Class Notes (837,000)
Canada (509,985)
BIOB32H3 (80)

cells living unit.docx

7 Pages
Unlock Document

Biological Sciences
Kenneth Welch

Cells The Living Units Cell Theory The cell is the basic structural and functional unit of life Organismal activity depends on individual and collective activity of cells Biochemical activities of cells are dictated by subcellular structure Continuity of life has a cellular basis Structure of a Generalized Cell Plasma Membrane Separates intracellular fluids from extracellular fluids Plays a dynamic role in cellular activity Glycocalyx is a glycoprotein area abutting the cell that provides highly specific biological markers by which cells recognize one another Fluid Mosaic Model Double bilayer of lipids with imbedded dispersed proteins Bilayer consists of phospholipids cholesterol and glycolipids Glycolipids are lipids with bound carbohydrate Phospholipids have hydrophobic and hydrophilic bipoles Functions of Membrane Proteins Transport Enzymatic activity Receptors for signal transduction Intercellular adhesion Cellcell recognition Attachment to cytoskeleton and extracellular matrix Membrane Junctions Tight junctionimpermeable junction that encircles the cell Desmosomeanchoring junction scattered along the sides of cells Gap junctiona nexus that allows chemical substances to pass between cells Passive Membrane Transport Diffusion Simple diffusionnonpolar and lipidsoluble substances Diffuse directly through the lipid bilayer Diffuse through channel proteins Facilitated diffusionlarge polar molecules such as simple sugars Combine with protein carriers Passive Membrane Transport Osmosis Occurs when the concentration of a solvent is different on opposite sides of a membrane Diffusion of water across a semipermeable membrane Osmolaritytotal concentration of solute particles in a solution Passive Membrane Transport Filtration The passage of water and solutes through a membrane by hydrostatic pressure Pressure gradient pushes solutecontaining fluid from a higherpressure area to a lowerpressure area Tonicity Isotonicsolutions with the same solute concentration as that of the cytosol Hypertonicsolutions having greater solute concentration than that of the cytosol
More Less

Related notes for BIOB32H3

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.