Food Components and Nutrition - Class VIII

The human body can last weeks without food, but only days without water. The body is made up of 50 to 75 per cent water. Water forms the basis of blood, digestive juices, urine and perspiration, and is contained in lean muscle, fat and bones. It helps to maintain the temperature of the body.

Chlorides are inorganic mineral salts that are highly stable and are not affected by biological processes like decomposition or bacterial action.

Autotrophs are organisms that produce their own food using sunlight (photosynthesis) or chemical energy, converting inorganic substances into organic matter.

Glucose is a simple monosaccharide sugar. It is a hexose sugar. It is an aldose sugar. Ingested carbohydrates are broken down into monosaccharides which are absorbed in the intestine. Glucose is absorbed in intestine. Glucose is also chief form of sugar in blood and circulates in blood to supply energy to visceral organs.

Calcium strengthens bones and teeth in our body. It is an inorganic substance which is later converted to its organic forms when it gets combined with carbon molecule.

Nutrients obtained by plants and animals are classified into two groups organic and inorganic. Inorganic nutrients are those that are not easily found in animals or plants. They are always converted into their organic forms. Ammonia is an organic nutrient generally found in animals for synthesis of various metabolite.

Rhizobium is a nitrogen-fixing bacteria found in symbiotic association with the root nodules of leguminous plants. 

Photosynthesis is a metabolic process of formation of glucose from carbon dioxide and water in presence of light energy.

In NH3 (ammonia), nitrogen is in the -3 oxidation state, which is its most reduced form. In CO2, carbon is in the +4 state (oxidized); in H2O, hydrogen is in the +1 state; in sulphate, sulphur is in the +6 state.

A comparison of elements present in non-living and living matter is given in the table below:

Sodium chloride (NaCl) is a classic example of an inorganic compound, as it is an ionic salt lacking carbon-hydrogen bonds. Oil, fats, and nutrients (like proteins/carbohydrates) are organic compounds.

The body burns fat after first exhausting the contents of the digestive tract along with glycogen (carbohydrates) reserves stored in muscle and liver cells. During short periods of energy abstinence, the human body will burn primarily free fatty acids from body fat stores. After prolonged periods of starvation when the body has depleted its body fat, it begins to burn lean tissue and muscle (protein) as a fuel source.

Chemical energy is stored in the bonds that connect atoms with other atoms and molecules with other molecules. Because chemical energy is stored, it is a form of potential energy. When a chemical reaction takes place, the stored chemical energy is released. Chemical Energy - is really a form of potential energy and is the energy stored in food or chemical combinations. Radiant Energy - is a combination of heat and light energy.

Carbohydrates (also called saccharides) are molecular compounds made from just three elements: carbon, hydrogen and oxygen. Monosaccharides (e.g. glucose) and disaccharides (e.g. sucrose) and polysaccharide (starch). They are often called sugars.

Nutrients that we obtain through food have vital effects on physical growth and development, maintenance of normal body function, physical activity and health. Nutritious food is, thus needed to sustain life and activity. Our diet must provide all essential nutrients in the required amounts. Requirements of essential nutrients vary with age, gender, physiological status and physical activity. Dietary intakes lower or higher than the body requirements can lead to under nutrition (deficiency diseases) or over nutrition (diseases of affluence) respectively. So, the correct option is 'True'.

• Malnutrition is the condition or state in which the body does not get proper nutrition or get overnutrition (imbalanced nutrition) and as a result a deficiency or excess or imbalanced of energy. 
• Malnutrition is referred to overnutrition resulting from overeating or excessive intake of specific nutrients. 
• The amount of nutrients exceeds the amount required for normal growth, development, and metabolism. Hence, If one's diet exceeds one's need, it is called overnutrition.
  

Option D is the correct answer here.

Protective components of foods are minerals and vitamins. Vegetables like spinach, cabbage, brinjal, beans, and fruits are called protective foods. These components protect us from diseases. Hence, they are called protective components of food. Carbohydrates and fats are the energy components of the food. Proteins are bodybuilding components of the food. 

The nutrient synthesized by plants through photosynthesis is carbohydrates. Plants are autotrophs and they synthesize their own food by the process of photosynthesis. During photosynthesis, they convert carbon dioxide and water in presence of sunlight and chlorophyll to produce carbohydrates (glucose) and oxygen. 

An inorganic nutrient is essentially any compound or element that is not carbon-based, but is otherwise necessary to maintain health and optimum growth of a plant, animal, or human. Nitrogen is an inorganic nutrient that is later converted to organic forms like nitrite, nitrate or ammonia.

Proteins are major element required in the growth of the plant cells. In plants, all the 20 amino acids should be formed in the plant body because they cannot take them up fro any other source. Proteins are essential as they are the basic constituents of enzymes, cell membrane, and transport systems.

Carbohydrates, as the name suggests, are the hydrates of carbon and thus are made up of molecules of hydrogen, oxygen and carbon.