Organisation
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What is a cell
The basic building block of a living organism.
What is a tissue?
A group of cells with a similar structure and function working together.
What is an organ?
A collection of tissues working together to perform a specific function.
What is an organ system?
A group of organs working together to perform specific functions.
What is the main function of the digestive system?
To digest food and absorb nutrients obtained from digestion.
What is the roles of the pancreas and salivary gland in the digestive system
Produce digestive juices containing enzymes
What is the role of the stomach in the digestive system?
Produces HCl which kills bacteria and provides optimum acidic pH for the protease enzyme to function
Role of small intestine in digestive system?
Site where soluble food molecules are absorbed into the bloodstream
Role of the liver in the digestive system?
Produces bile (stored in gall bladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently.
Role of the large intestine in the digestive system?
Absorbs water from undigested food, producing faeces.
Role of enzymes in the digestive system.
Biological catalysts which speed up rate of biological reactions without being used up.
How does the shape of an enzyme affect its function.
They have specific active sites which are complementary to their substrate
What is metabolism?
Sum of all reactions in a cell of organism
What metabolic reactions do enzymes catalyse?
Building larger molecules from smaller molecules (glucose to starch) Changing one molecule to another (glucose to fructose) Breaking down larger molecules to smaller molecules ( carbohydrates to glucose)
What is the lock and key hypothesis of enzyme function?
The shape of enzyme active site and substrate are complementary, so bind together forming enzyme-substrate complex
How can temperature affect enzyme action?
Increases it until a certain temperature where they denature. optimum is around 37
How does pH affect enzyme function?
Optimum is 7, if its too extreme, shape of active site may be altered and enzyme wont work.
Where are carbohydrases, proteases and lipases produced?
Carbohydrases: amylase - salivary gland and pancreas; maltase - small intestine Protease : pepsin - stomach, others in pancreas and small intestine Lipases : pancreas and small intestine
Where is bile made and stored?
Made in liver stored in gallbladder
How is epidermal tissue adapted for its function?
It covers the entire plant, has a waxy cuticle which helps reduce water loos from leafs surface
How is palisade mesophyll tissue adapted for its function?
Contains lots of chloroplasts which allows more photosynthesis
How is spongy mesophyll tissue adapted for its function?
lots of air spaces which allow gases to diffuse in and out
How is xylem adapted to its function.
Made of dead cells forming a hollow tube to allow movement of water and minerals through the plant, strengthened by lignin makes it strong and waterproof, has bordered pits which allow mineral transportation
How is phloem adapted for its function?
Made of elongated living cells, has seive plates so cell sap can move through plates into other cells, seive tube have few organelles to allow efficient transport of substances