Chapter 5 - Transport of Solutes & Water Flashcards
How is the small intestine able to absorb nutrients so well?
It has microvilli, projecting out of the lumen which increase its surface area for maximum amount of absorption.
Name three adaptations that the small intestine has.
- Rich Blood Supply
- maintains concentration
gradient
- maintains concentration
- Villi & Microvilli
- increase the surface area
- Cells Have Many Mitochondria
- ATP production used for
active transport
- ATP production used for
What is co-transport?
A. involves moving a substance against a concentration gradient while moving another substance along its own concentration gradient
B. involves active diffusion of two substances across a cell membrane
C. involves the movement of two substances into or out of a cell membrane together
D. none of the above
What is an example of co-transport or a symport mechanism?
The Na+/Glucose pump that allows glucose inside the epithelial membrane ONLY if there is a Na+ attached, moving from high [Na+] to low [Na+].
What is active transport and how does it differ from passive transport?
Active transport involves using ATP to carry material in a direction that opposes equilibrium, while passive diffusion is a process by which substances are able to cross membranes without the use of energy but instead the direction of equilibrium.
What is an example of active transport that is an antiport?
Na+/K+ Pump
- 3Na+ OUT and 2K+ IN
Think back to the hummingbird example, how does glucose move into the blood if it is hydrophobic?
A. It doesn’t, only hydrophilic molecules are able to move inside the bloodstream.
B. Through facilitated diffusion with the Na+/Glucose Pump, Glucose can only enter if it is attached with a Na+.
C. Even though it is hydrophobic it is able to passively diffuse into the bloodstream.
D. Through active transport, in which sodium is pumped out and glucose is pumped in.
B.
Where is K+ generally more concentrated?
Inside the cell, it leaves the cell through concentration gradients.
What is a boundary layer and does it inhibit or aid in diffusion?
Usually layer of water or air that surrounds an object, it inhibits diffusion since more solutes are present so the concentration outside is higher than the concentration inside.
If a boundary layer prevents diffusion rates from increasing, how can it be stopped?
It can be haltered by increasing the temperature to cause more movement or adding a solvent outside so the solutes will move out and diffusion can occur.
What is the difference between a ligand-gated channel and voltage-gated channel?
A. Ligand-gated channels and voltage-gated channels are the same.
B. Ligand-gated channels are a form of a voltage-gated channel.
C. Ligand-gated channels open in response to change in membrane potentials, while voltage-gated channels open in response to substance binding.
D. Ligand-gated channels open in response to ligands that bind to the channel, while voltage-gated channels open in response to the change in membrane potential.
D.
What is Fick’s Diffusion Equation and why is it useful?
J = D (C1-C2)/X
It is used to see how long it takes solutes to move from an area of high concentration to an area of low concentration.
How do cells regulate their water content?
A. Osmosis
B. Active Transport
C. Facilitated Diffusion
D. Secondary Active Transport
A.
What is the difference between Hypertonic and Hypotonic?
Hypertonic solutions have greater concentrations inside of the cell than outside of the cell.
Hypotonic solitons have lower concentrations inside the cell than outside of the cell.
If you were to drop a mammalian red blood cell in a 10 mOsm solution it would ______________ in this __________.
swell and burst; hyposomotic
