RESPIRATION NOTES FOR CLASS 10
Respiration:- Respiration commonly involves the use of oxygen to break down carbohydrates and other organic molecules, giving usable energy, carbon dioxide and water in this process.
Anaerobic respiration:- Partial oxidation of food in the absence of oxygen, resulting in release in some amount of energy is called anaerobic respiration.
1. How pyruvate is formed in anaerobic respiration?
=> Glucose has 6 carbon atoms joined to each other by covalent bond. Hydrogen and oxygen atoms are also attached to these carbon atoms. In anaerobic respirations of glucose; some of hydrogen atoms are removed and resulting in its oxidation. After a series of reaction the glucose get converted into two molecules of pyruvate, containing 3 atoms of carbon. This reaction also produces two molecules of ATP.
Glycolysis:- The oxidation of glucose in a series of reaction leading to formation of pyruvate is called glycolysis. How ethanol and lactic acid are formed in anaerobic respiration? In low supply of oxygen yeast converts pyruvate to ethanol and energy and carbon dioxide. Certain bacteria which lack mitochondria convert pyruvate to lactic acid. When our muscles are overworked our blood is unable to transport oxygen fast enough to produce energy through aerobic means. In case of low supply of oxygen pyruvate get converted into lactic acid. Accumulation of excess lactic acid in muscles causes pain.
Aerobic respiration:- The complete oxidation of food yielding carbon dioxide, water and energy in the presence of oxygen, is called aerobic respiration.
2. What happens in aerobic respiration?
=> Aerobic respiration takes place in mitochondria. After glycolysis, pyruvate enters the mitochondria and is oxidized in a series of reaction. After the complete oxidation of pyruvate convert into carbon dioxide, water and ATP. The numbers of molecules of ATP formed is 38.
3. How ATP is formed?
=> In mitochondria, when an inorganic phosphate group ( Po4 , represented here as Pi here) get attached to a compound ADP (adenosine diphosphate), a molecule of ATP (adenosine triphosphate) is formed.
ADP +Pi ATP
4. How ATP is broken to produce energy?
=>The bond holding last phosphate group gets broken when ATP reacts with water. In this reaction energy is produced. This energy is used to drive cellular processes that are endothermic. For ex: - protein synthesis, contraction of muscles take energy from ATP.
5. which parts of the plants help in exchange of gases?
=>The exchange of gases takes place in plants through stomata, intercellular spaces of this leaves and the lenticels present in the bark. How respiration of plants changes in day and night? The direction of exchange of gases between plants and its surrounding depend on time of the day or usages of gases by plants. During day time photosynthesis takes place, carbon- dioxide produced by plants in respiration used by plants for photosynthesis. So carbon dioxide do not released in atmosphere. In fact, plants take additional carbon dioxide from air for photosynthesis. Some amount of oxygen released in photosynthesis is used by plants and rest is released to air. During night time, no photosynthesis reaction occurs and the carbon dioxide produced by plants during respiration is not released in the air. And hence carbon dioxide is released to the air. So, you are advised to do not sleep under tree during night time.
6. which parts of the body helps in exchange of gases in animals?
=>In insects the exchange of gases takes place by tracheae, in fishes by gills and in animals by lungs.
Tracheae:- Trachea is fine system of air tubes reaching to all parts of the body. Oxygen reaches the tissue through tracheae.
Gills:- In aquatic animals, there are gills. Because they have to use the oxygen dissolved in water. In fish, as water enter through mouth; it passes through the chambers where gills are present. The exchange of gases takes place through gills. The blood vessels in the gills absorbed the oxygen from water and are transported to all parts of the body. Why the rate of breathing in aquatic organism is higher than those of terrestrial organism? The terrestrial organisms use the abundant oxygen from the air. Since the solubility of oxygen in water is low. The aquatic organism use the oxygen dissolved in water. Due to low availability of oxygen the breathing rate of aquatic organism is higher than terrestrial animals.
HUMAN RESPIRATORY SYSTEM
Air enters the nose through the nostrils. When air enters the nose it is warm, filtered and moistened. The air is filtered by hair in nose, moistened by mucus and warm by
blood capillaries running in nose. The respiratory tract from nose to bronchioles lined by mucous membrane and cilia. The mucus and cilia acts as additional filter. The air enters the pharynx, the pharynx lie behind the nose. There are two passages here- one for food and another for air. The air passes through pharynx to larynx. The opening leading to larynx is called glottis. It is protected by a lid called epiglottis, which prevent food from entering the passage of lungs. The air enters the trachea from larynx. The trachea is 11 cm long tube. It is guarded by C-shaped cartilage rings, which prevent trachea from collapsing. The trachea divided into two tubes called bronchi. Each bronchus divides into thinner tubes called bronchus. The bronchioles enter the lungs and divides further in finer branches called alveolar ducts. These alveolar ducts open in extremely thin walled grape shaped air sacs called alveoli. The alveoli are covered by web of blood capillaries. The lungs are spongy organ lie in chest cavity formed by ribs. The actual exchange of gases takes place inside the capillary covered alveoli. The oxygen from the air in alveoli goes into blood and carbon dioxide from the blood goes out. The oxygen binds to haemoglobin in red blood corpuscles and transported to different parts of the body.
Inspiration:- Inspiration is process of breathing in, by which air is brought into the lungs. The inspiration involves the following steps:- 1. The muscles attached to ribs on their outer side contract and pulled out to expand the chest cavity. 2. The muscular partition between chest and abdominal cavity diaphragm moves downward to further expand the chest cavity. 3. The abdominal muscles contract. 4. The expansion of chest cavity creates a partial vacuum, which sucks air and fill the expanded alveoli.
Expiration:- After exchange of gases, the air has to be expelled out. The expulsion of air from the lungs to the nose is called expulsion. In this process the following events occur:- 1. The muscles attached to the ribs on inner side contracts. 2. The abdominal muscle relaxes. 3. The diaphragm also relaxes. The expulsion of air from lungs causes decreasing the volume of chest cavity and increases the pressure on lungs. Not all of the air expelled from lungs. Some of it remains in lungs and prevent it from collapsing and allow more time for exchange of gases.
Comments
Post a Comment