Chem finals exam

Provide an analogy for an enzyme with relative specificity.

An analogy for an enzyme with relative specificity is a multi-bit screwdriver that can fit multiple types of screws, showing the enzyme can work with various similar substrates.

How can an enzyme be compared to a robot on a factory assembly line?

An enzyme is like a robot that can speed up the assembly of a car without getting worn out, similarly to how an enzyme accelerates biochemical reactions without being consumed.

What does an enzyme's provision of an alternative pathway equate to when crossing a mountain?

An enzyme providing an alternative pathway is like a tunnel through a mountain that allows easier crossing without changing the start and end points, analogous to an enzyme offering a pathway with lower activation energy.

Explain what an 'Inhibitor' is.

An inhibitor is a molecule that decreases the activity of an enzyme by binding to it and interfering with its ability to catalyze a chemical reaction.

How can an inhibitor be visualized in a real-world scenario?

An inhibitor is like a roadblock or detour sign on a highway that prevents traffic from reaching its destination efficiently.

How can competitive inhibition be visualized using an everyday analogy?

Competitive inhibition is like two people trying to fit through a doorway at the same time, where one person blocks the other from entering.

What is 'Competitive Inhibition'?

Competitive inhibition occurs when an inhibitor competes directly with the substrate for binding to the active site of an enzyme. It can often be overcome by increasing the concentration of the substrate.

True or False: An enzyme is consumed in the chemical reaction it catalyzes.

False. Enzymes are not consumed in the reactions they catalyze; they remain unchanged after the reaction.

Describe what would happen to the rate of a biochemical reaction if the enzyme was absent.

If the enzyme was absent, the rate of a biochemical reaction would significantly decrease, as the activation energy required for the reaction to proceed would be much higher, leading to a slower rate of reaction or no reaction at all.

Describe irreversible inhibition using an everyday analogy.

Irreversible inhibition is like gluing a lock shut, making it impossible for any key to unlock it.

What does 'Irreversible Inhibition' entail?

Irreversible inhibition occurs when an inhibitor permanently binds to an enzyme, often forming a covalent bond, and permanently deactivates the enzyme.

Explain the concept of isozymes and provide a scenario where they might be relevant.

Isozymes are different forms of the same enzyme that exist within an organism and can have slightly different structures and regulatory properties. They are relevant in scenarios where different tissues require subtly different enzyme activities, such as the different isozymes of lactate dehydrogenase found in heart and liver tissues.

If a protease enzyme can work on several peptide bonds in different proteins, is it demonstrating absolute or relative specificity?

It is demonstrating relative specificity, as it can catalyze reactions on various substrates (the different peptide bonds), akin to a master key used for different doors.

Explain how an enzyme speeds up a reaction using the metaphor of oiling a door hinge.

Just as oil on a hinge makes a door open more easily, an enzyme lowers the activation energy required for a reaction, making it proceed more rapidly.

How is an enzyme similar to an origami structure?

Just like an origami's shape determines its function, the three-dimensional structure of an enzyme determines its ability to bind to substrates and catalyze reactions.

How is an enzyme's action similar to a key opening multiple locks?

Like a key that can unlock many locks without changing its shape or becoming a part of the door, an enzyme can catalyze many reactions repeatedly without being consumed or altered permanently.

Why is relative specificity advantageous in certain biological processes like digestion?

Relative specificity is advantageous in digestion because it allows enzymes to break down a variety of similar food molecules, similar to how a master key can conveniently open multiple locks within a set.

What is relative specificity when discussing enzymes?

Relative specificity refers to an enzyme's ability to act on a range of substrates that are similar in structure, much like a master key that can open several locks.

What is 'Reversible Inhibition'?

Reversible inhibition involves an inhibitor binding temporarily to an enzyme, which can dissociate from the enzyme, restoring enzyme activity.

Provide an analogy for reversible inhibition.

Reversible inhibition is like using a temporary barrier to block a parking spot, which can be removed to allow cars to park again.

What is the 'Active Site' of an enzyme?

The active site is the specific region on an enzyme where the substrate binds and the chemical reaction occurs.

What everyday item can represent the active site of an enzyme?

