Chapter 3 Flashcards
(22 cards)
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 ?
C6H12O6
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 test:
-Biuret reagent turns purple if protein is present
How do you test for lipids ?
Ethanol test:
-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:
- Biological catalysts
- 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 ?
Temperature:
-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
pH:
-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:
- Carbohydrates
- -Starch
- Proteins
- Fatty Acids/lipids
- Carbohydrase
- -amylase
- protease
- lipase
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
What is bile ?
Bile is produced in the liver and stored in the gall bladder, it i s an alkaline that neutralises the stomach acid and emulsifies fat to form small droplet that increase the surface area to volume ratio
