Respiration
It can be described in the following points:
- Respiration is the mechanism by which living things transform oxygen into cellular energy. It takes place at the cellular level and is necessary for most living things’ survival.
- Aerobic and anaerobic are the two primary forms. The respiration which takes place in the absence of Oxygen is called Anaerobic Respiration whereas aerobic respiration needs oxygen to take place.
- The respiration which takes place in the presence of Oxygen is called Aerobic Respiration. This mechanism, which takes place in cells’ mitochondria, is the most effective energy generation.
- Breathing is different from respiration. Whereas respiration is the process through which oxygen is used to produce energy in the body, breathing is inhaling oxygen and releasing carbon dioxide.
Cellular Respiration
The metabolic process in which living cells get energy from ATP by inhaling oxygen and exhaling carbon dioxide is called respiration.
Cellular Respiration Equation
C 6 H 12 O 6 + 6 O 2 –> 6 CO 2 + 6 H 2 O + ATP
Internal Respiration
We use energy to walk and think and digest our food. We use energy for everything that goes on in our bodies. The energy comes from our food during respiration, which can be described as the chemical breakdown of food to produce life energy. This can also be called internal respiration because it takes place inside every cell of every living thing. Respiration usually needs oxygen and produces carbon dioxide as a waste product.
External Respiration
The word respiration is used to mean breathing, the movements that draw air into and push it out of the lungs. This is now called external respiration because it takes place outside cells and involves the exchange of oxygen and carbon dioxide between the body and the outside world.
Types of Respiration
There exist two types of Respirations which are as follows;
- Aerobic
- Anaerobic
What is the difference between aerobic and anaerobic respiration
The difference between Aerobic and Anaerobic are given below:
Aerobic Respiration
In most organisms, internal respiration requires oxygen and involves the complete breakdown of food by releasing all the Energy stored in it. This is called Aerobic respiration. The full breakdown (of one mole, which is 180 g) of glucose.
Anaerobic Respiration Equation
C 6 H 12 O 6 + 6 O 2 → 6 CO 2 + 6 H 2 O + ATP
OR
glucose + oxygen → carbon dioxide + water + energy (2898 kJ per mole)
The energy released in the Aerobic process is used in the following ways:
- Mechanical Energy is used to contract skeletal, heart, and gut muscles.
- Chemical Energy is used in the liver, kidneys, and nerve impulses.
- Growth and repairing Energy is used in cell division to develop new tissues and repair old and damaged tissues.
- Anabolism Energy makes proteins (enzymes and hormones), carbohydrates (e.g. glycogen), and fats.
- Heat Energy is used to maintain body temperature in warm-blooded animals.
Occurrence of Aerobic Respiration
- Most eukaryotic species, including animals, plants, and fungi, engage in this activity frequently. The peroxisomes, chloroplasts, and mitochondria are only a few cell organelles where this process can occur.
- Most living things depend on it to survive since it gives them the energy they need to perform their cellular tasks.
- This process occurs in tiny sausage-shaped objects called mitochondria, found in all types of cells. They contain enzymes which release energy from food.
Usage of Aerobic Respiration
- It is used for the production of ATP.
- It is used for the maintenance of cellular functions.
- It is used for the production of fuel for exercise.
- It is used for the breakdown of Proteins and Fats.
- It is used to remove toxins from the body.
Aerobic Respiration in Humans
Our respiratory system is used to breathe in oxygen for respiration and to breathe out carbon dioxide produced by respiration. The scientific name for the chest region of your body containing your respiratory system is the thorax, and the space inside it is the thoracic cavity.
The details of the components of the Respiratory System are as follows;
- The voice box or larynx. It makes sounds used in speaking.
- The windpipe or trachea. It is like the flexible hose of a vacuum cleaner or tumbles drier. It is held open by rings of cartilage.
- The lungs are soft and spongy.
- The ribs protect the lungs.
- The intercostal muscles help with breathing in and out.
