Biology Chapter 6 - Metabolism Flashcards

Questions and Answers

Which of these is exhibiting kinetic energy?

A space station orbiting Earth (correct)

A parked car

A book on a shelf

A rock at the top of a hill

"Conservation of energy" refers to the fact that ________.

energy cannot be created or destroyed but can be converted from one form to another

Chemical energy is a form of _______ energy.

potential

In your body, what process converts the chemical energy found in glucose to the chemical energy found in ATP?

cellular respiration Signup and view all the answers

Which of these are by-products of cellular respiration?

heat, carbon dioxide, and water Signup and view all the answers

Which of these is ATP?

3 phosphate groups attached to a ribose attached to adenine Signup and view all the answers

What type of reaction breaks the bonds that join the phosphate groups in an ATP molecule?

hydrolysis Signup and view all the answers

What is the correct label for 'A'?

energy of activation Signup and view all the answers

As a result of its involvement in a reaction, an enzyme _____

is unchanged Signup and view all the answers

What name is given to the reactants in an enzymatically catalyzed reaction?

substrate Signup and view all the answers

An enzyme _____

is an organic catalyst Signup and view all the answers

Enzymes work by _____

reducing energy of activation (EA) Signup and view all the answers

In general, enzymes are what kinds of molecules?

proteins Signup and view all the answers

The function of enzymes is to ____.

lower the activation energy of a reaction Signup and view all the answers

Why does the lock and key analogy fit the linkage between an enzyme and its substrate?

The key only fits one configuration of the lock, as the enzyme does with the substrate. Signup and view all the answers

What happens if an enzyme is not functioning in a chemical reaction in a living organism that needs it?

The reaction proceeds, but much more slowly. Signup and view all the answers

An allosteric inhibitor does which of the following?

binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate Signup and view all the answers

Which type of enzyme inhibitor binds to an enzyme away from the active site and changes the conformation of the active site, decreasing its affinity for the substrate?

allosteric Signup and view all the answers

Competitive inhibition is the inhibition by a binding event at a site different from the active site.

False Signup and view all the answers

Coenzyme

small organic molecule, such as a vitamin or its derivative, which is required to enhance the activity of an enzyme Signup and view all the answers

Cofactor

inorganic ion, such as iron and magnesium ions, required for optimal regulation of enzyme activity Signup and view all the answers

Active site

specific region of the enzyme to which the substrate binds Signup and view all the answers

Competitive inhibition

type of inhibition in which the inhibitor competes with the substrate molecule by binding to the active site of the enzyme Signup and view all the answers

Feedback inhibition

effect of a product of a reaction sequence to decrease its further production by inhibiting the activity of the first enzyme in the pathway that produces it Signup and view all the answers

Allosteric inhibition

inhibition by a binding event at a site different from the active site, which induces a conformational change and reduces the affinity of the enzyme for its substrate Signup and view all the answers

Denature

process that changes the natural properties of a substance Signup and view all the answers

What is the significance of the third phosphate on ATP?

Breaking its bond releases the most energy from an ATP molecule. Signup and view all the answers

ADP + Pi → ATP + H2O ΔG = +14.6 kcal/mol (+62 kJ/mol) is a true statement under standard conditions.

False Signup and view all the answers

Which of the following terms in the Gibbs free energy equation denotes enthalpy?

ΔH Signup and view all the answers

What does ∆H denote in the Gibbs equation?

the enthalpy change in a chemical reaction Signup and view all the answers

Entropy

measure of randomness or disorder within a system Signup and view all the answers

ATP is "recycled" through the reactions of ____.

ADP + energy + inorganic phosphate Signup and view all the answers

∆G values can be used to ____.

determine if a reaction is spontaneous or non-spontaneous Signup and view all the answers

Study Notes

Kinetic and Potential Energy

Kinetic energy is exemplified by a space station orbiting Earth.
Chemical energy, a form of potential energy, is stored in molecules.

Energy Conservation and Chemical Processes

"Conservation of energy" means energy cannot be created or destroyed, only transformed.
Cellular respiration converts chemical energy in glucose to ATP, releasing by-products like heat, carbon dioxide, and water.

ATP Structure and Function

ATP consists of three phosphate groups attached to a ribose sugar and adenine base.
Hydrolysis is the reaction that breaks bonds between phosphate groups in ATP, releasing energy.
The third phosphate's bond is crucial as its breakage releases significant energy.

Enzymatic Activity

Energy of activation is necessary for a reaction to occur.
Enzymes remain unchanged after participating in reactions and are classified as organic catalysts.
Enzymes reduce the energy of activation to speed up chemical reactions.

Substrates and Active Sites

Substrates are the reactants in enzymatically catalyzed reactions.
The active site is a specific region where substrates bind on an enzyme.

Inhibition Mechanisms

Allosteric inhibitors bind away from the active site, altering the active site's shape and reducing substrate affinity.
Competitive inhibition occurs when an inhibitor competes with a substrate for binding at the active site.
Feedback inhibition prevents overproduction of substances by inhibiting the first enzyme in the metabolic pathway.

Cofactors and Coenzymes

Cofactors are inorganic ions essential for enzyme regulation, such as iron and magnesium.
Coenzymes are small organic molecules, often vitamins, that enhance enzyme activity.

Thermodynamics in Biochemical Reactions

ΔG indicates the change in free energy during a reaction, while ΔH denotes the enthalpy change.
Entropy measures the randomness or disorder within a system.
ATP is regenerated through the combination of ADP, energy, and inorganic phosphate.

Enzyme Denaturation

Denaturation alters a substance’s natural properties, potentially rendering enzymes inactive.

Key Concepts on Reactions

Understanding reaction conditions, such as ΔG values, helps determine the spontaneity of reactions.
Enzymatic reactions are often influenced by temperature, pH, and substrate concentration.

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Description

Test your knowledge on metabolism with these flashcards covering key concepts from Biology Chapter 6. Explore topics like kinetic energy, conservation of energy, and chemical energy. Perfect for students looking to solidify their understanding of metabolic processes.