Answer quick
what is one way space travel affects the human body?
a) too much blood flows into the upper body.
b) the heart pumps harder with less gravity.
c) too little blood flows into the upper body.
d) the legs get stronger.

Molecules like glucose and amino acids are not lipid soluble, so cannot cross the cell membrane by simple diffusion. instead, they are shuttled across by carrier proteins in the membrane from high to low concentration. does this process require energy from the cell? this is an example of what type of molecular movement?