intro
Question 1:
What is the term for a detachable co-factor that is an inorganic ion?
Topic: Biochemical Components
Correct Answer: C) Activator
- In the realm of biochemistry, co-factors serve as non-protein chemical compounds that assist with biological chemical reactions.
- When a detachable co-factor is an inorganic ion, it is specifically termed an "activator."
- Thus, the correct answer is C, "Activator".
Question 2:
Which statement about enzymes does not hold true?
Topic: Biochemical Reactions
Correct Answer: D) Enzymes change the nature and properties of final products
- Enzymes are biological catalysts composed of proteins that accelerate biochemical reactions.
- They do this without altering the properties of the end products.
- Therefore, the statement D) "Enzymes change the nature and properties of final products" is incorrect.
Question 3:
What is the typical pH level of human blood?
Topic: Human Physiology
Correct Answer: B) 7.4
- The pH scale ranges from 0 (highly acidic) to 14 (highly alkaline), with 7 being neutral.
- Human blood is slightly alkaline and usually maintains a pH close to 7.4.
- Thus, the correct answer is B, "7.4", the typical pH level of human blood.
Question 4:
How does an increase in substrate concentration affect enzymatic reactions?
Topic: Enzymatic Reactions
Correct Answer: D) It increases the rate of reaction up to a certain limit
- The substrate is the substance on which an enzyme exerts its action.
- An increase in substrate concentration initially leads to an increase in enzymatic reaction rate, but only up to a certain point.
- After this point, further increases in substrate concentration will not lead to an increase in reaction rate.
- Thus, the correct answer is D, "It increases the rate of reaction up to a certain limit".
Question 5:
Under which circumstances would an enzyme fail to carry out its biological function?
Topic: Enzymatic Functions
Correct Answer: D) All of the above
- Enzymes are biological catalysts that require certain elements to be functionally active.
- The absence of a co-factor, an essential component that enables the enzyme to fulfill its function, will render the enzyme inactive.
- An Apoenzyme is an inactive form of an enzyme, typically due to the absence of its cofactor or prosthetic group.
- Activators are also essential for some enzymes to create a suitable active site for the reaction.
- If any of these conditions are not met, the enzyme will not perform its function, making D) "All of the above" the correct answer.
Question 6:
What term describes an enzyme from which its prosthetic group has been detached?
Topic: Enzyme Structure
Correct Answer: C) Apoenzyme
- Enzymes are specialized proteins that speed up biochemical reactions.
- When a prosthetic group (a non-protein component that is tightly or even covalently-bound) is removed, the enzyme becomes an Apoenzyme.
- As such, an Apoenzyme is an inactive enzyme.
- With its cofactor(s) attached, an Apoenzyme transforms into a Holoenzyme, its active form.
- Therefore, the correct answer is C) "Apoenzyme".
Question 7:
What term is used to describe regulatory sites found on enzymes, which are different from active sites?
Topic: Enzymatic Regulation
Correct Answer: D) Allosteric sites
- Enzymes have specific areas, known as active sites, where substrates bind and reactions take place.
- Allosteric sites are different from these active sites and provide a location for the attachment of molecules that can either activate or inhibit enzyme activity.
- These sites play a crucial role in enzyme regulation, and their binding with regulatory molecules can alter the shape of the enzyme, influencing its functionality.
- Therefore, the correct answer is D) "Allosteric sites".
Question 8:
Which of the following describes a key attribute of non-competitive inhibitors?
Topic: Enzyme Inhibition
Correct Answer: B) They establish an enzyme inhibitor complex at a location other than the active site.
- Non-competitive inhibitors can bind to an enzyme simultaneously with the substrate.
- However, they do not bind to the active site where the substrate binds.
- Instead, they bind elsewhere on the enzyme, creating an enzyme inhibitor complex.
- This binding can alter the conformation of the enzyme, preventing it from interacting efficiently with its substrate.
- Thus, option B) "They establish an enzyme inhibitor complex at a location other than the active site" is the correct answer.
Question 9:
What is the name of the enzymes that are involved in the digestion of carbohydrates?
