BIO Ch. 6 LC
A cell membrane contains many types of proteins. Which type of protein would most easily be removed from the cell membrane in aqueous conditions in a laboratory experiment?
Peripheral proteins
If a cell is bathed in an extracellular solution higher in Na+ concentration than the cytoplasm, it will use _______ to maintain its normal intracellular concentration of Na+
active transport against the concentration gradient of Na+
In cells lining the stomach, the movement of chloride ions into the cells is coupled to the transport of bicarbonate ions out of the cells. This type of transport system most likely uses
an antiporter.
Many animal cells have a sodium-potassium pump that moves Na+ ions out of the cell and K+ ions in. This is an example of a(n)
antiporter
A barrier to the rapid movement of hydrophilic compounds across biological membranes is made up chiefly of
lipids
The main components in biological membranes are
lipids, proteins, and carbohydrates.
Plants depend on their cell walls to limit the amount of water entering their cells and maintain _______, which helps keep plants upright.
turgor pressure
The fluid mosaic model of a biological membrane suggests that the membrane is made up of discrete units that can move freely. Which component most affects the fluidity of the membrane in an animal cell?
Cholesterol molecules
If hydrolysis of ATP is temporarily blocked, what will be the primary effect on the sodium-potassium pump?
It will not be phosphorylated.
A hibernating animal must make changes at the cellular level to prevent damage in colder temperatures. How might cell membranes of these animals be affected?
Unsaturated fatty acids would replace saturated fatty acids.
A specific ligand in receptor-mediated endocytosis is most likely
a specific macromolecule.
A protein that forms an ion channel in a membrane is most likely to be
a transmembrane protein.
If an animal cell needs to acquire more of a particular amino acid for a physiological process, it can employ _______ when the amino acid is more concentrated inside the cell than in the extracellular fluid.
active transport
Cells secrete materials to the exterior environment through the process of
exocytosis
Osmosis, the movement of water though specialized membrane channels, is an example of Correct: facilitated diffusion.
facilitated diffusion.
The cell membrane is said to _______ as it folds inward to form a pocket around materials in the environment during phagocytosis, pinocytosis, and receptor-mediated endocytosis.
invaginate
If a beneficial drug needed a carrier protein for it to enter the target cells in muscles, a good protein to ensure the highest rate of delivery would be
one that was present in the target cell membrane in high numbers.
The main difference between osmosis and diffusion is that
osmosis refers specifically to the movement of water, whereas diffusion refers to the movement of any molecules.
White blood cells can defend the body against invaders through
phagocytosis
Transporters that move two substances in the same direction are known as
symporters
Membrane fragments from different areas of a cell are constantly breaking down, moving, and in some cases fusing with other parts of a membrane. This is possible because of
the ability of lipids to associate with one another and seal themselves.
There are two basic types of active transport. The difference between them is
the energy source each uses to move substances across a membrane.
All of the following affect the rate of diffusion of a substance except
the presence of other solutes in the solution.
Freeze-fracturing is a useful tool for revealing _______ proteins.
transmembrane
Which analogy could best be used to describe the molecular structures interacting at the point of attachment between two animal cells physically bound to one another?
A key inserted into a lock
Which statement provides evidence supporting the fluid nature of the cell membrane?
A phospholipid molecule can move from one end of a bacterial cell to the other in one second.
In animal cells, which process does not involve the uptake of materials into the cell?
Exocytosis
If a person becomes dehydrated and needs to acquire dissolved solutes rapidly, which cellular process will likely be accelerated?
Pinocytosis