digestive system Flashcards
what are the three main large nutrients needed in large quantities?
carbohydrates, proteins and lipids
what is the major functions of carbohydrates?
source of energy
what is the major functions of proteins?
growth and repair
what is the main functions of lipids?
energy and they make up part of cell membranes
which sources are used for carbohydrates?
starch and sugars
what is glucose used for?
used for respiration
what are proteins made up from?
amino acids
where do excess amino acids go?
amino acids can be toxic in large amounts so they are broken down in the liver and removed in the urine
what are lipids made out of?
fatty acids and glycerol
what two things does the digestive system do?
digest and absorb
how does the mouth digest food?
it breaks down the food using saliva and your teeth
how does the stomach digest food?
starts to absorb certain foods, digests protein
how does the small intestine digest food?
completes the digestion of carbohydrates and protein into single sugars and amino acids and absorbs them
what does the large intestine absorb?
absorbs water and gets rid of unabsorbed food
how do the small intestine absorb?
the surface of the small intestine has villi which digest food molecules and absorb them
