Flashcards · 0610 · Topic 7

Human nutrition flashcards

25 cards on Topic 7, subtopics 7.1 to 7.5. Pick a subtopic or study them all.

Study mode needs JavaScript. Every card is listed below, so you can still cover the answers and test yourself.

All 25 cards

For a quick read-through or printing. Cover the right-hand side to test yourself. Cards marked Extended are Extended (Supplement) content only.

Balanced diet: A diet containing the right foods in the right amounts.
Why the body needs carbohydrates, fats and proteins: Carbohydrates: energy. Fats and oils: energy store and insulation. Proteins: growth and repair.
Deficiency diseases of vitamin C and vitamin D: Vitamin C: scurvy. Vitamin D: rickets.
Why the body needs calcium and iron: Calcium: bones and teeth. Iron: making haemoglobin.
Why the body needs fibre and water: Fibre (roughage): helps food move through the gut. Water: solvent and transport medium.

Parts of the alimentary canal, in order: Mouth, oesophagus, stomach, small intestine (duodenum and ileum), large intestine (colon, rectum), anus.
Associated organs of the digestive system: Salivary glands, pancreas, liver, gall bladder.
Ingestion and digestion: Ingestion: taking food and drink into the body. Digestion: the breakdown of food.
Absorption: The movement of nutrients from the intestines into the blood.
Assimilation: The uptake and use of nutrients by cells.
Egestion, and how it differs from excretion: Egestion is the removal of undigested food as faeces. It was never absorbed, so it is not excretion (removal of waste made by metabolism).

Physical digestion: The breakdown of food into smaller pieces without chemical change to the food molecules. It increases the surface area for chemical digestion.
Types of human teeth and their jobs: Incisors cut, canines tear, premolars and molars crush and grind.
Structure of a tooth (parts to name): Enamel on the crown, dentine beneath it, pulp in the centre containing nerves and blood vessels, and cement covering the root and fixing it in the jaw.
Role of the stomach in physical digestion: Churning the food.
Role of bile in emulsifying fatsExtended: Bile breaks large fat droplets into smaller ones, increasing the surface area for lipase. It is a physical change: bile is not an enzyme.

Chemical digestion: The breakdown of large insoluble molecules into small soluble molecules that can be absorbed.
Amylase, protease and lipase: substrate → product: Amylase: starch → simple reducing sugars. Proteases: protein → amino acids. Lipase: fats and oils → fatty acids and glycerol.
Two functions of hydrochloric acid in gastric juice: It kills harmful microorganisms in food, and it gives an acidic pH that is the optimum for enzymes in the stomach.
Amylase and maltase (Extended detail)Extended: Amylase breaks starch down to maltose. Maltase, on the membranes of the small intestine epithelium, breaks maltose down to glucose.
Pepsin vs trypsinExtended: Both are proteases. Pepsin works in the acidic stomach; trypsin works in the alkaline small intestine.
How bile helps chemical digestion in the duodenumExtended: Bile is alkaline. It neutralises the acidic mixture arriving from the stomach, giving a suitable pH for the enzymes in the small intestine.

Where are most nutrients and most water absorbed?: The small intestine absorbs nutrients and most of the water. Some water is also absorbed in the colon.
How is the absorbing surface of the small intestine increased?Extended: By villi and microvilli.
In a villus, what do the capillaries and the lacteal absorb?Extended: Capillaries: sugars and amino acids. Lacteal (part of the lymphatic system): fatty acids and glycerol.