Enzymes

• Enzymes are catalysts made of protein. They speed up a reaction without being used up themselves in the reaction
• Most enzymes are globular proteins.
• Each enzyme has its own specific shape that will only “fit” the molecule that the enzyme is designed to work on.
• The substance that an enzyme acts on is its substrate.
• The substance(s) that the enzyme forms is called the product(s).
• Enzymes control metabolic reactions.
• A catabolic enzyme breaks a big molecule into a smaller one. e.g amylase converts starch into maltose
• Anabolic enzymes convert simple molecules into more complex ones and are found in almost all living things. e.g. DNA polymerase forms and repairs DNA.
• When enzymes and their substrates meet and come together they form an Enzyme/Substrate complex.
• Enzyme reactions are reversible.
• Lipases are enzymes that act on lipids.
• Inhibitors attach to enzymes and destroy their shape. When this happens, the enzymes are said to be denatured.
• Examples of beneficial inhibitors include insecticides, painkillers, and antibiotics.
• Temperature, pH, substrate concentration, and enzyme concentration all affect enzymes.
• Human enzymes work best at body temperature (37°C) while plant enzymes work best at 20-30°C.
• Most enzymes work at pH 6-8.
• Bioprocessing is the use of enzymes to control reactions to produce a product.
• A bioreactor is a container in which living cells are used to make a product.
• Immobilized enzymes are attached or fixed to each other.
• Bioprocessing is used to make cheeses, beers, yogurts, bread, antibiotics, vaccines and vitamins.
• Immobilized enzymes are used to prevent wasting free enzymes when the product is removed from the vessel.
• ATP , NADP+ and NAD+ play a vital role in trapping and transferring energy in cellular activities.
• ​ADP is an abbreviation for Adenosine Diphosphate. This is a molecule found in the cells of all organisms.
• ADP is a low-energy molecule and is made of adenine, 5 carbon sugars, and 2 phosphate groups.
• If another phosphate is added to ADP it forms ATP (Adenosine Triphosphate)​. Extra energy is also added as there is an extra bond between the last two phosphate groups. Addition of a phosphate like this is called Phosphorylation​.
• ATP is rich in energy but cannot store it for very long and converts back to ADP.
• NADP+ stands for Nicotinamde Adenine Dinucleotide Phosphate.
• NADP+ is a low-energy molecule. It can be combined with 2 high-energy electrons and a proton to form NADPH.
• The addition of electrons to a molecule is called a reduction.
• NADPH​ is a very high-energy molecule. Its energy is used to form glucose in photosynthesis.
• NADPH is an electron carrier and carries hydrogen. When NADPH breaks down it releases energy in the form of 2 high-energy electrons and a hydrogen ion (H+) or proton. ​
• NAD+ is used in respiration.
• NAD+ can combine with two high-energy electrons and a proton to form NADH.