After a police car with flashing lights and blaring siren passes Tom and pulls over another driver for speeding, Tom's heartbeat soon slows down, his blood pressure decreases, and he stops sweating. These calming physical reactions are MOST directly regulated by his nervous system.

You have just sequenced a new protein found in mice and observe that sulfur-containing cysteine residues occur at regular intervals. what is the significance of this finding? it will be important to include cysteine in the diet of the mice. cysteine residues are required for the formation of α helices and β pleated sheets. cysteine residues are involved in disulfide bridges that form tertiary structure. cysteine causes bends, or angles, to occur in the tertiary structure of proteins.