Nutritional requirements of the body - class-VIII

The leaf on the right shows a positive test for starch in the areas which contained chlorophyll, and a negative test for starch in the areas which lack chlorophyll. This is evidence that chlorophyll is required for photosynthesis. A plant can be 'de-starched' by leaving it in the dark for a few hours.
So, the correct option is "C" (Starch will be found only in the part of the leaf exposed to light).

The iodine test is used for the determination of the presence of starch in a sample. Molecular iodine is not soluble in water and hence potassium iodide is added to it. Together they form polyiodide complex which upon addition of starch turns intense blue-black colour. Starch is a polymer of amylose and amylopectin, of which amylose is responsible for the blue colour of the reaction. In the absence of starch solution remain as light brown colour which is the colour of iodine solution.

Gastric acid is a digestive fluid, formed in the stomach. It is composed of hydrochloric acid (HCl) 0.05–0.1 M (roughly 5,000–10,000 parts per million) potassium chloride (KCl) and sodium chloride (NaCl). The acid plays a key role in digestion of proteins, by activating digestive enzymes, and making ingested proteins unravel so that digestive enzymes break down the long chains of amino acids. The highly acidic environment in the stomach lumen causes proteins from food to lose their characteristic folded structure (or denature). This exposes the protein's peptide bonds. The gastric chief cells of the stomach secrete enzymes for protein breakdown (inactive pepsinogen, and in infancy rennin). Hydrochloric acid activates pepsinogen into the enzyme pepsin, which then helps digestion by breaking the bonds linking amino acids, a process known as proteolysis. In addition, many microorganisms have their growth inhibited by such an acidic environment, which is helpful to prevent infection. HCl is digestive juice. Fatty acids are digested by bile acids.

Iodine test is used to distinguish between the presence of starch and glycogen and other saccharides.
When starch solution is treated with iodine, it gives a blue color. The blue color develops because of the trapping of iodine in the helical coils of amylose. When this test solution is heated, the color disappears due to disruption of the helical coils of amylose and the color reappears upon cooling, due to the reformation of helical coils. Glycogen however gives red color with iodine.
Therefore, the correct answer is option B.

• Raw potato contains approximately 17% starch. when iodine solution added to the raw potato sample, it turns blue-black. Iodine reacts with the starch present in the raw potato which results in the formation of blue-black colored complex. 

When two drops of copper sulphate and ten drops of caustic soda or NaOH is added to egg, it turns violet. This indicates the presence of proteins.
This is Biuret's test and the principle is simple as follows:
In the presence of alkaline medium (caustic soda or NaOH), the Cu2+ ions get reduced to Cu+ and binds to the egg proteins, thereby giving a violet color.
Therefore, the correct answer is option B.

Shake or crush the food to make it dissolve. Filter or dilute the food and ethanol mix so that you get a clear liquid (a solution of fat in ethanol). Add this to a test tube of water. A white (milk-like) emulsion indicates the presence of fats or oils.

Oils are complex mixtures of various hydrocarbons, primarily triglycerides derived from fatty acids, which are long-chain hydrocarbons.

The iodine test is used to test for the presence of starch. Iodine dissolved in an aqueous solution of potassium iodide reacts with the starch, producing a purple-black colour. The intensity of the colour decreases with increasing temperature and with the presence of water-soluble organic solvents, such as ethanol.

Fats and oils are esters formed by the condensation reaction between glycerol (an alcohol) and three fatty acid molecules (carboxylic acids).

A chemical test for starch is to add iodine solution (red) and see if it turns blue/black in colour. It is possible to distinguish starch from other carbohydrates using this iodine solution test. For example, if iodine is added to an peeled potato then it will turn black. 

The Biuret test is a chemical test used for detecting the presence of peptide bonds. In the presence of peptides, a copper (II) ion forms violet-coloured coordination complexes in an alkaline solution. The Biuret reaction can be used to assess the concentration of proteins because peptide bonds occur with the same frequency per amino acid in the peptide. 

If an animal needed to store energy for long-term use, but not be encumbered with the weight of extra tissue, then high-calorie fat molecules are the best molecules for storage. So, the correct answer is "high-calorie fat molecules".

Sugars, when broken down, produces toxic amino groups. During Cellular Respiration, sugar is broken down to CO$ _2$and H$ _2$O, and in the process, ATP is made that can then be used for cellular work. Carbohydrates, fats, and proteins can all be used as fuels in cellular respiration, but glucose is most. In glycolysis, the 6-carbon sugar, glucose, is broken down into two molecules.

Considering all the four options we find that Enzymes, Antibodies and Muscle tissue all are made up of amino acids as their basic structural component only the glycogen stored in the liver is made up of monosaccharides as it's structural component. So, protein intake in the person will affect the formation of enzymes, antibodies and muscle tissue but will not affect the Glycogen stores in the Liver.

Cereals like wheat, rice, maize etc., are good source of carbohydrates. They contain starch as reserve food in their endosperm. The starch is a polymer of glucose.

