Biol 4610 1st Edition Lecture 10Outline of Current Lecture 1. ATP powered pumps and intracellular ionic environment2. Ca2+ PumpCurrent Lecture11.3 ATP powered pumps and intracellular Ionic EnvironmentActive transporters All require the ATP hydrolysis to functionGroup into 4 different classes of pumps:1. P-class pumps – move ions up the concentration gradient; move a variety of ions2. V- class – pump hydrogen ions; used for acidification; lysosomes3. F- class – pump hydrogen ions; ATP synthase molecule; use H ions to generate ATP form ADP4. ABC superfamily – pump many diff thingsPumIon gradient between outside the cell in the blood and inside the cell.Caà 10,000X outside cellMake sure we know the differences in concentration gradients- Na, K, and CaK ^^ inside cellNa ^^ outside cellps generate and maintain ion gradients 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.1. First example of a P-class pump is Ca +2 ATPase – store in mitochondria, endoplasmic reiculumTwo ‘states’: E1 - binding sites for Ca+2 face cytosol; E2- binding sites for Ca+2 face SR lumen. Ca+ comes into cells and muscles contract then Ca leaves and muscle relaxes.SR= sarcoplasmic reticulumGrey area is the cell membrane. In this case we are trying to store Ca in SR. so concentration gradient must be much higher in SR. so we need ATP pump to pump ions up gradient. Two ‘states’: conformational changesE1- binding site faces the cytoplasm1. 2 binding sites for Calcium. So 2 Ca molecules will be moved every cycle. Once they bind,ATP also binds. 2. 2. Hydrolysis of ATP which phosphorylates ATP into ADP3. Conformational change- switch to E2 where NOW Ca is open and available to the SR4. Calcium now released into SR5. Phosphate gets cleaved
View Full Document
Unlocking...