Ch. 4 Study Guide
1. In living (biological) systems, potential energy is stored in concentration gradients and chemical bonds and transformed into kinetic energy to do work. List the 3 basic forms of work and give a physiological example of each.
Chemical Work – Enables cells and organisms to grow, maintain suitable internal environment and store information needed for reproductions, et al
Transport Work – Enables cells to ions, molecules, and larger particles through cell membrane and through organelle membranes in the cell.
Mechanical Work – At cellular level, moves organelles around in the cell, cells changing shape and cilia and flagella.
2. The 2nd law of…show more content…
Enzymes provide this energy in living systems functioning as biological catalysts by lowering the amount of energy required for reactions to proceed. Most are large protein molecules that exhibit specificity. Isozyymes are enzymes that catalyze the same reaction but under slightly different conditions or perhaps in different tissues. Sometimes these are valuable diagnostic tools for medical conditions. One example that your book gives is the case of elevated creatine kinase (CK) in the blood due to a heart attack. Give 3 other examples of diagnostically important enzymes and the diseases they are indicating. 1. Elevated acid phosphatase could indicate cancer of the prostate 2. Elevated amylase could indicate pancreatic disease. 3. Elevated glutamate dehydrogenase indicates liver disease.
5. Enzymes are not always in an active state. Some are synthesized as inactive molecules called proenzymes or zymogens and are activated only when needed. Why might this be advantageous to the cell? (hint, think about digestive enzymes)
When inactive they can’t harm the cell if accidently released.
Others require inorganic cofactors such as calcium or magnesium to become active. The water soluble vitamins (like B and C) are organic and function as coenzymes which act as receptors and carriers for the substrates.
List 3 other factors that influence the rate of a reaction.
1. Change in