Answer:
the 4th one The lumen, is my guess
Lactic acid is a byproduct of short-term cellular respiration do to exercise, but if you mean lactose, then it's just the enzymes, that your stomach produces
Answer:
The correct statement concerning the cell membrane lipid molecules is that "energy is not expended during diffusion" (Option d)
Explanation:
Biological membranes are formed by two lipidic layers arranged with their hydrophilic polar heads facing the exterior and the interior of the cells, and their hydrophobic tails against each other. Membranes are fluid, which means that molecules that form it have the capability to move through it.
Lipids can easily change places with other neighbor lipids by <u>lateral diffusion</u> in the same layer. This is passive diffusion, which means that it does not need energy to happen.
Lipids can also diffuse transversally to the other layer, but this kind of movement is not as easy as lateral diffusion.
There are also other lipidic movements as rotational diffusion that imply the rotation of the molecule.
Through this lipidic bilayer, there is also a passive transport of some particles from one side of the cell to the other which happens because of concentration differences.
The answer is d. all of the above. The amount of nitrogen in the atmosphere can be affected by the inorganic nitrogen fertilizers, sewage treatment plants and pollution coming from factories. Hope this is the answer and this would be of help.
