Biology Chapter 8: Metabolism Flashcards

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Questions and Answers

What is metabolism?

A process that requires energy input

The study of energy transformations

A specific molecule altered in defined steps

The totality of an organism's chemical reactions (correct)

What is a metabolic pathway?

A specific molecule which is altered in a series of defined steps.

What does a catabolic pathway do?

Releases energy by breaking down complex molecules to simpler compounds.

What is an anabolic pathway?

Consume energy to build complicated molecules from simpler ones. Signup and view all the answers

What is thermodynamics?

The study of energy transformations that occur in a collection of matter. Signup and view all the answers

A closed system is open to the surrounding environment.

False Signup and view all the answers

Organisms are open systems.

True Signup and view all the answers

What is the First Law of Thermodynamics?

The energy of the universe is constant; energy can be transferred and transformed but not created or destroyed. Signup and view all the answers

Why is energy not recycled?

During every energy transfer, some energy becomes unusable energy, unavailable to do work. Signup and view all the answers

What is entropy?

A measure of disorder or randomness. Signup and view all the answers

The Second Law of Thermodynamics states that every energy transfer increases order.

False Signup and view all the answers

What are spontaneous processes?

Processes that can occur on their own without outside help. Signup and view all the answers

What defines nonspontaneous processes?

A process that cannot occur on its own; energy must be added. Signup and view all the answers

What is free energy?

Measures the portion of a system's energy that can perform work when temperature and pressure are uniform. Signup and view all the answers

What is the Change in Free Energy formula?

ΔG=ΔH-TΔS Signup and view all the answers

What is enthalpy?

A measure of energy in a system. Signup and view all the answers

What does -ΔG indicate?

Decrease in free energy Signup and view all the answers

What does +ΔG indicate?

Nonspontaneous process Signup and view all the answers

What is exergonic?

Energy outward, net release of free energy, -G. Signup and view all the answers

What is endergonic?

Energy inward, net gain of free energy, +G. Signup and view all the answers

What are the three kinds of work a cell does?

Mechanical, transport, and chemical. Signup and view all the answers

What is energy coupling?

The use of an exergonic process to drive an endergonic one. Signup and view all the answers

What is adenosine triphosphate (ATP)?

A sugar ribose with the nitrogenous base adenine and a chain of three phosphate groups bonded to it. Signup and view all the answers

What are the five factors that affect reaction rates?

Molecular orientation, temperature, pressure, concentration, catalysts. Signup and view all the answers

What is molecular orientation in reactions?

Molecules must collide at the correct angle with enough force to break bonds. Signup and view all the answers

How does temperature affect reactions?

Increases molecular motion and increases the chances of proper collisions. Signup and view all the answers

How does pressure influence reactions?

Increases and forces molecules into a smaller space/closer together. Signup and view all the answers

What does concentration mean in reactions?

The number of particles per volume. Signup and view all the answers

What are catalysts?

Any substance that will increase reaction rates without affecting the reaction or being used up. Signup and view all the answers

What is an enzyme?

A catalytic protein. Signup and view all the answers

What are some properties of enzymes?

Organic compounds, increase reaction rates without increasing temperature, lower activation energy. Signup and view all the answers

Study Notes

Metabolism

Metabolism encompasses all chemical reactions within an organism, crucial for sustaining life.

Metabolic Pathways

Metabolic pathways involve a series of chemical reactions where a specific molecule is modified step-by-step, yielding a final product.

Catabolic Pathways

Catabolic pathways break down complex molecules into simpler ones, releasing energy useful for cellular functions, exemplified by cellular respiration.

Anabolic Pathways

Anabolic pathways utilize energy to synthesize complex molecules from simpler components and are often referred to as biosynthetic pathways.

Thermodynamics

Thermodynamics studies energy transformations within matter, underpinning metabolic processes.

Closed and Open Systems

Closed systems do not exchange matter with their environment, whereas open systems, like organisms, do interact with their surroundings.

First Law of Thermodynamics

Energy in the universe remains constant; it can be transformed but not created or destroyed, adhering to the conservation principle.

Energy Transfer and Usability

Energy transfers result in some energy becoming unusable, hence cannot be recycled entirely within a system.

Entropy

Entropy measures disorder in a system, increasing with energy transformations, ultimately leading to greater disorganization in the universe.

Second Law of Thermodynamics

Every energy transformation raises entropy, emphasizing the natural tendency towards disorder.

Spontaneous Processes

Spontaneous processes can occur without external energy input, increasing overall entropy; they do not imply a rapid occurrence.

Nonspontaneous Processes

Nonspontaneous processes require external energy to occur and cannot proceed independently.

Free Energy

Free energy quantifies the portion of a system's energy available for work under uniform temperature and pressure conditions.

Change in Free Energy

The formula ΔG = ΔH - TΔS illustrates the change in free energy during reactions.

Enthalpy

Enthalpy indicates energy content within a system; exothermic reactions tend to lower the system's energy, leading to negative values.

Free Energy Changes

A negative ΔG signifies a spontaneous reaction, while a positive ΔG indicates nonspontaneity, reflecting energy stability.

Exergonic and Endergonic Reactions

Exergonic reactions release free energy (-G), whereas endergonic reactions absorb free energy (+G).

Cell Work Types

Cells perform mechanical, transport, and chemical work to maintain functions.

Energy Coupling

Energy coupling allows energy from exergonic reactions to drive endergonic processes, facilitating various biological functions.

Adenosine Triphosphate (ATP)

ATP, comprised of ribose, adenine, and three phosphate groups, is central to energy transfer in cells; its hydrolysis releases energy.

Factors Affecting Reaction Rates

Key factors include molecular orientation, temperature, pressure, concentration, and the presence of catalysts.

Molecular Orientation in Reactions

Successful reactions depend on correct molecular collision angles and sufficient force to disrupt existing bonds.

Temperature Effects on Reactions

Increased temperature enhances molecular motion and collision frequency; however, excessive heat can damage living cells.

Pressure in Reactions

Higher pressure compresses gas molecules, leading to increased collision rates and reaction speeds.

Concentration in Reactions

Higher particle concentration boosts reaction rates, as closely packed particles are more likely to collide.

Catalysts

Catalysts increase reaction rates without participating in the reaction, remaining unchanged post-reaction.

Enzymes

Enzymes are proteins that act as biocatalysts, significantly speeding up biochemical reactions.

Properties of Enzymes

Enzymes are organic compounds (proteins) that enhance reaction rates without raising temperature, by lowering activation energy, while remaining unchanged during reactions.

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Description

Explore key concepts and terminology in metabolism with these flashcards covering Chapter 8. Learn about metabolic pathways, catabolic and anabolic processes, and their significance in life. Perfect for mastering the critical aspects of metabolism in biological systems.