Cellular Respiration: Energy Production of Cells

These flashcards cover vocabulary related to cellular respiration, focusing on key terms, processes, and concepts discussed in the lecture.

Cellular Respiration

The essential metabolic process in cells that consumes oxygen and organic molecules to produce carbon dioxide and ATP.

Mitochondria

Organelles known as the power stations of the cell, responsible for the production of ATP.

ATP (Adenosine Triphosphate)

The main energy currency of cells, consisting of adenine, ribose, and three phosphate groups.

Glycolysis

The first step in energy production where glucose is broken down into two pyruvate molecules, producing NADH and ATP.

Citric Acid Cycle (Krebs Cycle)

A series of chemical reactions in mitochondria that generates energy through the oxidation of Acetyl-CoA.

Oxidative Phosphorylation

The final stage of cellular respiration where ATP is produced through the electron transport chain.

NADH (Nicotinamide Adenine Dinucleotide)

An energy-carrying molecule that provides hydrogen protons for oxidative phosphorylation.

Pyruvate Oxidation

The process converting pyruvate into Acetyl-CoA, involving the release of carbon dioxide.

Acetyl-CoA

A two-carbon molecule formed from pyruvate that enters the citric acid cycle.

Electrochemical Gradient

A gradient formed by the difference in concentration of ions across a membrane, crucial for ATP synthesis.

Protein Complexes

Protein structures in mitochondria that facilitate electron transport during oxidative phosphorylation.

Active Transport

The movement of substances across a cell membrane against a concentration gradient, requiring energy.

Passive Transport

The movement of substances across a cell membrane without the use of energy, following the concentration gradient.

Phenotype

The observable physical properties of an organism, which can be influenced by mitochondrial DNA.

Mitochondrial DNA

DNA located in mitochondria, inherited only from the mother and capable of affecting phenotype.

Aerobic Conditions

Conditions requiring oxygen, where organisms produce energy through cellular respiration.

Greenhouse Gases

Gases that trap heat in the atmosphere, contributing to climate change, often released during cellular respiration.

Biological Macromolecules

Large molecules, such as proteins and lipids, that can serve as energy sources in the absence of glucose.

Overall chemical equation for cellular respiration

C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + \text{Energy (ATP)}

Location of Glycolysis

The cytoplasm of the cell.

Final electron acceptor in aerobic respiration

Oxygen (O_2).

ATP Synthase

An enzyme located in the inner mitochondrial membrane that uses the energy from the electrochemical gradient to produce ATP.

FADH_2 (Flavin Adenine Dinucleotide)

An energy-carrying molecule, similar to NADH, that carries electrons to the electron transport chain during oxidative phosphorylation.

Anaerobic Respiration / Fermentation

Metabolic processes that produce energy in the absence of oxygen, yielding less ATP than aerobic respiration.

Net ATP yield from Glycolysis

2 ATP molecules per glucose molecule.

Location of the Citric Acid Cycle

The mitochondrial matrix.

Primary role of oxygen in aerobic cellular respiration

Acts as the final electron acceptor in the electron transport chain, forming water.

Electron Transport Chain (ETC)

A series of protein complexes embedded in the inner mitochondrial membrane that uses the energy from electrons carried by NADH and FADH_2 to pump protons and generate an electrochemical gradient.

Products of Pyruvate Oxidation (per glucose)

Two Acetyl-CoA molecules, two NADH molecules, and two carbon dioxide molecules.

Intermembrane Space of Mitochondria

The region between the inner and outer mitochondrial membranes where protons accumulate to form the electrochemical gradient during cellular respiration.

What is the primary purpose of cellular respiration?

To convert oxygen and organic molecules into ATP and carbon dioxide, providing energy for cellular functions.

What are the four main stages of cellular respiration?

Glycolysis, Pyruvate Oxidation, Citric Acid Cycle (Krebs Cycle), and Oxidative Phosphorylation.

Who discovered mitochondria and when?

Albert von Kölliker in 1857.

What does the symbiosis hypothesis suggest about mitochondria?

Mitochondria were once free-living prokaryotes that were captured by early eukaryotic cells.

How is mitochondrial DNA inherited?

It is inherited strictly from the mother.

What are the key inputs and outputs of glycolysis?

Inputs: 1 glucose, 2 ATP. Outputs: 2 pyruvate, 4 ATP (net gain of 2 ATP), 2 NADH.

What are the products of one turn of the Citric Acid Cycle (Krebs Cycle)?

3 NADH, 1 FADH_2, 1 ATP, and 2 CO_2.

How is ATP produced during oxidative phosphorylation?

Electrons from NADH and FADH_2 move through protein complexes, creating a proton gradient that powers ATP synthase to produce ATP.

Approximately how much ATP is produced from one glucose molecule through complete aerobic respiration?

About 38 ATP total (2 from glycolysis, 2 from Krebs cycle, 34 from oxidative phosphorylation).

Describe how ATP synthase creates ATP.

Protons pass through the enzyme, causing it to rotate and join ADP with inorganic phosphate to form ATP.

How has research on cellular respiration benefited agriculture?

It led to discoveries about how different light wavelengths affect plant growth.

What environmental technology is inspired by respiration?

Hydrogen fuel cells, which mimic respiration to produce clean energy from hydrogen and oxygen.

Besides glucose, what other macromolecules can cells use as energy sources?

Lipids, proteins, and nucleic acids (which can be converted to Acetyl-CoA).

Name two diseases linked to abnormal cellular respiration processes.

Alzheimer’s disease and cancer.

ADP (Adenosine Diphosphate)

A molecule formed when ATP loses a phosphate group, representing a lower energy state.

CoA (Coenzyme A)

A coenzyme that helps the acetyl group enter the Citric Acid Cycle.