1. you are studying the amino acid sequence of a protein shared by four organisms. you want to know which organism is most closely related to organism a. you have data that shows the number of amino acid differences between organism a and each of the other organisms. study the data in the chart and use it to answer question 1.

which organism does this data suggest is most closely related to organism a?

organism b
organism c
organism d

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.