Campbell Biology Ch 8 Intro to Metabolism

Metabolism is the totality of an organism's chemical reactions, essential for converting energy and building materials necessary for growth and survival.

Catabolic pathways break down complex molecules to release energy, while anabolic pathways consume energy to build complex molecules from simpler ones.

Bioenergetics studies how energy flows through living organisms, focusing on the transformations and utilizations of energy.

<p>The first law of thermodynamics states that energy cannot be created or destroyed, only transformed or transferred, highlighting the conservation of energy in the universe.</p> Signup and view all the answers

<p>The second law of thermodynamics states that energy transformations are not 100% efficient, meaning organisms cannot infinitely recycle energy.</p> Signup and view all the answers

<p>Kinetic energy is the energy of movement; for example, it is seen when muscles contract to enable movement in organisms.</p> Signup and view all the answers

<p>Enzymes act as catalysts in metabolic pathways, speeding up chemical reactions and regulating metabolic processes.</p> Signup and view all the answers

<p>Potential energy in molecules is based on the arrangement of bonds; breaking and forming bonds during reactions can release or store energy.</p> Signup and view all the answers

<p>The symbol 𝚫 represents 'the difference between' two states, often used to indicate changes in variables such as enthalpy or Gibbs free energy.</p> Signup and view all the answers

<p>ATP hydrolysis during shivering produces heat that helps warm the body, aiding in thermoregulation.</p> Signup and view all the answers

<p>A reaction is spontaneous if 𝚫G is negative; this indicates a release of free energy.</p> Signup and view all the answers

<p>In endergonic reactions, ATP donates a phosphate group to form a phosphorylated intermediate, enabling the reaction to proceed by lowering the free energy requirement.</p> Signup and view all the answers

<p>A positive 𝚫G indicates the reaction is not spontaneous and absorbs free energy.</p> Signup and view all the answers

<p>Exergonic reactions release free energy (negative 𝚫G), while endergonic reactions absorb free energy (positive 𝚫G).</p> Signup and view all the answers

<p>If the energy required (ΔG) for the endergonic reaction is less than the energy released from ATP hydrolysis, the two reactions can be coupled to make the overall reaction exergonic.</p> Signup and view all the answers

<p>At equilibrium, the forward and reverse reactions occur at the same rate, and 𝚫G is minimized.</p> Signup and view all the answers

<p>During ATP hydrolysis, the terminal phosphate group is cleaved off, resulting in ADP and inorganic phosphate, releasing approximately 7.3 kcal of energy.</p> Signup and view all the answers

<p>ATP serves as the energy currency of the cell, releasing energy through hydrolysis to fuel various cellular processes.</p> Signup and view all the answers

<p>Enzymes act as catalysts that lower the activation energy required for chemical reactions, enabling ATP to effectively participate in metabolic processes.</p> Signup and view all the answers

<p>The phosphorylation of ADP to form ATP is an endergonic reaction with a ΔG of +7.3 kcal under standard conditions.</p> Signup and view all the answers

<p>This exergonic reaction releases 686 kcal of energy, indicating that glucose is oxidized to release energy.</p> Signup and view all the answers

<p>A cell at metabolic equilibrium is considered dead, unable to perform necessary chemical reactions.</p> Signup and view all the answers

<p>The phosphate bonds in ATP are referred to as 'high-energy bonds' because breaking them releases significant energy, transitioning ATP into a state of lower energy.</p> Signup and view all the answers

<p>Energy coupling allows cells to harness energy from exergonic reactions to drive endergonic reactions.</p> Signup and view all the answers

<p>ATP powers mechanical work by providing the energy required for movements such as muscle contractions and the action of cilia.</p> Signup and view all the answers

<p>Cellular respiration provides the energy needed to regenerate ATP from ADP and inorganic phosphate through exergonic reactions.</p> Signup and view all the answers

<p>A high 𝚫G indicates an unstable system that is more likely to change toward a stable state.</p> Signup and view all the answers

<p>Temperature contributes to 𝚫G through the term -T𝚫S, affecting spontaneity based on entropy changes.</p> Signup and view all the answers

<p>Spontaneous reactions occur without external input of energy, while catalysts, like enzymes, are required to lower the activation energy for reactions that would otherwise take much longer.</p> Signup and view all the answers