- Lungs are in a space in the chest called the thoracic cavity.
- This cavity is lined with a slippery skin called the pleural membrane. It protects the lungs as they rub against the ribs.
- The windpipe has thousands of branches which end in tiny air sacs. This is where oxygen is taken into the body, and carbon dioxide is eliminated.
- The diaphragm is a sheet of muscle below the lungs. It helps with breathing in and out.
Anaerobic Respiration
Respiration can also take place without oxygen. It is then called anaerobic respiration. It produces less energy than aerobic respiration because food is not entirely broken down into carbon dioxide and water by releasing all its stored energy.
Yeasts get energy from a type of anaerobic respiration called fermentation. It produces alcohol:
Anaerobic Respiration Equation
C6H12O6 → 2C3H6O3 (Glucose → Lactic acid)
glucose → carbon dioxide + alcohol + energy (210 kJ per mole)
Yeast is used to creating alcoholic beverages by fermenting the sugar in fruit juice. Apple juice is fermented and used to make cider. Malt derived from barley seeds is fermented by yeast to produce beer.
Baking also uses fermentation. That happens when the dough is enriched with yeast and sugar. It releases carbon dioxide gas, which causes bubbles to form in the dough and raise it. The yeast is destroyed when the dough is baked in a hot oven.
Occurrence of Anaerobic Respiration
- Many bacteria produce energy through anaerobic respiration. For instance, Clostridium and other soil-dwelling bacteria.
- Yeast is an example of a fungus that can use anaerobic respiration to create ATP.
- Muscle tissue may employ anaerobic respiration to produce energy during strenuous activity if insufficient oxygen is not available to meet the energy needs. The muscle tissue makes lactic acid in this situation, which can cause muscle exhaustion.
- Plant roots may become oxygen-deprived in damp soil and turn to anaerobic respiration to generate energy. As a result, poisonous substances like ethanol and acetaldehyde may accumulate and harm the plant tissues.
Usage of Anaerobic Respiration
- It is used for the production of energy in micro-organisms.
- During hard work, it produces Lactic Acid in muscles which leads to fatigue.
- This process is used to remove pollution from the environment.
- This process is used in Anaerobic Fermentation which is used to preserve foods.
Anaerobic Respiration in Muscle
Walking or jogging is called aerobic exercise because the body can quickly obtain enough oxygen for aerobic respiration to supply all the energy it needs. Food is broken down into water and carbon dioxide and breathed out so it does not accumulate in the body. This is why walkers and fit joggers can continue for several hours.
Very fast running soon becomes anaerobic exercise because, no matter how quickly you breathe or your heart beats, your body cannot obtain enough oxygen for aerobic respiration to supply all its energy needs. Under these circumstances, your body gets extra energy from anaerobic respiration because this does not need oxygen. But it produces lactic acid instead of carbon dioxide and much less energy than aerobic respiration:
glucose → lactic acid + energy (150 kJ per mole)
The Oxygen debt
Our muscles ache as lactic acid builds up there. Within a minute, so much lactic acid is in your muscles that they stop working, and you must stop running. When you recover, breathe rapidly and deeply until you have enough oxygen to react with the lactic acid to produce carbon dioxide and water, which are then expelled.
“The oxygen debt is the quantity of oxygen required to eliminate lactic acid from muscles.“
How Living Things use and Store Energy
The energy released during respiration is not used directly. It is first used to build up a chemical called ATP (adenosine triphosphate), which is a temporary energy store. Think of ATP molecules as ‘packets‘ of energy which are ‘filled‘ during respiration. These packets can be ‘emptied‘ to release instant energy whenever needed without cells having to break down glucose molecules.
ATP delivers energy in precise amounts and can transfer energy to other chemicals, turning them from inert substances into highly reactive ones.
Where does Cellular Respiration take place
All organisms go through the metabolic process of breathing. It is a biological process that takes place inside an organism’s cells. The breakdown of glucose in this process results in the production of energy (ATP-Adenosine triphosphate), which is then utilized by cells to carry out numerous tasks. Respiration is a function of all living things, from simple single-celled creatures to dominant multicellular ones. This process of cellular respiration takes place in the Lungs.
