Evolution by natural selection is one of the best substantiated theories in the history of science, supported by evidence from a wide variety of scientific disciplines
Answer: air, water, food
, a place to live
Explanation:
The living beings are composed of multiple cells, blood and water. They require certain necessities to survive and reproduce. The air is necessary for respiration. Water is necessary for fulfilling the thirst and maintaining the balance of fluid in the body. Food is necessary as it provides energy to do various biological functions. A place to live is necessary as it is the place where the living being rests, eat food and does other important activities.
Answer:
the hormone receptor is a heterotetramer composed of two subunits with 95 kDa and two subunits with 135 kDa
Explanation:
In this case, the heterotetramer is composed of two heterodimers, each composed of two subunits that held together by disulfide bonds. These heterodimers bind together through hydrophobic interactions in order to form a tetramer. The Sodium Dodecyl Sulfate (SDS) is a denaturing detergent that dissociates both heterodimers by interfering with hydrophobic interactions that hold heterodimers together. It is for that reason that only a single band of 230 kDa is observed (135 kDa + 95 kDa = 230 kDa). Moreover, 2-Mercaptoethanol breaks disulfide bonds, thereby separating the two subunits in the heterodimer. In consequence, after the use of this chemical compound (2-Mercaptoethanol), two different bands with 135 kDa and 95 kDa can be observed.