<p>Standard conditions include 1M concentration of reactants/products, 25°C, and pH 7.</p> Signup and view all the answers

<p>A phosphorylated intermediate is a reactive molecule that has gained a phosphate group, facilitating its conversion into a product in energy-coupling reactions.</p> Signup and view all the answers

<p>Activation energy is the initial energy needed to distort reactants into an unstable state, allowing chemical reactions to occur.</p> Signup and view all the answers

<p>Chemical work involves endergonic reactions, transport work refers to moving substances against gradients, and mechanical work includes physical movements like muscle contractions.</p> Signup and view all the answers

<p>ATP is renewable because it can be regenerated from ADP and inorganic phosphate through energy-releasing reactions, particularly during cellular respiration.</p> Signup and view all the answers

<p>The term is misleading because it suggests energy is inherently stored, whereas it's the potential energy released upon bond formation that is significant.</p> Signup and view all the answers

<p>The standard free energy change (ΔG) for the hydrolysis of ATP is approximately -7.3 kcal/mol.</p> Signup and view all the answers

<p>Competitive inhibitors resemble the substrate and compete for the active site, while noncompetitive inhibitors bind to another part of the enzyme, altering its shape.</p> Signup and view all the answers

<p>Irreversible inhibitors, like penicillin, covalently bond to enzymes, permanently blocking their activity.</p> Signup and view all the answers

<p>Activation energy is the initial energy required to distort reactants into an unstable transitional state for a chemical reaction to occur.</p> Signup and view all the answers

<p>The active site provides a specific location for substrate binding and catalytic activity, enabling the conversion of substrates into products.</p> Signup and view all the answers

<p>The induced fit model suggests that the active site undergoes a conformational change upon substrate binding, enhancing the fit between enzyme and substrate.</p> Signup and view all the answers

<p>At high substrate concentrations, enzymes can become saturated, meaning all active sites are engaged and the reaction rate plateaus.</p> Signup and view all the answers

<p>Environmental factors like temperature and pH can affect enzyme structure and function, impacting the rate of reaction.</p> Signup and view all the answers

<p>The enzyme-substrate complex refers to the intermediate formed when an enzyme binds to its substrate during a reaction.</p> Signup and view all the answers

<p>Enzymes lower activation energy by providing an alternative reaction pathway and stabilizing the transition state of the substrate.</p> Signup and view all the answers

<p>Metabolic reversibility allows enzymes to catalyze both forward and reverse reactions, depending on the substrate concentration and reaction conditions.</p> Signup and view all the answers

<p>The substrate is typically held in the active site by weak bonds such as hydrogen and ionic bonds.</p> Signup and view all the answers

<p>Exergonic reactions release energy, while the hydrolysis of sucrose, despite being exergonic, does not occur spontaneously in the absence of an enzyme.</p> Signup and view all the answers

<p>Toxins like sarin bond covalently to specific amino acid R groups in enzymes, permanently inhibiting their function.</p> Signup and view all the answers

<p>The specificity of enzymes is determined by their structure, particularly the arrangement of amino acids in the active site.</p> Signup and view all the answers

<p>A flexible structure allows enzymes to adapt their shape for better substrate binding and catalytic efficiency.</p> Signup and view all the answers

<p>The only way to increase the rate of production is by adding more enzymes.</p> Signup and view all the answers

<p>The transitional state is when molecules have absorbed sufficient energy to break unstable bonds.</p> Signup and view all the answers

<p>Temperature and pH influence the 3D structure of enzymes, which in turn affects their catalytic activity.</p> Signup and view all the answers

<p>Catalysts lower the activation energy, enabling the reactants to absorb the temperatures needed for a reaction at moderate conditions.</p> Signup and view all the answers

<p>The optimal temperature range for most human enzymes is approximately 35-40°C.</p> Signup and view all the answers

<p>A cofactor is a non-protein molecule that assists enzyme activity, while a coenzyme is an organic cofactor.</p> Signup and view all the answers

<p>Competitive inhibitors resemble substrate molecules and block substrates from entering the active site.</p> Signup and view all the answers

