The use of EDI is one way in which HSBC is helping its customers to manage this complex supply chain. EDI is where two or more companies in the supply chain exchange information in agreed formats electronically, so that the computers can process the data automatically. (E-mail is not the same as EDI.)

The electronic banking services system within the HSBC Group is known as Hexagon. Hexagon includes trade services, cash management, payments and information reporting.

Hexagon has a specially designed module for the transfer of electronic commercial documents. These can then be moved from a computer in one company to a computer in another. This removes the problem of reproducing documents and the possibility of errors.

21. What is the secondary structure of a protein?

22. What is the difference between alpha-helix and beta-sheet protein conformations?

23. What is the tertiary structure of a protein? What are the main types of tertiary structures?

24. What is the quaternary structure of a protein? Do proteins have a quaternary structure?

25. What is protein denaturation? Are there any changes in the primary structure when a protein is denatured?

26. How can denaturation be classified according to its reversibility?

27. What are some factors that can lead to protein denaturation?

28. Do changes in the primary, secondary or tertiary structure of a protein normally have consequences for their function?

29. In sickle cell anemia, a hereditary disease, one amino acid is substituted by another in one of the four polypeptide chains of hemoglobin. In this case are all of the structural levels of the protein modified?

30. What is the difference between essential and nonessential amino acids?