Respiration In Organisms

Respiration is a vital process because it breaks down food molecules like glucose to release energy. This energy is needed for all life activities such as growth, movement, repair of cells, and maintaining body temperature.

Cellular respiration takes place inside the mitochondria of cells. Its main job is to convert the chemical energy stored in glucose into a usable form of energy (ATP) that the cell can use to perform its functions.

The word “aerobic” means “with air” or “with oxygen.” In aerobic respiration, cells use oxygen to completely break down glucose into carbon dioxide and water, which releases a large amount of energy.

During aerobic respiration, glucose (from food) reacts with oxygen to produce carbon dioxide and water. Along with these two waste products, a lot of energy is also released for the body to use.

Mitochondria are often called the “powerhouses of the cell” because they are the specific organelles where oxygen is used to break down glucose and release energy during aerobic respiration.

The word “anaerobic” means “without air” or “without oxygen.” In this type of respiration, cells break down glucose without using oxygen. This process releases less energy compared to aerobic respiration.

Yeast are tiny organisms that perform anaerobic respiration (also called fermentation). They break down sugar into ethyl alcohol and carbon dioxide gas, and this process releases a small amount of energy.

When yeast is added to dough, it starts respiring anaerobically. It produces carbon dioxide gas, which forms tiny bubbles in the dough. These bubbles get trapped and make the dough rise or become fluffy.

When we run or exercise hard, our muscles may not get enough oxygen immediately. They then switch to anaerobic respiration, which produces lactic acid. The build-up of lactic acid in muscles causes pain and cramps.

Anaerobes are organisms that do not need oxygen to live and grow. In fact, for many of them, oxygen is poisonous. Some bacteria that live deep in the soil or in the guts of animals are anaerobes.

ATP stands for Adenosine Triphosphate. It is the energy currency of the cell. The energy released from breaking down food is used to make ATP, and when a cell needs energy for work, it breaks down ATP.

Photosynthesis (in plants) uses carbon dioxide and water to make glucose and oxygen in the presence of sunlight. Respiration uses oxygen and glucose to make carbon dioxide, water, and energy. So they are reverse of each other.

Breathing is a physical process. It is the movement of air into and out of the lungs. It has two steps: inhalation (taking in oxygen-rich air) and exhalation (giving out carbon dioxide-rich air).

When we breathe in, the muscles between our ribs contract and pull the ribs up and out. At the same time, the diaphragm (a dome-shaped muscle below the lungs) flattens and moves down. This increases the space in the chest cavity.

During exhalation, the diaphragm relaxes and moves up into its original dome-like shape. The rib muscles also relax, moving the ribs down and in. This decreases the chest cavity space and pushes air out of the lungs.

A normal adult at rest usually breathes about 12 to 20 times per minute. One breath means one inhalation and one exhalation. This rate can change depending on the body’s need for oxygen.

During running, our muscles work harder and need more energy. To produce this extra energy, cells need more oxygen. So, we breathe faster to take in more oxygen and also to get rid of the extra carbon dioxide produced.

Whether it is aerobic or anaerobic, respiration breaks down glucose. In humans, aerobic respiration produces carbon dioxide as a waste product. This carbon dioxide is carried by the blood to the lungs and breathed out.

Glycolysis is the first step of respiration that happens in the cytoplasm. It breaks one glucose molecule into two smaller molecules called pyruvate. This step does not require oxygen and releases a small amount of energy.

Yeast is a unicellular fungus. When there is no oxygen available, yeast performs anaerobic respiration called alcoholic fermentation. In this process, sugar is converted into alcohol (ethanol) and carbon dioxide.

Our brain constantly monitors the level of carbon dioxide in our blood. When we hold our breath, carbon dioxide levels rise. The brain detects this increase and sends strong signals to the breathing muscles to start breathing again.

The diaphragm is a large, dome-shaped sheet of muscle that separates the chest cavity from the abdominal cavity. It is the primary muscle for breathing. Its contraction and relaxation change the volume of the chest cavity.

Our body maintains a temperature of about 37°C (98.6°F). When cold air from outside enters our body, it gets warmed up as it passes through the nasal passages and lungs. So when we breathe out, the air is warmer.

A stethoscope is used to listen to internal sounds of the body. By placing it on the chest, a doctor can hear the sound of air moving in and out of the lungs (breathing sounds) and also the heart beating.

When glucose is broken down without oxygen, it is only partially broken down. The end products (like lactic acid or alcohol) still contain a lot of chemical energy. Therefore, anaerobic respiration releases much less energy (only about 5% of aerobic respiration).

Aerobic respiration breaks down glucose completely into carbon dioxide and water. This complete breakdown releases a large amount of energy (about 36-38 ATP molecules). Anaerobic respiration releases only 2 ATP molecules per glucose, so much less energy.

