The Protein nature of enzymes Flashcards
What does it mean by the term metabolism?
It refers to all reactions of the body. Reactions occur in sequences called metabolic pathways.
What is an anabolic reaction?
It is the building up of molecules e.g. protein synthesis.
What is a catabolic reaction?
It is the breaking down of molecules e.g. digestion.
What are metabolic pathway is controlled by?
They are controlled by enzymes. The products of one controlled reaction becomes the reactants in the next.
What sort of protein are enzymes?
They are globular proteins in the tertiary structure which catalyse a reaction.
Why are enzymes are biological catalysts?
They are made up of living cells.
Name for properties of enzymes as catalysts?
They speed up reactions, they are not used up, they stay unchanged and have a high turnover rate e.g. catalyse many reactions per second.
Why are enzymes similar?
They are held in specific shapes by hydrogen, ionic and disulphide bonds with an activity being affected by temperature and pH. They are specific and will only catalyse one type of substrate. The substrate is complimentary to the active site and the substrate changes into the product in the reaction. They are important indigestion as they hydrolyse polymers into monomers.
What is the structure of an enzyme?
They are proteins in the tertiary structure where the polypeptide chain thousand to a globular shape with hydrophilic or groups on the outside of the molecule making it soluble with water. All enzymes have a similar specific sequence of amino acid with the elements in the R group determining the bonds that the amino acid will make.
What bonds do they form?
Hydrogen, ionic and disulphide bonds hold the enzyme together
What are the sites of enzyme action?
Extracellular, intracellular (in solution), intracellular (membrane-bound).
What is the extra cellular enzymes?
It is when some enzymes secreted from cells by exocytosis and catalyse extra cellular reactions.
What are the intracellular (in solution) enzymes?
These enzymes act in the solution inside cells.
What are intracellular membrane-bound enzymes?
It’s when they are attached to membranes.
What is two example of an extracellular enzyme?
Amylase is produced from the salivary glands, which moves down the salivary ducts to the mouth. Saprotrophic fungi and bacteria secrete amylase, lipase and protease onto their food which digests it and absorb the products of digestion.