Lungs
Adults have an internal lung area of 90m², which is 40 times the external area of the body. You breathe about 13500 litres of air daily to obtain oxygen and remove carbon dioxide from your body.
The details of the components of the Lungs which take part in the process of Lungs are as follows;
- The windpipe divides into two tubes called bronchi.
- The bronchi divide into smaller, bronchiole-shaped tubes thousands of times.
- There are air sacs at the ends of the bronchioles. Here is where the exchange of gases happens.
- The air sac looks like a bunch of grapes. The ‘grapes’ are called alveoli. They are smaller than grains of salt, and 300 million are in your lungs. Alveoli have thin, moist walls, so gases can quickly pass through them.
- Blood flows to the lungs from around the body. It carries carbon dioxide produced by respiration in the cells of the body.
- Alveoli get carbon dioxide from the blood. The body exhales it after that.
- Alveoli are covered with narrow blood vessels called capillaries. Oxygen passes into the capillaries from the alveoli.
- Alveoli are only 0.2 mm in diameter. They give lungs a spongy texture and an enormous internal surface area: 90m², the size of a singles tennis court. This large area is needed for the efficient absorption of oxygen and to release carbon dioxide at rest and during exercise.
- Blood carries oxygen away from the lungs to every cell in the body, where it is used for respiration.
- Oxygen is breathed into the lungs. It disintegrates in the alveoli’s water. From there, it passes into the blood.
Breath In
- When intercostal muscles contract. These pull the ribcage upwards. So the chest increases in volume.
- The diaphragm contracts. This makes it flatten out, so the chest gets even more significant.
- By forcing air through the windpipe and into the lungs, this pressure differential inflates them. This pressure difference forces air down the windpipe into the lungs, inflating them. The movement of air in and out of the lungs is called ventilation.
Breath Out
- When intercostal muscles relax, which lowers the rib cage. The chest decreases in volume.
- The diaphragm relaxes and bulges upwards. This decreases the volume of the chest even more.
- Because the chest has got smaller, the air is forced out of the lungs.
How Air changes in our Lungs
| Gas | Amount of gas in the air we breathe in | Amount of gas in the air we breathe out |
| Oxygen | 21% | 16% |
| Carbon dioxide | 0.04% | 4% |
| Nitrogen | 70% | 79% |
| Water Vapour | a little | a lot |
The internal Surface area of adult lungs is 90m2, which is the size of a singles tennis court. Why do you think it needs to be so large?
The internal Surface area of the lungs should be significant because the large surface area allows for a rapid exchange of gases, which is essential for meeting the body’s metabolic demands. As we engage in physical activity or experience stress, our body’s oxygen needs increase. The large surface area of the lungs enables us to take in more oxygen quickly and efficiently to meet this demand.
FAQ’s
Why is Respiration essential for life?
The essential requirement of the body of living organisms is energy to carry out all the functions of life, and this energy is required in the form of ATP. Respiration is the only process by which ATP can be generated in the body to carry out all life functions. This process can occur when our body takes in oxygen and takes out carbon dioxide. So in this way, this process is necessary for the survival of living organisms.
What is the difference between Respiration and Breathing?
The act of breathing involves taking in oxygen and releasing carbon dioxide. The contraction and relaxation of the muscles in the chest and belly move the air. The exchange of gases between the body and the environment depends on breathing.
The process of respiration is how cells turn oxygen and nutrients into energy. It includes the transfer of gases from the lungs to the blood and reaching oxygen to the cells via the blood.
Why can joggers run for hours but sprinters have to stop after a few seconds?
Jogging is an aerobic exercise that primarily uses the body’s aerobic energy system. This energy system utilizes oxygen to break down carbohydrates and fats, providing a slow but steady energy source. Because this energy system can be sustained for extended periods, joggers can maintain their activity for extended periods, such as hours.
