Long Answer Question 3 Flashcards
Definition of E. S. E. I.
- (E)nzyme
- (S)ubstrate
- (E)nzyme substrate complex
- (I)nduced fit model
Enzymes are proteins that speed up chemical reactions in the body. Substrates combine with enzymes at their active site to form an enzyme substrate complex. The active site changes its shape to accommodate its substrates. This is called the induced fit model.
Types (2) of enzymatic reactions
When an enzymatic reaction results in degradation of a substrate into 2 or more products it is called catabolism. If an enzymatic reaction results in the synthesis of its substrates then it is called anabolism.
3 things that impact enzymatic speed and explain how they do so
pH, temperature, and substrate concentration all impact enzymatic speed. Enzymes all have their preferred pH at which they work their best. Changes in pH that stray from an enzyme’s preferred pH can prevent enzymes from working efficiently. Drastic changes in pH can alter an enzyme’s shape and make it unable to combine with substrates. When temperatures rise, more collisions occur between enzymes and substrates causing enzyme activity to increase. After a certain point, depending on what the enzyme is, enzyme activity levels out and then declines rapidly. This is because the enzyme becomes denatured due to the rise in temperature. Enzyme activity increases when substrate concentration increases because there are more collisions between substrate molecules and enzymes. However, when all enzyme active sites are filled continuously with substrate, the activity rate has reached its maximum rate.
Name 2 things that help enzymes function. Explain a component of one of these things.
Inorganic ions or organic non-proteins that help enzymes function properly are called cofactors. Coenzymes are organic, non-protein molecules that also help enzymes function properly. Vitamins from our diet can contribute to components of our coenzymes.
- define enzyme inhibition
- state the three types
- explain each type
- explain how poisons can also inhibit enzymes
Enzyme inhibition is when a substrate cannot bind to the active site of an enzyme. Competitive inhibition, feedback inhibition, and allosteric inhibition are three different types of enzyme inhibition. Competitive inhibition is when an inhibitor similar to the intended substrate binds to an enzyme’s active site, preventing the intended substrate from binding to the enzyme. Feedback inhibition is when a large amount of product has built up and binds to an enzyme’s active site, preventing substrates from binding to the active sites until the product is used up. Allosteric inhibition is when an inhibitor binds to the side of the enzyme without the active site. This inhibitor changes the shape of the active site and prevents the enzyme from forming a substrate complex. Poisons can also inhibit enzymes. For example, penicillin prevents active sites from being used to construct the cell walls of bacteria.
- explain the different enzymes(9) that break down our food. group your explanation by the macromolecules they help break down
There are several enzymes that work in the digestive system to speed up the breakdown of food into the four macromolecules (carbohydrates, proteins, fats, and nucleotides). Salivary amylase, pancreatic amylase, and maltase are produced in the salivary glands, pancreas, and small intestine respectively. They all interact with the food we consume to speed up the breakdown of our food into carbohydrates. Pepsin, trypsin, and peptidases interact with the food we consume to speed up the breakdown of our food into proteins. Lipase speeds up the breakdown of food into glycerol and fatty acids. Finally, nuclease and nucleosidases speed up the breakdown of our food into nucleotides and then into bases, sugars, and phosphates.
TO SUMMARIZE, the enzymes in our digestive tracts are all part of the hydrolysis chemical reactions occurring in our digestive system.
- explain the two hormones that affect our glucose levels (including where they are produced and how they affect glucose levels)
- explain the other hormone produced in the same place the above hormones are produced
Insulin and glucagon are two hormones secreted by the pancreas. Insulin stimulates cells to take up glucose. In the liver, this stimulation causes glucose to be stored as glycogen. Adipose tissue uses glucose to form fat. These two events cause blood glucose levels to drop. Just before glucose levels drop beyond normal levels, glucagon stimulates the liver to break down glycogen into glucose. Adipose tissues are stimulated to break down fat into glycerol and fatty acids. This glycerol is converted to glucose by the liver. Blood glucose levels now begin to rise. Somatostatin is also secreted by the pancreas. It is known as a growth hormone inhibitor. In the digestive tract, its overall effect decreases the absorption of nutrients.
explain the chemical reactions that occur in the liver
The liver, a structure belonging to the digestive system, is responsible for maintaining blood glucose levels. It does so through chemical reactions involving glucose and glycogen. When the blood glucose levels rise in the body, the liver stores glucose as glycogen. When the blood glucose levels lower in the body, it breaks down glycogen back into glucose. This is one example of how chemical reactions occur in the digestive system.
explain how water is important in the digestive system (3)
- Water is essential to the digestive system because it is a reactant in every digestive reaction. The hydrolysis reactions that occur in our digestive system would not be possible without water.
- Saliva is also mostly made of water. It helps keep the mouth moist and contains salivary amylase, which begins starch digestion.
- Finally, water is a component of gastric, intestinal, and pancreatic juice.
list all of the subtopics(9) to elaborate on for question 3 of the long answer. you may look at the long answer handout for hints!
- definitions (E.S.E.I.)
- types of enzymatic reactions (supplementary drawing)
- factors that affect of enzymatic speed
- things that help enzymes function
- enzyme inhibition
- enzymes of the digestive system
- hormones
- chemical reactions
- importance of water
supplementary drawings: draw a synthesis and degradation reaction that uses an enzyme
refer to page 160 of your textbook
