Life Process in Living Organisms Part- 1

• Living organisms require a continuous source of energy for various life processes.
• Carbohydrates, fats and lipids are the main sources of energy harvested by the mitochondria present in each cell.
• Oxygen is also necessary for energy production.
• All these require continuous supply of foodstuffs and oxygen, which are transported up to the cell via circulatory system.
• Each life process contributes in its own way in the process of energy production.
• Functioning of all these life processes also requires the energy.
• Human and other animals consume the fruits and vegetables, which are autotrophs and prepare their own food.
• Plants store some of the food in various parts like fruits, leaves, stem, roots, etc.
• Human and other animals consume these various plant materials and obtain different nutrients like carbohydrates, fats, proteins, vitamins, minerals, etc.
• Carbohydrates are obtained from milk, fruits, jaggary, cane sugar, vegetables, potatoes, sweet potatoes, sweet meats and cereals like wheat, maize, ragi, jowar, millet, rice, etc.
• Carbohydrates provide 4Kcal energy per gram.
• In living organisms, respiration occurs at two levels as body and cellular level.
• Oxygen and carbon dioxide are exchanged between body and surrounding in case of respiration occurring at body level.
• In case of respiration at cellular level, foodstuffs are oxidized either with or without help of oxygen.
• Human respiratory system consists of various organs like nose, pharynx, larynx, trachea, bronchi, alveoli, etc.
• Carbohydrates of the food that we consume everyday are mainly utilized for production of energy required for daily need.
• This energy is obtained in the form of ATP.
• Proteins of animal origin are called as ‘first class’ proteins and we get 4 Kcal of energy per gram of proteins.
• Sir Hans Krebs was a British biochemist who lived from 1900 to 1981.
• The cell organelle necessary for complete oxidation of glucose is the mitochondria.
• Plants produce the necessary amino acids from minerals denovo and thereby produce different proteins.
• An enzyme RUBISCO present in the plant chloroplasts is the most abundant protein found in nature.
• Aerobic respiration is the process of energy production through the oxidation of carbohydrates, proteins and fats.
• Glycolysis is the first step of anaerobic respiration, where glucose is incompletely oxidized and less amount of energy is obtained.
• Seeds perform anaerobic respiration if the soil is submerged under water during germination.
• Anaerobic respiration in living organisms/ cells is a process where organic compounds are oxidized to release energy without the need for oxygen.
• Excess of the carbohydrates are stored in liver and muscles in the form of glycogen.
• Lipids, carbohydrates, proteins, fatty acids, glycolysis, amino acids, pyruvic acid, acetyl-CoA, Krebs Cycle, CO2, H2O, and energy are all part of cellular respiration.
• Proteins are macromolecules formed by bonding together many amino acids.
• Glucose is completely oxidized in the process of aerobic respiration.
• Some higher plants, animals and aerobic microorganisms also perform anaerobic respiration instead of aerobic respiration if there is depletion in oxygen level in the surrounding.
• Our muscle cells also perform anaerobic respiration while performing the exercise, due to which less amount of energy is produced in our body and lactic acid accumulates due to which we feel tired.
• Amino acids are obtained after digestion of proteins and are absorbed in the body and transported up to each organ and cell via blood.
• Fermentation is the second step of anaerobic respiration, where pyruvic acid produced through glycolysis is converted into other organic acids or alcohol with the help of some enzymes.
• Excess of amino acids obtained from proteins are not stored in the body and are broken down and the ammonia formed is eliminated out of the body.
• If necessary, excess of proteins are converted into other useful substances like glucose through the process of gluconeogenesis.
• All chromosomes are arranged parallel to the equatorial plane (central plane) of the cell in Metaphase.
• In case of plant cells, instead of the notch, a cell plate is formed exactly along midline of the cell and thus cytokinesis is completed.
• In Anaphase, centromeres split and thereby sister chromatids of each chromosome separate and they are pulled apart in opposite directions with the help of spindle fibers.
• Chromosomes complete their condensation and become clearly visible along with their sister chromatids in Metaphase.