Enzyme Function and Metabolic Pathways
42 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is a ribozyme?

  • An RNA molecule that can act as an enzyme (correct)
  • A ribonucleotide sequence that catalyzes reactions
  • A carbohydrate that functions as a catalyst
  • A type of protein enzyme

What effect does increased CO2 concentration have on blood acidity?

  • It neutralizes blood acidity
  • It causes the blood to become more acidic (correct)
  • It has no effect on blood acidity
  • It makes the blood alkaline

What does the Michaelis-Menten constant (Km) indicate?

  • The concentration of substrate at which reaction velocity is half of Vmax (correct)
  • The rate of reaction at maximum substrate concentration
  • The total number of enzyme-substrate complexes formed
  • The effectiveness of an enzyme inhibitor

Why do some scientists believe early protocells were RNA-based?

<p>RNA can perform multiple roles, including self-replication and catalysis (C)</p> Signup and view all the answers

What was a significant obstacle faced by Maude Menten during her studies?

<p>She faced gender discrimination preventing her from conducting research in Canada (A)</p> Signup and view all the answers

What effect does ethanol have on the NMDA receptor?

<p>It inhibits its function. (B)</p> Signup and view all the answers

Which statement correctly describes the characteristics of non-competitive inhibition?

<p>Vmax is lower and Km is unchanged. (C)</p> Signup and view all the answers

Which of the following is an example of competitive inhibition?

<p>Cocaine competing with dopamine at the re-uptake receptor. (C)</p> Signup and view all the answers

What is a primary function of membranes in relation to enzymes?

<p>Membranes help compartmentalize products from substrates. (A)</p> Signup and view all the answers

How are membrane proteins typically produced?

<p>In the Golgi apparatus after being synthesized. (A)</p> Signup and view all the answers

What was Buchner's contribution to the understanding of fermentation?

<p>He showed that it could occur without living cells using zymase. (A)</p> Signup and view all the answers

What does the term 'induced fit' refer to in enzyme function?

<p>The enzyme's shape is modified to fit the substrate upon binding. (C)</p> Signup and view all the answers

What factors can influence the rate of enzyme-controlled reactions?

<p>Temperature, pH, and concentration of both enzyme and substrate. (D)</p> Signup and view all the answers

Which of the following statements about enzymes is accurate?

<p>Enzymes can be saturated and are unchanged by reactions. (C)</p> Signup and view all the answers

What role do cofactors play in enzyme activity?

<p>They assist enzymes in catalyzing reactions. (A)</p> Signup and view all the answers

Which of the following is true about lysozyme?

<p>It can kill bacteria by hydrolyzing complex sugars. (D)</p> Signup and view all the answers

How does lysozyme interact with its substrate?

<p>By destabilizing the substrate and lowering the activation energy. (A)</p> Signup and view all the answers

What is a coenzyme and provide an example?

<p>An organic cofactor; e.g., NAD+ or B vitamins. (A)</p> Signup and view all the answers

What is indicated by Gibb’s Free Energy in a closed system?

<p>The amount of energy available to do work (D)</p> Signup and view all the answers

What does the First Law of Thermodynamics state?

<p>Energy can only be transformed or transferred (A)</p> Signup and view all the answers

How does the Second Law of Thermodynamics relate to cellular processes?

<p>It implies that energy input is necessary to prevent disorder (B)</p> Signup and view all the answers

What is the relationship between activation energy and enzyme-catalyzed reactions?

<p>Enzymes lower activation energy to facilitate reactions (B)</p> Signup and view all the answers

What role do genes play in metabolism?

<p>Genes regulate which proteins are synthesized, influencing metabolism (D)</p> Signup and view all the answers

What concept did Erwin Schrödinger introduce regarding living cells?

<p>Living systems can reverse entropy through energy flow (D)</p> Signup and view all the answers

What does end product inhibition achieve in metabolic pathways?

<p>It prevents excessive production of metabolites (D)</p> Signup and view all the answers

What primarily composes most enzymes?

<p>Proteins (C)</p> Signup and view all the answers

What phenomenon does diffusion illustrate regarding physical laws?

<p>Order can emerge from chaos. (B), Highly ordered processes stem from randomness. (D)</p> Signup and view all the answers

In an exergonic reaction, what happens to electrons?

<p>They move to a lower energy level. (D)</p> Signup and view all the answers

What process is described by the term 'oxidation' in the context of electrons?

