Fill in the blank. At pH 6.0 the N-terminus of His-His-His-His would have a Entry field with correct answer positive charge. The C-terminus would have a Entry field with correct answer negative charge. Since the pKa for His is 6.0, essentially half of the residues would carry a Entry field with correct answer positive charge on their side chains, so that the charge per residue could be considered to be Entry field with incorrect answer 2.0 . The result would be a net charge on the tetrapeptide of Entry field with incorrect answer 1.0 . Partially correct answer. Your answer is partially correct. Try again. The tetrapeptide would be Entry field with correct answer less soluble in water than Histidine itself. When the carbon bonds are formed between the carboxylate and amino groups to form the tetrapeptide, the groups that would interact with water are lost.

Nanotechnology, the field of trying to build ultrasmall structures one atom at a time, has progressed in recent years. one potential application of nanotechnology is the construction of artificial cells. the simplest cells would probably mimic red blood cells, the body's oxygen transporters. for example, nanocontainers, perhaps constructed of carbon, could be pumped full of oxygen and injected into a person's bloodstream. if the person needed additional oxygen-due to a heart attack perhaps, or for the purpose of space travel-these containers could slowly release oxygen into the blood, allowing tissues that would otherwise die to remain alive. suppose that the nanocontainers were cubic and had an edge length of 24 nanometers. part a part complete what is the volume of one nanocontainer? (ignore the thickness of the nanocontainer's wall.) express your answer using two significant figures. v v = 1.4ă—10â’20 l previous answers correct significant figures feedback: your answer 1.3824â‹…10â’20 = 1.382ă—10â’20 l was either rounded differently or used a different number of significant figures than required for this part. if you need this result for any later calculation in this item, keep all the digits and round as the final step before submitting your answer. part b suppose that each nanocontainer could contain pure oxygen pressurized to a density of 81 g/l . how many grams of oxygen could be contained by each nanocontainer?