<p>The rate is influenced by substrate concentration, temperature, and pH levels.</p> Signup and view all the answers

<p>Noncompetitive inhibitors bind to a different site on the enzyme, causing a change in shape that reduces activity.</p> Signup and view all the answers

<p>Induced fit describes how the active site of an enzyme changes shape when a substrate binds, enhancing the fit and facilitating the reaction.</p> Signup and view all the answers

<p>When saturated, all active sites of the enzyme are engaged, and the reaction rate can only increase with the addition of more enzymes.</p> Signup and view all the answers

<p>Allosteric regulation involves molecules that bind to a site's regulatory region, altering the enzyme's activity.</p> Signup and view all the answers

<p>Cooperativity amplifies the response of enzymes, making it easier for additional substrates to bind after one has bound.</p> Signup and view all the answers

<p>This temperature range matches the normal body temperature, where enzyme activity is highest due to effective molecular collisions.</p> Signup and view all the answers

<p>Cofactors assist enzymes in their catalytic activity, often facilitating electron transfer during reactions.</p> Signup and view all the answers

<p>Feedback inhibition occurs when the end product of an enzyme-catalyzed reaction acts as an inhibitor to that enzyme.</p> Signup and view all the answers

<p>Multienzyme complexes organize enzymes in a metabolic pathway to enhance efficiency and substrate transfer.</p> Signup and view all the answers

<p>Changes in pH can alter the charge and shape of the enzyme, affecting its ability to bind to substrates.</p> Signup and view all the answers

<p>The active site is where substrate binding and the catalytic activity occur, often formed by a few key amino acids.</p> Signup and view all the answers

<p>Fluctuating concentrations of inhibitors and activators create a dynamic response pattern in enzyme regulation.</p> Signup and view all the answers

<p>Enzyme regulation prevents chaos in metabolic processes, allowing organisms to maintain stability and adapt to changes.</p> Signup and view all the answers

<p>Initially, increasing temperature raises the reaction rate by increasing molecular collisions, but after a certain point, it denatures the enzyme, reducing activity.</p> Signup and view all the answers

<p>Enzyme inhibitors are molecules that bind to enzymes to slow down or stop their activity, regulating metabolic pathways.</p> Signup and view all the answers

<p>High temperatures can lead to thermal agitation that disrupts hydrogen and ionic bonds, destabilizing enzyme structure.</p> Signup and view all the answers

<p>Thermophilic bacteria have enzymes optimized for functioning at about 70°C, allowing them to thrive in hot environments.</p> Signup and view all the answers

<p>Enzymes ending in '-ase' typically denote a specific function, such as sucrase acting on sucrose, indicating substrate specificity.</p> Signup and view all the answers

<p>The 'R' groups of amino acids in the active site interact directly with substrates, facilitating bond formation and breakage.</p> Signup and view all the answers

<p>Allosteric regulation modifies enzyme activity by allowing regulatory molecules to bind and change the enzyme's shape, affecting its ability to catalyze reactions.</p> Signup and view all the answers

<p>ATP acts as an inhibitor when it binds to catabolic enzymes, reducing their activity, while ADP functions as an activator, promoting enzyme activity when ATP levels are low.</p> Signup and view all the answers

<p>Cooperativity is a phenomenon where the binding of a substrate to one subunit of an enzyme increases the likelihood of additional substrates binding to the other subunits.</p> Signup and view all the answers

<p>Feedback inhibition occurs when the product of an enzymatic reaction accumulates and binds to the enzyme, inhibiting its activity to prevent overproduction.</p> Signup and view all the answers

<p>Allosteric enzymes typically consist of multiple subunits, each with its own active site, allowing for regulatory sites to influence the enzyme's overall activity.</p> Signup and view all the answers

<p>A multienzyme complex is a group of enzymes that work sequentially in a metabolic pathway, with the product of one enzyme serving as the substrate for the next.</p> Signup and view all the answers

<p>The binding of oxygen to one subunit of hemoglobin increases the affinity of the remaining subunits for oxygen, facilitating rapid oxygen uptake.</p> Signup and view all the answers

<p>The enzymes for the second and third stages of cellular respiration are found in multienzyme complexes located in different areas of the mitochondria.</p> Signup and view all the answers

