Membrane Transport

The exchange of respiratory gases in a cell takes place through the:

cell membrane mostly consists of

in cells, the selectivity of the cell membrane is closely associated with the maintenance of:

During which process do molecules move from a region of higher concentration to a region of lower concentration?

Osmosis is a physical process most closely associated with the life function of:

Normally, the process of osmosis, the net flow of water molecules into or out of the cell depends on the difference in the:

If red blood cells are placed in distilled water, they will eventually be destroyed. Which process is most likely to be the chief cause of this destruction?

The destruction of all ATP (energy) molecules in a cell would interfere most immediately with the process of:

Active transport of certain proteins from a cell's environment into the cell is most closely associated with the:

Sodium ions are "pumped" from a region of lower concentration to a region of higher concentration in the nerve cells of humans. This process is an example of:

during which process is ATP not essential?

The process of osmosis would explain the net movement of water into a cell if the percentage of:

Freshwater protozoa may be distinguished from many marine protozoa by the fact that the freshwater species contain:

An important role of the cell membrane is to:

the cell membrane is said to be selectively permeable because it

what happens during diffusion?

during passive transport

a plant cell shrinks when placed in salt water due to the movement of

a plant cell shrinks when placed in salt water due to the movement of

placing limp celery in water will make the celery stalk firm again due to

the organelle that stores water for the cell is the

a red blood cell placed in distilled (100%) water will swell and burst due to the diffusion of

some single-celled organisms live in fresh water (100% water) lakes. what problem do they encounter on a daily basis?

human blood cells placed in a 2% salt solution appear to shrink, but those placed in a 0.4% salt solution burst. which statement best supports these observations?

which process would include a net movement of sugar molecules through a membrane from a region of lower concentration to a region of higher concentration

In the human body, potassium is small and can pass easily through the cell membrane. potassium is constantly diffusing out of the cell. however, there is always a higher concentration of potassium inside cells and a lower concentration outside of the cells. what process is responsible for maintaining this concentration gradient?

when a cell uses energy to move materials across the cell membrane, the process is known as

the net movement of molecules across the cell membrane is dependent upon the

a process that requires energy by cell and is used to engulf large macro-molecules is called

what happens during active transport

the sodium-potassium pump of a cell is located in