B4 Enzymes Flashcards
What is a catalyst?
A substance that changes the speed of the reaction, often making it faster
Enzymes are specific to what?
To one substance or a group of similar-shaped substrates
An active site is a sequence of…?
Amino acids with a specific shape
Protease breaks down…?
Proteins into amino acids
List the factors affecting enzyme action
- pH
- Temperature
Define enzyme
Proteins that function as biological catalysts
Define enzyme
Proteins that function as biological catalysts
The active site and substrate are ______.
complementary
Substrate fits tightly into the active site, forming an _______.
Enzyme-substrate complex
Once products are formed, they no longer fit into the _____.
active site
Amylase breaks down…?
Starch into simple sugars
Lipase breaks down…?
Lipids into fatty acids and glycerol
Enzymes work best at what temperature?
Optimum
Why won’t enzymes work at higher temperatures?
Since the structure of the enzyme has permanently changed. The enzyme has denatured.
Why do enzymes work best at their optimum temperature?
The molecules have the perfect amount of kinetic energy at this temperature
Why do enzymes work more slowly at low temperatures?
This is because the enzyme and substrate molecules move slowly, so they may take a long time to bump into each other with enough force to join and start the reaction.
Why are enzymes denatured past their optimum temperature?
This is because the molecules vibrate so much that they start to change the shape of the active site. This means that the substrate doesn’t fit as well, so the chance of an enzyme-substrate molecule forming decreases. The rate of reaction decreases.
What is pepsin?
An enzyme released in the stomach(acidic).
What is trypsin?
An enzyme released in the small intestine(alkaline).
The shape of the enzyme depends on the ___.
Optimum pH
A very high pH can ____ the enzyme
denature
A very low pH can ____ the rate of action of the enzyme
Slows down
Explain the investigation of pH on enzymes
- Once tube for each pH
- Add buffer solution
- Add starch and amylase solution
- Sample and test for starch with iodine solution
- The sample that is the first to stop turning iodine solution blue-black comes from the tube where digestion of starch to glucose was fastest, and therefore from the tube kept at the optimum pH for that enzyme.
