Respiration: Aerobic vs. Anaerobic

• Respiration is the process of releasing energy from food.
• Respiration involves taking in oxygen into cells, releasing energy by burning food, and eliminating waste products.
• The formula for respiration is: Glucose + Oxygen yields Carbon Dioxide + Water + Energy.

Aerobic and Anaerobic Respiration

• Breakdown of food in the cells with release of energy is respiration.

Aerobic Respiration

• Breakdown of food occurs using oxygen.
• Most organisms, like dogs, cats, and lions, carry out aerobic respiration.

Anaerobic Respiration

• Breakdown of food occurs without oxygen.
• Organisms like yeast respire this way.
• Glucose yields Alcohol + Carbon Dioxide + Energy.

Yeast

• Yeast is an anaerobe.
• It is a single-celled organism.
• Yeast converts glucose into alcohol.
• It's used to make wine, beer, and bread.

Anaerobic Respiration in Muscles

• Oxygen in muscle cells gets used up faster during vigorous physical activity.
• Glucose is partially broken down to form lactic acid, providing some energy.
• Glucose yields Lactic Acid + Energy.
• Accumulation of lactic acid in the muscle causes cramps.

Breathing

• Breathing is the process by which oxygen is taken in and carbon dioxide is expelled.
• Breathing supplies oxygen to the body and removes waste carbon dioxide.
• Mountaineers carry oxygen tanks because higher altitudes contain less air.

Breathing Rate

• The average adult breathes 15-18 times per minute.
• Breathing rate changes according to the body's needs.
• During heavy exercise, a human can breathe up to 24 times per minute.
• The breathing rate of children is higher than adults.

How We Breathe

• Lungs are connected to the nostrils through the nasal passage and windpipe.
• Lungs hang in an airtight space called the chest cavity, with the rib cage around the sides and sheets of muscle between the ribs.
• At the bottom of the chest cavity is a curved sheet of muscle called the diaphragm.

Air Composition (Inhaled vs. Exhaled)

• Inhaled air contains 21% oxygen, 0.04% carbon dioxide, and a little water vapor.
• Exhaled air contains 16.4% oxygen, 4.4% carbon dioxide, and a lot of water vapor.
• Exhaling on a mirror forms moisture due to the water vapor.

Respiration in Humans

• The respiratory system includes the nose, nasal passage, trachea, bronchi, lungs, and diaphragm.
• The nasal passage joins the nose to the windpipe (trachea).
• The upper end of the trachea has a voice box called the larynx.
• The trachea branches into two smaller tubes called bronchi.
• Each bronchus divides in the lungs to form bronchioles.
• Bronchioles have air sacs at their ends known as alveoli.
• Exchange of gases takes place in the walls of alveoli.

Breathing in Animals

• Animals like lions, cows, goats, and frogs have lungs.
• Cockroaches have small openings called spiracles.
• Insects have a network of air tubes called tracheae.
• Oxygen rushes through spiracles into tracheae, diffusing into tissues and reaching every cell.
• Earthworm skin feels moist and sticky, allowing air to pass through.
• Frogs breathe through their skin.

Breathing Underwater

• Gills are projections of the skin.
• They are supplied with blood vessels for the exchange of gases.

Respiration in Plants

• Root cells need oxygen to generate energy.
• Roots take up air spaces between soil particles.

Additional Notes

• Amoeba is a microorganism that exchanges gases through its general body surface.
• Air becomes warmer after passing through the nasal cavity.
• Hot water baths relieve cramps by improving blood circulation, increasing oxygen supply, and breaking down lactic acid into carbon dioxide and water.
• Root oxygen in soil particles diffuses into root hair and reaches all cells of the body.
• Hemoglobin is a pigment that carries oxygen to all parts of the body.