Organisation Flashcards
Principles of Organisation
What is a cell?
The basic building block of a living organism
Principles of Organisation
What is a tissue?
A group of similar cells with a similar structure and function working together.
Principles of Organisation
What is an organ?
A collection of tissues working together to perform a specific function.
Principles of Organisation
What is an organ system?
A group of organs working together to perform a specific function.
The human digestive system
What is the main function of the digestive system?
To digest food and absorb the nutrients obtained from digestion.
The human digestive system
What is the role of the pancreas and the salivary gland in the digestive system?
These are glands which produce digestive juices containing enzymes.
The human digestive system
What is the role of the stomach?
Produces hydrochloric acid - which kills any bacteria present and provides the optimum acidic pH for the protease enzyme to function.
The human digestive system
What is the role of the small intestine?
The site where soluble food molecules are absorbed into the bloodstream.
The human digestive system
What is the role of the liver?
Produces bile which emulsifies lipids and allows the lipase enzyme to work more efficiently.
The human digestive system
What is the role of the large intestine?
Absorbs water from undigested food, producing faeces.
The human digestive system
What is the role of enzymes?
Act as biological catalysts which speed up the rate of reactions without being used up.
The human digestive system
How does the shape of an enzyme affect its function?
Enzymes have a specific active site which is complementary to their substrate.
The human digestive system
What is the lock and key hypothesis of enzyme function?
The shape of the enzyme active site and the substrate are complementary, so can bind together to form an enzyme substrate complex
The human digestive system
How does temperature affect anzyme action?
Up to a certain, increasing temperature increases the enzyme action, as molecules have a higher kinetic energy. Above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37.
The human digestive system
How does pH affect enzyme function?
The optimum pH for most enzymes is 7. If the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work.