Answer:
Constitutive activation is the alteration of a protein or signaling pathway such that it is functional or engaged even in the absence of an upstream activating event. For example, RasD is constitutively active because it cannot bind GAP and therefore remains in the GTP-bound, active state even when cells are not stimulated by growth factor to activate a receptor tyrosine kinase.
Constitutively active Ras is cancer promoting because cells will proliferate in the absence of growth factors, and thus normal regulatory mechanisms for cell proliferation are bypassed.
(a) A mutation that resulted in Smad3 binding Smad4, entering the nucleus, and activating transcription independent of phosphorylation by the TGFβ receptor would render Smad3 constitutively active.
(b) A mutation that made MAPK active as a kinase and able to enter the nucleus without being phosphorylated by MEK would render MAPK constitutively active.
(c) A mutation that prevented NF-KB from binding to IK-B or that allowed NF-KB to enter the nucleus and regulate transcription even when bound to IK-B would render NF-KB constitutively active.
The cell membrane lets in stuff and gets rid of the bad stuff
Answer:
If the oil spilled in the gulf would have been processed oil, it would be worse than a normal oil spill as these oils have a higher shelf life.
Explanation:
Oil spills happen when a large quantity of oil gets mixed with large water bodies like <em>sea and oceans</em>. The oil being denser than water floats on the surface and does not mix with the water. It forms a coating on top of the water.
The difference between processed oil and normal oil is that they are heated at very <u>high temperatures</u> and this results in oxidation which creates <em>free radicals</em>, which are not good for the body and its cells. Also they have a very long shelf life due to which they will remain on water for a long time.
When oil spills happen, the <em>wind</em> cause the spill to spread over the water surface, thereby engulfing a large amount of area. The major disadvantages of the spill are:-
- The oil gets stuck in the feathers of the birds who come by to dip themselves,
- Animals like whale, dolphins have blow holes for releasing water. the oil covers these holes and makes it difficult for them to breathe.
- The fur of animals like <u>seal and otter </u>gets mixed with the oil and can prove harmful to them as it gets them exposed to cold.
- The overall BOD of the water body decreases, and organisms which use sun rays coming inside the ocean suffer as these get blocked.
- Since processed oil has longer shelf life, a large quantity of animals will suffer and die.
Sanitary landfill burial technology could help to reduce the amount of
waste going into a landfill
Explanation:
The land which is carefully designed into the top of the ground where trash is easily isolated. The main purpose of landfill is to keep It dry and care try to not come in contact with air. It is not like a compost pile.
This method is introduced by England in 1912. It is also called controlled tipping. It is about 1- or 3-meter feet. It is covered with clay.
