What is the function of the Cell (plasma membrane?
Dynamic and fluid structure consisting of organized arrangement of lipids, carbohydrates, and proteins; separates ICF and ECF compartments.
o Main structural component is the lipid bilayer (hydrophilic exterior and hydrophobic interior), which is relatively impermeable to all but lipid-soluble substances
o Destruction of cell/plasma membrane = death of cell
o Cell surface surrounded by cell coat (glycocalyx)
§ Can regenerate
§ Necessary for cell recognition (e.g. blood cells, ABO)
§ Channel proteins – assist molecules that are not lipid soluble (e.g. electrolytes) in moving across cell membrane
§ Peripheral proteins bind to cell membrane temporarily to assist with molecule transport
What is cromatin?
complex structure of DNA and associated proteins in the nuclear matrix
What is cilia?
hair-like process projecting for a cell, composed of microtubules; beat rhythmically to move the cell around in its environment or to move mucus/fluids over the surface
What are free ribosomes?
sites of protein synthesis, mainly of enzymes that aid in the control of cell function
What is the Golgi apparatus?
stacks of thin, flattened vesicles or sacs; found near the nucleus and function in association with the endoplasmic reticulum; modifies substances produced in the ER and packages them into secretory granules or vesicles; produces large carbohydrate molecules
What is a lysosome?
digestive system of the cell; membrane-enclosed sacs containing hydrolytic enzymes; produced by the Golgi apparatus
What are microtubules?
long, stiff, hollow cylinders formed from protein subunits called tubulin; able to rapidly disassemble in one location and reassemble in another; involved in development and maintenance of cell form and participate in intracellular transport mechanisms
What is cellular respiration?
The mitochondria of the cell transforming organic substances into energy for the cell
What are peroxisomes?
membrane-bound organelles that contain a special enzyme to degrade peroxides; self-replicating, NOT formed by Golgi apparatus
What is the rough ER?
system of paired membranes and flat vesicles that connect various parts of the inner cell; studded with ribosomes (attached to specific binding sites) which translate mRNAs that code for proteins secreted from the cell or stored within it
What Specific protien is sythsised in the RER and nowhere else?
synthesis of lysosomal enzymes.
What is the SER?
continuous with the rough ER, but does not participate in protein synthesis; its enzymes are involved in the synthesis of lipid molecules, regulation of intracellular calcium, and metabolism and detoxification of certain hormones and drugs.
What is an embyronic stem cell?
Pluripotent cells derived from inner cell mass of blastocyst stage of embryo
All cells differentiate from pluripotent embryonic stem cells
What is an adult stem cell?
(AKA Somatic stem cells)
Found in bone marrow, peripheral blood, umbilical cord blood, some organs
Contribute to tissue regeneration and replacement of cells lost to cell death
What is diffusion?
free movement of small particles (solute) across a permeable membrane from an area of higher concentration to an area of lower concentration (down a gradient)
What is Filtration?
movement of a fluid due to hydrostatic pressure differences
What is Osmosis?
movement of water through a selectively permeable membrane, from a less concentrated solution to a more concentrated solution (up concentration gradient)
What is facilitated diffusion?
Facilitated Diffusion (passive) – specific transport protein in the cell membrane binds a substance and transports it across the cell membrane down the concentration gradient
What is active transport?
“pumps” against concentration gradient, always requires energy (such as ATP); common example is Na/K ATPase pump that accounts for the high concentration of Na outside the cell and high concentration of K inside the cell.
What are two examples of transport by vesicles?
Endocytosis:membrane enfolds a substance and incorporates it into a vesicle
Exocystosis – mechanism for the secretion of intracellular substances into the extracellular spaces; important in removing cellular debris and releasing substance.
What is Mitosis?
Prophase – chromatin condenses into chromosomes; nuclear envelope disappears