A phospholipid is a lipid made of a phosphate group with two fatty acids.
A second messenger is a molecule inside cells that acts to transmit signals from a receptor to a target.
Hoped this helped.
~Bob Ross®
THE ACTIN has the active site to which the heads of the thick filament will bind.
The muscle is made up of two major protein fibers, which are the actin and the myosin. Muscle contractions occur when myosin and actin slide over each other in a series of repetitive events. The protein actin has a thin structure and is abundant in eukaryotic cells while myosin is a thick filament.
A nervous system because worms don't have nerves
D. the <span>stomata close to preserve water and gas exchange decreases.</span>
