Scoring Rubric for essay (20 minutes time, up to 10 points)
Describe the four levels of protein structure and how they form.
_____Proteins are polymers made of amino acid monomers
_____the nucleotide sequence of a protein coding mRNA (or gene) define the primary sequence
_____the primary sequence, the simplest level, is the linear order of the amino acids in a protein
_____the primary sequence is made when dehydration synthesis links amino acids by peptide bonds
____the secondary structure forms when the primary sequence folds onto itself by formation of
hydrogen bonds between carbonyl and amino groups of different amino acids of the backbone
____the secondary structure may be an alpha helix which is more elastic (labeled drawing showing H
bonds will work) or a beta pleated sheet which has more hydrogen bonds and is more rigid (labeled
drawing showing H bonds will work
____the tertiary structure is the folding of the secondary structure onto itself as R groups interact
____a correct example of an interaction or a correctly labeled drawing will help
____the tertiary structure is also the three dimensional and functional structure of a polypeptide
____quarternary structure is the interaction of two different polypeptides due to interaction of the R
groups in their already folded tertiary structure.
____example like hemoglobin explained will work as will a labeled drawing
_____each protein has an optimal set of physical conditions (like ph OR temperature that affects its
shape)
____in the cell, proteins called chaperones assist proteins in folding