enzymes

• what are enzymes?

  globular proteins that act as biological catalysts
• what type of biological molecule are enzymes?

  globular proteins
• the chemical reaction required for growth are anabolic reactions and are all catalysed by enzymes
• what is another name for reactions where things break down?

  catabolic reactions
• describe the lock and key hypothesis?

  active site is complementary to the specific substrate and fits perfectly
• what hypothesis most commonly describes how enzymes and substrates bind?

  Induced fit model
• describe induced-fit hypothesis?


  initial interaction between the enzyme and substrate is weak but they induce changes in the enzymes tertiary structure that strengthen binding.
• why are enzymes globular proteins?

  soluble in water so can be carried in the blood and work in the cytoplasm
• where do chemical reactions take place?

  cytoplasm
• where does the substrate bind to an enzyme?

  Active site
• what controls the shape of an enzyme?

  allosteric site
• what forces bind substrates to active site?

  hydrogen bonds and ionic forces
• what are intracellular enzymes?

  enzymes that work in cells
• what is the role of catalase?

  break down hydrogen peroxide to oxygen and water
• what are extracellular enzymes?

  Enzymes that work outside of cells.
• why are enzymes needed for digestion?

  large molecules cannot enter cells through cell surface membrane, they need to be broken down first
• what type of enzymes are used in digestion?

  extracellular
• is catalase intracellular or extracellular?

  Intracellular
• describe the digestion of starch?

  amylase breaks starch down into maltose. maltose is broken into alpha glucose by maltase
• where is amylase produced?

  salivary glands and pancreas