1.
What is metabolism?
Correct Answer
A. All of the chemical reactions in an organism
Explanation
Metabolism refers to all the chemical reactions that occur within an organism. These reactions include both the breakdown of complex molecules into simpler ones (polymer to monomer reactions) that release ATP, as well as the synthesis of complex molecules from simpler ones (monomer to polymer reactions) that require ATP. Therefore, the correct answer is "All of the chemical reactions in an organism."
2.
What is catabolism?
Correct Answer
B. Polymer to monomer reactions that release ATP and break down
Explanation
Catabolism refers to the process of breaking down complex molecules into simpler molecules. In this case, the correct answer states that catabolism involves polymer to monomer reactions, where larger molecules are broken down into smaller units. This process releases ATP, which is the energy currency of cells. Therefore, the correct answer accurately describes catabolism as the breakdown of polymers into monomers, releasing ATP in the process.
3.
What is anabolism?
Correct Answer
C. Monomer to polymer reactions that require ATP and build up
Explanation
Anabolism refers to the metabolic process in which smaller molecules, known as monomers, are combined to form larger molecules, known as polymers. This process requires the input of energy in the form of ATP and is responsible for building up complex molecules such as proteins, nucleic acids, and carbohydrates. Therefore, the correct answer is "Monomer to polymer reactions that require ATP and build up."
4.
What is adenosine made of?
Correct Answer
D. Adenine and ribose
Explanation
Adenosine is a nucleoside composed of adenine, a nitrogenous base, and ribose, a pentose sugar. Adenine is a purine base, while ribose is a five-carbon sugar. Together, they form the structure of adenosine, which is an important component of nucleic acids like DNA and RNA.
5.
How many high energy bonds does ATP have?
Correct Answer
C. 2
Explanation
ATP (adenosine triphosphate) has two high-energy bonds. These bonds are found between the phosphate groups in ATP's molecular structure. When these bonds are broken, energy is released, which is used by cells for various metabolic processes. Therefore, ATP is often referred to as the "energy currency" of the cell.
6.
How many high energy bonds does ADP have?
Correct Answer
B. 1
Explanation
ADP (adenosine diphosphate) has one high energy bond. This bond is found between the second and third phosphate groups in the molecule. When this bond is broken by the enzyme ATP synthase, energy is released, and ADP is converted back into ATP (adenosine triphosphate), which is the primary energy currency of cells. Therefore, ADP has one high energy bond.
7.
How many high energy bonds does AMP have?
Correct Answer
A. 0
Explanation
AMP, or adenosine monophosphate, does not have any high energy bonds. High energy bonds are typically found in molecules such as ATP (adenosine triphosphate), which is the primary energy currency of cells. AMP only contains one phosphate group, while ATP has three, and it is the presence of these additional phosphate groups that give ATP its high energy bonds. Therefore, the correct answer is 0.
8.
Are enzymes proteins?
Correct Answer
B. All of them are, but not all proteins are enzymes
Explanation
This answer is correct because it acknowledges that all enzymes are proteins, but not all proteins are enzymes. Enzymes are a specific type of protein that catalyze chemical reactions in living organisms. However, there are many other types of proteins that perform different functions in the body, such as structural proteins or transport proteins. So while all enzymes are proteins, not all proteins have enzymatic activity.
9.
What do enzymes do?
Correct Answer
B. Speed up chemical reaction
Explanation
Enzymes are biological catalysts that speed up chemical reactions by lowering the activation energy required for the reaction to occur. They do this by binding to the reactant molecules and bringing them closer together, allowing them to collide more frequently and with greater energy. This increases the rate of the reaction without being consumed in the process. Therefore, the correct answer is "Speed up chemical reaction."
10.
What is the substrate?
Correct Answer
E. A and D
Explanation
The substrate refers to the molecule or molecules that undergo a chemical reaction catalyzed by an enzyme. In this context, the substrate would be the reactant(s) that the enzyme acts upon. The correct answer, A and D, suggests that the substrate can be either the products or the reactant(s) themselves.
11.
What is the part of enzyme where the substrate is given an induced (tight) fit?
Correct Answer
D. Active site
Explanation
The active site of an enzyme is the region where the substrate molecule binds and undergoes a chemical reaction. It provides a specific environment and arrangement of amino acids that allows the substrate to fit tightly and interact with the enzyme. This induced fit is crucial for the enzyme to catalyze the reaction effectively, as it brings the substrate molecules into close proximity and facilitates the formation of the transition state. Therefore, the active site is where the substrate is given an induced (tight) fit.
