bio tema 2

FOOD AND NUTRITION NUTRITION: Study of nutrients in food, how the body uses them, and the relationship between diet, health, and disease Consists of taking in matter and energy in order to grow, survive and reproduce; waste matter and waste energy are produced as by-products. FOOD: Food is any solid or liquid substance consumed to provide nutritional support for an organism. NUTRIENTS: Nutrients are compounds in foods essential to life and health, providing us with energy, the building blocks for repair and growth and substances necessary to regulate chemical processes. Inorganic compounds: water and mineral salts; Organic compounds: Carbohydrates, Fats, Proteins and Vitamins. WATER In most organisms, almost 80% of the body is made up of water. Humans beings are holding about 65% of water in relation to their total weight. Remember that the cytoplasm is a solution of many different substances in water. Functions: a) Inside every living organism, chemical reactions are going on all the time. Metabolic reactions can only take place in water. b) Water is an important solvent. c) Plasma, the liquid part of blood, contains a lot of water and dissolved substances are transported around the body. d) Water regulates body temperature. e) Water is needed to get rid of waste products ( urine ). MINERALS Inorganic substances. Small amounts of them are needed in the diet. E.g.:  a) Calcium. It is needed for bones and teeth; for blood clotting. Deficiency disease: brittle bones and teeth, poor blood clotting. Foods that contain it: dairy products, bread. b) Iron. It is needed for making haemoglobin, the red pigment in blood which carries oxygen. Deficiency disease: Anaemia, tissues do not get enough oxygen delivered to them from red blood cells. Foods that contain it: liver, red meat, egg yolk, dark green vegetables. CARBOHIDRATES These molecules are made of long chains of smaller molecules or building blocks: glucose. Types of Carbohydrates or Glucids: a) Simple: They are soluble in water and taste sweet. They are called sugar too. Monosaccharides: e.g. glucose and fructose and Disaccharides: two simple sugar molecules join together. E.g. sucrose, maltose and lactose. b) Complex or Polysaccharides: Many sugars join together. E.g. Starch and cellulose ( plant cell walls). animals cells often contain glycogen. Functions: a) Carbohydrates are needed for energy. b) Structural purpose: cell membrane contains carbohydrates. c) Cellulose fibres are very strong, so the cell wall helps to maintain the shape of the plant cell. Fibres help human beings avoid getting constipated. FATS They are also known as lipids. They are insoluble in water. Fats that are liquid at room temperature are called oils. These molecules are made of long chains of smaller molecules or building blocks: fatty acids and glycerol.  Types: Saturated fat ( found predominantly in foods from animals ) and unsaturated fat (found predominantly in foods from plants) Functions: a) They can be used in a cell to release energy. Most cells use carbohydrates first when they need energy, and only use fats when all the available carbohydrates have been used. Adipose tissue stores drops of fat b) They help to keep heat inside the body. c) Some vitamines and hormones are made of lipids. d) Cell membranes comprises lipids. PROTEINS These molecules are made of long chains of smaller molecules or building blocks: Amino acids. There are about 20 different kins of amino acids. Any of these can be joined together in any order. Functions: a) Making new cells. New cells are needed for growing, and for repairing damaged parts of the body. b) Structural purpose: cell membrane and cytoplasm contain a lot of protein. c) They are also needed to make antibodies. This help to kill bacteria and viruses inside the body. d) Enzymes are also proteins.  VITAMINS Vitamins are organic compounds that people need in small quantities. Most vitamins need to come from food because the body either does not produce them or produces very little. Fat-soluble vitamins. The body stores fat-soluble vitamins in fatty tissue and the liver, and reserves of these vitamins can stay in the body for days and sometimes months. The body absorbs fat-soluble vitamins through the intestinal tract. E.g. Vitamins A, D, E, and K. Water-soluble vitamins.  They do not stay in the body for long and cannot be stored. They leave the body via the urine. Because of this, people need a more regular supply of water-soluble vitamins than fat-soluble ones. E.g. Vitamin C and all the B vitamins.   

Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness. 

