What are the 3 types of passive Transport
1. Simple diffusion
2. Facilitated diffusion
Explain Simple diffusion
No transported Required
small non-polar, lipid-soluble
high to low concentrations
Explain Facilitated diffusion
Uses transporters to move impermeable solutes across the cell membrane
The movement/diffusion of water from high to low concentration of (h2o)
Explain active transport and it's two forms
Requires energy from ATP or an existing favorable gradient.
2. Secondary ( antiport and symport)
exocytosis, pinocytosis, and phagocytosis
Endocytosis engulfing material into cell
Exocytosis Releasing material out of cell
Pinocytosis: solutes and liquid into vessicles endo
Phago: bacteria ingestion, larger molecules, solid.
How is the membrane potential maintained?
By the sodium potassium ATPASE pump and K+ Leak channels
3 Na out and 2 Na in
More Na outside, total one + charge to outside in one round.
E = Electrical potential created by one ion
E = RT/zf ln (ion) outside / (ion) inside
61.5 log @ 310K
Osmotic Pressure Equation
II = iMRT
i = number of particles
M = Molarity of solution
R = Gas Constant
T = Absolute T in Kelvin
What are ion channels and the 3 main types
Ion channels help regulate the movement of ions in and out of the cell
UNGATED: Always open
VOLTAGE-GATED: open within a range of membrane potentials
LIGAND-GATED: Open in presence of a specific binding substance, like hormone or neurotransmitters
What is an Enzyme-linked Receptor?
An enzyme-linked receptor, also known as a catalytic receptor, is a transmembrane receptor, where the binding of an extracellular ligand causes enzymatic activity on the intracellular side. Hence a catalytic receptor is an integral membrane protein possessing both enzymatic catalytic and receptor functions.
Receptor tyrosine kinase, as in the fibroblast growth factor receptor. Most enzyme-linked receptors are of this type. Serine/threonine-specific protein kinase, as in bone morphogenetic protein.
What is a G Protein-coupled receptor?
DPCR have a membrane bound protein associated with a trimeric G protein. They initiate second messenger systems.
- Ligand binding engages g protein
- GDP is replaced with GTP ; the alpha subunits detaches from the other two
- The activated alpha subunits alters the activity of adenylate cyclase or phospholipase C
- GTP is dephosphorylayed, and alpha subunit rebinds