BiologyWise
Biology Wise: Effect of P H on Enzymes
Every enzyme has an optimal pH value at which it functions best. This article explains why pH has an effect on enzyme activity and how it affects them.
Science4Fun
Science4 Fun: Enzymes
What are enzymes? Discover how enzymes work and learn about the different types.
Wikimedia
Wikipedia: Cytoplasm
Wikipedia offers brief but accurate information on cytoplasm, the matter contained within the plasma membrane of a cell.