AP Bio Chapter 8: Metabolism Flashcards

Questions and Answers

Which reactions release energy?

Anabolic

Catabolic (correct)

Endergonic

Exergonic

Which reactions consume energy?

Catabolic

Exergonic

Anabolic (correct)

Spontaneous

What type of reaction is photosynthesis?

Catabolic

Anabolic (correct)

Exergonic

Endergonic

What type of reaction is cellular respiration?

Catabolic Signup and view all the answers

Contrast kinetic energy with potential energy.

Kinetic energy is associated with the relative motion of objects while potential energy is energy matter possesses because of its location or structure. Signup and view all the answers

Which type of energy does water behind a dam have?

Potential energy Signup and view all the answers

What is free energy and what is its symbol?

Free energy is the portion of a system's energy that can perform work when temperature and pressure are uniform throughout the system. Its symbol is G. Signup and view all the answers

The equation for the change in free energy is ∆G = __________.

∆H - T∆S Signup and view all the answers

For an exergonic reaction, is ∆G negative or positive?

Negative Signup and view all the answers

Is cellular respiration an endergonic or exergonic reaction?

Exergonic Signup and view all the answers

Is photosynthesis endergonic or exergonic?

Endergonic 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 a catalyst?

A chemical agent that speeds up a reaction without being consumed by the reaction. Signup and view all the answers

What is activation energy (Ea)?

The amount of energy that reactants must absorb before a chemical reaction will start. Signup and view all the answers

What is meant by induced fit?

A clasping handshake which brings chemical groups of the active site into positions that enhance their ability to catalyze the chemical reaction. Signup and view all the answers

Explain how temperature can affect the rate of enzyme action.

Enzymatic rate increases with increasing temperature and eventually denatures. Signup and view all the answers

Name a human enzyme that functions well at pH 2. Where is it formed?

Digestive enzyme in human stomach: pepsin. Signup and view all the answers

Distinguish between cofactors and coenzymes. Give examples of each.

Cofactors are inorganic and coenzymes are organic. Cofactor example: metal atoms in zinc or iron; coenzyme example: vitamins. Signup and view all the answers

What is allosteric regulation?

The term used to describe any case in which a protein's function at one site is affected by the binding of a regulatory molecule to a separate site. Signup and view all the answers

Study Notes

Metabolism Reactions

Catabolic reactions release energy by breaking down larger molecules.
Anabolic reactions consume energy to build up larger molecules.
Photosynthesis is an anabolic reaction; it requires energy to synthesize glucose.
Cellular respiration is a catabolic reaction that releases energy.

Energy Concepts

Kinetic energy is the energy of motion; potential energy is stored due to an object's position or structure.
Water behind a dam and a mole of glucose both possess potential energy.

Free Energy

Free energy (symbol: G) indicates the portion of energy in a system that can perform work under uniform conditions.
Change in free energy is represented by the equation: ∆G = ∆H - T∆S.
In exergonic reactions, ∆G is negative; for cellular respiration, it is -686 kcal/mol.

Cellular Work Types

Cells perform three main types of work:
- Chemical work: synthesizing polymers from monomers.
- Transport work: moving substances across membranes against their gradient.
- Mechanical work: activities like cilia beating and muscle contraction.

ATP and Energy Release

The hydrolysis of ATP (ATP → ADP + Pi) releases -7.3 kcal/mol of energy, categorized as an exergonic reaction.
Energy coupling refers to using the energy from exergonic processes to drive endergonic reactions.

Enzymatic Action

Catalysts speed up reactions without being consumed.
Activation energy (Ea) is the energy required to initiate a chemical reaction.
Induced fit describes how enzymes adjust their shape to better catalyze reactions.
Enzyme specificity is influenced by protein structure.

Factors Affecting Enzymes

The rate of enzyme action can be affected by substrate concentration; more substrate can lead to increased reaction rates until saturation.
Extreme pH levels and temperatures can denature enzymes, rendering them inactive.
Pepsin, a digestive enzyme, functions at a pH of 2, found in the stomach.

Cofactors and Inhibitors

Cofactors are inorganic, while coenzymes are organic; examples include zinc for cofactors and vitamins for coenzymes.
Competitive inhibitors block substrates from binding to the active site, while noncompetitive inhibitors bind at a different site, altering enzyme shape and function.

Allosteric Regulation

Allosteric regulation modifies enzyme activity, with regulatory molecules binding at sites other than the active site.
Allosteric activators enhance enzyme activity, whereas allosteric inhibitors decrease it.
Hemoglobin demonstrates cooperativity in O₂ binding, enhancing its efficiency in oxygen transport, particularly in the gills of fish.

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Description

Explore the fundamental concepts of metabolism with these flashcards from AP Biology Chapter 8. Learn about catabolic and anabolic reactions, their functions, and their relevance in biological processes such as photosynthesis. Perfect for students preparing for exams in biology.