Home > Uncategorized > Human Anatomy: Cell Membranes

Human Anatomy: Cell Membranes


Today, we’ll look over cell membranes.  The cost today is very low, about 25 minutes.



Osteoarthritis comes from trauma, rheumatoid arthritis from immune disease and gout from diet, a metabolic disorder.

Acts as a semipermeable barrier.  Inside is ICF or cytoplasm, outside is ECF or tissue fluid.  Double phospholipid bilayer with proteins embedded.  All living cells are surrounded by fluid.  The balloons are hydrophillic and the springs are hydrophobic.  An Oreo cookie or a butter sandwich.

Channel proteins allow ions to flow into or out of the cell.  Most ion channels are closed at a given time.

Glucose = 24 atoms large

If a protein needs ATP to move a chemical, its active transport.  Passive transport or facilitated diffusion uses a sphere shape.

Ion channels are specific for Na, K, Cl, or Ca.  Transporter proteins transport sugars and AAs.  Enzymes catalyze biochemical reactions.

Linker proteins affect the cytoskeleton or the shape of the cell.  This is for cells that change shape like WBCs.

Receptor site proteins are hormone activated by ligands or signal molecules.  A hormone is a chemical carried in the bloodstream.  A cell may have any number of receptor sites.

Receptor site activation can cause:

open and close ion channels
enzyme activity
change cell shape

There are protein hormones from AAs and steroid hormones from cholesterols.  Steroids can be taken orally.  Hydrophobic cholesterols easily diffuse across the cell membrane.  The receptors are on the nucleus or inside the cell in the cytosol.

Adrenergic receptors react to adrenaline and epinephrine.  Mimetics are agonists who react to similar things.  Blockers inactivate a receptor site.

Islets of langerhans create insulin.


Tissue: muscle, nerve, connective, epithelial

Epithelial: simple/stratified/pseudo, cuboidal/columnar/squamous

Nucleophile: electrons available, negatively charged, less electronegative

Leaving Group: electron withdrawing, stabilizing, polarizing

Hydrogen Bonding: N 3, O 3.5, F 4, Cl 3

Polar Protic: OH or NH, SN1 reaction,

Intermolecular forces: ionic, hydrogen bonding, dipole dipole, van der Waals

Acetone (CH3)C=O(CH3) 24.2

Ammonia NH3 32.5

Methanol CH3OH 15.2

Ethanol CH3CH2OH 15.9

Categories: Uncategorized
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