Which of these factors make hydrogen fuel cells a better option than burning fossil fuels? Hydrogen fuel cells have a higher energy efficiency.
Hydrogen fuel cells create less pollution.
Burning fossil fuels relies on outdated devices and technology.
Hydrogen is the most abundant element in the universe.
Hydrogen fuel cells are more expensive than fossil fuels.

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.