Pernicious anemia and Vitamin B12

Loss of Vitamin B12 leads to a disease called Pernicious anemia.The chemical reaction involved is discussed here.

PROTEINS AND ENZYMES

In answer to the question "discuss the general structure of enzyme proteins and how the structure of enzymes allows them to fulfuil their biological role" I have written the following short account. I cannot exceed 400 words. Can you let me know if I am on the right track. Please note I have not included any references in this message to you although the finished work will be fully referenced. "There are two classes of protein: fibrous proteins which are elongated and twisted together; and globular proteins, which are compact, folded and coiled around each other. Enzymes (and all proteins) are made up of amino acids linked to each other through condensation reactions known as peptide ... click for more

Working with chemical equations

Series of questions attached about working with chemical equations.

Please Help

What is the pH of 4% (w/v) solution of Ca(OH)2? Assume that Ca(OH)2 is 100% dissociated.

finding titration curve with unknown volumes

Draw the titration curve for the titration of a 0.05M solution of acetic acid with 0.1M sodium hydroxide. I can find the initial pH of the solution, but I am not given any initial volumes so can you point me in the right direction of how to solve this problem? I asked my professor and she said that I don't need volumes to do this, but all the books that I've looked at say I need volumes. If I don't need volumes can you give me a hint as to how this problem should be solved?