Answer:
a mutation that blocks the GTPase activity of Ras
Explanation:
A G protein in inactive state is GDP bound but as soon as a guanine exchange factor (GEF) exchanges it with GTP it gets activated which means that in GTP bound state it is active. G - protein has endogenous GTPase activity. Upon interaction of GAP, the GTPase activity of this protein is exhibited. When GAP is present, hydrolysis of GTP into GDP occurs which leads to inactivation of G protein. A mutation which will block GTPase activity of Ras will therefore result in constitutive active signaling even in the absence of ligand binding to it's receptor. In such scenario, GTP will not be hydrolyzed into GDP so signaling will be up-regulated.
I need the full question but we breathe air which is 02
B) It is a fluid mosaic model, with proteins interspaced in the phospholipids, both of which can freely move laterally.
Explanation:
The fluid mosaic model proposed by Singer and Nicolson describes the plasma membrane’s structure as a mosaic pattern of components consisting of phospholipids, proteins, cholesterol, and carbohydrates; all of which provides the unique fluid character of the membrane.
According to this model, the phospholipids constitute the main fabric, cholesterol attaches between the phospholipids in between the layers, integral proteins embedded within the bilayers of the phospholipids, peripheral proteins along the peripheries of the layers and carbohydrates outside the membranous layers.
B. Bacteria
The bacteria break the dead leaves down and release the nutrients back to the soil.
