B3 - Organisation and The Digestive System Flashcards
What is a tissue?
- A group of cells with similar structure and function.
What is an organ?
- Collections of tissues performing specific functions.
What is an organ system?
- Organs are organised to make them, they work together to form organisms.
What does a liver do?
- Produces bile.
What does the mouth do?
- Where food enters and digestion begins.
What is the function of the salivary glands?
- Produce saliva containing amylase.
What is the function of the oesophagus?
- Muscular tube which moves ingested food to the stomach.
What is the function of the stomach?
- Muscular organ where digestion continues.
What is the function of the gall bladder?
- Stores bile before releasing it to the duodenum.
What is the function of the small intestine?
- Food is mixed with digestive enzymes and bile.
- Where digested food is absorbed into the blood and lymph.
What is the function of the large intestine?
- Where water is reabsorbed.
What is the function of the rectum?
- Where faeces are stored.
What is the function of the anus?
- Where faeces leave the body.
What are simple sugars?
- Type of carbohydrate that only contain one or two sugar units.
What are complex carbohydrates?
- Type of carbohydrate that contain long chains of simple sugar units bonded together.
What are fatty acids?
- Lipids that consist of 3 molecules to make up glycerol.
What are protein molecules?
- Type of protein made up of long chains of amino acids.
What is a catalyst?
- Increase the rate of chemical reactions without chemically changing themselves.
What is an enzyme?
- Biological catalysts and catalyse specific reactions in living organisms due to the shape of their active site.
What type of food is an enzyme?
- Protein.
- Amino acid chains are folded to from the active site which matches the shape of a specific substrate molecule.
What happens to the substrate and the active site after the amino acids form the active site?
- Substrate binds to the active site and the reaction is catalysed by the enzyme.
What is a metabolism?
- Sum of all the reactions in a cell or the body.
How is enzyme activity affected?
- Temperature and pH.
How do high temperatures denature the enzyme?
- They change the shape of the active site.
How does a pH affect the shape of an active site?
- Make it work very efficiently or stop it work.
What happens during the process of digestion?
- Breakdown of large insoluble molecules into soluble substances that can be absorbed into the blood across the small intestine.
How are digestion enzymes produced?
- Specialised cells in the glands and in the lining of the digestive system.
What do carbohydrases catalyse?
- Breakdown of carbohydrates to simple sugars.
- Amylase.
What do proteases catalyse?
- Breakdown of proteins to amino acids.
What do lipases catalyse?
- Breakdown of lipids to fatty acids and glycerol.
How does Hydrochloric acid affect the stomach?
- Gives the stomach a low pH suitable for the protease secreted there to work efficiently.
How does alkaline bile affect organs like the small intestine and the pancreas?
- Neutralises the acid and gives a high pH for the enzymes to work well.
What does bile do and what is it?
- Not an enzyme as it doesn’t break down fat molecules.
- Emulsifies the fat into tiny droplets which increases the surface area for lipase to increase the rate of digestion.
- Produced by liver stored in the gall bladder and released through the bile duct.