<p>Electron loss. (B)</p> Signup and view all the answers

Which of these correctly defines metabolism?

<p>All the chemical reactions that occur within a cell. (A)</p> Signup and view all the answers

What is the primary role of enzymes in metabolic reactions?

<p>To reduce the energy required for the reactions. (D)</p> Signup and view all the answers

Which statement correctly differentiates between catabolic and anabolic reactions?

<p>Anabolic reactions require energy, while catabolic reactions release energy. (A)</p> Signup and view all the answers

What is the relationship between chaos and the laws of physics as indicated in the content?

<p>Chaos at a small scale can give rise to observable ordered phenomena. (C)</p> Signup and view all the answers

What occurs when the state of a cat is observed in the context of quantum mechanics?

<p>It collapses into a single state of being alive. (C)</p> Signup and view all the answers

What is the role of NAD+ in oxidation-reduction reactions?

<p>It binds to enzymes and facilitates the transfer of hydrogen atoms. (B)</p> Signup and view all the answers

Which statement accurately describes the function of enzymes in metabolic pathways?

<p>Enzymes catalyze specific biochemical reactions without being consumed. (C)</p> Signup and view all the answers

What happens to NAD+ during the reaction described in the content?

<p>It gets oxidized to form NADH. (C)</p> Signup and view all the answers

In the described metabolic pathways, which product is formed as an end result?

<p>End product G (C)</p> Signup and view all the answers

How are metabolic pathways generally evolved based on the content provided?

<p>From end products backwards to initial substrates. (C)</p> Signup and view all the answers

What describes the role of enzymes in the process shown in the diagrams?

<p>They function to facilitate the conversion of substrates into intermediates. (C)</p> Signup and view all the answers

What is the primary function of energy-rich molecules in metabolic pathways?

<p>To provide the energy needed for cellular processes. (A)</p> Signup and view all the answers

Which intermediate substrate is associated with the enzyme pathway described?

<p>Intermediate substrate A (A)</p> Signup and view all the answers

Flashcards

Gibbs Free Energy

The amount of energy available to do work in a closed system at fixed temperature and pressure.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transferred or transformed.

Second Law of Thermodynamics

Every energy transfer or transformation results in an increase in entropy (disorder).

Entropy

A measure of disorder or randomness in a system.

Signup and view all the flashcards

Open System

A system that exchanges both energy and matter with its surroundings.

Signup and view all the flashcards

Closed System

A system that exchanges only energy with its surroundings, not matter.

Signup and view all the flashcards

ΔG

The change in Gibbs Free Energy during a reaction. A negative ΔG indicates a spontaneous reaction.

Signup and view all the flashcards

Schrödinger's Cat

A thought experiment that illustrates the strangeness of quantum mechanics. It describes a cat that is both alive and dead until observed.

Signup and view all the flashcards

Enzyme-Substrate Complex

A temporary complex formed when a substrate binds to the active site of an enzyme.

Signup and view all the flashcards

Induced Fit

The enzyme's active site changes shape slightly to accommodate the substrate, improving the fit and promoting catalysis.

Signup and view all the flashcards

Activation Energy

The minimum amount of energy required for a reaction to occur.

Signup and view all the flashcards

Cofactor

A non-protein molecule that assists enzymes in carrying out their reactions.

Signup and view all the flashcards

Coenzyme

An organic cofactor that helps enzymes carry out their reactions.

Signup and view all the flashcards

Ligand

A molecule that binds to a specific site on a protein, often an enzyme.

Signup and view all the flashcards

Enzymes and Temperature

Enzymes have an optimal temperature at which they work best. Too high or too low temperatures can reduce enzyme activity.

Signup and view all the flashcards

Enzymes and pH

Enzymes have an optimal pH at which they work best. Extremes in pH can disrupt enzyme structure and activity.

Signup and view all the flashcards

What is a ribozyme?

A ribozyme is a type of RNA molecule that can act as an enzyme. Enzymes are proteins that speed up chemical reactions.

Signup and view all the flashcards

What is an enzyme?

An enzyme is a biological catalyst, a substance that speeds up a chemical reaction without being consumed in the process.

Signup and view all the flashcards

What is the Michaelis-Menten constant (Km)?

The Michaelis-Menten constant (Km) is a measure of how well an enzyme binds to its substrate. A lower Km indicates a stronger binding affinity.

