Enzymes

• What are enzymes used for?

  catalyst

  
• What do chemical reactions need to get started?

  they need a certain amount of energy called the activation energy

  
• What is the purpose of activation energy?

  to start a reaction and the time it takes for the reaction to complete
• What is a common way to speed up reactions?

  increase the temperature
• Why would increasing the temperature be harmful for living organisms?

  for the reactions to work, the body temperature must be really high, which can denature the protein
• How do you increase the rate of reaction?

  use a catalyst, a substance that decreases activation energy but it is not used in the reaction itself

  
• What is an enzyme?

  a protein that catalyzes chemical reactions in biological systems

  
• What are the enzyme shapes?

  primary, secondary, tertiary, quaternary

  mostly globular with indentations
• What are active sites?

  the region of an enzyme that interacts with a substrate

  
• What is a substrate?

  a reactant that interacts with the enzyme in an enzyme-catalyzed reaction

  
• How do enzymes lower the activation energy?

  - change the substrate

  - change the environment
• How does the enzyme change the substrate?

  it changes its shape, weakens bonds, transfers electrons, or add/remove H+ ions
• What happens after the reaction?

  the products are released from the enzyme and the process begins again
• What are coenzymes?

  organic molecules that assist the enzyme

  
• What are cofactors?

  ions that assist enzymes

  
• Why do we need minerals and vitamins?

  to assist the enzyme's function
• How are enzymes classified?

  according to the reaction they are involved in
• What is hydrolase?

  enzyme that catalyzes hydrolysis reactions

  
• What is protease?


  enzyme that breaks down proteins
• How are enzymes named?

  first part of substrate name and end in -ase
• How is enzyme activity influenced?

  by the pH or temperature
• How does temperature affect enzyme activity?

  as temperature increases, so does the rate of reaction

  the optimal temperature is around 37 C

  
• What happens to the enzyme if the temperature is too extreme?

  too low: active sites are not flexible enough for substrates to fit properly

  too high: the enzyme denatures and cannot maintain its shape
• What pH do most enzymes work best in?

  pH of 6 or 8 (except for pepsin in the stomach as the contents of the stomach are acidic)
• What does the speed of activity depend on?

  the concentration of both enzymes and substrates
• What happens if there is more substrate?

  the enzyme will have more activity until it works at maximum capacity, then adding more substrate will have no effect
• What are inhibitors?

  molecules that bind to the enzyme to decrease activity

  
• What are competitive inhibitors?

  inhibitors that bind to the active site of the enzyme, so the substrate cannot bind

  
• What are noncompetitive inhibitors?

  inhibitors that bind to the allosteric site of the enzyme, which changes the shape of the enzyme's active site, so the substrate cannot fit

  
• What are activators?

  molecules that bind to allosteric site and keeps the enzyme active
• What is allosteric regulation?


  the regulation of enzyme activity using inhibitors and activators
• What is an example of a technology that uses enzymes?

  CRISPR-Cas9

  
• Who invented CRISPR?

  Emmanuelle Charpentier
• When was CRISPR-Cas9 invented?

  2012
• What does CRISPR do?

  edits DNA, some bacteria use it as an antiviral mechanism
• What is the enzyme involved in CRISPR?

  Cas9
• What does Cas9 do?

  forms a complex between 2 small RNA molecules, which helps it cut and bind to DNA at a specific location so the DNA can be edited or removed

  
• What other enzyme is involved in CRISPR?

  RNase III
• What does RNase III do?

  it works with tracrRNA sequences and transforms crRNA into a mature and functional molecule