Clostridium is a type of bacteria that cannot survive in the presence of oxygen. It lives in places like deep mud, soil, or inside animal intestines where there is no oxygen. These are called obligate anaerobes.

Yawning is a deep, involuntary inhalation. When we are tired, sleepy, or bored, our breathing may become shallow. This can lower oxygen levels in the blood. A yawn helps to quickly bring a large gulp of oxygen into the lungs.

All living cells, whether in the skin, muscles, brain, or roots of a plant, need energy to survive and do their jobs. Therefore, cellular respiration (the breakdown of food to release energy) happens continuously in every living cell.

When we sleep, our body is at complete rest and needs less energy. Therefore, the demand for oxygen is lower. As a result, our breathing rate slows down compared to when we are awake or active.

Oxygen is used as an input in aerobic respiration. It is never a product or waste of respiration. In fact, respiration produces carbon dioxide and water, not oxygen. Oxygen is produced by plants during photosynthesis.

The lungs contain millions of tiny, balloon-like structures called alveoli. They are surrounded by blood capillaries. Here, oxygen from the air passes into the blood, and carbon dioxide from the blood passes into the air to be exhaled.

Most of the carbon dioxide (about 70%) is carried in the blood plasma in the form of bicarbonate ions. This is a safe and efficient way to transport this waste gas from the tissues to the lungs, where it is converted back to CO2 and exhaled.

Slow, deep breathing means each breath takes longer. So even though the amount of air exchanged per minute might be similar, the number of breaths taken in one minute (the breathing rate) goes down compared to normal, shallow breathing.

While yeast does produce alcohol, that is not useful for baking bread. The carbon dioxide gas produced by yeast is what makes the dough rise and gives bread a soft, fluffy texture. The alcohol evaporates during baking.

Smaller animals generally have a higher metabolic rate and lose heat faster than larger animals. To maintain their body temperature and energy needs, they need more oxygen relative to their size. So a small bird like a sparrow breathes much faster (about 30-40 breaths per minute) than a human.

Hemoglobin is a red protein inside red blood cells. It has a very high affinity for oxygen. In the lungs, oxygen binds to hemoglobin to form oxyhemoglobin. When blood reaches tissues that need oxygen, hemoglobin releases it.

Breathing is a mechanical or physical process. It involves the movement of the diaphragm and rib muscles to change air pressure in the chest, causing air to move in and out. It does not produce energy; that is the job of cellular respiration.

Air enters through the nostrils, passes into the nasal cavity, then goes down the trachea (windpipe). The trachea splits into two tubes called bronchi (singular: bronchus). Each bronchus goes into a lung and branches into smaller tubes (bronchioles) ending in alveoli.

Underwater, humans cannot separate the oxygen dissolved in water using our lungs. The oxygen cylinders carry compressed air (which contains oxygen) so that divers can breathe normally and get the oxygen needed for respiration.

When jogging, leg muscles work hard and need a lot of energy, requiring more oxygen. After resting, the muscle activity decreases, so the need for energy and oxygen goes down. Therefore, the breathing rate returns to normal.

When human muscles do not get enough oxygen during sudden, intense activity, they produce energy anaerobically. This process breaks down glucose into lactic acid. The accumulation of lactic acid causes muscle fatigue, soreness, and cramps.

Breathing rate is simply the number of breaths (one inhalation + one exhalation) taken per minute. It is an important vital sign that tells us how fast or slow a person is breathing.

During deep inhalation, the diaphragm contracts strongly. It flattens and moves downward toward the abdomen. This greatly increases the volume of the chest cavity, allowing the lungs to expand and fill with a large amount of air.

Insects do not have lungs. They have a network of air tubes called tracheae. The openings of these tubes on the outside of the insect’s body are called spiracles. Air enters and leaves through these small holes.

A good respiratory surface needs to be thin and moist so that gases (oxygen and carbon dioxide) can diffuse easily across it. It should have a large surface area to exchange more gas, and a rich blood supply to carry gases away. Thick and dry surfaces would prevent gas exchange.

Aerobic respiration is much more efficient. It releases about 18 times more energy from one glucose molecule than anaerobic respiration does. This is because aerobic respiration breaks glucose down completely, while anaerobic leaves energy trapped in alcohol or lactic acid.

In the wine and beer industry, yeast is grown in large vats without oxygen. The yeast performs anaerobic respiration (fermentation) on the sugar from grapes or barley. This process produces ethyl alcohol, which gives alcoholic drinks their intoxicating property.

When a person has a fever, the body’s temperature rises. This increases the body’s metabolic rate, meaning cells are working faster and need more energy and oxygen. To meet this demand, the breathing rate increases to bring in more oxygen and remove more CO2.

Breathing rate is lowest when the body requires the least amount of energy. Sleeping is a state of complete physical and mental rest. During sleep, muscles are relaxed, heart rate slows, and the demand for oxygen is minimal, so the breathing rate is at its slowest.