B2 Flashcards
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 and work together
What is an organ
A collection of tissues working together to perform a function
What is an organ system
A group of organs working together
What is main function of digestive system
Digest food +absorb nutrients
What is an enzyme
A biological catalyst- increases the speed of reaction without being changed or used up in a reaction
What is an enzyme’s active site
A unique shape that fits onto the substance involved in the reaction
What breaks down carbohydrates
Amylase - carbohydrate to simple sugars
What breaks down proteins
Proteases- proteins to amino acids
What breaks down lipids
Lipases- lipids to glycerol + fatty acids
Where is bile produced
In the liver
Stored in the gall bladder
What are carbohydrates for
Source of energy
What are proteins for
Growth + repair
Lipids
Energy (stored)
How to test for sugars
Benedict’s test
Heat in water
Changes colour
Test for starch
Iodine
Turns blue/black
Test for proteins
Biuret reagent
A purple colour/ purple rings are present
Test for fats
Sudan III test
A red layer will form on the surface of the water
What does the human digestive system do
- breaks down complex food substances
- provides very large surface area for maximum absorption of food
What does the mouth and the stomach do
- mouth
Begins digestion of carbohydrates
-stomach
Begins digestion of protein; small molecules such as alcohol absorbed
What does the small and large intestine do
- small intestine
Digests carbohydrates, protein and lipids- into single sugars, amino acids, fatty acids and glycerol - large intestine
Absorption of water
What does the gut do
Has digestive enzymes which break down food into small soluble molecules that can be absorbed through the gut wall
What is villi
Finger-like projections in the small intestine that provide a large surface area for the absorption of food
What affects enzyme action
- temperature
Too high - enzyme denatures
Too low - not enough successful collisions - pH
Not too acidic or alkaline for that certain enzyme- can change the shape of the active site
Need to finish
Good luck :)
