Spinal fluid contains 15 to 45 mg/dL protein. If you were to take a 5.0 mL sample of spinal fluid, how much protein could you expect to find? Express your answer as a range.

A gel filtration column with a fractionation range of 1.5-20 kDa is used to separate out the proteins shown below. If these proteins are collected into separate fractions in between the void volume and total volume, in which order will they elute? Indicate if any of the proteins are found in the void volume or total volume fractions.                                                                        Protein Z - 3330Da                                                                        Protein Y - 13kDa                                                                        Protein X - 1.3kDa I. Total volume fraction II. Third protein fraction III. Second protein fraction IV. First protein fraction V. Void volume fraction

You have a mixture of peptides (RE; EQ; DW; EE; KG). Which peptide will bind most strongly in a column filled with anionite at pH 6.0? Which peptide will bind most strongly to a column packed with a cation at pH 6.0?

Proteins can be separated into 9 general classifications based on the role they play in a cell. List or briefly describe two of these functional classifications and provide an example of a protein that falls into each of those two categories.

Pepsin is the name given to a mix of several digestive enzymes secreted (as larger precursor proteins) by glands that line the stomach. Theseglands also secrete hydrochloric acid, which dissolves the particulate matter in food, allowing pepsin to enzymatically cleave individual protein molecules. The resulting mixture of food, HCl, and digestive enzymes is known as chyme and has a pH near 1.5. What pI would you predict for the pepsin proteins? What functional groups must be present to confer this pI on pepsin? Which amino acids in the proteins would contribute such groups?

A typical animal cell is thought to contain some 10 billion protein molecules that need to be sorted into their proper compartments. That’s a lot of proteins! Can 10 billion proteins even fit into a cell? The average length of a human protein is 450 amino acids, and the average mass of an amino acid in a protein is 110 daltons (1 dalton = 1 g/mol). Given that the average density of a protein is 1.4 g/cm3, what fraction of the volume of a cell would 10 billion average protein molecules occupy? Consider first a liver cell, which has a volume of about 5000 µm3. Then consider a pancreatic β cell, which has a volume of 1000 µm3.

a. How many peptide bonds are there? b. How many amino acid residues are there? c. In exact order, identify the name of the amino acids in the peptide chain. d. Give the full name of this peptide. e. Give the 3-letter abbreviation and 1-letter abbreviation. f. Calculate the pI of this peptide.

You have a protein with MW 48kDa. How many grams of protein are in a 200 mL sample at 50 μM?

A) List each of the five major functional classes of proteins. B) Discuss the function for each class, give an example of a protein for each class and mention how the function of the protein example fits the function of the class (40 words or less for each class with its example

Amino acids are ionic compounds, very soluble in water. Proteins, however, which are made up of amino acids are much less soluble, and must be folded up very precisely to maximize their solubility. Why are proteins so much less soluble than the amino acids of which they are made?