Lecture 12: Cellular Respiration 1

Heterotrophs

Organisms that obtain organic molecules from other organisms.

Cellular respiration

The process in which cells convert glucose and oxygen into energy, carbon dioxide, and water.

ATP

Adenosine triphosphate, the energy currency of the cell.

Organic molecules

Compounds that contain carbon and are produced by living organisms.

Glycolysis

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

Pyruvate

The end product of glycolysis, a three-carbon molecule.

Acetyl CoA

The two-carbon molecule formed from the oxidation of pyruvate.

Citric Acid Cycle

A series of reactions that further oxidize acetyl CoA to produce electron carriers.

NADH

An electron carrier that stores energy by holding electrons gained from oxidation.

FADH2

Another electron carrier similar to NADH, derived from riboflavin.

Fermentation

A metabolic process that converts sugar to acids, gases, or alcohol in the absence of oxygen.

Oxidation

The process of losing electrons, often associated with the loss of hydrogen.

Reduction

The process of gaining electrons, often associated with the gain of hydrogen.

Electron transport chain

A series of protein complexes in mitochondria that transfer electrons to produce ATP.

Substrate level phosphorylation

The direct transfer of a phosphate group to ADP to form ATP during glycolysis and the citric acid cycle.

Oxidative phosphorylation

The process of generating ATP using the electron transport chain and proton gradients.

Mitochondria

Organelles responsible for producing ATP through cellular respiration.

CO2

Carbon dioxide, a waste product of cellular respiration.

Photosynthesis

The process used by plants to convert sunlight into chemical energy, producing glucose and oxygen.

Chemical energy

Energy stored in the bonds of chemical compounds.

Autotrophs

Organisms that produce their own organic molecules through processes like photosynthesis.

Cytoplasm

The jelly-like substance in cells where glycolysis occurs.

Heat loss

The unavoidable energy loss during metabolic processes.

Photosynthetic organisms

Organisms that perform photosynthesis to produce glucose.

Energy budget

The balance of energy produced and used by cells.

GTP

Guanosine triphosphate, an energy-carrying molecule similar to ATP.

Carbon sources

Compounds that provide carbon for metabolic processes, usually in the form of sugars or fats.

Digestive tract

The system responsible for breaking down food and absorbing nutrients.

Enzymes

Proteins that catalyze biochemical reactions in the body.

Intermediate metabolites

Compounds that are formed during metabolic pathways.

Electrons

Negatively charged particles that carry energy.

Oxidation-reduction reaction

A chemical reaction that involves the transfer of electrons.

Matrix of mitochondria

The innermost compartment of mitochondria where the citric acid cycle occurs.

Free energy change

The change in energy during a biochemical reaction, often measured in kilojoules or kilocalories.

Cellular processes

Biological processes that occur within living cells.

Metabolize

To convert substances into energy or other compounds within the body.

Energy investment phase

The initial phase of glycolysis where ATP is consumed to modify glucose.

Energy payoff phase

The phase of glycolysis where ATP is generated.

Kinase

An enzyme that adds phosphate groups to other molecules.

Isomerase

An enzyme that converts a molecule into one of its isomers.

Allosteric regulation

The regulation of an enzyme's activity through the binding of molecules at sites other than the active site.

Electron carriers

Molecules that transport electrons during cellular respiration.

Hydrogen ions (protons)

Positively charged particles involved in generating ATP through proton gradients.

Glycolytic pathway

The series of steps in glycolysis that break down glucose.

Crital pathways

Main metabolic pathways essential for energy production in cells.

Reduction potential

The tendency of a compound to gain electrons.

Dehydrogenase

An enzyme that removes hydrogen atoms from a molecule.

High-energy state

A condition where electrons have absorbed energy, allowing them to do work.

Unstable molecules

Molecules that readily react or break down to release energy.

Phosphate group

A functional group composed of phosphorus and oxygen, significant in energy-transfer reactions.