Sprinting is an anaerobic exercise. This energy system does not require oxygen and instead breaks down carbohydrates stored in the muscles for energy. Lactic acid is produced in muscles as a byproduct of this process which causes fatigue. This is why sprinters can only maintain their activity at maximum effort for a few seconds before needing to stop and recover.
Which of the two builds up an oxygen debt?
During hard work, the body requires more energy which is produced anaerobically to fulfill the need. This anaerobic energy generates Lactic Acid in muscles, which causes fatigue. This anaerobic energy production can also lead to the accumulation of what is known as oxygen debt. An oxygen debt occurs when the body’s demand for oxygen during exercise exceeds its supply capacity.
Therefore, the anaerobic activity builds up an oxygen debt, as it is the period when the body produces energy without enough oxygen to meet its needs.
What kind of respiration is going on in our body now, and when we run very fast?
In the stable form, our body respires Aerobically, and when we start to do running, our body respires Anaerobically because during running demand for oxygen is high.
Which gases are exchanged in your lungs?
In the lungs, oxygen (O2) and carbon dioxide (CO2) are the gases that are exchanged. The bloodstream receives oxygen upon intake from the atmosphere, which diffuses into the body’s tissues together with red blood cells. The body’s cells produce carbon dioxide, which is carried by the bloodstream and diffuses from the blood into the lungs’ air before exhaling.
Where in the lungs does a gas exchange take place?
The Alveoli in the Lungs are tiny air sacs, where the gas exchange occurs. Although carbon dioxide is distributed out of the bloodstream and into the alveoli for exhalation, oxygen from the air is spread into the bloodstream.
Do we use all the Oxygen we breathe in?
No, Not all of the oxygen we breathe in is used by humans. In addition to other gases like nitrogen, carbon dioxide, and argon, the air we breathe contains around 21% oxygen.
What are the products of cellular respiration?
Carbon Dioxide, Water and Energy.
Which of these are by-products of cellular respiration?
Carbon dioxide (CO2)
Water (H2O)
ATP (adenosine triphosphate)
Which metabolic pathway is common to both cellular respiration and fermentation?
Glycolysis is the metabolic route that connects fermentation with cellular respiration. Basically, it is the conversion of glucose into pyruvate. Both times, glucose is broken down into two pyruvate molecules and a little quantity of ATP. Pyruvate is further oxidized and increases the quantity of ATP produced by the Krebs cycle and electron transport chain. Pyruvate is converted during fermentation into a range of byproducts such as lactic acid, ethanol, or other organic acids without the usage of oxygen.
What organelle does cellular respiration occur in?
In Mitochondria.
What role does cellular respiration play in the water cycle?
In all living organisms, the process of cellular respiration results in the production of water. By actions including perspiration, expiration, and urination, this water is discharged into the environment.
The organism can also utilize the water created during cellular respiration for a number of biological functions, including hydration maintenance for cells and temperature control.
For photosynthesis, plants, which are an important part of the water cycle, utilize the water created during cellular respiration. During photosynthesis, plants employ water, carbon dioxide, and sunshine to produce glucose and oxygen. The cycle is completed when the plant uses the glucose created during photosynthesis for energy through cellular respiration.
During cellular respiration, acetyl Coa accumulates in which location?
In the mitochondrial matrix, acetyl CoA builds up during cellular respiration. For the production of Acetyl Coa, pyruvate is broken down in the mitochondrial matrix. In the Krebs cycle, acetyl CoA undergoes further oxidative phosphorylation to produce ATP. As a result, during cellular respiration, acetyl CoA is primarily deposited in the mitochondrial matrix.
What organisms perform cellular respiration?
Protists, fungi, plants, and mammals. This process happens in plants in addition to photosynthesis, which harnesses the energy of sunlight. To obtain power from organic molecules, animals and other heterotrophic creatures rely solely on this cellular respiratory process.
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