cell energetics chicken butt

Acetyl CoA

A molecule involved in metabolism that contributes to energy production in the citric acid cycle.

Activation Energy

The minimum amount of energy required for a chemical reaction to occur.

Active Site

The specific region on an enzyme where the substrate binds and undergoes a chemical reaction.

ADP (Adenosine Diphosphate)

A nucleotide that helps in cellular energy transfer, converted to ATP.

Aerobic Respiration

A metabolic process where cells use oxygen to convert glucose into ATP, producing carbon dioxide and water.

Alcohol Fermentation

An anaerobic respiration process where glucose is converted into ethanol and carbon dioxide, typically performed by yeast.

Allosteric Regulation

A mechanism whereby a molecule binds to an enzyme at a site other than the active site, altering its function.

Anabolic Pathway

A metabolic route that builds complex molecules from simpler ones, requiring energy input.

Anaerobic Respiration

A process generating ATP without oxygen, producing lactic acid or ethanol as byproducts.

ATP (Adenosine Triphosphate)

The primary energy carrier in cells, providing energy for biological processes.

ATP Hydrolysis

The chemical reaction in which ATP is broken down into ADP and inorganic phosphate, releasing energy.

ATP Synthase

An enzyme that synthesizes ATP from ADP and inorganic phosphate during energy production.

Autotrophs

Organisms that produce their own food using light or chemical energy.

C3 Plants

Plants using the Calvin cycle for carbon fixation, thriving in cool, moist environments.

C4 Plants

Plants with a modified photosynthetic pathway that reduces photorespiration, more efficient in hot, dry environments.

Calvin Cycle

The light-independent reactions of photosynthesis that convert carbon dioxide into glucose.

CAM Plants

Plants that open their stomata at night to minimize water loss, performing photosynthesis during the day.

Carbon Cycle

The biogeochemical process exchanging carbon between the atmosphere, organisms, and Earth.

Carbon Fixation

The process of incorporating inorganic carbon dioxide into organic molecules during photosynthesis.

Carotenoids

Pigments in plants that absorb light for photosynthesis and provide photoprotection.

Catabolic Pathway

A metabolic process that breaks down complex molecules into simpler ones, releasing energy.

Catalysis

The process whereby a catalyst speeds up a chemical reaction without being consumed.

Catalyst

A substance that reduces the activation energy of a reaction, increasing its speed.

Cellular Respiration

The process by which cells convert glucose into ATP, utilizing oxygen in aerobic respiration.

Chemical Energy

Energy stored in the bonds of molecules, released during chemical reactions.

Chemiosmosis

The process of producing ATP through the movement of hydrogen ions across a membrane.

Chemoautotrophs

Organisms that obtain energy by oxidizing inorganic substances.

Chemosynthesis

The process of producing organic molecules using chemical energy in the absence of light.

Chlorophyll

The green pigment in plants that absorbs light energy for photosynthesis.

Chlorophyll a

The primary pigment involved in photosynthesis, absorbing mostly blue-violet and red light.

Chlorophyll b

An accessory pigment that absorbs additional wavelengths of light for photosynthesis.

Chloroplast

Organelles in plant cells where photosynthesis occurs.

Citric Acid Cycle / Krebs Cycle

A series of reactions in the mitochondria that produce ATP, NADH, and FADH₂ from acetyl CoA.

Coenzymes

Organic molecules that assist enzymes in catalyzing reactions.

Competitive Inhibitors

Molecules that bind to the active site of an enzyme, blocking substrate attachment.

Cristae

Folds in the inner mitochondrial membrane that increase surface area for ATP production.

Cyclic Electron Flow

A process in photosynthesis where electrons cycle back to photosystem I to generate ATP.

Cytochromes

Proteins in the electron transport chain that transfer electrons.

Decomposition

The breakdown of organic matter into simpler substances by decomposers.

Dissolved Oxygen (DO)

The amount of oxygen available in water, essential for aquatic life.

Ectotherm

Organisms that rely on external sources for heat regulation.

Electron Transport Chains

Series of protein complexes in the inner mitochondrial membrane that produce ATP.

Endergonic Reaction

A chemical reaction requiring an input of energy.

Endotherm

Organisms that generate their own body heat through metabolism.

Energy Coupling

The process of using energy released from exergonic reactions to drive endergonic reactions.

Entropy

A measure of disorder or randomness in a system.

Enzyme

A biological catalyst that speeds up chemical reactions by lowering activation energy.