FOOD AND NUTRITION NUTRITION: Study of nutrients in food, how the body uses them, and the relationship between diet, health, and disease Consists of taking in matter and energy in order to grow, survive and reproduce; waste matter and waste energy are produced as by-products. FOOD: Food is any solid or liquid substance consumed to provide nutritional support for an organism. NUTRIENTS: Nutrients are compounds in foods essential to life and health, providing us with energy, the building blocks for repair and growth and substances necessary to regulate chemical processes. Inorganic compounds: water and mineral salts; Organic compounds: Carbohydrates, Fats, Proteins and Vitamins. WATER In most organisms, almost 80% of the body is made up of water. Humans beings are holding about 65% of water in relation to their total weight. Remember that the cytoplasm is a solution of many different substances in water. Functions: a) Inside every living organism, chemical reactions are going on all the time. Metabolic reactions can only take place in water. b) Water is an important solvent. c) Plasma, the liquid part of blood, contains a lot of water and dissolved substances are transported around the body. d) Water regulates body temperature. e) Water is needed to get rid of waste products ( urine ). MINERALS Inorganic substances. Small amounts of them are needed in the diet. E.g.:  a) Calcium. It is needed for bones and teeth; for blood clotting. Deficiency disease: brittle bones and teeth, poor blood clotting. Foods that contain it: dairy products, bread. b) Iron. It is needed for making haemoglobin, the red pigment in blood which carries oxygen. Deficiency disease: Anaemia, tissues do not get enough oxygen delivered to them from red blood cells. Foods that contain it: liver, red meat, egg yolk, dark green vegetables. CARBOHIDRATES These molecules are made of long chains of smaller molecules or building blocks: glucose. Types of Carbohydrates or Glucids: a) Simple: They are soluble in water and taste sweet. They are called sugar too. Monosaccharides: e.g. glucose and fructose and Disaccharides: two simple sugar molecules join together. E.g. sucrose, maltose and lactose. b) Complex or Polysaccharides: Many sugars join together. E.g. Starch and cellulose ( plant cell walls). animals cells often contain glycogen. Functions: a) Carbohydrates are needed for energy. b) Structural purpose: cell membrane contains carbohydrates. c) Cellulose fibres are very strong, so the cell wall helps to maintain the shape of the plant cell. Fibres help human beings avoid getting constipated. FATS They are also known as lipids. They are insoluble in water. Fats that are liquid at room temperature are called oils. These molecules are made of long chains of smaller molecules or building blocks: fatty acids and glycerol.  Types: Saturated fat ( found predominantly in foods from animals ) and unsaturated fat (found predominantly in foods from plants) Functions: a) They can be used in a cell to release energy. Most cells use carbohydrates first when they need energy, and only use fats when all the available carbohydrates have been used. Adipose tissue stores drops of fat b) They help to keep heat inside the body. c) Some vitamines and hormones are made of lipids. d) Cell membranes comprises lipids. PROTEINS These molecules are made of long chains of smaller molecules or building blocks: Amino acids. There are about 20 different kins of amino acids. Any of these can be joined together in any order. Functions: a) Making new cells. New cells are needed for growing, and for repairing damaged parts of the body. b) Structural purpose: cell membrane and cytoplasm contain a lot of protein. c) They are also needed to make antibodies. This help to kill bacteria and viruses inside the body. d) Enzymes are also proteins.  VITAMINS Vitamins are organic compounds that people need in small quantities. Most vitamins need to come from food because the body either does not produce them or produces very little. Fat-soluble vitamins. The body stores fat-soluble vitamins in fatty tissue and the liver, and reserves of these vitamins can stay in the body for days and sometimes months. The body absorbs fat-soluble vitamins through the intestinal tract. E.g. Vitamins A, D, E, and K. Water-soluble vitamins.  They do not stay in the body for long and cannot be stored. They leave the body via the urine. Because of this, people need a more regular supply of water-soluble vitamins than fat-soluble ones. E.g. Vitamin C and all the B vitamins.   

Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness.

