human nutrition Flashcards
How is food moved through the digestive system?
Peristalsis - it happens in the oesophagus, the small intestine and the large intestine. The muscular walls of the digestive system contract in waves to squeeze lumps of food along
How is water and nutrients (amino acids, glucose) absorbed into the blood stream?
Most water and all digested food is absorbed into the blood in the small intestine. This happens through the wall of the small intestine, which is covered in villi. Each villus is covered in smaller projections called microvilli, creating a large surface area for absorption.
Where is most water and all digested food absorbed into the bloodstream?
The small intestine
Four examples of digestive enzymes are:
Amylase
Maltase
Protease
Lipase
What should a balanced diet include?
The correct proportions of lipids, proteins, carbohydrates, vitamins, minerals, water and dietary fibre
Where is bile produced?
In the liver
Where is bile stored?
In the gallbladder
What do amylase and maltase break down?
They are both enzymes that breaks starch down into glucose
What does protease break down?
Protease is an enzyme that breaks down proteins into amino acids
What does lipase break down?
Lipase is an enzyme that breaks down fats and oils (lipids) into fatty acids and glycerol
Where is amylase produced?
Salivary glands, pancreas and small intestines
What are pepsin and trypsin?
Pepsin is a protease that works in the stomach and trypsin is a protease that works in the small intestine
Where are proteases produced?
In the stomach, pancreas and small intestine
Where are lipases produced?
In the small intestine and the pancreas
What is biles function?
Enzymes in the small intestine operate best in alkaline conditions. Bile is an alkaline substance so it neutralises stomach acid so the enzymes don’t get denatured (lose their activity).