Topic: Enzymes in Digestion
Correct Answer: B) Amylase
- The process of digesting carbohydrates into simple sugars is facilitated by specific enzymes.
- Amylase, released from saliva, initiates the breakdown of dietary carbohydrates.
- Thus, Amylase is the correct answer, option B).
Question 10:
What is the impact on the reaction rate when the enzyme concentration is doubled?
Topic: Enzyme Concentration
Correct Answer: B) The reaction rate doubles.
- Generally, enzymatic reaction rates are directly proportional to enzyme concentration, up to a certain limit.
- This means that if the concentration of the enzyme is doubled, the reaction rate should also double, assuming that there is an excess of substrate.
- Therefore, the correct answer is B) "The reaction rate doubles".
Question 11:
Who is the proponent of the Induced Fit Model?
Topic: Enzyme Models
Correct Answer: B) Koshland
- The Induced Fit Model was proposed as a modification to the more rigid Lock and Key hypothesis of enzyme action.
- This model was brought forth by Koshland in 1958.
- It suggests that the interaction between enzyme and substrate results in conformational adjustments that allow for an optimized binding.
- As such, the correct answer is B) "Koshland".
Question 12:
Enzymes predominantly consist of which of the following?
Topic: Enzyme Composition
Correct Answer: A) Proteins
- Enzymes are known to catalyze a wide array of biochemical reactions.
- Most enzymes identified to date are proteins.
- There are some RNA molecules that function as enzymes, but they are not the norm.
- Therefore, the answer is A) "Proteins".
Question 13:
Which of the following are examples of biologically active proteins?
Topic: Active Proteins
Correct Answer: B) Enzymes
- Biologically active proteins play a variety of roles in cellular processes.
- Among them, enzymes are crucial as they greatly enhance the efficiency of biochemical reactions and are specific to each reaction type.
- These enzymes ensure reactions occur at a speed that supports life.
- As a result, the correct answer is B) "Enzymes".
Question 14:
Which of the following bears a structural resemblance to the substrate?
Topic: Inhibition Mechanisms
Correct Answer: C) Competitive inhibitor
- Inhibitors work in different ways to impede enzymatic reactions.
- A competitive inhibitor is unique in that it shares structural similarities with the substrate.
- This allows it to bind to the active site of the enzyme, but it cannot trigger the catalytic action.
- Thus, the correct answer is C) "Competitive inhibitor".
Question 15:
How do enzymes accelerate the rate of biochemical reactions?
Topic: Enzyme Function
Correct Answer: C) By reducing the activation energy
- Enzymes perform the crucial function of speeding up biochemical reactions.
- They do this by lowering the activation energy required for the reaction to proceed.
- Activation energy is the minimum energy needed for a reaction to occur.
- Therefore, the correct answer is C) "By reducing the activation energy".
Question 16:
In certain reactions, the product itself inhibits the enzyme that catalyzes the reaction. What is this phenomenon called?
Topic: Enzyme Regulation
Correct Answer: D) Feedback inhibition
- Enzymatic reactions are regulated in a variety of ways.
- One of these is feedback inhibition, where the product of the reaction inhibits the enzyme that catalyzed it.
- This serves as a control mechanism, preventing overproduction of the product.
- Hence, the correct answer is D) "Feedback inhibition".
MCQ 17:
From what are all coenzymes derived?
Topic: Coenzyme Origin
Correct Answer: B) Vitamins
- Coenzymes are organic molecules that function alongside enzymes.
- They can be synthesized from a variety of sources.
- Vitamins, in particular, are often precursors to coenzymes.
- Thus, the correct answer is B) "Vitamins".
MCQ 18:
How would you best describe the prosthetic group in an enzyme?
Topic: Prosthetic Groups
Correct Answer: C) Tightly bound co-enzymes
- Enzymes may contain non-protein components known as co-enzymes or prosthetic groups.
- These have distinct roles in the function of the enzyme.
- Prosthetic groups, in particular, are co-enzymes that are tightly bound to the enzyme.
- Therefore, the correct answer is C) "Tightly bound co-enzymes".
