B3 Flashcards
What is a cell
It is the basic building block of life.
What is a tissue?
A tissue is a group of cells of the same type.
What is an organ?
It is a group of tissues that work together to perform a function.
What is an organ system?
It is a group of organs working together for e.g. circulatory system
What is a organelle?
It is a smaller thing in a cell for e.g. mitochondria
What is digestion?
Digestion is the process where large molecules are broken down into smaller molecules to be absorbed into the blood.
What is the order of the digestion system?
1) Digestion starts in the mouth - where food is chewed and saliva added.
2) Food goes down the oesophagus and enters the stomach.
3) The stomach churns the food and hydrochloric acid is added.
4) Then it enters the small intestine where digested food is absorbed into the blood stream.
5) Anything remaining enters the large intestine where water is absorbed.
6) Finally any undigested food exits via the anus.
What do the villi do in the small intestine?
The villi provide the small intestine with a large surface area so more digested food can be absorbed into the blood stream.
Villi also have a good blood supply to assist quick absorption
They also have a one cell thick wall so that the nutrients have a shorter distance to diffuse over
What is the function of a liver?
It produces bile
What is the function of the stomach?
Breaking down large insoluble molecules into smaller soluble molecules
What is the function of the small intestine?
It produces protease, lipase and amylase enzymes
It is also the place where digested food is absorbed into the blood
What is the function of the large intestine?
It absorbs excess water from the food
Give an example of a simple sugar
Sucrose, glucose
What are lipids?
They are fats and oils
What do the salvary glands produce?
Amylase enzyme in the saliva
What does the pancreas produce?
Protease, amylase and lipase enzymes
What is a protein?
A molecule that is made up of long chains of amino acids
What is an enzyme?
Its a biological catalyst
Whats another thing that the stomach does?
-It pummels the food with its muscular walls
-It produces the protease enzyme, pepsin.
-It produces hydrochloric acid
What enzyme catalyses starch and what does it break it into?
Amylase(carbohydrase) catalyses starch and turns it into maltose
What is a catalyst?
It is a substance that speeds up a chemical reaction without getting used up or changed
What enzyme catalyses protein and what does it break it into?
Protease catalyses protein and breaks it up into amino acids
What enzyme catalyses lipids and what does it break it up into?
Lipase catalyses lipids and breaks it up into glycerol and fatty acids
What does bile do and where is it stored and produced?
Bile neutralises the stomach acid and emulsifies fats
Bile is produced in the liver
It is stored in the gall bladder before its released into the small intestine
It breaks down lipids into smaller droplets so that the lipase enzyme has a bigger surface area to work on so it breaks down lipids quicker.
It neutralises stomach acid so that the lipase is at its optimum pH to break down fat