Kin 101: Chapter 5 Flashcards
Osmosis
Movement of water across membranes in response to a solute gradient
Osmolarity
The number of osmotically active particles
Body Fluid Compartments
There are two: ECF and ICF both osmotic equilibrium
Transport Process (what you need to know)
Diffusion and Protein mediated transport
Where do ECF and ICF exist
Dynamic Equilibrium
Resting membrane potential
Determined by the uneven distribution of ions (charged particles) between the inside and the outside of the cell
Aquaphorens
Channel for water that promotes active transport
How much of the body is ICF
2/3
How much of the body is ECF
1/3
25% of ECF is what?
Plasma
Selective Permeability
The cell membrane has this: restricts free exchange movement between cell and interstitial fluid. movement will depend on permeability of wall and substance
Diffusion
Passive movement of molecules down a chemical gradient. movement stops at EQ
Who can cross a membrane?
Water, oxygen, carbon dioxide, and lipids move easily. Ions, most polar molecules and large molecules can’t cross easily
Tonicity
hypertonic (shrinks), isotonic (perfect), and hypotonic (swells)
What are channels made of?
Many protein sub units, that come together around some channels
Membrane Protein and Functional Categories
- Structural Proteins
- Enzymes
- Receptors
- Transporters
What do Membrane Transporters do?
Conceptualize saturation so they limit transport. A higher [] has more motivation to move, however to diffuse you need a co-transporter or specificity is required
Co-transport
A type of transport across cell membrane and it requires transport proteins embedded in the membrane of the cell
Symport
One of the types of secondary active transport, in which substance A moves across the membrane against a chemical or concentration gradient
Gated Channels
Border control, open in response to chemical, mechanical, and electrical signals
What does depolarizing membranes do?
Inactivates sodium and potassium channels
What are carriers?
They form an open channel between two sides of the membrane. They do this by binding to a molecule, changing shape and carrying across the membrane
Uniport Carriers
Transport only one kind of substance
Symport Carriers
Move two or more substrates in the same direction along the membrane
Antiport Carriers
Move the substrates in opposite directions
Carrier-Mediated Transport
Specificity (ability to move), competition (related molecules compete when specificity is met), and saturation (occur at max rate)
Competitive Inhibitor
Decreases the turnover rate for an Enzyme
GLUT Transporter
Proteins that aid the transportation of glucose to various tissues where they are effectively utilized as an energy source
Chemical Disequilibrium
Most solutes are concentrated in either one compartment or the other, creates this state
Electrical Disequilibrium
Cations and anions are not distributed equally between the body compartments, creates this state
Osmotic Equilibrium
Water moves freely between the cells and extracellular fluid, resulting in this state
What can a Lipid-Soluble Substance do?
Can diffuse through the phospholipid bilayer. Less lipid-soluble molecules require the assistance of a membrane protein or vesicle to cross the membrane
What do Membrane-associated enzymes do?
Catalyze chemical reactions and help transfer signals across the membrane
Passive Transport
Does not require input of energy
Structural Proteins
Maintain cell shape and form junctions
What system are Receptor Proteins
Part of the signalling system
What are Transport Proteins meant for
Move many molecules into or out of the cell
Channel Proteins
Form water-filled channels that link the intracellular and extracellular compartments
Gated Channels
Regulate movement of substances through them by opening and closing. Gated channels may be regulated by ligands, by the electrical state of the cell, or by physical changes such as pressure
Facilitated Diffusion is also know as?
Protein-mediated diffusion
Active Transport
Moves molecules against their concentration gradient and requires an outside source of energy
Primary/Direct Active Transport
The energy comes directly from ATP
Secondary/Indirect Active Transport
Uses the potential energy stored at a [] gradient and is indirectly driven by energy
What is the most Important Primary Active Transporter?
Sodium-potassium-ATPase
