chapter 15

A collection of flashcards covering key vocabulary and concepts from Chapter 15 on metabolism.

Free Energy

Energy available to do work in biological systems.

Homeostasis

A steady state of internal conditions maintained by living organisms.

Phototrophs

Organisms that capture energy from sunlight.

Chemotrophs

Organisms that obtain energy through the oxidation of chemicals.

Metabolism

The sequence of chemical reactions in the cell involving energy extraction and material synthesis.

Catabolism

Reactions that break down complex molecules to generate energy.

Anabolism

Reactions that construct complex molecules from simpler ones, requiring energy.

Amphibolic pathways

Pathways that can be either anabolic or catabolic depending on energy conditions.

Thermodynamic favorability

The tendency of a reaction to occur spontaneously based on its ΔG value.

ΔG

Change in free energy; a key factor in determining reaction spontaneity.

ATP (Adenosine Triphosphate)

The primary energy currency of the cell, consisting of adenine, ribose, and three phosphate groups.

Exergonic reaction

A reaction that releases energy, such as ATP hydrolysis.

Hydrolysis

The chemical breakdown of a compound due to reaction with water.

Phosphorylation

The addition of a phosphate group to a molecule.

Creatine phosphate

A high-energy compound in muscle that donates phosphoryl groups to regenerate ATP.

Nucleoside triphosphate

A molecule consisting of a nucleoside and three phosphate groups, crucial for energy transfer.

Kinetic stability

The property of a molecule that makes it resistant to rapid reaction in the absence of a catalyst.

Phosphate esters

Compounds formed from the esterification of a phosphate group; stable yet reactive.

Electrochemical gradients

Differences in charge and chemical concentration across membranes, used to generate ATP.

NAD+ (Nicotinamide Adenine Dinucleotide)

A major electron carrier in cellular oxidation reactions.

FAD (Flavin Adenine Dinucleotide)

Another important electron carrier in oxidation reactions in metabolism.

Acetyl CoA

A key metabolic intermediate involved in energy production and biosynthesis.

Oxidative phosphorylation

The process of ATP generation that occurs in the mitochondria using electron transport chains.

Reductive biosynthesis

An anabolic process that requires high-potential electrons and reducing power.

Vitamin coenzymes

Vitamins that have been chemically modified to serve as coenzymes in metabolic reactions.

Enzyme regulation

Mechanisms by which the activity of enzymes is controlled in metabolic pathways.

Substrate availability

The control of access to substrates for metabolic reactions, impacting reaction rates.

Feedback inhibition

A regulatory mechanism where the end product of a pathway inhibits its own production.

Energy charge

A measure of the energy status of a cell, based on the ratio of ATP, ADP, and AMP.

Phosphoryl-transfer potential

The capacity of a molecule to transfer a phosphoryl group to another molecule.

ATP synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate during oxidative phosphorylation.

Citrate

An intermediate in the citric acid cycle, not sufficiently charged to prevent hydrolysis.

Hydration stabilization

The stabilization of molecules through interactions with water.

NADPH

The reduced form of NADP+, used primarily in anabolic reactions.

Thioester

A compound that has a sulfur atom bonded to an acyl group, often involved in energy transfer.

Lipogenesis

The metabolic process of synthesizing lipids from carbohydrates and proteins.

Glycogenesis

The synthesis of glycogen from glucose.

Glycogenolysis

The breakdown of glycogen into glucose when energy is needed.

Gluconeogenesis

The metabolic pathway where glucose is synthesized from non-carbohydrate precursors.

Protein kinases

Enzymes that add phosphate groups to proteins, regulating their activity.

Protein phosphatases

Enzymes that remove phosphate groups from proteins, altering their function.

Allosteric regulation

Regulation of enzyme activity through the binding of effectors at sites other than the active site.

Compartmentalization

The organization of cellular processes into different areas or organelles to enhance metabolic flexibility.

Isoenzymes

Different forms of an enzyme that catalyze the same reaction but may vary in kinetics or regulation.

Metabolic flexibility

The ability of a cell to adapt its metabolism according to the availability of nutrients and energy.

Oxidation-reduction reactions

Reactions that involve the transfer of electrons between molecules.

Amino acids

Organic compounds that serve as building blocks for proteins.

Fatty acids

Carboxylic acids that are important components of lipids, providing energy and structure.

Carbohydrates

Organic compounds consisting of carbon, hydrogen, and oxygen, serving as key energy sources.

Clinical insight

Understanding how metabolic processes affect health and disease conditions.

Metabolic pools

Storage pools of biomolecules within the body that can be mobilized when needed.

Glycolysis

The metabolic pathway that converts glucose into pyruvate, generating ATP in the process.

Krebs cycle (Citric acid cycle)

A series of reactions that produce energy through the oxidation of acetyl-CoA.

Reduced forms of carriers

Molecules that have gained electrons and thus can donate them in metabolic reactions.

High-energy intermediates

Molecules that can readily provide energy for biochemical reactions.

Signal amplification

The process by which a small signal is transformed into a much larger signal in cellular processes.

Metabolic channels

Pathways that lead metabolites from one reaction to another efficiently.

Synthesis of biomolecules

The creation of complex molecules like proteins, nucleic acids, and lipids from simpler ones.

Thermodynamic coupling

Using a favorable reaction to drive a thermodynamically unfavorable reaction.

Glycogen storage disease

A genetic disorder affecting the metabolism of glycogen.

Nutrient excess

Condition where nutrient intake exceeds the body's needs.

Energy homeostasis

The balance of energy intake and energy expenditure in living organisms.

Nutritional influences

The impact of diet and nutrient availability on metabolic functions.

External environment

The surrounding conditions that can affect cellular metabolism.

Internal environment

The physiological state within an organism that affects metabolic reactions.

Biochemical pathways

Series of chemical reactions occurring within a cell.

Metabolic disorders

Diseases that result from abnormalities in the metabolism.

Nutritional biochemistry

The study of how nutrients affect metabolism and overall health.