Flashcards in Chapter 3 Deck (22):
What is a tissue ?
A group of cells working together to preform a specific function
What is an organ ?
A group of tissue's that work together to preform a specific function
What is an organ system ?
A group of organs working together to preform a specific function
What does the mouth do in digestion ?
-Physical digestion by teeth
-Chemical digestion by saliva
How does the stomach aid digestion
-Digestion by stomach acid and digestive enzymes
How does the liver aid digestion ?
-Produces bile which emulsifies fat (breaks them down into smaller pieces) and neutralises stomach acid
How does the pancreas aid digestion ?
Sits below stomach:
-Creates digestive enzymes to help break down food
How does the small intestine aid digestion ?
Food moves here after the stomach:
-Digested food is absorbed from small intestine into the blood stream
-Enzymes produced to break down food
How does the Large intestine aid Digestion ?
-Water is re-absorbed into the bloodstream and the rest is passed onto the rectum where the left over is excreted from the anus
What is the chemical formula for glucose ?
How do you test for Carbohydrates ?
Iodine test for starch:
-yellow/red iodine turns blue if starch is present
Benedict's test for sugars:
-Blue solution turns red on heating if starch is present
How do you test for Protein ?
-Biuret reagent turns purple if protein is present
How do you test for lipids ?
-Ethanol gives a solution containing lipids a cloudy white layer
What are proteins ?
Molecules used for growth and repairing muscle tissue:
-Made up of long chains of amino acids
What are Carbohydrates ?
Main source of energy for humans:
-Made up of simple sugars such as glucose and sucrose
what are Lipids ?
Fats and oils used as energy stores in our body:
-Made up of 3 molecules of fatty acids joined to 1 molecule of glycerol
What are enzymes and how do they work?
Proteins made up of amino acids:
-Work by lock and key theory
--substrate locks into the enzymes active site
--substrate splits into 2 products making it easier and quicker to digest
--enzyme can be used again
What is metabolism ?
The sum of all reactions in your body
What and how does it affect the effect of enzymes on a reaction ?
-Greater temperature the greater the kinetic energy the faster the reaction
-If temperature is too great the chains of amino acids begin to unravel and the enzyme becomes denatured
-A change in pH can stop the forces holding an active site in place meaning that the enzyme stops working completely
Which enzyme breaks down:
Describe lock and key theory
-Substrate fits into the active site of the enzyme
-Substrate splits into products, making them quicker to digest
-Products leave the active site and the enzyme can be used again