Respiration in Organisms

• Organisms respire to obtain energy from food.
• Breathing involves inhaling air containing oxygen and exhaling air rich in carbon dioxide.
• Air breathed in is transported to all parts of the body and to each cell.
• Oxygen aids in the breakdown of food in cells in a process called cellular respiration.
• Cellular respiration occurs in the cells of all organisms.

Types of Respiration

• During cellular respiration, glucose breaks down into carbon dioxide and water using oxygen.
• Aerobic respiration happens when glucose breaks down with the use of oxygen.
• Anaerobic respiration happens when food breaks down without using oxygen.
• Both aerobic and anaerobic respiration releases energy.
• Yeasts are single-celled organisms that respire anaerobically, producing alcohol.
• Anaerobes are organisms like yeast which can survive without air.
• Muscle cells respire anaerobically for a short time when there is a temporary lack of oxygen.
• During heavy exercise, anaerobic respiration in muscle cells produces lactic acid, leading to muscle cramps.
• Cramps can be relieved by hot water baths or massages.
• These increase blood circulation and oxygen supply to muscle cells, breaking down lactic acid.

Breathing

• Breathing involves inhaling oxygen-rich air and exhaling carbon dioxide-rich air.
• Inhalation is taking air rich in oxygen and exhalation is giving out air loaded with carbon dioxide.
• Breathing is a continuous process.
• Breathing rate is the number of breaths per minute.
• A breath includes one inhalation and one exhalation.
• An adult human breathes 15-18 times per minute when resting and breathing rate increases up to 25 times per minutes during heavy exercise.
• During exercise the body needs more energy, breathing faster supplies more oxygen to the cells for energy production.
• Air normally enters the nostrils, passes through the nasal cavity, and reaches the lungs via the windpipe.
• The chest cavity which holds the lungs is surrounded by ribs and has a diaphragm as its floor.
• Rib cage and diaphragm movement facilitates breathing.
• During inhalation, ribs move up and outwards and diaphragm moves down.
• During exhalation, ribs move downwards and inwards and diaphragm moves up to its former position.
• Sneezing expels foreign particles from inhaled air.
• It's vital covering the nose while sneezing to prevent spreading foreign particles.
• Smoking damages lungs and is linked to cancer, smoking is best avoided.

Breathing Out

• Air exhaled is a mixture of gases, not just carbon dioxide.

Other Animals Breathing

• Animals like elephants, lions, cows, goats, frogs, lizards, snakes, and birds have lungs.
• Cockroaches have spiracles and tracheae for gas exchange.
• Earthworms breathe through their moist skin.
• Frogs use both lungs and their skin for breathing.
• Aquatic animals like fish have gills to utilize dissolved oxygen in water.
• Gills are projections of the skin supplied with blood vessels for gas exchange.

Respiration in plants

• Plants respire like other living organisms.
• Each part of a plant can independently take in oxygen and give out carbon dioxide.
• Tiny pores called stomata on leaves exchange oxygen and carbon dioxide.
• Root cells take up air from air spaces between soil particulars.

Explore how organisms respire to get energy from food, focusing on breathing mechanisms and cellular respiration. Learn about aerobic and anaerobic respiration, including how yeasts respire anaerobically. Also, understand how muscle cells respire when there is a lack of oxygen.