Human Biology Lab- Cell Structure and Function

hypertonic

A hypertonic solution has a greater concentration of solutes than another solution. In biology, the tonicity of a solution usually refers to its solute concentration relative to that of another solution on the opposite side of a cell membrane; a solution outside of a cell is called hypertonic if it has a greater concentration of solutes than the cytosol inside the cell.

hypotonic

A hypotonic solution has a lower concentration of solutes than another solution. In biology, a solution outside of a cell is called hypotonic if it has a lower concentration of solutes relative to the cytosol.

isotonic

A solution is said to be isotonic when its effective osmole concentration is the same as that of another solution. In biology, the solutions on either side of a cell membrane are isotonic if the concentration of solutes outside the cell is equal to the concentration of solutes inside the cell. In this case the cell neither swells nor shrinks because there is no concentration gradient to induce the diffusion of large amounts of water across the cell membrane.

buffering ability ?

Buffer capacity is a measure of the efficiency of a buffer in resisting changes in pH. Conventionally, the buffer capacity ( ) is expressed as the amount of strong acid or base, in gram-equivalents, that must be added to 1 liter of the solution to change its pH by one unit.

Cell cytoplasm

Cytoplasm is a thick solution that fills each cell and is enclosed by the cell membrane. It is mainly composed of water, salts, and proteins. In eukaryotic cells, the cytoplasm includes all of the material inside the cell and outside of the nucleus.

Selectively permeable

Definition of Selectively Permeable Membranes. All cells are enclosed with a cell membrane. A selectively permeable cell membrane is one that allows certain molecules or ions to pass through it by means of active or passive transpor

tonicity

Tonicity is a measure of the effective osmotic pressure gradient, as defined by the water potential of two solutions separated by a semipermeable membrane. In other words, tonicity is the relative concentration of solutes dissolved in solution which determine the direction and extent of diffusion. It is commonly used when describing the response of cells immersed in an external solution.

hydrogen peroxide

a colorless, viscous, unstable liquid with strong oxidizing properties, commonly used in diluted form in disinfectants and bleaches.

Osmosis

a process by which molecules of a solvent tend to pass through a semipermeable membrane from a less concentrated solution into a more concentrated one, thus equalizing the concentrations on each side of the membrane.

substrate

a substance or layer that underlies something, or on which some process occurs, in particular. the surface or material on or from which an organism lives, grows, or obtains its nourishment. the substance on which an enzyme acts.

enzymes

a substance produced by a living organism that acts as a catalyst to bring about a specific biochemical reaction.

catalase

an enzyme that catalyzes the reduction of hydrogen peroxide.

crenation

crenation. noun. A rounded projection, as on the margin of a shell. The condition or state of being crenate. A process resulting from osmosis in which red blood cells, in a hypertonic solution, undergo shrinkage and acquire a notched or scalloped surface.

hemolysis

the rupture or destruction of red blood cells.

Cell membrane

the semipermeable membrane surrounding the cytoplasm of a cell.

Diffusion

the spreading of something more widely.