Physio 001 Chapter 4

Faster Net Flux

1. Large concentration difference 2. Diffusion through air versus water 3. Large cell surface area

Slower Net Flux

1. Lower temperature 2. Low permeability coefficient 3. Large molecules like protein

Higher in the ECF

1. Na+ 2. Glucose 3. Ca2+ 4. Cl-

Greater in the ICF

1. Proteins 2. Amino acids 3. ATP 4. K+

Isotonic

A solution that does not change the cell in volume; one that contains 300 mOsmol/ L of non penetrating solutes regardless of the concentration of membrane-penetrating solutes present

What is the source of energy used to power the Na+/K+-ATPase pump?

Breakdown of ATP

Hypertonic solution

Cell shrinks

Hypotonic solution

Cell swells

endosomes

Clathrin-coated vesicles can then merge with ________ inside the cell.

Which of the following is an example of an antiport transport mechanism?

Coupling of the inward movement of sodium with the outward movement of calcium

ligand

Each receptor recognizes one ______ with high affinity

T or F: Unlike simple diffusion, facilitated diffusion requires energy expenditure by the cell.

False

T or F: If a cell is immersed in an isotonic solution, there will be no net movement of water.

False?

Plasma membrane

Finally, protein receptors are typically recycled back to the __________.

Receptor

In receptor-mediated endocytosis, certain molecules in the extracellular fluid bind to ________ proteins on the outer surface of the plasma membrane.

clathrin-coated pits

Ligand-bound receptors then become localized in regions of the membrane called _______.

Isotonic solution

No change in cell volume

clathrin-coated vesicles

Receptor-mediated endocytosis brings the ligand-receptor complexes into the cell in the form of _______.

To which of the following is the plasma membrane the most freely permeable?

Small nonpolar molecules

Golgi apparatus; lysosomes

Subsequently, unbound ligands may be routed to the ________ for further processing or to _______ for enzymatic break down of the vesicular contents.

T or F: A 5% urea solution is hypotonic compared with a 10% urea solution.

TRUE?

Which of the following is the most direct source of energy for symport transport?

The movement of one of the transported substances down its concentration gradient

T or F : Facilitated diffusion requires a specific transporter for a specific molecule.

True

T or F: Net diffusion continues until there is an equal concentration of molecules on both sides of a semipermeable membrane.

True

T or F: The Na+/K+-ATPase pump maintains a high concentration of Na+ in the cell.

True

Hypotonic

a lower concentration of solutes than another solution. Due to osmotic pressure, water diffuses into the cell, and the cell often appears turgid, or bloated.

When there is net flux of molecules into the cell:

a point is eventually reached where the concentration of molecules inside and outside the cell are equal.

Red blood cells placed in a hypotonic solution will

be destroyed by hemolysis.

Facilitated diffusion requires

carrier proteins.

Red blood cells are also called

erythrocytes

Solutes within a solution

exhibit random thermal motion.

According to the phrasing of the video, diffusion of solutes occurs:

from an area where they are common to an area where they are scarce.

Isoosmotic

having the same osmotic pressure.

Facilitated diffusion is a membrane transport mechanism to move molecules

in either direction depending on the concentration gradient of the molecule.

Human erythrocytes function best in a/an

isotonic solution

Red blood cells placed in an isotonic solution appear

lozenge-shaped.

clathrin

n one form of receptor-mediated endocytosis, a cytosolic protein called ________ is recruited to the plasma membrane after the ligand binds to its receptor.

The Na+/K+-ATPase pump is an example of

primary active transport.

Based upon your knowledge of osmosis, predict the most likely response to the immersion of a red blood cell into a hypertonic solution. It will

shrink.

Red blood cells placed in a hypertonic solution will

shrivel and become crenated.

Hypoosmotic

solution with a lesser concentration of solute ( fresh water compared to salt water). If a cell from a fresh water fish is placed into a beaker of salt water, the cell is said to be hypoosmotic to the water.

Hyperosmotic

solutions that have increased osmotic pressure, or a greater difference between solutes and solutions between a membrane

Facilitated diffusion is used to transport molecules such as

sugars and animo acids

Conformational changes in the shape of the Na+/K+-ATPase pump allow for the binding and release of Na+ and K+ in order to move each ion from one side of the cell membrane to the other.

symport with sodium.

One transport mechanism to move sugars into cells against their concentration gradient is

symport with sodium.

Hypertonic

the environment outside of the cell has a higher concentration of solutes than the cell itself.

Two compartments of equal volume are separated by a membrane. Side 1 contains a solution with low osmolarity, and Side 2 contains a solution with high osmolarity. If the membrane was permeable to water but impermeable to solute,

the osmolarities and the water concentrations of both compartments are equal, but the volume of water in Side 1 is less than the volume of water in Side 2.

Two compartments of equal volume are separated by a membrane. Side 1 contains solution a with low osmolarity, and Side 2 contains solution with high osmolarity. In this scenario

the water concentration is higher and the solute concentration is lower on Side 1 compared with Side 2.

Two compartments of equal volume are separated by a membrane. Side 1 contains a solution with low osmolarity, and Side 2 contains a solution with high osmolarity. If the membrane was permeable to both solute and water,

there will be net diffusion of water from Side 1 to Side 2, and there will be net diffusion of solute from Side 2 to Side 1 until a diffusion equilibrium is reached.

The Na+/K+-ATPase pump functions to move

three sodium ions out of the cell and two potassium ions into the cell.

Osmosis is best defined as the net movement of

water molecules across a membrane from an area of higher water concentration to an area of lower water concentration.