MCQ 19:
What is the term for a non-protein part of an enzyme that is covalently and permanently bound?
Topic: Enzyme Components
Correct Answer: A) Prosthetic group
- Enzymes are complex proteins that may have non-protein components.
- These components, if permanently attached to the enzyme, are known as prosthetic groups.
- They play a crucial role in the activity of the enzyme.
- Hence, the correct answer is A) "Prosthetic group".
MCQ 20:
What is the optimum pH for Sucrose?
Topic: Sucrose Optimum pH
Correct Answer: B) 4.5
- Sucrose is a common carbohydrate found in many plants.
- The pH at which Sucrose is the most stable and functional is considered its optimum pH.
- The optimum pH for Sucrose is 4.5, making it most active in this slightly acidic condition.
- Hence, the correct answer is B) "4.5".
MCQ 21:
At what level can the rate of enzyme-controlled reactions increase?
Topic: Enzyme Reaction Rates
Correct Answer: C) Temperature up to the optimum level
- The rate of enzyme-controlled reactions is influenced by various factors, including temperature.
- As the temperature increases, the rate of reaction also increases, up to an optimum level.
- Beyond this optimum temperature, the rate of reaction decreases due to denaturation of enzyme molecules.
- Therefore, the correct answer is C) "Temperature up to the optimum level".
MCQ 22:
Which inhibitors bind permanently to enzymes, altering their structure and activity?
Topic: Enzyme Inhibition
Correct Answer: A) Irreversible inhibitors
- Enzyme activity can be modulated by various types of inhibitors.
- Irreversible inhibitors form a strong, often covalent bond with enzymes, causing permanent changes to their structure and function.
- These changes lead to the loss of catalytic activity, rendering the enzyme non-functional.
- Thus, the correct answer is A) "Irreversible inhibitors".
MCQ 23:
What is the specific feature or site on an enzyme that facilitates the reaction with the substrate?
Topic: Enzyme-Substrate Interaction
Correct Answer: C) Active site
- Enzymes interact with substrates to facilitate biochemical reactions.
- This interaction occurs at a specific location on the enzyme, known as the active site.
- The active site is where the substrate binds and the reaction is catalyzed.
- Therefore, the correct answer is C) "Active site".
MCQ 24:
What is the optimum temperature for the enzymes present in the human body (in degrees Centigrade)?
Topic: Optimum Temperature for Enzymes
Correct Answer: C) 37
- Enzymes exhibit maximum activity at a specific temperature, known as the optimum temperature.
- For the enzymes found in the human body, this temperature is 37°C, which closely matches the normal human body temperature.
- At this temperature, the enzymes work most efficiently to catalyze biochemical reactions.
- Hence, the correct answer is C) "37".
Question 25:
How many distinct regions does the active site of an enzyme consist of?
Topic: Active Site Composition
Correct Answer: A) 2
- The active site of an enzyme, where the substrate binds and the reaction occurs, comprises two distinct regions.
- These include the binding site, which attaches to the substrate, and the catalytic site, where the reaction is accelerated.
- These two regions work together to catalyze the biochemical reaction.
- Thus, the correct answer is A) "2".
Question 26:
What type of proteins are all enzymes classified as?
Topic: Enzyme Structure
Correct Answer: D) Globular proteins
- Enzymes are specialized protein molecules that catalyze biochemical reactions.
- They are primarily classified as globular proteins, exhibiting a compact, spherical form.
- Unlike fibrous proteins, which have elongated structures and are found in muscle and hair, globular proteins have a more rounded shape.
- Therefore, the correct answer is D) "Globular proteins".
Question 27:
What is the term for a cofactor that is permanently and tightly bound to an enzyme?
Topic: Enzyme Cofactors
Correct Answer: C) Prosthetic group
- Enzymes may interact with additional non-protein components, termed cofactors, which can enhance their catalytic activity.
- A prosthetic group is a type of cofactor that is permanently attached to the enzyme molecule.
- Unlike an activator or co-enzyme, which may associate or dissociate with the enzyme, a prosthetic group is persistently bound.
