Lecture 10Outline of Last Lecture1) Describe the Singer and Nicholson fluid mosaic model of cell membrane structure.2) Describe how membrane proteins (integral and peripheral membrane proteins) associate with the lipid bilayer. Compare and contrast the Relative mobility of lipids vs. proteins in a typical plasma membrane.3) What is the ECM? Describe the 4 main components of the ECM and the functions of each component, What are two human diseases of the ECM? 4) What is the P side and what is the E side of the plasma membrane? What does the rER have to do with how do proteins get to the E side? How proteins become integral membrane proteins?Outline of Current Lecture1) What are the 4 types of intracellular junctions? Give an example of each.2) Describe the 7 major functions for plasma membrane proteins.3) Make sure you can determine “which way” water containing solutes will move when separated by a semipermeable membrane. Be able to use the terms hypo- hyper- and iso-tonic. 4) Differentiate between the two types of passive transport (including the differences between channels and carriers) and active transport.5) Compare endocytosis (phagocytosis), pinocytosis, receptor-mediated endocytosis (clathrin coated pits) and exocytotic transport mechanisms.I. Intracellular JunctionsThese 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. BIOL 101 1st EditionIntracellular junctions hold cells together via the membrane. There are 4 types of extracellular junctions:- Tight Junctions: These are tight connectors that prevent anything from going inbetween or out of the membranes the cells is connected to. These are commonly found in the intestine.- Desmosomes: These types of junctions are keratin filaments that allow for elasticity while still being strong. An example would be skin.- Gap Junctions: These junctions allow for the passage of small ions and communication between cells via connexin pores/channels. An example would be cardiac cells.- Plasmodesmata: Similar to gap junctions, but for plant cells. It communicates via cytoplasmic and ER channels.II. Plasma Membrane ProteinsPlasma membrane proteins have 7 major functions:- Transporters: Transporters deal with facilitated diffusion (moving solids past the membrane)- Pumps: Active transport ATP pumps transport ATP- Enzymes: Enzymes such as ATP synthase- Signal Transduction: External signals cause a shape change in receptors that delay the message to the cytoplasm- Cell-cell Recognition & Adhesion: Identification tags so they can be seen as self, and the ability to stick to other cells- Intracellular junctions: Gap junctions, tight junctions- Attachment to the Cytoskeleton & ECM: Integrins attach to the cytoskeletonIII. Osmosis- Osmosis is when water travels across a membrane to achieve equilibrium in the amount of solvent in water. What the 3rd question asks is which way the water wouldgo if it was put in the situation for osmosis. If you had .10m of sucrose solute, and .35m of sucrose solute, the water would always go towards the higher concentration.When concentration is high and only water can cross the membrane, the solute molecules are too big to pass through the membrane, so nothing goes through to 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. BIOL 101 1st Editionthe other side besides a little bit of water. However, the lower solution will go through to the other side because less water molecules are bound to the solute. - Hypotonic means a low concentration gradient, Hypertonic means a high concentration gradient, and Isotonic means a concentration gradient equal to that of human blood.IV. Passive & Active Transport- Passive Transport is when something goes through the membrane without any energy needed, making it spontaneous. The two types of transport are Diffusion andFacilitated Diffusion. Diffusion deals with hydrophobic or small uncharged polar molecules, while Facilitated diffusion deals with Hydrophillic substances, ions, etc. These types of transport occur in Transporter channels or carrier proteins, the difference being transporter channels allowing the cells to pass through, while carrier proteins selectively grab molecules and bring them in.- Active Transport needs ATP to move substances against their concentration gradient.V. Cytosis- Endocytosis is a form of Phagocytosis that is when a cell brings something in through the cell membrane. Pinocytosis is when a cell ingests liquid by budding of little vesicles from the membrane. Receptor-mediated endocytosis is when cells internalize molecules by the inward budding of membrane vesicles that contain proteins with specific receptors to internalize what molecules are being taken in. These require clathrin, a protein that forms coated vesicles. If a cell needs to get something out of it, it goes through the process of exocytosis, where vesicles push out whatever is a waste product into the extracellular environment. This process required energy.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. BIOL 101 1st