12.
How do enzymes speed up chemical reactions?
Correct Answer
E. B and C
Explanation
Enzymes speed up chemical reactions by lowering the activation energy required for the reaction to occur. They achieve this by binding to the reactant molecules and bringing them closer together, allowing them to interact more easily and increasing the likelihood of a successful reaction. Additionally, enzymes can also stabilize the transition state of the reaction, further lowering the activation energy. The answer B and C is correct because it states that enzymes lower activation energy and we are not entirely sure about the exact mechanism.
13.
What happens if you denature an enzyme?
Correct Answer
C. Change shape of active site, no longer works
Explanation
Denaturing an enzyme refers to the process of altering its structure, usually by exposing it to extreme conditions such as high temperature or extreme pH. This causes the enzyme's active site, which is responsible for binding to the substrate and catalyzing the reaction, to change shape. In this case, the correct answer suggests that the enzyme no longer works because the altered shape of the active site prevents it from effectively binding to the substrate and carrying out the catalytic function.
14.
What is an enzyme inhibitor?
Correct Answer
B. Something that slows down the enzyme
Explanation
An enzyme inhibitor is a substance that slows down the enzyme. It does not completely stop the enzyme or denature it. Instead, it interferes with the enzyme's activity by binding to it and preventing it from carrying out its normal function at its usual rate. This can occur through various mechanisms, such as blocking the active site of the enzyme or altering its structure. By slowing down the enzyme, an inhibitor can regulate the enzyme's activity and control the rate of a biochemical reaction.
15.
What is a competitive inhibitor?
Correct Answer
A. An inhibitor that moves into active site of enzyme
Explanation
A competitive inhibitor is an inhibitor that binds to the active site of an enzyme, preventing the substrate from binding and reducing the enzyme's activity. This type of inhibitor competes with the substrate for binding to the active site. By occupying the active site, the inhibitor physically blocks the substrate from binding and carrying out its normal reaction. This ultimately leads to a decrease in the enzyme's catalytic activity.
16.
How do you overcome the inhibitor?
Correct Answer
D. Increase concentration of substrate
Explanation
To overcome the inhibitor, increasing the concentration of substrate is the correct answer. This is because inhibitors work by binding to the active site of an enzyme, preventing the substrate from binding and inhibiting the enzyme's activity. By increasing the concentration of substrate, there will be more substrate molecules available to bind to the enzyme's active site, effectively outcompeting the inhibitor and allowing the enzyme to function properly.
17.
What is a non-competitive inhibitor?
Correct Answer
E. B and C
Explanation
A non-competitive inhibitor is an inhibitor that binds to a site on the enzyme that is not the active site. This binding causes a change in the conformation of the protein, leading to a decrease in enzyme activity. This type of inhibitor is different from a competitive inhibitor, which competes with the substrate for binding to the active site. A non-competitive inhibitor can be considered a poison because it disrupts the normal functioning of the enzyme. Therefore, the correct answer is B and C.
18.
What are allosteric enzymes?
Correct Answer
C. Enzymes that change shape to toggle between active and inactive
Explanation
Allosteric enzymes are enzymes that change their shape to switch between active and inactive forms. This change in shape is triggered by the binding of a molecule, called an allosteric regulator, to a specific site on the enzyme, known as the allosteric site. The binding of the allosteric regulator causes a conformational change in the enzyme, which either enhances or inhibits its activity. This mechanism allows for the regulation of enzyme activity in response to the concentration of specific molecules in the cell, ensuring that metabolic pathways are finely tuned and balanced.
19.
How do allosteric enzymes become active?
Correct Answer
A. Activator attaches
Explanation
Allosteric enzymes become active when an activator molecule attaches to the enzyme. This binding causes a conformational change in the enzyme's structure, leading to an increase in its catalytic activity. The activator molecule can bind to a specific regulatory site on the enzyme, which is distinct from the active site where the substrate binds. This allosteric regulation allows for the fine-tuning of enzyme activity in response to cellular conditions and metabolic needs.
20.
How do allosteric enzymes become inactive?
Correct Answer
B. Inhibitor attaches
Explanation
When an inhibitor attaches to an allosteric enzyme, it causes a conformational change in the enzyme's structure. This change prevents the enzyme from effectively binding to its substrate and carrying out its catalytic function. As a result, the enzyme becomes inactive and is unable to perform its normal biological role.