Respiration

Respiration is the process by which living organisms take in oxygen and release carbon dioxide. There are two main types of respiration: cellular respiration and breathing.

Cellular Respiration

Cellular respiration is the process by which cells break down glucose and other organic molecules to produce energy in the form of ATP. This process occurs in the mitochondria of the cell and involves three main stages: glycolysis, the Krebs cycle, and the electron transport chain.

Glycolysis

In glycolysis, glucose is broken down into pyruvate, producing a small amount of ATP and NADH in the process. This stage takes place in the cytoplasm of the cell.

The Krebs Cycle

The pyruvate from glycolysis enters the mitochondria and is further broken down in the Krebs cycle, producing more ATP, NADH, and FADH₂.

Electron Transport Chain

The NADH and FADH₂ produced in the previous stages donate their electrons to the electron transport chain, which generates a large amount of ATP through oxidative phosphorylation.

Breathing

Breathing, or ventilation, is the process of inhaling oxygen and exhaling carbon dioxide. This exchange of gases occurs in the respiratory system, specifically in the lungs.

Inhalation

During inhalation, the diaphragm contracts and the ribcage expands, creating a vacuum in the chest cavity. This causes air to be drawn into the lungs, where oxygen is transferred to the bloodstream.

Exhalation

During exhalation, the diaphragm and ribcage relax, causing the chest cavity to decrease in size and expel air from the lungs, along with carbon dioxide.

Study Guide

1. What is respiration?
2. What are the two main types of respiration?
3. Describe the process of cellular respiration.
4. What are the three main stages of cellular respiration?
5. Where does glycolysis take place?
6. Where does the Krebs cycle occur?
7. What is the role of the electron transport chain in cellular respiration?
8. Explain the process of breathing.
9. What happens during inhalation?
10. Describe the process of exhalation.

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