<p>Enzymatic activity must be regulated to prevent disorder and ensure that metabolic processes respond appropriately to the needs of the cell.</p> Signup and view all the answers

<p>Fluctuating concentrations of regulators create a dynamic response in enzymes, enabling them to adapt to varying cellular conditions.</p> Signup and view all the answers

<p>Gibbs Free Energy is the portion of a system's energy that can perform work and is symbolized by the letter 'G'.</p> Signup and view all the answers

<p>Spontaneous processes tend to increase the total entropy of the universe despite local decreases in entropy within systems.</p> Signup and view all the answers

<p>An exergonic reaction releases free energy and has a negative ΔG, indicating that it is spontaneous and can perform work.</p> Signup and view all the answers

<p>A negative ΔG value indicates that a reaction is spontaneous, while a positive ΔG suggests that the reaction is non-spontaneous.</p> Signup and view all the answers

<p>Equilibrium is reached when forward and reverse reactions occur at the same rate, resulting in maximum stability and a ΔG at its lowest value.</p> Signup and view all the answers

<p>Energy typically enters ecosystems as light and exits as heat, following the thermodynamic principles.</p> Signup and view all the answers

<p>This equation relates the change in Gibbs Free Energy (ΔG) to changes in enthalpy (ΔH) and entropy (ΔS) at a given temperature (T).</p> Signup and view all the answers

<p>Endergonic reactions absorb energy and have a positive ΔG, making them non-spontaneous, while exergonic reactions release energy and have a negative ΔG.</p> Signup and view all the answers

<p>A more unstable glucose molecule is easier to break down into simpler chemicals, thus releasing energy in exergonic reactions.</p> Signup and view all the answers

<p>Cells must prevent equilibrium by continuously importing and exporting reactants and products to perform metabolic functions and sustain life.</p> Signup and view all the answers

<p>Temperature (T) influences the ΔG by modifying the impact of entropy changes (ΔS), which can determine whether a process is spontaneous.</p> Signup and view all the answers

<p>When a reaction is pushed away from equilibrium, its ΔG increases, making it less spontaneous.</p> Signup and view all the answers

<p>Living organisms maintain low entropy through constant energy input and chemical transformations, existing within the larger context of an increasing universe entropy.</p> Signup and view all the answers

<p>Every energy transfer or transformation increases the entropy of the universe.</p> Signup and view all the answers

<p>Entropy is the measure of molecular disorder or randomness, with more disorder indicating higher entropy.</p> Signup and view all the answers

<p>A spontaneous process is one that leads to an increase in entropy without input of energy; an example is combustion.</p> Signup and view all the answers

<p>Catabolic pathways break down complex molecules and release energy, while anabolic pathways build complex molecules from simpler ones and consume energy.</p> Signup and view all the answers

<p>Energy typically enters an ecosystem as light and exits as heat.</p> Signup and view all the answers

<p>Much of the entropy in the universe takes the form of heat and less ordered forms of matter.</p> Signup and view all the answers

<p>Bioenergetics is the study of how energy flows through living organisms.</p> Signup and view all the answers

<p>The first law of thermodynamics states that energy cannot be created or destroyed, only transferred or transformed.</p> Signup and view all the answers

<p>Physical degradation, like the decay of a building over time, demonstrates an increase in entropy as molecules become more unorganized.</p> Signup and view all the answers

<p>Thermal energy can only be utilized when there is a temperature difference; otherwise, it only warms the system.</p> Signup and view all the answers

<p>Complex organisms can evolve into simpler forms without violating the second law as long as the total entropy of the universe continues to increase.</p> Signup and view all the answers

<p>Chemical energy is the potential energy of a chemical that can release energy through its bonds during a chemical reaction.</p> Signup and view all the answers

<p>Kinetic energy involves the energy of movement while potential energy is due to position; organisms transform these energy types during metabolic processes.</p> Signup and view all the answers

The entire set of chemical reactions in an organism.

A series of linked chemical reactions.

Metabolic pathway that breaks down molecules to release energy.

Metabolic pathway that builds molecules by consuming energy.

Study of energy flow in living organisms.

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

Every energy transfer increases disorder (entropy) in the universe.