- Hence, the correct answer is C) "Prosthetic group".
Question 28:
What is the optimum temperature for the majority of enzymes in the human body, in degrees Centigrade?
Topic: Optimum Temperature for Enzymes
Correct Answer: A) 37
- Every enzyme has an optimum temperature at which it exhibits peak activity.
- For most enzymes found in the human body, this temperature is 37°C.
- This temperature coincides with the normal body temperature of humans, allowing the enzymes to work most efficiently.
- Thus, the correct answer is A) "37".
Question 29:
What impact does an extreme shift in pH have on enzymes?
Topic: Effect of pH on Enzymes
Correct Answer: B) It causes enzyme destruction
- Enzymes, as catalysts of biochemical reactions, are sensitive to changes in the surrounding pH.
- An extreme change in pH impacts the enzyme's structure, disrupting the bonds that maintain its shape.
- This structural alteration leads to enzyme destruction, which ultimately halts the biochemical reaction it was facilitating.
- Therefore, the correct answer is B) "It causes enzyme destruction".
Question 30:
Which of the following establishes a weak connection with an enzyme?
Topic: Enzyme Inhibition
Correct Answer: C) Reversible inhibitor
- Enzyme activity can be influenced by various molecules, some of which form weak linkages with the enzyme.
- A reversible inhibitor is one such molecule, which forms a temporary and weak bond with the enzyme.
- Unlike a co-factor, prosthetic group, or irreversible inhibitor, which tightly bind to the enzyme, a reversible inhibitor's bond can be easily broken.
- Consequently, the correct answer is C) "Reversible inhibitor".
Question 31:
What factor is enzymatic reactions most sensitive to?
Topic: Factors Affecting Enzymatic Reactions
Correct Answer: C) pH
- Various factors influence the rate of enzymatic reactions, including enzyme and substrate concentrations, temperature, and pH.
- pH is one of the most critical factors, with even minor changes potentially inhibiting or completely stopping an enzymatic reaction.
- This is because pH changes can ionize the amino acids at the enzyme's active site, disrupting its ability to bind to the substrate.
- Hence, the correct answer is C) "pH".
Question 32:
What term describes the non-protein component of an enzyme that is crucial for its functionality?
Topic: Enzyme Cofactors
Correct Answer: D) Cofactor
- Enzymes are composed of protein parts and sometimes non-protein parts.
- These non-protein parts are known as cofactors, and they're essential for the enzyme's activity.
- Together with the apoenzyme (the protein part), the cofactor forms a fully functional holoenzyme.
- Therefore, the correct answer is D) "Cofactor".
Question 33:
What is the term for the reactant in enzymatic reactions?
Topic: Enzyme Substrates
Correct Answer: B) Substrate
- The substances on which enzymes act in biochemical reactions have a specific name.
- Such a substance is identified as a substrate, which interacts with the enzyme's active site.
- The enzyme catalyzes the conversion of the substrate into the product.
- Hence, the correct answer is B) "Substrate".
Question 34:
What is the origin of all coenzymes?
Topic: Origin of Coenzymes
Correct Answer: D) Vitamins
- Coenzymes are a type of cofactor, which are loosely attached to the protein part of an enzyme.
- They play a vital role in the function of the enzyme and are derived from specific nutrients.
- Coenzymes are closely associated with vitamins, which are their essential raw material.
- Thus, the correct answer is D) "Vitamins".
Question 35:
What term is used to describe an activated enzyme composed of a polypeptide chain and a cofactor?
Topic: Enzyme Activation
Correct Answer: C) Holoenzyme
- An enzyme can be composed of a polypeptide chain and a cofactor.
- When these two components combine, they create an activated enzyme.
- This activated enzyme is referred to as a holoenzyme.
- Therefore, the correct answer is C) "Holoenzyme".
Question 36:
What is the term used for a non-protein part that aids in efficient enzyme functioning?
Topic: Enzyme Helpers
Correct Answer: B) Cofactor
- Enzymes sometimes require additional components for optimal functionality.
