Chapter 7: Human nutrition Flashcards
Define ‘balanced diet’
A diet that contains all of the required nutrients, in suitable proportions, and the right amount of energy
What are the 6 types of nutrients needed for a balanced diet?
Carbohydrates, proteins, fats, vitamins, minerals, water
What is the importance of carbohydrates in the diet?
Provide energy
What is the importance of protein in the diet?
For growth, building new cells and making proteins such as haemoglobin, insulin (hormone), and antibodies
What is the importance of fats and oils in the diet?
For energy, make cell membranes, act as an insulator, form a layer around and protect large body organs
What is the importance of vitamins C and D in the diet?
C: make the stretchy protein collagen, which is found in skin and other tissues, keeps tissues in good repair
D: helps absorb calcium, for making bones and teeth
What is the importance of calcium and iron in the diet?
Calcium: for bones and teeth, and blood clotting
Iron: for making haemoglobin
What is the importance of fibre in the diet?
Keeps the bowel healthy, stimulates peristalsis, and prevents constipation
What is the importance of water in the diet?
For cytoplasm, where many metabolic reactions take place. For plasma, in which many substances are dissolved and transported around the body. To get rid of waste products
What are the causes of scurvy and rickets?
Scurvy: Vitamin C deficiency, causes pain in joints and muscles, and bleeding from gums
Rickets: Vitamin D deficiency, causes soft and deformed bones
What does the digestive system consist of?
Salivary glands, mouth, oesophagus, liver, gall bladder, stomach, pancreas, small intestine, large intestine, anus
What does the alimentary canal consist of?
Mouth, oesophagus, stomach, small intestine (duodenum and ileum), large intestine (colon, rectum), anus
What are the functions of the mouth and the salivary glands?
Salivary glands: make saliva, which contains mucus, water, and amylase. The water helps dissolve substances, mucus helps the chewed food bind together and lubricates it, and the amylase begins to break down starch
What is the function of the oesophagus?
Transport food through the throat and into the stomach
What is the function of the stomach?
Contracts and relaxes (churning motion) to mix food with enzymes and mucus, secretes mucus, enzymes (protease), and hydrochloric acid
What is the function of the pancreas?
Secretes pancreatic juice, which contains many different enzymes
What is the function of the small intestine?
Further digests food and absorbs nutrients and water
What is the function of the liver?
Secretes bile, an alkaline fluid, which helps with fat digestion and neutralises the stomach’s acidic mixture
Define ‘physical digestion’
The breakdown of food into smaller pieces, without making any chemical changes
What is the importance of physical digestion?
Increases surface area of food for increased enzymatic activity in chemical digestion
What is the structure of human teeth, from inner to outer?
Pulp (containing nerves and blood vessels), dentine, cement, enamel
What is the role of bile in physical digestion?
Breaks down large fat globules into smaller molecules through emulsification, to increase surface area for chemical digestion
Define ‘chemical digestion’
The breakdown of large insoluble molecules into small soluble molecules so that they can be absorbed
How is starch broken down and where?
Amylase breaks starch into maltose in the mouth, maltase breaks maltose into glucose in the small intestine
