The structure is D. a substrate
Answer:
Explanation: In facilitated diffusion, molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers. A concentration gradient exists for these molecules, so they have the potential to diffuse into or out of, the cell by moving down it.
<span>A measure of subcutaneous fat at various body sites using special calipers is: tomography which is consider to be the gold standard. the purpose of studying this fact was to compare skinfold caliper and ultrasound measurement of subcutaneous body. Subcutaneous fat thickness of 26 young males was measured at eight sites using a commercial high-resolution B-scan ultrasound equipment.</span>
1. B. A process in which electrons are transferred from one compound to another with a release of energy occurring in the production of ATP
2. A. The gel-like material within a living cell
3. D. An organic molecule that occurs as an intermediate in many metabolic processes
4. C. The chemical breakdown of a substance