- These components, which are not proteins, aid biochemical transformations in the enzyme.
- These helper non-protein parts are referred to as cofactors.
- Hence, the correct answer is B) "Cofactor".
Question 37:
What term describes a three-dimensional globular protein?
Topic: Protein Structure
Correct Answer: D) Enzyme
- Proteins can have various forms and configurations.
- One such form is a three-dimensional globular structure.
- Enzymes are an example of proteins that typically have this structure.
- Consequently, the correct answer is D) "Enzyme".
Question 38:
How do enzymes influence the rate of reactions?
Topic: Enzyme Function
Correct Answer: C) By reducing the activation energy
- One of the fundamental roles of enzymes in biochemical reactions is to alter reaction rates.
- Enzymes achieve this by interacting with the reactants of the reaction.
- The key to this process is the reduction of the activation energy which makes the reaction proceed faster.
- Thus, the correct answer is C) "By reducing the activation energy".
Question 39:
Where can you find the enzymes involved in cellular respiration within a cell?
Topic: Enzyme Location
Correct Answer: B) Mitochondria
- Enzymes play crucial roles in various cellular processes, including cellular respiration.
- The location of these enzymes is directly tied to where the processes occur in the cell.
- Cellular respiration is a process that primarily occurs in the mitochondria of cells.
- Therefore, the correct answer is B) "Mitochondria".
Question 40:
What term is used to describe the small portion of an enzyme where catalytic activity is confined?
Topic: Enzyme Structure
Correct Answer: C) Active site
- The structure of an enzyme is complex, but its function is often localized to a specific area.
- This area is where the enzyme interacts with its substrate to catalyze a biochemical reaction.
- This specific region is referred to as the active site of the enzyme.
- Hence, the correct answer is C) "Active site".
Question 41:
As the concentration of an enzyme is incrementally raised, what impact does this have on the reaction rate?
Topic: Enzyme Concentration
Correct Answer: C) It escalates until reaching a plateau, after which it remains steady
- The concentration of an enzyme can directly influence the rate of a biochemical reaction.
- As the enzyme concentration increases, the reaction rate typically escalates.
- However, once a certain concentration level is reached, the reaction rate tends to stabilize and does not increase further.
- This saturation point indicates that all enzymes are engaged in the reaction and adding more doesn't enhance the rate.
- Therefore, the correct answer is C) "It escalates until reaching a plateau, after which it remains steady".
Question 42:
Who proposed the lock and key model?
Topic: Enzyme Mechanism
Correct Answer: B) Emil Fischer
- The lock and key model is a fundamental concept in the study of enzymology.
- This model illustrates how enzymes and substrates interact, emphasizing the specificity of enzymes.
- Emil Fischer, a German chemist, proposed this model in 1894.
- Hence, the correct answer is B) "Emil Fischer".
Question 43:
Competitive inhibitors share structural similarities with which of the following?
Topic: Enzyme Inhibition
Correct Answer: C) Substrate
- Competitive inhibitors are substances that interrupt enzymatic activity.
- Their mode of action involves competing with the substrate for the active site of the enzyme.
- To compete effectively, they possess structural similarities with the substrate which facilitates their binding to the active site.
- Therefore, the correct answer is C) "Substrate".
Question 44:
What are the reactants that enzymes act upon called?
Topic: Enzyme-Substrate Interaction
Correct Answer: C) Substrates
- Enzymes are catalysts that accelerate chemical reactions within the cell.
- They operate by binding to certain reactants, which are referred to as substrates.
- Each enzyme potentially interacts with one or more substrates, depending on the distinct chemical reaction involved.
- Hence, the correct answer is C) "Substrates".
Question 45:
What is the primary influence of inhibitors on the catalytic activity of enzymes?
Topic: Enzyme Inhibition
Correct Answer: C) They decrease the reaction rate
- Inhibitors are molecules that interfere with enzymatic activity.
- They accomplish this by either occupying the active sites or disrupting the globular structure of the enzymes.
- This interaction typically results in a decrease in the reaction rate.
- Therefore, the correct answer is C) "They decrease the reaction rate".