B3 - Organisation And The Digestive System Flashcards
What are carbohydrates made up of?
Units of sugar
Test for sugar?
Colour change?
Benedicts solution
Blue - brick red on heating.
What are complex carbs?
Examples?
Made up of long chains of simple sugar units bonded together.
Starch and cellulose.
What are simple sugars?
Examples?
They contain only one sugar unit.
Glucose.
What are lipids?
Fats (solid) and oils (liquids).
What are the most efficient energy store in the body?
Lipids.
Test for complex carbs?
(Starch test) yellow red iodine - blue/black
What are lipids made up of?
3 molecules of fatty acids bonded to a molecule of glycerol.
Test for lipids?
Ethanol, gives a cloudy white layer.
What are proteins made of?
Long chains of amino acids, that are coiled and folded to make unique shapes.
What happened when a protein is denatured?
The bonds that hold proteins into break and the shape of the protein is lost.
Test for proteins?
Biuret regent turns from blue to purple.
What are enzymes?
Biological catalysts - they speed up a reaction, whilst remaining unchanged.
What do enzymes control in the body?
Metabolism.
What are enzymes? (Structure)
Proteins.
How do enzymes speed up reactions?
The substrate of the reaction fits into the active site and they join together.
THEY DECREASE THE ACTIVATION ENERGY REQUIRED FOR THE REACTION TO TAKE PLACE.
What is metabolism?
The sun of all the reactions in the body.
Factors that affect enzyme activity?
Temperature and PH
Enzymes that break down carbs?
Amylase.
Effect of ph on enzyme action?
The shape of the active site is controlled by forced between different parts of the protein molecule. Change in ph affects the forces so the active site shape changes.
D. Denatured?
The breakdown of the molecular structure of a protein so it no longer functions.
Optimum temperature for most enzymes?
37 degrees
Effect of temperature on enzyme activity?
After about 40 degrees, the protein structure is affected and the long amino acid chains begin to unravel so the shape of the active site changes.
Enzymes that break down proteins?
Protease
What are proteins broken down into?
Amino acids.
What enzyme breaks down fats?
Lipase
What are fats broken down into?
Fatty acids and glycerol
Where is amylase produced?
Salivary glands and pancreas.
Where are carbohydrates digested?
Starch is mostly digested in the small intestine.
Where is protease produced?
Stomach, pancreas and small intestine.
Where does the digestion/break down of proteins occur?
Stomach and small intestine.
Where is lipase produced?
Pancreas and small intestine.
Where are lipids broken down?
Small intestine
What conditions do the protease enzymes of the stomach work best in?
Acid
How does the stomach maintain a low pH?
By producing hydrochloric acid so the protease secreted there can work.
How is the acidic liquid from the stomach become alkaline in the small intestine?
The liver produces alkaline bile.
Where is bike stored?
Gall bladder
Why is bile important? (2 points)
- It neutralises the acidity of the food from the stomach and provides alkaline conditions for the enzymes in the small intestine.
- it also emulsified the fats in your food, so they are broken up into smaller droplets that lipase can act in. (Bigger surface area)
Examples of diffusion in the body?
- Urea from cells to the blood plasma that goes to kidneys.
* Digested food molecules from small intestine into the blood
Examples of diffusion in plants.
Oxygen and carbon dioxide diffuse during gas exchange.
Active transport in the body?
Sugar molecules from gut to blood.
Active transport in plants?
Mineral ions and water from soil to roots.
Why is it important to add a buffer to the enzyme before the solution is added?
As the reaction will start as soon as the enzyme meets the starch (1). If the buffer is not already mixed with the amylase so the amylase is at the correct pH, you will be changing the pH after the reaction has started (1) and the results will be invalid (1).
