Core component 4 - Properties and Uses of Enzymes Flashcards
What is a metabolism
A combination of anabolic (building) and catabolic reactions (breaking down) that are catalysed by enzymes
What is an enzyme?
Globular proteins that are catalysts. They are called ‘biological catalysts’ because they are made by living cells.
What are key facts about enzymes when they catalyse a reaction?
1) they speed up reactions
2) they are not used up
3) they are not changed
4) they have a high turnover number i.e they catalyse many reactions per second
Describe the structure of an enzyme?
Enzymes are proteins with a tertiary structure. Each enzyme has a particular sequence of amino acids which is primary structure and then they are folded and twisted into an alpha helix or beta pleated sheet because of hydrogen bonds then, the protein chain folds into a spherical globular shape to make it more complex and compact with hydrophilic R groups on the outside of the molecule, making them soluble in water but also the different R groups determine the bonds the amino acids make with each other (Hydrogen bonds, disulphide bridges, ionic bonds) and ultimately hold the enzyme together.
What gives an enzyme many of its properties?
A specific 3D shape called the active site.
Describe and give an example of enzymes catalysing reactions in an extracellular site
Some enzymes are secreted by exocytosis snd catalyse extracellular reactions. E.g amylase made in the salivary glands moves down the salivary ducts to the mouth.
Describe and give an example of enzymes catalysing a reaction in an intracellular site (in solution and membrane bound)
Intracellular enzymes act in solution inside cells. E.g. Enzymes that catalyse the synthesis of glucose in the stroma of chloroplasts
Or on a membrane e.g in the cristae of mitochondria
What is the difference between bacterial amylase and humans amylase?
Bacterial amylase can resist much higher temperatures and has a higher optimum temperature
