Terminology
What is -ase?
Common names of enzymes end in this
What is Optimum?
The temperature or pH at which an enzyme is most functional
What is Effector or regulator?
Small molecules that alter activity of enzyme.
What is a cofactor in enzyme activity?
A cofactor is a non-protein chemical compound that helps an enzyme function properly. It can be a metal ion or an organic molecule.
What are enzymes made of?
Enzymes are mostly proteins made up of amino acids. Some may have non-protein parts like cofactors or coenzymes.
What is apoenzyme and cofactor
Holoenzymes are made up of these two components.
What is Lock-and-Key model?
in this model, the active site has a well defined shape that is complementary to the substrate
What is irreversible inhibitor?
Binds tightly to enzyme and permanently inhibits enzyme activity.
Q: What is the difference between a cofactor and a coenzyme?
A: A coenzyme is a specific type of organic cofactor (like vitamins), while cofactors can be either inorganic ions (like Zn²⁺ or Fe²⁺) or organic molecules.
What is the function of amylase in the human body?
Amylase breaks down starch (a carbohydrate) into simpler sugars like maltose. It is found in saliva and the pancreas.
What is cofactor?
Metal ions are examples of this protein required for an enzymes functional activity.
What is activation energy?
The barrier a reaction needs to cross to go to completion.
What is noncompetitive inhibitor?
Inhibitor that binds and alters shape of active site.
Q: Name one metal ion that commonly acts as a cofactor for enzymes.
A: Magnesium ion (Mg²⁺) is a common cofactor, especially for enzymes involved in ATP-related reactions.
Which enzyme is responsible for breaking down proteins in the stomach?
Pepsin is the main enzyme in the stomach that breaks down proteins into peptides. It works best in acidic conditions.
What is active site?
The site at which at substrate binds to an enzyme
What is enzyme-substrate complex?
Intermediate formed when substrate binds to active site
Explain denaturation
Denaturation is a process where a protein, like an enzyme, loses its three-dimensional structure, which is essential for its function. When this shape is disrupted, the enzyme can no longer bind to its substrate or carry out its job.
Q: What is a prosthetic group in relation to enzymes?
A prosthetic group is a tightly or permanently bound cofactor to an enzyme that is essential for its activity (e.g., heme in hemoglobin or cytochromes).
Why do enzymes in the human body function best at around 37°C?
Human enzymes evolved to work optimally at body temperature (around 37°C). Higher or lower temperatures can disrupt the enzyme’s shape (denature it), reducing its activity.
What is acetylcholinesterase?
The enzyme that hydrolyzes the ester bond of the neurotransmitter involved in muscle contraction.
What is Hyperbolic?
The shape shown in the graph of changing substrate concentration vs. rate.
What is competitive?
molecules that bind to an enzyme's active site, mimicking the substrate and preventing the actual substrate from binding and undergoing a reaction
Explain how cofactors influence the enzyme's active site and reaction rate.
Cofactors can alter the shape or charge of the enzyme's active site, making it more suitable for substrate binding. This helps stabilize the transition state, reduce activation energy, and thus increase the reaction rate.
How does the enzyme lactase function in the human digestive system, and what happens when it's deficient?
Lactase is produced in the small intestine and breaks down lactose (milk sugar) into glucose and galactose for absorption. When lactase is deficient, it leads to lactose intolerance, causing symptoms like bloating, gas, and diarrhea after consuming dairy.