Potential energy stored in chemical bonds.

Measure of molecular disorder or randomness; the more disordered, the higher the entropy.

A process that increases the entropy of the universe and can occur without input energy.

The capacity to cause change or do work.

Energy of motion

Energy stored by position.

Energy associated with random movement of atoms or molecules.

Energy from light waves.

Spontaneous processes always increase the entropy of the universe, even if the system itself becomes more ordered.

The portion of a system's energy that can perform work.

A thermodynamic function representing the free energy of a system, denoted by "G".

The difference in free energy between the initial and final states of a system.

Reactions with a negative 𝚫G, meaning they release free energy and are energetically favorable.

A state of maximum stability where forward and reverse reactions occur at the same rate.

A reaction that releases free energy, has a negative 𝚫G, and is spontaneous.

A reaction that absorbs free energy, has a positive 𝚫G, and is not spontaneous.

A state where an organism is no longer carrying out chemical reactions, signifying death.

A system that exchanges matter and energy with its surroundings, like a living cell.

Reactions where the energy released from an exergonic reaction is used to drive an endergonic reaction.

The potential energy stored in chemical bonds is released when the bonds break and new bonds form.

A set of defined conditions (1 M of each reactant and product, 25°C, pH 7) used to compare the energy changes in different reactions.

The breaking down of ATP into ADP and inorganic phosphate (Pi) by the addition of water, releasing energy.

The energy available to do work in a system, considering both enthalpy (total energy) and entropy (disorder).

Exergonic reactions RELEASE energy, having a negative ΔG, while endergonic reactions REQUIRE energy, having a positive ΔG.

The use of energy released from an exergonic reaction to drive an endergonic reaction.

The addition of a phosphate group to a molecule, usually a reactant.

A molecule that has been covalently bonded to a phosphate group through phosphorylation.

ATP hydrolysis releases energy, which is used to phosphorylate reactants, creating a phosphorylated intermediate with enough energy to drive the endergonic reaction.

This is the standard free energy change (ΔG) of ATP hydrolysis, indicating the amount of energy released per mole of ATP.

The ΔG of ATP hydrolysis is negative, meaning the reaction releases energy and is thermodynamically favorable, though it may not occur instantly.

ATP can be regenerated from ADP and Pi by using energy from exergonic reactions like cellular respiration.

Enzymes speed up reactions by lowering the activation energy (EA) required to start the reaction.

The amount of energy needed to start a chemical reaction, by distorting reactants into an unstable state.

Lower EA means a faster reaction rate, because less energy is required to reach the transition state.

Enzymes catalyze (speed up) metabolic reactions by reducing activation energy, allowing reactions to occur at physiological temperatures.

A negative ΔG indicates an exergonic reaction, which is spontaneous and releases energy. A positive ΔG indicates an endergonic reaction, which requires energy and is non-spontaneous.

Inhibitors that bind to enzymes through weak bonds, allowing them to detach and re-bind, unlike irreversible inhibitors.

Inhibitors that resemble the substrate and compete for binding to the enzyme's active site, slowing down the reaction.

Inhibitors that bind to a different site on the enzyme, causing a conformational change that disrupts its activity.

Inhibitors that permanently bind to the enzyme, often through covalent bonds, disabling its activity.

A toxic, irreversible inhibitor that covalently binds to enzymes, disrupting their function. Often used as a chemical weapon.

An irreversible inhibitor that targets enzymes in bacteria involved in cell wall synthesis, effectively killing bacteria.

The minimum amount of energy that reactants must absorb to reach a transition state and start a chemical reaction.

The unstable, high-energy state that reactants must reach before they can transform into products.

A substance that speeds up a chemical reaction without being consumed, by lowering the activation energy.

A biological catalyst, typically a protein, that speeds up specific chemical reactions in living organisms.

The specific molecule that an enzyme binds to and acts upon in a chemical reaction.

The temporary intermediate formed when an enzyme binds to its substrate during a chemical reaction.

The specific region on an enzyme where the substrate binds and the catalytic reaction occurs.

The theory that the active site of an enzyme changes shape slightly when the substrate binds, creating a more precise fit.

The minimum amount of energy that reactants must absorb before a chemical reaction can begin. It's like the energy needed to push a boulder over a hill.

