Digestive System Flashcards
What does amylase break down?
Carbohydrates
What does protease break down?
Protein
What does lipase break down?
Lipids
What do carbs get broken down to?
simple sugars
What do lipids get broken down into?
fatty acids and glycerol
What do proteins get broken down to?
amino acids
Where is amylase produced?
mouth (salivary) and small intestine (pancreatic and intestinal)
Where is protease produced?
Stomach (gastric) and small intestine (pancreatic and intestinal)
Where is lipase produced?
small intestine (pancreatic and intestinal)
What is the function of enzymes?
Enzymes break down the starch, fats and proteins in food into smaller components to be absorbed into the blood.
What are villi?
tiny, finger-like projections made up of cells that line the entire length of your small intestine
What is the purpose of villi?
They increase the surface area of the small intestine.
What is the function of villi?
They secret enzymes to break down food and absorb the nutrients and shuttle them into the bloodstream
How are nutrients absorbed by the villi?
Monosaccharides and amino acids -> active transport
Vitamins -> diffusion
Fatty acids - absorbed by lacteal
What are enzymes affected by?
pH and temperature
What temperature do enzymes work best at?
37C. Lower they are inactive, higher they are denatured.
What is bile?
A fluid produced in the liver, stored in the gall bladder, and released into the small intestine to aid digestion
What is the function of bile?
- It neutralises the stomach acid (as it is alkaline) before the food passes to the small intestine, as enzymes cannot work at stomach pH
- It emulsifies fat (breaks it up) making it easier to digest
What is the pH of the mouth?
6-7 weakly acidic
What is the pH of the stomach?
1-3 strongly acidic
What is the pH of the small intestine?
7-8 slightly alkaline
What are the five essential nutrients?
Sugars
Fatty acids
Amino acids
Vitamins/minerals
Water
What is an organic compound?
Found in living things
Contains carbon
Usually made with carbon, oxygen and hydrogen
Describe carbon’s bonding-ness
Carbon atoms can form four bonds
Can bond covalently in single, double or triple bonds
Chemical energy is found in the bonds
What is a carbohydrate?
Either monosaccharide (glucose) or disaccharide (sucrose) or polysaccharide (amylose)
They are a quick supply for the body’s metabolism
What is a lipid?
- Insoluble in water
- Include steroids, waxes, fatty acids and triglycerides
- Fats are solid at room temperature
- Oils are liquid at room temperature
- Can be saturated or unsaturated
What is the difference between a saturated and unsaturated fat?
Saturated fats – mostly found in animal tissues (meat, cheese, butter)
Unsaturated fats – plant foods (nuts, soybeans)
Unsaturated has a double carbon bond in it and two less hydrogens than saturated.
What is a protein?
Comprised of one or more chains of amino acids
There are 20 amino acids
All contain carbon, hydrogen, oxygen and nitrogen
2 contain sodium
What is a nucleic acid?
Contains C, H, O, N and P
RNA or DNA
What is a monomer?
Repetitive units that form a larger compound
What is a polymer?
Formed when monomers link together.
