Cell Renewal and ApoptosisKali Burkhardt Thu Dec 11 21:10:40 CST 2014

Stem cells

Specialized cells that have the potential to develop into any type of cell

common prop of stem cells:

1. not terminally differentiated2. potential to divide indefinitely.3. undergo differentiation to give rise to different kinds of cells

pluripotenthave potential to differentiate into a number of different kinds of cells.

The only way to get new blood cells is by the division of _______. stem cells

The blastocyst includes three structures

1. the trophoblast, which is the layer of cells that surrounds the blastocoel, 2. a hollow cavity inside the blastocyst; and 3. the inner cell mass, which is a group of cells at one end of the blastocoel that develop into the embryo proper

blastocyst- hollow fluid-filled ball of cells - 7 to 9 days after fertilization it embeds itself into the endometrial lining of the uterus

somatic cell nuclear transfer nucleus of somatic cell is removed and placed inside an oocyte (non fertilized egg)

embryo results using the genetic info from the nucleus of the somatic cell.

What is the ethical challenge to somatic cell nuclear transfer?

still embryoDNA can be matched to donor

induced pluripotent stem cells "reprogram" more highly differentiated cells to make them behave like embryonic stem cells. -very preliminary

Programmed cell Death built-in cellular process by which cells die via a regulated series of changes within the cell. apoptosis

Good reasons for cells to die:

1. give form to developing embryos 2. maintain adult tissues in balance b/w cell proliferation and cell death3. eliminate cells that ma be infected with viruses4. get rid of cells that have suffered a lot fo DNA damage

Caspasesenzymes that are activated when the cell receives a signal telling it to commit suicide, that they dismantle the cell

Ways cells can be prompted to die:

1. p53 (internal)2. cell death signals

-these external factors bind to a death signal receptor and activating the first of a series of caspases or suicide proteases.

HOw are caspases activated? made as inactive precursors that are converted to the active form by being cut to size by a protease. The first cut caspase can thengo on to activate more caspases.

caspase cascade an event that activates the first caspase leads to a series of events taht results in the activation of many different caspases.

cell survival signals tell cells to express genes that inhibit apoptosis

two ways to get stem cells

1. induced pluripotent2. somatic cell nuclear transfer

somatic cell nuclear