through the lipid bi-layer (phospholipid) membrane. Simple Diffusion is also kind of like of like a cousin with osmosis due to water. Because water can be transported through the bi-layer in two ways, simple diffusion (simply traveling across) or Osmosis. Carrier-Mediated Facilitated Diffusion: This is when there are protein carriers that line the inside of the membrane. These protein carriers are chemical specific so it only lets what is specific for through the membrane. The protein carrier will have an opening for the molecule to go into. Once the molecule is in the opening, the protein carrier will change shape. This change in shape closes where the molecule came in, and opens the These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.side that is on the inside of the cell, allowing the molecule to move into the cell. The shape change in the carrier is caused by the binding of the substrates. Channel-Mediated Facilitated Diffusion: Unlike the other diffusions, this one is like an open door. It freely let’s particles move into and out of the cell. There are two types of channel-mediated facilitated diffusion. Leakage Channels: these are always open. (the door is always open)Gated Channels: these are controlled by chemical or electrical signals. (you have to do a secret knock to get the door to open)Osmosis: Water can either travel through the lipid bi-layer through simple diffusion or it can go through a process called osmosis. In osmosis, water needs a water specific channel protein (aquaporin) to help it get across. This allows the water molecules through the membrane one at a time. However, osmosis only occurs when there is an imbalance of water molecules inside the cell and the water molecules outside of the cell.Certain compounds can’t move (glucose or sodium) but because we can move water,we will move the water where our cell needs it in order to balance our cell out.*A few lectures ago we learned that the tails of the membrane lipids are hydrophobic (don’t like water). However this does not cause a problem when water molecules need to get across. If you would like more information on how this is possible, page 69 of our book has a hypothesis available.* Toxicity: this what we call our cells when they either shrink or swell. There are three terms that are directly associated with this. Isotonic, Hypertonic, and Hypotonic.Isotonic: (iso: means same) this is where the concentration of water inside the cell equals the concentration of water outside of the cellHypertonic: this is where the cells loose to much water and they shrink upHypotonic: this is where the cells gain too much water and they swell up, these can swellup so much they can possibly burst.Active Membrane Transport: there are two types of active membrane transport called Active Transport and Vesicular Transport. Unlike passive transport where no energy is needed, these active transports require ATP (energy) to do the process. Active Transport: This active transport needs the carrier proteins that we talked about above. And yes, while it is free to move from a high concentration to low concentration, energy is needed to move from low to high. This is where the active transport comes in.Vesicular Transport: this is used to move those really large particles like macromolecules.This can move molecules into or out of the cell, and it can also move particles around within the cell as well. This also requires ATP. Vesicular sounds like “Vessel,” and so I use that to remember it because it kind of ships things around. There are four functions to vesicular transport. Exocytosis, Endocytosis, Transcytosis, and Substance (Vesicular) Trafficking.Exocytosis: ATP is required, this has to do with waste and secretion. Some examples are hormone secretion, and ejection of wastes. Endocytosis: ATP is required, and this is very selective of what molecules it will let through because they are often “started” by a receptor. There are two types of endocytosis. Phagocytosis, and Pinocytosis.Phagocytosis: (“cell eating”) there are pseudopods that envelop solids outside of the cell and then bring them back into the cellPinocytosis: (“cell drinking”) this happens with nutrient absorption in the small intestine, this is when the cell membrane brings in fluid and other solutes into the cellTranscytosis:this is very selective of what molecules it will let throughbecause they are often “started” by a receptor, like endocytosis.Substance (Vesicular) Trafficking:this is traveling from one organelle in the cell to anotherOur Cells Organelles: *Remember that organelles are like organs of the cell.* There are many different organelles in cells and they have many different functions, so there will be many subunits to this one. There are also things called Inclusions that are in the cell. And while these are not organelles they can perform functions in the cell. An example would be glycogen granules. Keep in mind though that some do not, some merely give pigmentation (color) to the cell.Membranous Organelles: some examples are mitochondria, lysosomes, Golgi apparatus, and othersNonmembranous Organelles: some examples are centrioles and ribosomes, among