Core Flashcards
What are enzymes?
Enzymes increase the speed of reactions. They are often called biological catalysts
What factors affect the rate of an enzyme?
Temperature, pH, substrate concentration, enzyme concentration
Affect of change in temperature on enzyme activity
Increasing the temperature initially increases the reacting activity.
However after the optimum temperature, the activity decreases.
After a certain temp, the active site of the enzyme becomes denatured.
Affect of change in pH on enzyme activity
Enzymes have an optimum pH.
A too far change from the optimum pH, causes enzyme activity to decrease.
If the pH is too low or too high, then the enzyme is denatured.
Affect of change in substrate concentration on enzyme activity
Increasing the substrate concentration will increase the rate of activity to a certain point until it levels off.
With more substrate molecules available, the rate increases.
But once there are enough substrate molecules for all the enzymes, increasing the concentration more will have no effect on the rate.
How is rate of reaction calculated?
Rate of reaction = change in mass ÷ change in time
Name three digestive enzymes
Amylase, Protease, Lipase
What do digestive enzymes do?
Speed up the breakdown of large, insoluble food molecules into smaller, soluble molecules, small enough to be absorbed into the bloodstream.
What can digestive molecules be used to construct?
Lipids, proteins, carbohydrates
What is the purpose of amylase?
Amylase breaks down starch into its constituent simple sugars (predominantly maltose).
Where is amylase produced?
Small intestine, pancreas, salivary glands
Where are the active sites of amylase?
Salivary glands, small intestine
What is the purpose of protease?
Proteases break down proteins into amino acids.
Where are the active sites of protease?
Stomach, small intestine
Where are proteases produced?
Pancreas, small intestine, stomach
What is the purpose of Lipase?
Lipase breaks down lipids into a molecule called glycerol and fatty acids.
Where is Lipase produced?
Small intestine, pancreas
Recall steps in the reaction between an enzyme and substrate
Substrate binds to the complementary active site of the enzyme like a lock and key
This forms and enzyme substrate complex
The substrate is then broken down and products are released
What is diffusion
Where molecules move across a PARTIALLY PERMEABLE MEMBRANE from an area of high to an area of low concentration
What is active transport
Movement of molecules across a partially permeable membrane from an area of low to an area of high concentration (requires energy)
What is osmosis
Net movement of particles from an area of high to an area of low concentration across a partially permeable membrane