Carbon skeleton

The chain or ring of carbon atoms in organic molecules.

Biochemical pathways

A series of enzymatic reactions that lead to the transformation of a substrate into a final product.

Entropy

A measure of disorder or randomness in a system.

Coenzyme A

A molecule involved in the transfer of acetyl groups to the citric acid cycle.

Hydroxyl group

A functional group consisting of an oxygen atom bonded to a hydrogen atom.

Chemical bonds

Forces that hold atoms together in molecules.

Lungs

Organs responsible for gas exchange in air-breathing organisms.

Nutrient absorption

The process by which nutrients are taken up into cells from the digestive tract.

Cyclic pathway

A metabolic pathway that regenerates its starting materials to continue the cycle.

Microscale reactions

Small-scale chemical reactions that occur at the level of cells or organelles.

Biological oxidation

The process of breaking down compounds to produce energy.

Metabolic pathways

The series of enzymatic reactions that transform substrates into products in metabolism.

Hydrogen atoms

Atoms consisting of one proton and one electron, often involved in redox reactions.

Organic chemistry

The study of the structure, properties, and reactions of organic compounds.

Reducing agent

A substance that donates electrons in a redox reaction and is oxidized in the process.

Oxidizing agent

A substance that gains electrons in a redox reaction and is reduced in the process.

ATP yield

The amount of ATP produced from a metabolic process.

Energy-rich compounds

Molecules such as ATP or glucose that store energy.

Energy transformation

The process of changing one form of energy into another.

Macromolecules

Large, complex molecules such as proteins, nucleic acids, carbohydrates, and lipids.

Glycogen

A form of stored glucose found in animals.

Caloric content

The amount of energy provided by food when consumed.

Enzymatic catalysis

The acceleration of biochemical reactions through the action of enzymes.

Metabolic rate

The rate at which energy is expended in the body.

Oxidative phosphorylation

The final stage of cellular respiration, where ATP is produced using energy derived from electrons.

Mitochondrial membranes

The inner and outer membranes of mitochondria where various metabolic processes occur.

Bacterial endosymbiotic origin

The evolutionary theory suggesting that mitochondria originated from engulfed bacteria.

Eukaryotic cells

Complex cells that contain a nucleus and membrane-bound organelles.

Chemical equilibrium

A state where the rates of forward and reverse reactions are equal.

Phosphorylation

The process of adding a phosphate group to a molecule.

Nutrient metabolism

The biochemical processes that modify nutrients for use by the body.

Oxygen consumption

The intake of oxygen necessary for aerobic cellular respiration.

Biochemical efficiency

The effectiveness of converting substrates into useful end products.

Cellular function

The activities that occur within cells to maintain life.

Redox potential

A measure of the tendency of a chemical species to acquire electrons and be reduced.

Catabolic pathways

Metabolic pathways that break down molecules to produce energy.

Anabolic pathways

Metabolic pathways that build complex molecules from simpler ones.

Biological systems

Complex networks of biologically relevant processes and components.

Macromolecule synthesis

The process by which cells create complex macromolecules from simpler units.

Metabolic intermediates

Compounds that form in the middle of metabolic pathways.

Sugar metabolism

The biochemical process of breaking down sugars for energy.

Respiratory quotient

The ratio of carbon dioxide produced to oxygen consumed during respiration.

Biological fuel

Substances used by living organisms to produce energy.

Metabolic homeostasis

The maintenance of stable metabolic conditions within an organism.

Fuels utilization

The process of metabolizing nutrients to generate energy.

Biological energy conversion

The transformation of energy from food into usable forms within organisms.

Homeostasis

The ability of an organism to maintain stable internal conditions.

Hydrolysis

The chemical breakdown of compounds due to the reaction with water.

Aerobic condition

A condition that requires oxygen for the process of cellular respiration.

Anaerobic condition

A condition requiring no oxygen for the process of respiration.