The active site of an enzyme is like a specific docking station on a space station where only certain spacecraft can dock and unload their cargo.

If an enzyme acts on glucose and only glucose, what type of specificity does it display?

The enzyme displays absolute specificity because it acts exclusively on glucose, analogous to a key crafted for a single lock.

What is the primary function of an enzyme?

The primary function of an enzyme is to accelerate (catalyze) chemical reactions within the body.

What term is used to describe the substance that an enzyme acts upon?

The substance on which an enzyme acts is called the substrate.

How does a round trip to the store, regardless of transportation method, relate to an enzyme's conservation of net energy in a reaction?

Whether walking or cycling (like using an enzyme), the total distance (net energy change) of a round trip to the store remains the same, demonstrating that an enzyme doesn't alter the overall energy balance of the reaction.

How does using a ramp to load goods onto a truck illustrate an enzyme's function?

A ramp lowers the effort needed to load heavy goods onto a truck, much like an enzyme lowers the activation energy needed for a chemical reaction without altering the overall energy required to complete the task.

Where does a substrate bind on an enzyme?

A substrate binds at the active site of an enzyme.

How can the concept of a substrate be explained with a simple analogy?

A substrate is like a key to a car's ignition, where turning the key starts the engine, analogous to the substrate binding and reacting at the enzyme's active site.

Define 'Substrate'.

A substrate is the molecule upon which an enzyme acts. The substrate binds to the enzyme's active site, where the chemical reaction is catalyzed.

How does the concept of absolute specificity impact the efficiency of an enzyme?

Absolute specificity ensures that an enzyme is highly efficient at catalyzing its specific reaction, preventing unwanted side reactions, similar to how a precise key smoothly opens a particular lock without fitting into or turning any others.

What does absolute specificity mean in terms of an enzyme's function?

Absolute specificity means that an enzyme can only catalyze a reaction with one specific type of substrate, similar to a key that only opens one specific lock.

Define allosteric regulation in the context of enzyme activity.

Allosteric regulation is when a molecule binds to an enzyme at a site other than the active site, causing a change in the enzyme's shape and, subsequently, its activity.

What is an analogy for an allosteric site on an enzyme?

An allosteric site can be compared to a light switch that controls the brightness of a light bulb; it isn't the bulb itself but still affects how brightly it can shine.

What is an 'Allosteric Site'?

An allosteric site is a place on an enzyme other than the active site where a molecule can bind, causing a change in the enzyme's shape and activity.

Provide an analogy for an enzyme with absolute specificity.

An analogy for an enzyme with absolute specificity is a key that opens only one specific lock, indicating the enzyme's selectivity for one substrate.

What does enzyme inhibition resemble in everyday life?

Enzyme inhibition is like putting a block in a pipeline, which prevents water from flowing freely.

Define 'Enzyme Inhibition'.

Enzyme inhibition is the process by which a molecule decreases or halts the activity of an enzyme, affecting the enzyme's ability to catalyze reactions.

How does enzyme specificity contribute to the efficiency of metabolic pathways?

Enzyme specificity ensures that enzymes only catalyze their specific reactions, preventing unwanted side reactions and thus contributing to the efficiency and regulation of metabolic pathways.

How do enzymes affect the activation energy of a chemical reaction?

Enzymes lower the activation energy required for a chemical reaction, allowing the reaction to occur more quickly and efficiently.

Can an enzyme with absolute specificity act on multiple substrates?

No, an enzyme with absolute specificity acts only on one type of substrate, just as a key is designed to open only one particular lock.

Could an enzyme that digests different proteins be considered to have absolute specificity?

No, it would have relative specificity because it can act on a range of protein substrates, not just one.

Describe 'Non-Competitive Inhibition'.

Non-competitive inhibition happens when an inhibitor binds to an enzyme at a site other than the active site, causing a change in enzyme shape that makes the active site less effective.

Give an everyday analogy for non-competitive inhibition.

Non-competitive inhibition is similar to a distraction in a theater audience causing an actor on stage to perform poorly, regardless of their access to the stage.

Give an example of enzyme regulation.

One example of enzyme regulation is the inhibition of an enzyme by a molecule that binds to the enzyme at a location other than the active site, known as non-competitive inhibition.