Enzyme Inhibitors

Molecules that decrease enzyme activity by binding to the enzyme.

Enzyme-Substrate Complex

The temporary binding of an enzyme and substrate during a reaction.

Eutrophication

Excessive nutrient enrichment in water bodies leading to algal blooms.

Exergonic Reaction

A chemical reaction that releases energy.

FADH2

An energy carrier produced in the citric acid cycle that donates electrons to the electron transport chain.

Feedback Inhibition

A mechanism where the product of a metabolic pathway inhibits an earlier enzyme.

Fermentation

An anaerobic process converting glucose into ATP without oxygen.

First Law of Thermodynamics

Energy cannot be created or destroyed, only transformed.

Homeostasis

The maintenance of a stable internal environment in an organism.

Glycolysis

The first step of cellular respiration where glucose is broken down into pyruvate.

Grana

Stacks of thylakoids in chloroplasts where light-dependent reactions occur.

Hibernation

A state of reduced metabolic activity during winter to conserve energy.

Induced Fit

Model describing how enzymes change shape to accommodate substrate binding.

Irreversible Inhibitors

Inhibitors that permanently disable an enzyme by binding covalently.

Lactic Acid Fermentation

Anaerobic process converting glucose to ATP and lactic acid, occurring in muscle cells.

Light Reactions

The first stage of photosynthesis where light energy is converted into ATP and NADPH.

Light-Dependent Reactions

Reactions in thylakoid membranes that produce ATP and NADPH using light energy.

Light-Independent Reactions

Reactions using ATP and NADPH to fix carbon dioxide into glucose.

Matrix

The fluid-filled interior of mitochondria where the Krebs cycle occurs.

Mesophyll

The tissue in plant leaves where most photosynthesis occurs.

Metabolic Pathway

A sequence of chemical reactions in a cell, catalyzed by enzymes.

Metabolic Rate

The rate at which an organism converts energy from food into biological energy.

Metabolism

All biochemical reactions within a living organism.

Mitochondria

Organelles known as the powerhouses of the cell, producing ATP through respiration.

NADH

An electron carrier produced during glycolysis and the Krebs cycle.

NADP+

An electron carrier in photosynthesis that becomes NADPH.

NADPH

An energy-rich molecule providing reducing power for the Calvin cycle.

Negative Feedback Loop

A mechanism that reverses an initial change to maintain stability.

Noncompetitive Inhibitors

Inhibitors that bind to an enzyme at a site other than the active site.

Noncyclic Electron Flow

The main pathway of electron movement in photosynthesis, generating ATP and NADPH.

Oxidation

The loss of electrons from a molecule in a chemical reaction.

Oxidative Phosphorylation

The final stage of cellular respiration where ATP is produced using electron energy.

Phosphorylated

A molecule that has gained a phosphate group, increasing reactivity.

Phosphorylation

The addition of a phosphate group to a molecule.

Photoautotrophs

Organisms that use sunlight to synthesize organic molecules via photosynthesis.

Photophosphorylation

ATP production using light energy during photosynthesis.

Photorespiration

A process where Rubisco fixes oxygen instead of carbon dioxide, causing energy loss.

Photosynthesis

The process where organisms convert light energy into chemical energy, producing glucose.

Photosystem I

A photosystem in the thylakoid membrane that absorbs light energy to produce NADPH.

Photosystem II

The first protein complex in light-dependent reactions that splits water and releases oxygen.

Positive Feedback Loop

A mechanism amplifying change, leading to rapid physiological responses.

Primary Electron Acceptor

A molecule that receives high-energy electrons in the electron transport chain.

Pyruvate

The three-carbon end product of glycolysis that enters mitochondria for further processing.

Reaction Center

The specialized complex in photosystems where excited electrons are transferred.

Reduction

The gain of electrons in a chemical reaction.

Reversible Inhibitors

Inhibitors that temporarily bind to enzymes, reducing activity but allowing normal function when removed.

Rubisco

The enzyme that catalyzes the first step of the Calvin cycle by fixing carbon dioxide.

Second Law of Thermodynamics

States that energy transfer increases disorder (entropy) in the universe.

Stomata

Tiny pores on leaves that regulate gas exchange.

Stroma

The fluid-filled space in chloroplasts where the Calvin cycle takes place.

Substrate

The reactant that binds to an enzyme’s active site for a chemical reaction.

Thylakoids

Membrane-bound structures within chloroplasts where light-dependent reactions occur.

Torpor

A state of decreased physiological activity to conserve energy.