The normal tonicity conditions for a typical plant and animal cell is what?
The animal cell is in an isotonic solution and the plant cell is in a hypotonic solution
A situation that would cause a need for osmoregulation?
Cells of a tidepool animal such as an anemone
When a plant cell, such as one from a peony stem, is submerged in a very hypotonic solution, what is likely to occur?
The cell will become turgid.
A membrane activity that requires energy from ATP hydrolysis?
Na+ ions moving out of a mammalian cell bathed in physiological saline.
Phosphate import depends on a pH gradient across the membrane-more acidic outside the cell than inside the cell. Phosphate transport is an example of
Glucose diffuses slowly through artificial phopholipid bilayers. The cells lining the small intestine, however, rapidly move large quantities of gluccose from the glucose-rich food into the glucose-poor cytoplasm. Which transport mechanism is most probably functioning in the intestinal cells?
What is the voltage across a membrane called?
In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually only one or two electrogenic pumps present in the membrane. The gradienst of the other ions are most likely accounted for by what?
Sodium-Potassium pump is called an electrogenic pump because it
Contributes to the membrane potential
The movement of potassium into an animal cell requires
An energy source such as ATP
Ions diffuse across membranes through specific ion channels on which gradients
Down their electochemical gradients
True or False
A potassium channel would increase the elctrochemical potential across a membrane.
A proton pump would.
When the proteins of a sodium-potassium pump are first synthesized in the rough ER, what sid eof the ER membrane will the ATP binding sites be on?
It will be on the cytoplasmic side of the ER.
Proton pumps are used in various ways by members of every domain of organisms. What does this most likely mean?
Proton gradients across a membrane were used by cells that were the common ancestor of all cells.
Several epidemic microbial diseases of earlier centuries incurred high death rates becase they resulted in severe dehydration due to vomiting and diarrhea. What do we have today that helps to keep this non-fatal.
Hydrating drinks that include high concetrations of salts and glucose.
An organism with a cell wall would most likely be unable to take in materials through what process.
White blood cells engulf bacteria through what process?
Defective LDL receptors on the cell membranes is a characteristic of what?
Difference between pinocytosis and receptor-mediated endocytosis is that_____
Pinocytosis is nonselective in the molecules it brings into the cell, whereas receptor-mediated endocytosis offeres more selectivity.
In receptor-mediated endocytosis, receptor molecules initially project to the outside of the cell. Where do they endo up after endocytosis?
On the inside surface of the vesicles
A bacterium engulfed by a white blood cell through phagocytosis will be digested by enzymes contained in
What is a peripheral protein?
A protein that temporarily binds onto the cell's membrane, either phospholipid bilayer or to an integral protein.
Where is cholesterol located?
it is part of the cells membrane, helps give the membrane its integrity.