BIOMG 1350 1st Edition Lecture 9Outline of Last Lecture I. Membrane Structure, Proteins in membraneOutline of Current Lecture II. Transporters and channelsIII.Passive TransportIV. Active TransportV. Ion ChannelsCurrent Lecture- Lipids diffuse faster than proteins- Saturated proteins diffuse slower than unsaturated- Diffusion rate of proteins is influenced by lipid composition of the membrane- Diffusion of proteins depends on what proteins are attached to it- Transporters and channels:o Transport proteins move water-soluble molecules across cell membraneso Channels: All ions go through channels Specific, selective Open like a dooro Transporters: Bind specific molecules and transport them from one side to another (selective, specific, active) Only let one molecule in at a time- Passive transport:o Uncharged molecules move down their concentration gradient Membrane potential is irrelevanto Require no input of energyo For charged molecules, membrane potential also plays a role (wherever there is less of the molecule, it will be pulled that way) Electrochemical gradient: voltage and concentration gradient- Active Transport:o Used to move molecules up their electrochemical gradiento Can use a coupled transporter: one molecule goes up gradient, one goes downThese 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. Uniport: single type of a single type of molecule Symport/Antiport: same direction/opposite direction of two different molecules- These are coupled transport- Can be active of passive: if one of them is going up gradient an one is going down, it’s active Example: glucose has a higher concentration inside of the cell, but glucose wants to be inside the cell.- Sodium ions and glucose molecules are taken up: when the transport flips sodium is released and glucose follows it.- Sodium changes the conformation of the transporter and increases the affinity for glucose - Without glucose outside of the cell, sodium will not be transported- Sodium goes down its electrochemical gradiento Can be driven by ATP hydrolysis Example: sodium potassium pump Two types of glucose transporters enable glucose uptake:- 1. Sodium potassium pump- 2. Sodium driven glucose symporter- 3. Passive glucose transportero Light driven pumps- Ion Channels:o Ion channels are ion-selectiveo When concentration gradient and voltage gradient are equal is creates a membrane potentialo Ion channels open and closeo Example: acid secretion in the stomacho Many diseases are caused by defects in ion