True or false: mollusks have a heart and a closed circulatory system

What happened to rosalind franklin in 1956?

How many types of rock can form from the rock cycle

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?