Pectin is a molecule similar to starch except that the repeating unit (residue) of pectin is galacturonic acid instead of glucose as in starch. Galacturonic acid is still very similar to glucose, except one of the carbons has a -COOH group attached instead of a CH2-OH. The pectin chain is held together by a bond between carbon 1 of one galacturonic acid and carbon 4 of the next one and so on. Pectinase splits the bonds between these galacturonic acids to shorten the pectin chain from large fragments in to many more small fragments. The actual catalytic mechanism introduces water so pectinase is known as a hydrolytic enzyme. It splits a water molecule and adds -H to one carbon in the bond and an -OH to the other one. Another type of pectinase also breaks this bond but by a different ca
Below optimum up to optimum temperature: Like all enzymes, amylase catalyses a (bio) chemical reaction. A fundamental of chemical thermodynamics is that all reaction rates will increase as the temperature increases. With a typical amylase, therefore as you increase the temperature to the optimum, the rate at which an enzyme catalyses the breakdown of starch increases. The first reason for this is because you increase the rate at which the enzyme and the starch substrate collide (faster Brownian motion). Also the amylase has an optimum shape or flexibility and will hold this ideal shape at the optimum temperature. For pancreatic amylase this will be at body temperature. Enzymes that do well at very high temperatures tend to have a more rigid, inflexible structure that may be held toget
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