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BIO120H1 (1,000)
Lecture

Notes taken during lecture


Department
Biology
Course Code
BIO120H1
Professor
Jean Jiang Nash

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47 – water, urea, glycerol – not completely
Down the concentration gradient
Faster diffusion across lipid bilayer
48 – all ions cannot pass through membrane; tiny bit and very slow diffusion of large uncharged polar
molecules
49 – transport polar and charged molecules
Uniqueness in cell membranes in transport proteins, also in cells
Transports specific class of molecules
50 – passive transport includes simple diffusion
Against concentration gradientactive transportneed energy, in form of ATP or secondary transport
51 – net negative charge inside; net positive outsidedue to concentration of ions
Firstpositively charged from high to low concentration
Second – electrical potential gradient determines rate of movement positive charges repelled by exterior
positive charges, attracted to the negative chargesincrease transport of molecules across membrane
Third – membrane potential switched positive charges attracted to negative charges outside
52 – electrochemical gradient first three moving down gradient (facilitated…)
When charged molecules involved, use ELECTROCHEMICAL GRADIENT always
Active transport and facilitated diffusion all need protein transporers
Passive transportwith the gradient; active goes against gradient
(both gradient)
53 – need energy
1. First molecule down gradient: two molecules are moving; one moving down electrochemical
gradient, releasing a bit of energy to transport the second molecule against electrochemical
gradient
2. Second molecule against gradient
3. Second is: ATP hydrolysis; molecule against gradient
4. Third is : Light energy; molecule against gradient
54 – movement down electrochemical gradient
Movement against electrochemical gradient
Yes; No -> concentration + membrane potential ---- this is typical test question
56 – channel proteins, either open or closed
57 – solute specific
Conformational change –when interact with that solute
Solute binding site open one side is now closed, the other side opens
**examples that should be known are in purple
59 – transport one molecule
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