Cellular Respiration and Energy Transformation Vocabulary Flashcards

Vocabulary flashcards reviewing cellular respiration pathways, organelle structure, anaerobic fermentation, key scientists, and ATP energy dynamics based on the lecture content.

Mitochondria

Organelles that serve as the sites of cellular respiration, utilizing oxygen to drive the generation of ATP by extracting energy from sugars, fats, and other fuels.

Cristae

The highly folded inner structures of the mitochondrial membrane that function to increase the surface area to volume ratio.

Mitochondrial Matrix

The innermost compartment of the mitochondrion containing appropriate enzymes and a suitable pH for the Krebs cycle.

Intermembrane Space

The small compartment between the inner and outer mitochondrial membranes where protons quickly accumulate to form a gradient.

Glycolysis

A 10-step sequence of enzyme-catalyzed reactions in the cytoplasm that converts glucose ($C_6H_{12}O_6$) into two pyruvic acid molecules ($CH_3COCOOH$), producing a net gain of 2 ATP and 2 NADH without using oxygen.

Pyruvate Oxidation

A 1-step process in the mitochondrial matrix where pyruvate loses a carbon to release $CO_2$, reduces $NAD^+$ to NADH, and links to Coenzyme A to form Acetyl CoA.

Acetyl CoA

A 2-carbon molecule produced from carbohydrates, fats, or proteins linked to Coenzyme A before entering the Krebs cycle.

Krebs Cycle

An 8-step cyclic sequence of chemical reactions in the mitochondrial matrix that completes the metabolic breakdown of glucose by oxidizing acetyl-CoA to release $CO_2$, producing 1 ATP (or GTP), 3 NADH, and 1 $FADH_2$ per turn.

Sir Hans Adolf Krebs

The scientist who discovered the Citric Acid Cycle pathway in cellular respiration and won the Nobel Prize for his discovery.

Oxaloacetate

The 4-carbon acceptor compound in the Krebs cycle that combines with the 2-carbon acetyl group of Acetyl CoA to form citrate.

Citrate

The 6-carbon compound formed in the first step of the Krebs cycle from the combination of Acetyl CoA and oxaloacetate.

Electron Transport Chain (ETC)

A set of enzymes and protein complexes located on the inner mitochondrial membrane that shuttle high-energy electrons from NADH and $FADH_2$ to pump protons into the intermembrane space.

Chemiosmosis

The process in which protons diffuse down their electrochemical gradient from the intermembrane space into the matrix through ATP synthase to produce ATP.

Peter Mitchell

The scientist who proposed the chemiosmotic theory in the 1960s and received the Nobel Prize in 1978.

ATP Synthase

An enzyme and transport channel protein in the inner mitochondrial membrane that utilizes the energy stored in a proton gradient to synthesize ATP from ADP and inorganic phosphate.

Oxidative Phosphorylation

The overall mitochondrial metabolic process combining the Electron Transport Chain and chemiosmosis to generate the majority of cellular ATP.

Adenosine Triphosphate (ATP)

The primary biological energy-transfer molecule composed of an adenine nitrogenous base, a ribose sugar, and three phosphate groups connected by high-energy bonds.

Adenosine Diphosphate (ADP)

A lower-energy molecule formed when ATP loses its third phosphate group to release energy for cellular processes.

Aerobic Respiration

The cellular respiration process occurring in the presence of oxygen gas to produce energy, carbon dioxide, and water from food ($C_6H_{12}O_6 + 6O_2 \rightarrow 6CO_2 + 6H_2O + \text{ATP}$).

Anaerobic Respiration

The breakdown of glucose to release energy in the cytoplasm without the presence of oxygen gas.

Fermentation

A natural anaerobic process by which microorganisms convert carbohydrates into alcohol or organic acids.

Alcoholic Fermentation

An anaerobic biological pathway converting sugars like glucose into cellular energy, ethanol, and carbon dioxide ($C_6H_{12}O_6 \rightarrow 2C_2H_5OH + 2CO_2 + \text{ENERGY}$).

Lactic Acid Fermentation

An anaerobic metabolic pathway occurring in muscle cells and specific bacteria that converts six-carbon sugars into lactate/lactic acid ($C_6H_{12}O_6 \rightarrow 2C_3H_6O_3 + \text{ENERGY}$).

Cyclic Electron Flow

A photosynthetic process involving Photosystem I with active center P700 that cycles electrons to produce ATP without generating NADPH or oxygen.

Non-Cyclic Electron Flow

A photosynthetic pathway involving both Photosystems I and II (active center P680) that requires water photolysis to produce ATP, NADPH, and oxygen as a by-product.