CAS BI 105 Lecture 7: BI105 Human Micro-Biome (pt.2)
30 Apr 2018
School
Department
Course
Professor
9/23: The Human Micro-biome
Composed of
1. Hydrophilic regions of protein + membrane
2. Hydrophobic region of protein + membrane (Phospholipid Bilayer)
Membrane Molecules
•Proteins are the second most common molecule in the membrane and impart most of the function
•Carbohydrate Chains - “tag” cells for cell-recognition
•Cholesterol - helps maintain fluidity
Membrane Proteins
•Proteins are the second most common type of molecule in the membrane
•25% of all genes encode for transmembrane proteins
•Membrane proteins participate in transport
•Join two cells together
•Joining a cell to the extracellular matrix
Extracellular Matrix (ECM)
•Cells taken out of the body and cultured in dishes
•Decreases in longevity & changes in behavior - why?
•Scientists discover integrins (membrane anchoring proteins)
•Scientists discover cells are tied to an outside matrix that holds them together
•Significance:
•Some scientists think that ECM is actually the functional unit of the body
•Arthritis/Infection/Inflammation/Heart Disease/some Cancer types - ALL PROBABLY ECM
DISEASES
•Animal Cells
•Cells secrete protein fibers into extracellular fluid, weave together to form matrix
•Cells express integrins on mb, attach the ECM
•Provides strength and rigidity to tissues
•ex: Cartilage/Bone/Skin
•Provides a system to organize cells, allow them to move or stay in place
•Provide signals to cells to guide function & development
•ECM is important
•too little of it = arthritis
•too much of it = atherosclerosis
•changes in it = leads to cancer
•useful in = curing infection
•VERY STRONG
•ex: you can boil animal tissues to isolate a concentrated ECM into glue and gelatin
The Plasma Membrane
•Separates the cell’s internal environment from its external environment
•Controls entrance and exit from the cell (selectively permeable)
•Layer of non-polar lipids between two aqueous environments
•Membrane is fluid
Diffusion
•The movement of molecules from an area of greater concentration to an area of lesser concentration
•Concentration Gradient - describes the areas of higher and lower concentration of a given molecule
•Continues until equilibrium (equal concentration) is reached
•Diffusion continues until the molecule is in dynamic equilibrium
•Passive Process - does not use cellular energy
find more resources at oneclass.com
find more resources at oneclass.com