The unstable, high-energy state that molecules reach during a reaction, where bonds are breaking and forming. It's like a molecule in between its starting and ending point.

The change in shape of the active site of an enzyme as a substrate binds to it, causing it to fit more snugly. It's like a glove that fits snugly after putting it on.

A non-protein molecule that helps an enzyme function. It's like a helper for the enzyme.

A molecule that slows down or stops an enzyme's activity. It's like a blocker that stops an enzyme from working.

When so much substrate is present that all the enzyme active sites are occupied, so the reaction rate plateaus. It's like a full restaurant where there are no more tables.

The temperature at which an enzyme works most effectively. It's like the perfect temperature for an enzyme to function.

The pH at which an enzyme works most effectively. It's like the perfect acidity/basicity for an enzyme to function.

Bacteria that thrive in extremely hot environments, such as hot springs. They have enzymes that function at high temperatures.

Change in Gibbs Free Energy, representing the energy available to do work in a system. A negative 𝚫G indicates a spontaneous process.

Adenosine Triphosphate (ATP)

ATP stores energy in the bonds between its phosphate groups. When a phosphate group is broken off (hydrolysis), energy is released, and ATP becomes ADP.

1. Chemical work: using energy to fuel endergonic reactions (e.g., building polymers)
2. Transport work: moving substances across membranes against concentration gradients
3. Mechanical work: movement of cilia, muscle contraction, chromosome movement

The process where energy released from exergonic reactions is used to drive endergonic reactions.

It dies. Living cells must continuously perform chemical reactions to maintain life.

They constantly import reactants and export products, preventing the buildup of products and depletion of reactants.

It tells us if a reaction is spontaneous or not. A negative 𝚫G means the reaction will occur naturally.

A reference point for measuring energy changes. Standard conditions are 1M of reactants and products, 25°C, and pH 7.

Change in enthalpy, the total energy of a system. It's a measure of heat energy involved in a reaction.

False. The phrase is misleading. Phosphate bonds in ATP are not unusually strong. The high energy comes from the difference in energy between reactants and products.

They are opposite processes. Exergonic reactions release energy, while endergonic reactions require energy. Often, an exergonic reaction can fuel an endergonic reaction.

Enzyme regulation where a non-covalently bound molecule alters the enzyme's shape, affecting its activity.

An enzyme with multiple subunits that can exist in active and inactive forms, regulated by binding of activators or inhibitors.

A molecule that binds to an allosteric enzyme, stabilizing its active shape.

A molecule that binds to an allosteric enzyme, stabilizing its inactive shape.

A mechanism where binding of one substrate molecule to an enzyme makes it easier for subsequent substrates to bind.

A protein in blood that carries oxygen, exhibiting cooperativity by binding oxygen more readily as more oxygen is bound.

A type of enzyme regulation where the product of a metabolic pathway acts as an inhibitor of an enzyme earlier in the pathway.

A group of enzymes involved in a metabolic pathway organized together, often within specific cellular locations.

Enzymes for the second and third stages of cellular respiration are found in multienzyme complexes located in different areas of the mitochondria.

Enzymatic activity is regulated to prevent chaos within the organism, and this is often achieved through allosteric regulation, feedback inhibition, and multienzyme complexes.

When all active sites of enzymes are occupied by substrate molecules, increasing substrate concentration won't increase the reaction rate.

Each enzyme has a specific temperature where its activity is highest, beyond which its structure is disrupted and activity decreases.

Bacteria that thrive in hot environments have enzymes with optimal temperatures much higher than those found in humans.

Every enzyme has a particular pH where its structure and activity are optimal.

Non-protein molecules that assist enzymes in their catalytic activity, often involved in electron transfer.

Reversible inhibitors bind weakly, allowing the enzyme to regain function. Irreversible inhibitors bind permanently, disabling the enzyme.

A regulatory molecule that binds to an allosteric site on an enzyme, stabilizing its active conformation.

A regulatory molecule that binds to an allosteric site on an enzyme, stabilizing its inactive conformation.

A mechanism where the binding of one substrate molecule to an enzyme increases the affinity of the enzyme for subsequent substrate molecules.