Types of tonicity:
describes the behavior of cells in a fluid environment.
soultion has higher concentration of solute on the outside. This
results in a net movement of water out of the cell. (EX- food preservation)
solution has a lower concentration on the outside. This results in water
moving into the cell.
an extracellular solution that has the same concentration of soulute as what is in the cell.
There is no net movement of water in or out of cells.
) The pressure at a point in a fluid at rest due to the weight of the fluid above it. Also
known as gravitational pressure. The negative of the stress normal to a surface in a fluid.
exerted or transmitted by the
) at rest.
particles present, the higher the
osmotic pressure, (Osmotic
pressure depends only on the number of
particles present in a
, not the kinds of
The process whereby relatively unspecialized cells, e.g. embryonic or
regenerative cells, acquire specialized structural and/or functional features that characterize the cells,
tissues, or organs of the mature organism or some other relatively stable phase of the organism's life
history. Differentiation includes the processes involved in commitment of a cell to a specific fate.
*governed by genes. Your body "tunes" the genes of each cell type differently. Depending on where in
the body it is located, a given gene can be turned off, weakly on, or strongly on. For example, the gene
for globin, which composes hemoglobin, is strongly on in cells that will mature into red blood cells and
off in every other cell type.
Cells control the tuning, or expression, of genes by keeping a tight rein on RNA polymerase. For genes
that are strongly on, cells use special molecular tags to lure in RNA polymerase and to ensure that the
machine works overtime transcribing those genes. For genes that are off, cells use different tags to
repel RNA polymerase.
Receptor mediated endocytosis:
is a process by which cells internalize molecules or viruses. As
its name implies, it depends on the interaction of that molecule with a specific binding protein in the
cell membrane called a
("cell-drinking", "bulk-phase pinocytosis", "non-specific, non-adsorptive pinocytosis",
"fluid endocytosis") is a form of
in which small particles are brought into the cell
suspended within small
which subsequently fuse with
to hydrolyze, or to break