Signup and view all the flashcards

What is the effect of CO2 on blood acidity?

CO2 dissolves in blood to form carbonic acid (H2CO3), which releases hydrogen ions (H+). This increases blood acidity, making it more acidic.

Signup and view all the flashcards

Why is it important to breathe faster when blood becomes acidic?

Breathing faster helps to remove CO2 from the blood. As CO2 is removed, the blood becomes less acidic (more alkaline).

Signup and view all the flashcards

Chaos Theory in Physical Laws

Many physical laws that appear ordered on a large scale are actually due to random events at a smaller scale. For example, diffusion, which seems highly organized, is just the result of molecules moving randomly.

Signup and view all the flashcards

Redox Reactions and Energy Levels

In redox reactions, electrons move between molecules. When electrons move to a higher energy level, the reaction is endergonic (requires energy). When electrons move to a lower energy level, the reaction is exergonic (releases energy).

Signup and view all the flashcards

Oxidation

Oxidation is the loss of electrons from a molecule. This often involves electrons moving closer to a more electronegative atom, like oxygen.

Signup and view all the flashcards

ATP in Metabolism

ATP is a high-energy molecule that is used to power cellular processes. It is used in both catabolic (breaking down) and anabolic (building up) reactions.

Signup and view all the flashcards

Catabolic Reactions

Catabolic reactions break down large molecules into smaller ones, releasing energy in the process. Think of it like breaking down a complex meal into simpler components.

Signup and view all the flashcards

Anabolic Reactions

Anabolic reactions build up large molecules from smaller ones, requiring energy to do so. Think of it like putting together blocks to make a larger structure.

Signup and view all the flashcards

Enzymes and Metabolism

Enzymes are biological catalysts that speed up metabolic reactions. They do this by lowering the activation energy needed to start the reaction.

Signup and view all the flashcards

Metabolic Pathway

A series of connected biochemical reactions where the product of one reaction serves as the substrate for the next.

Signup and view all the flashcards

Intermediate Substrate

A molecule produced during a metabolic pathway, serving as the input for the next step.

Signup and view all the flashcards

End Product Inhibition

The product of a metabolic pathway inhibits an enzyme earlier in the process, controlling the pathway's speed.

Signup and view all the flashcards

Oxidation-Reduction Reaction

A reaction involving the transfer of electrons from one molecule (oxidation) to another (reduction).

Signup and view all the flashcards

NAD+

A common cofactor that carries electrons in oxidation-reduction reactions.

Signup and view all the flashcards

NADH

The reduced form of NAD+, carrying electrons and energy from a reaction.

Signup and view all the flashcards

Enzyme Binding Site

A specific region on an enzyme where a substrate binds to initiate catalysis.

Signup and view all the flashcards

Competitive Inhibition

A type of enzyme inhibition where the inhibitor competes with the substrate for the active site, preventing the substrate from binding and reducing the reaction rate.

Signup and view all the flashcards

Non-competitive Inhibition

A type of enzyme inhibition where the inhibitor binds to a site other than the active site, changing the enzyme's shape and reducing its activity.

Signup and view all the flashcards

Ethanol's Effect on NMDA Receptor

Ethanol binds to the NMDA receptor, a type of glutamate receptor involved in learning and memory, impacting brain function and leading to the effects of intoxication.

Signup and view all the flashcards

Metabolic Pathways and Membranes

Metabolic pathways, a series of enzyme-catalyzed reactions, often take place on membranes, which provide compartmentalization and a dynamic environment for efficient reactions.

Signup and view all the flashcards

Examples of Non-competitive Inhibition

Some examples include silver, lead, and mercury binding to disulfide bridges in proteins, strychnine blocking the glycine receptor, and penicillin blocking the enzyme DD-transpeptidase.

Signup and view all the flashcards

Study Notes

Enzyme Function

  • Enzymes are organic catalysts, primarily proteins (sometimes RNA)
  • Enzymes are specific, meaning they catalyze specific reactions
  • Enzymes can become saturated with substrate
  • Enzymes are unchanged by participating in reactions
  • Enzymes function within a narrow range of optimal conditions
  • Cofactors and coenzymes help enzymes in their reactions
  • Cofactors are non-protein helpers, e.g., zinc, iron
  • Coenzymes are organic cofactors, e.g., NAD+, and B vitamins
  • Enzymes usually work better in the presence of a cofactor or coenzyme
  • Substrates bind to active sites on enzymes allowing chemical reactions to be sped up. Enzyme-substrate complex (ES).
  • Proteins, including enzymes, are flexible, allowing substrates to bind. This is called induced fit
  • Enzymes catalyze reactions by lowering the activation energy
  • Many enzymes work together in metabolic pathways that are frequently associated with membranes.

