A person moved the ends of two magnets together and felt them attracting each other. Which is the most accurate description of the magnetic poles involved? A. Both ends must be magnetic north poles only. B. Both ends must be magnetic south poles only. C. The ends must be either both magnetic south poles or both magnetic north poles. D. One end must be a magnetic north pole and the other a magnetic south pole.

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.