B5 - Digestion Flashcards
What is physical digestion?
Breaking down of food particles by teeth or muscles.
What is a digestive system?
The long system that handles and digests food.
How do muscles in the stomach help to digest food?
The muscles squeeze the food in order to physically digest it.
What do enzymes do?
Enzymes break down food into smaller and soluble molecules so that they can be absorbed into the blood.
What is chemical digestion?
Chemical digestion is breaking down large food molecules into smaller ones through the use of enzymes.
How long is our digestive system?
Approximately 7m long.
Why is physical digestion important?
Food is broken down into smaller pieces which increases its surface area so it can pass through the digestive system more easily and can be chemically digested quicker.
Where are enzymes produced?
Enzymes are produced in the mouth, stomach and small intestine.
Once food has been chemically digested what happens?
The small molecules diffuse through the digestive system.
What type of enzyme breaks down fat?
Enzymes called lipases break down fat.
What type of enzyme breaks down protein?
Enzymes called proteases break down proteins.
What type of enzyme breaks down carbohydrates?
Enzymes called carbohydrases break down carbohydrates.
What are carbohydrates broken into?
Carbohydrates are broken down into simple sugars.
What are proteins broken down into?
Proteins are broken into amino acids.
What are fats broken down into?
Fats are broken down into fatty acids.
What types of foods are carried in the blood plasma?
Digested food is carried in the blood.
Why are fats difficult to digest and absorb?
Fats are not soluble in water.
Where is bile produced?
Bile is produced in the liver.
What is bile?
Bile is an alkaline substance produced by the liver and stored in the gall bladder.
What does bile do?
It is secreted into the small intestine, where it emulsifies fats.
What are gall stones?
Gall stones are made from bile pigments, cholesterol and calcium salts where they block the bile duct.
What is optimum pH?
An optimum pH is a pH where enzymes work best.
Which part of the digestive system joins the mouth and stomach?
The oesophagus joins the mouth and stomach.
What does the small intestine do?
The small intestine is the part of the intestines where a lot of the digestion and absorption of food occurs,.
What do salivary glands do?
Salivary glands produce saliva which moistens food and contains an enzyme.
What is peristalsis?
Peristalsis is the waves of muscle action when they contract and relax.
What does the liver do?
The liver produces bile and stores carbohydrates.
What does the gall bladder do?
The gall bladder stores bile.
What does the pancreas do?
The pancreas produces enzymes and insulin.
What does the large intestine do?
The large intestine absorbs water, concentrating the waste.
Name the two main functions of the small intestine.
Production of enzymes and absorbing digested food.
Why are fatty acids not passed into the blood?
Fatty acids are not passed into the blood because they are insoluble.
How is the small intestine adapted for efficient absorption of digested food?
- it is about 7m long, allowing time for complete absorption
- it has villi and micro villi which gives it a large surface area
- its lining is thin and permeable so food molecules can easily pass through
- it is surrounded by a network of blood capillaries to carry the digested food away from the small intestine.