Metabolic Pathways

  • Metabolic pathways are series of enzyme-catalyzed reactions that build up (anabolism) or break down (catabolism) molecules
  • Metabolic pathways often occur in sequential stages, increasing the speed and efficiency of the process
  • Membranes help to compartmentalize metabolic products so that the reaction rates stay high. The membranes are usually complex and dynamic structures. Membrane proteins are made in the Golgi body.

Enzyme Inhibition

  • Enzyme inhibition is the process of altering the natural action of an enzyme -Competitive inhibitors resemble the substrate and bind to the active site preventing the substrate from binding -Noncompetitive inhibitors bind to an allosteric site which changes the shape of the enzyme so it can no longer bind to the substrate.

Enzyme Kinetics

  • Enzyme kinetics studies how factors affect the rate of enzyme-controlled reactions
  • Factors determining reaction rate (enzyme-kinetics) include enzyme-substrate collisions, enzyme binding ability, substrate concentration, temperature, pH, ionic concentration, and any chemicals that interfere with enzyme shape. -Michaelis-Menten equation is a quantitative description of enzyme kinetics.
  • Km is a measure of how well the enzyme binds the substrate, and Vmax is the maximum rate of reaction.
  • Graphs, such as Lineweaver-Burk plots, are used to visualize enzyme kinetics, and can show the effects of competitive versus non-competitive inhibitors
    • Competitive inhibitors increase KM
    • Non-competitive inhibitors decrease Vmax

Redox Reactions

  • Redox reactions are chemical reactions that involve a transfer of electrons.
  • In oxidation, electrons move away from a molecule, in reduction electrons move toward a molecule. -Oxidation reactions release energy -Reduction reactions absorb energy -Oxidation-reduction reactions can be coupled. Reactions tend to happen as a pair.

Activation Energy

  • Activation energy is the minimum amount of energy needed for a reaction to start and proceed.
  • Enzymes work by lowering the activation energy, and thereby speeding up the reaction
  • This occurs because enzymes orient and hold reactants together, strain their chemical bonds, and provide a favorable chemical environment near the active site.

ATP

  • ATP (adenosine triphosphate) is a high-energy molecule that acts as an energy currency in cells
  • ATP is involved in catabolic anabolic reactions
  • Catabolism is the breakdown of complex molecules into simpler molecules releasing energy that is stored in ATP
  • Anabolism is the energy requiring building up of complex molecules from simpler molecules using the energy stored in ATP

End Product Inhibition

  • End-product inhibition is a regulatory mechanism in which the output of a metabolic pathway inhibits an enzyme earlier in the pathway.
  • End-product inhibition is also called feedback inhibition
  • It helps regulate the rate of reaction of enzymes in metabolic pathways
  • This mechanism ensures that an excess amount of the end product is avoided

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Quiz Team

Related Documents

Enzymes: A Biology Overview PDF

Description

This quiz explores the key aspects of enzyme function and metabolic pathways. It covers concepts such as enzyme specificity, the role of cofactors and coenzymes, and the dynamics of enzyme-substrate interactions. Test your understanding of how enzymes catalyze reactions and their essential role in metabolism.

More Like This

Biochemistry Quiz: Enzymes and Metabolism
81 questions

Biochemistry Quiz: Enzymes and Metabolism

EntrancedAstronomy avatar
EntrancedAstronomy
Biochemistry: Enzymes and Their Functions
16 questions

Biochemistry: Enzymes and Their Functions

RetractableNephrite6474 avatar
RetractableNephrite6474
Metabolic Disorders and Pathways
47 questions

Metabolic Disorders and Pathways

AffirmativePlanet4143 avatar
AffirmativePlanet4143
Biochemistry Enzyme Functions and Metabolism
47 questions

Biochemistry Enzyme Functions and Metabolism

ComplimentaryGenius8542 avatar
ComplimentaryGenius8542
Use Quizgecko on...
Browser
Open
Browser
Browser