Proteins are the major body building biomolecules. Proteins serve a variety of structural and functional roles. Meat, milk and eggs are an important source of proteins. Soybean and other pulses are an important source of plant proteins.

Carbohydrates are a source of energy and primary cellular fuel. Cereals like rice, wheat, maize are a primary source of carbohydrate for man. Humans can digest starch present in cereals but not cellulose. Hence, dietary starch is broken down into glucose inside the body which provides us with energy.

Rice and Wheat are cereals belonging to Family Poaceae. They are rich in carbohydrates. Gram and Soybean are legumes of Family Leguminosae. Legumes are rich in proteins. Soyabean is also an important oilseed crop. Among legumes Soyabean are richest source of proteins. Together, soyabean oil and protein content account for about 60% of dry soyabeans by weight (protein at 40% and oil at 20%).

Cajanus cajan is a puise seed crop and belongs to family Leguminosae. Its english name is pigeon pea and is commonly called Arhar or Toor in hindi. Being a pulse seed crop it is rich in proteins.

The percentage of lactose in milk varies with species. Human milk has a high lactose content, the percentage of lactose in human milk ranges from 6.5 to 7.5%. Unprocessed cow milk has about 4.7% lactose, unprocessed goat milk has about 4.7% lactose, unprocessed buffalo milk has about 4.86% lactose. The average in cow and goat milk is less than 5% and vary according to the breed. When human babies are reared on cow or goat milk, it is customary to add lactose, sucrose, glucose, or malto-dextrin in their feed.

Cirrhosis is an abnormal liver condition in which there is irreversible scarring of the liver. People with cirrhosis may develop jaundice, itching and extreme tiredness. When liver tries to break down alcohol, the resulting chemical reaction damage its cells. This damage can lead to inflammation and scarring as the liver tries to repair itself.

Meat, eggs and pulses are good sources of proteins. Proteins are body building substances and are an important part of a balanced diet. For vegetarian people pulses can be a good source of proteins. Our country produces a variety of 'dals' and these can be consumed as protein sources.

Carbohydrates provide us energy and are the primary cellular fuel. Carbohydrates can be simple sugars or polymers like cellulose and starch. Cereal grains like rice, wheat, maize etc. are rich in carbohydrates.

Carbohydrates provide us with energy. Carbohydrates can be monosaccharides (composed of one monomer unit only like glucose, fructose etc.), disaccharide (composed of two monomer units like maltose which is made up of two units of glucose; sucrose made up of one unit of glucose and one unit of fructose) or polysaccharide (made up of multiple monomer units example starch which is composed of multiple units of glucose).

Carbohydrates can be stored in body for subsequent use. Starch is an important storage polysaccharide in plants and glycogen is an important storage polysaccharide in animals. Both starch and glycogen are homopolymers of glucose.

The food guide pyramid is a pyramid-shaped guide of healthy foods divided into sections. Each section shows the recommended intake for each food group (i.e. Protein, Fat, Carbohydrates, and Sugars). Therefore, (b) is the correct answer.

Fish flour is a source of amino acids and vitamin with very high protein content, made of fresh sea fish or unprocessed fish wastes. Due to its rich nutritional content, it is the most important material in the rations of barn animals, poultry and fish and is commonly used in the feed industry.

During fasting, the body first utilizes glycogen (carbohydrates) for energy, followed by stored fats (lipids), and finally breaks down proteins (muscle tissue) as a last resort.

• Fiber is the indigestible part of plant foods that travels through the digestive system and absorbs the water along the way.
  
• It is also known as roughage.
  
• Dietary fiber contains non-starch polysaccharides such as cellulose, dextrins, inulin, lignin, beta-glucans, and waxes. 

Proteins are called the building blocks of body. They are needed for growth and development and to repair the normal wear and tear of the body. The body needs to digest proteins to make them available to fulfill these functions. Protein is the important part of the diet as it helps in building muscles. Hence, proteins are the major components of food which is required by the body for wear and tear.

Good sources include wheat bran, corn bran, rice bran, the skins of fruits and vegetables, nuts, seeds, dried beans and wholegrain foods. Most plant-based foods, such as oatmeal and beans, contain both soluble and insoluble fiber. The fibers helps to increase bowel movement and helps in digestion. So, the correct option is 'All of the above'.

The body uses minerals to perform many different functions from building strong bones to transmitting nerve impulses. Some minerals are even used to make hormones or maintain a normal heartbeat. 

Vitamins and minerals function as regulators in growth and development process in living being. They also act as catalyst for various processes. Vitamin D acts as regulator in mineral metabolism. Some forms of vitamin A acts as regulator in growth and differentiation process. Minerals are part of enzymes that are part of many physiological processes.

Fried foods contain high fat, calories and salt. They are cooked in hydrogenated fats(transfats). Eating them can put at a higher risk of developing diseases like heart diseases, diabetes etc.