LessonNo3GeneTonicityFall2010

LessonNo3GeneTonicityFall2010 - Physiology BIO 240 Lecture...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Click to edit Master subtitle style Physiology BIO 240 Lecture No. 3 Tonicity Genetics Fall 2010 Dr. Ana M Jimenez
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Click to edit Master subtitle style Membrane Transport Passive and Active Transport, osmosis, tonicity
Background image of page 2
Thinking About Cell Membranes Most of the cell membrane is made of phospholipids, Cell membranes are hydrophobic , How do hydrophilic molecules such as water cross the membrane? What forces water to move across the cell membrane?
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Membrane Transport Cells have a selectively permeable membrane Allow some but NOT other molecules to go through, Factors : size, charge, polarity, hydrophilic/hydrophobic Passive Movement : does not require cell to spend energy (ATP), Simple Diffusion Facilitated Diffusion Filtration Active Movement : requires cell to spend cellular energy (ATP) Active Transport
Background image of page 4
Simple Diffusion Movement of particles from an area of HIGH concentration to an area of LOW concentration ([]=concentration), Concentration gradient - difference between area of [high] and area of [low]
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Factors that Affect Diffusion Rate Temperature : Higher temperature, faster rate. Molecular weight : Higher molecular weight, slower rate. ‘Steepness of concentration gradient : Larger difference between concentrations, faster rate. Membrane surface area : Larger surface area, faster rate. Membrane permeability : Increased permeability, faster rate.
Background image of page 6
Filtration vs. Osmosis of Fluid Filtration - hydrostatic (water) pressure Forces water to go through a filter, Kidney filtration is important in removing waste from the blood, Filtration of fluid at capillaries is governed by Starling Law of capillary diffusion. Osmosis – tonicity (solute) pressure Forces water to go through a membrane, Water does not cross plasma membrane easily, but crosses through water pores called aquaporins .
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Facilitated Diffusion Carrier or pore - mediated transport DOES NOT require energy, Cells transport hydrophilic molecules that would not go through the membrane such as glucose or water, Specific for each molecule, transport is dependent on solute concentration: Large concentration gradient = faster rate Small concentration gradient = slower rate Some carriers glucose – saturate (glucose)
Background image of page 8
High [molecule] Low [molecule]
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Only molecules that cannot cross plasma membrane determine ‘tonicity’, Tonicity – force of solutes that moves water across a membrane, Large particles (albumin) cannot move through the membrane, No transporters for proteins only for amino acids. Small particles and water, glucose can move through membrane due to transporters found on membrane (Ex. Aquaporins, glucose transporter - GLUT)
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 10/04/2011 for the course BIOLOGY 240 taught by Professor Anamjimenez during the Fall '10 term at Barry Univesity.

Page1 / 61

LessonNo3GeneTonicityFall2010 - Physiology BIO 240 Lecture...

This preview shows document pages 1 - 11. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online