ORGANISATION Flashcards
What is a tissue?
A group of similar cells that work together to carry out a particular function
What do muscular tissues do?
Contract to move whatever it is attached to
What do glandular tissues do?
Make and secrete chemicals like enzymes and hormones
What do epithelial tissues do?
Cover some parts of the body
What is an organ?
A group of different tissues that work together to perform a certain function
What do the different tissues in the stomach do?
Muscular = move stomach wall to churn food
Glandular = makes digestive juices to digest food
Epithelial = covers outside and inside of stomach
What is an organ system?
A group of organs working together to perform a particular function
What is the function of the glands?
To produce digestive juices
What is the function of the stomach and small intestines?
To digest food
What is the function of the liver?
To produce bile
What is the function of the small intestine?
To absorb soluble food molecules
What is the function of the large intestine?
Absorb water from undigested food
What are enzymes?
Biological catalysts
They reduce the need for high temperatures and speed up only the useful chemical reactions taking place in the body
What are enzymes made up of?
Large proteins which are made up of chains of amino acids
How do enzymes only catalyse one specific reaction?
They have an active sit which only a specific substrate can fit into
If the substrate doesn’t match then the reaction won’t be catalysed
How does temperature affect an enzyme?
Increasing the temp too much means some of the bonds in the enzyme will break therefore changing the enzymes active site so it has become denatured
How does the pH affect an enzyme?
If the pH is too high or too low it interferes with the bonds holding the enzyme together and therefore making it denatured
What is the optimum pH of an enzyme?
The pH the enzyme works best at (usually neutral pH 7)
What are examples of big molecules?
Starch
Proteins
Fats
Why do starch, proteins and fats have to be broken down?
Because they are too big to pass through the walls of the digestive system so they are broken down into smaller soluble molecules that can pass easily through the walls
What is starch broken down into?
Maltose (and then glucose by the enzyme maltase)
What enzyme breaks starch down into maltose?
Amylase
Where is amylase made?
Salivary glands
Pancreas
Small intestine
What are proteins broken down into?
Amino acids
What enzyme breaks proteins down into amino acids?
Protease
Where is protease made?
Stomach
Pancreas
Small intestine
What are lipids broken down into?
Glycerol and fatty acids
What enzyme breaks down lipids into glycerol and fatty acids?
Lipase
Where is lipase made?
Pancreas
Small intestine
Where is bile made and stored?
Made in the liver
Stored in the gall bladder
How does bile work with stomach acid?
Acid in the stomach makes the pH too acidic for enzymes in the small intestine to work properly
Bile is alkaline so neutralises the acid so enzymes work better
Where are enzymes used in the digestive system made?
They are produced by specialised cells in glands and gut lining
What do the salivary glands do?
Produce amylase enzyme in the saliva
Why does the stomach produce hydrochloric acid?
To kill bacteria
To give the right pH for the protease enzyme to work
What solution is used to test for sugars?
Benedicts solution (blue)
What colour will the food turn if sugars are present?
Blue to green/yellow/brick-red depending on how much sugar is present
What solution is used to test for starch?
Iodine solution (browny orange)
What colour will the food turn if starch is present?
Browny orange to blue-black
What solution is used to test for proteins?
Biuret solution (blue)
What colour will the food turn if proteins are present?
Blue to purple
What solution do you use to test for lipids?
Sudan III stain solution
What will happen to the food if lipids are present?
The liquid will separate into two sections and the top one will be red
What is the top part of your body called?
The thorax
What happens when oxygenated blood meets body cells?
Oxygen diffuses from the blood to the cells (area of high to low concentration)
Opposite with carbon dioxide
Where does the right ventricle pump blood to?
Pumps deoxygenated blood to the lungs to take oxygen back to the heart
Where does the left ventricle pump blood to?
Pumps oxygenated blood around all the other organs in the body and deoxygenated blood returns to the heart to be pumped to the lungs again