activation

Transmembrane receptor

...pore through the membrane, or ion channel . Upon activation of an extracellular domain by binding of the appropriate ligand, the pore becomes accessible to ions, which then pass through. In other receptors, the transmembrane domains are presumed to undergo a conformational change upon binding, which exerts an...

Signal transduction

...nses triggered by signal transduction include the activation of a gene , the production of metabolic energy ...through remodelling of the cell skeleton . Gene activation leads to further effects, since genes are expressed as proteins , many of which are enzymes, trans...

Parthenogenesis

...e offspring. Since gynogenetic species lack males, activation of the egg requires mating with males of a cloesly related species. Some salamanders of the genus Ambystoma are gynogenetic and appear to have been so for over a million years. It is believed that the success of those salamanders may be due to...

Origin of life

...Huber, C. and Wchterhuser, G., (1998) "Peptides by activation of amino acids with CO on (Ni,Fe)S surfaces: implications for the origin of life". Science 281 , 670–672. (Cited on p. 108). Brooks, J. and Shaw, G., 1973. Origins and Development of Living Systems. Academic Press, London and New York, p...

Oncogene

...nals, usually through its protein product. Upon activation , it (or its product) becomes a tumor inducing age...tion of its original function. There are two basic activation types: A mutation within a protooncogene can cause a change in the protein structure, caused by...

Nervous system

... and jellyfish , have a nerve net , in which the activation of any one neuron triggers a wave of activation across the entire network. These waves are both afferent and efferent , representing both the sen...

Memory

... and is merely a reflection of differing levels of activation within a single store. If we are given a random seven-digit number, we may remember it only for a few seconds and then forget (short-term memory). On the other hand, we can remember telephone numbers for many years (assuming we use them often enoug...

Major histocompatibility complex

... A full-force immune response usually requires the activation of B cells via BCRs and T cells via the Mhc -TC...ad to a full-force antibody immune response due to activation of B cells. MHC evolution and allelic diversity MHC gene families are found in essentially all ...

Ion channel

...tures 2 Biological role 2.1 Diversity and activation 3 Detailed structure 4 History 5 See ... channels are a favorite target. Diversity and activation Voltage-gated channels sense the transmembrane potential and open or close in response to ...

Immune system

...ogen, destruction of the pathogen by formation and activation of the membrane attack complex , and inflammation....ion. After they leave the thymus, T cells require activation to proliferate and differentiate into "killer" T cells (CTLs). Activation is provided by antigen pre...

Hormone

...uppression of apoptosis (programmed cell death), activation or inhibition of the immune system , regulating metabolism and preparation for a new activity (e.g. fighting, fleeing, mating) or phase of life (e.g. puberty, caring for offspring, menopause). In many cases, one hormone may regulate the production...

Enzyme

... Like any catalyst, enzymes work by lowering the activation energy of a reaction, thus allowing the reaction ...nabling a different reaction pathway with a lower activation energy , making it easier for the reaction to occur. The overall rate of enzyme mediated reactions ...

Diabetes mellitus

...d, sweaty, and have many symptoms of sympathetic activation of the autonomic nervous system - they may experience feelings similar to dread and immobilized panic. Consciousness can be altered, or even lost, in extreme cases, leading to coma and/or seizures or even death and brain damage. Experienced diabeti...

Dendrite

...passively, without action potentials and without activation of voltage-gated ion channels . In such dendrites...ackpropagating action potential is mediated by the activation of voltage-gated ion channels and can interact with synaptic input to alter the synaptic activity. ...

Chromatography

...thick slurry on the carrier, drying the plate, and activation of the adsorbent by heating in an oven. The thickness of the adsorbent layer is typically around 0.1 - 0.25 mm for analytical purposes and around 1 - 2 mm for preparative TLC. Several methods exists to make colorless spots visible: Often a small...

Biomechanics

...sin to allow for the crossbridges to bind to the activation sites on the actin. It has been shown that applied loads and deformations can affect the properties of living tissue. There is much research in the field of growth and remodeling as a response to applied loads. For example, the effects of elevated b...

B cell

...ate in blood plasma and lymph ) involves B cell activation . Cell activation can be gauged using the ELISPOT technique, which can determine the percentage of B cells that secr...

Apoptosis

...role in maintaining genomic integrity, and massive activation of PARP-1 can deplete the cell of energy-providing...xtrinsic and intrinsic pathways have in common the activation of central effectors of apoptosis , a group of cysteine proteases called caspases , which carry ...

Antibody

... and protects the body against them by complement activation (classic pathway), opsonization for phagocytosis and neutralisation (immunology) of their toxins. There are 4 subclasses: IgG1 (66%), IgG2 (23%), IgG3 (7%) and IgG4 (4%). IgA IgA represent about 15 to 20% of immunoglobulins in the blood althou...

Allostery

...at enhance activity are referred to as allosteric activation , while the opposite is called allosteric inhibit...ted model 1.2 Sequential model 2 Allosteric activation 3 Allosteric inhibition 4 Related topics Models of allostery Most allosteric effe...

Allostery

...at enhance activity are referred to as allosteric activation , while the opposite is called allosteric inhibit...ted model 1.2 Sequential model 2 Allosteric activation 3 Allosteric inhibition 4 Related topics Models of allostery Most allosteric effe...

Activation energy

The activation energy in chemistry is the energy needed by a...heir electron clouds repel. This requires energy - activation energy - and comes from the heat of the system, i.e. the translational , vibrational , and rota...