FOOD AND NUTRITION NUTRITION: Study of nutrients in food, how the body uses them, and the relationship between diet, health, and disease Consists of taking in matter and energy in order to grow, survive and reproduce; waste matter and waste energy are produced as by-products. FOOD: Food is any solid or liquid substance consumed to provide nutritional support for an organism. NUTRIENTS: Nutrients are compounds in foods essential to life and health, providing us with energy, the building blocks for repair and growth and substances necessary to regulate chemical processes. Inorganic compounds: water and mineral salts; Organic compounds: Carbohydrates, Fats, Proteins and Vitamins. WATER In most organisms, almost 80% of the body is made up of water. Humans beings are holding about 65% of water in relation to their total weight. Remember that the cytoplasm is a solution of many different substances in water. Functions: a) Inside every living organism, chemical reactions are going on all the time. Metabolic reactions can only take place in water. b) Water is an important solvent. c) Plasma, the liquid part of blood, contains a lot of water and dissolved substances are transported around the body. d) Water regulates body temperature. e) Water is needed to get rid of waste products ( urine ). MINERALS Inorganic substances. Small amounts of them are needed in the diet. E.g.:  a) Calcium. It is needed for bones and teeth; for blood clotting. Deficiency disease: brittle bones and teeth, poor blood clotting. Foods that contain it: dairy products, bread. b) Iron. It is needed for making haemoglobin, the red pigment in blood which carries oxygen. Deficiency disease: Anaemia, tissues do not get enough oxygen delivered to them from red blood cells. Foods that contain it: liver, red meat, egg yolk, dark green vegetables. CARBOHIDRATES These molecules are made of long chains of smaller molecules or building blocks: glucose. Types of Carbohydrates or Glucids: a) Simple: They are soluble in water and taste sweet. They are called sugar too. Monosaccharides: e.g. glucose and fructose and Disaccharides: two simple sugar molecules join together. E.g. sucrose, maltose and lactose. b) Complex or Polysaccharides: Many sugars join together. E.g. Starch and cellulose ( plant cell walls). animals cells often contain glycogen. Functions: a) Carbohydrates are needed for energy. b) Structural purpose: cell membrane contains carbohydrates. c) Cellulose fibres are very strong, so the cell wall helps to maintain the shape of the plant cell. Fibres help human beings avoid getting constipated. FATS They are also known as lipids. They are insoluble in water. Fats that are liquid at room temperature are called oils. These molecules are made of long chains of smaller molecules or building blocks: fatty acids and glycerol.  Types: Saturated fat ( found predominantly in foods from animals ) and unsaturated fat (found predominantly in foods from plants) Functions: a) They can be used in a cell to release energy. Most cells use carbohydrates first when they need energy, and only use fats when all the available carbohydrates have been used. Adipose tissue stores drops of fat b) They help to keep heat inside the body. c) Some vitamines and hormones are made of lipids. d) Cell membranes comprises lipids. PROTEINS These molecules are made of long chains of smaller molecules or building blocks: Amino acids. There are about 20 different kins of amino acids. Any of these can be joined together in any order. Functions: a) Making new cells. New cells are needed for growing, and for repairing damaged parts of the body. b) Structural purpose: cell membrane and cytoplasm contain a lot of protein. c) They are also needed to make antibodies. This help to kill bacteria and viruses inside the body. d) Enzymes are also proteins.  VITAMINS Vitamins are organic compounds that people need in small quantities. Most vitamins need to come from food because the body either does not produce them or produces very little. Fat-soluble vitamins. The body stores fat-soluble vitamins in fatty tissue and the liver, and reserves of these vitamins can stay in the body for days and sometimes months. The body absorbs fat-soluble vitamins through the intestinal tract. E.g. Vitamins A, D, E, and K. Water-soluble vitamins.  They do not stay in the body for long and cannot be stored. They leave the body via the urine. Because of this, people need a more regular supply of water-soluble vitamins than fat-soluble ones. E.g. Vitamin C and all the B vitamins.   

Body Mass Index (BMI) is a person’s weight in kilograms divided by the square of height in meters. A high BMI can indicate high body fatness.