B2 - Organisation Flashcards
What are cells?
Building blocks that make up all living organisms
What is a tissue?
Group of similar cells that work together to carry out a particular function and it can include more than 1 type of cell
What are organs?
Group of different tissues that work together to a certain function
What are organ systems?
A group of different tissues that work together to perform a certain function
What are catalysts?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
Why are enzymes produced in our body?
To speed up digestion and prevent the rising of our body temperatures which could damage cells
What are enzymes?
Biological catalysts made out of large proteins and chains of amino acids which are folded into unique shapes. They are used to speed up a reaction without being used up
Where does the reaction take place in enzymes?
Active Site
What is an Active Site on an enzyme?
A unique shape that fits onto the substance
What is the ‘lock and key’ model?
Where the specific enzyme can only bind to certain substances (e.g protein) and if doesn’t they won’t be catalysed
What is the ‘included fit’ model?
The active site changes shape a little as the substrate binds to get a tighter fit
What is the substance that an enzyme acts on?
Substrate
How does temperature affect enzyme-catalysed reactions?
The rate
What is the optimum body temperature for enzymes?
37 (body temperature)
Do different enzymes have different optimum temperatures?
yes
How does pH affect enzymes?
The pH interferes with the bonds holding the enzyme together which changes the shape of the active site and denatures the enzyme
Can enzymes die?
No, they become DENATURED
How do you calculate the rate of reaction?
1000/time s^-1
OR (for measuring how much something changes over time)
change/time cm^3 s^-1
Where are enzymes used?
In the digestive system
Why do we need enzymes to break down nutrients?
- Because they are too big pass through the walls of the digestive system
- Would take too long to do
Where is amylase produced? (carbohydrase)
- Salivary glands
- Pancreas
- Small intestine
Where are proteases made?
- Stomach
- Pancreas
- Small Intestine
Where are lipase made?
- Pancreas
- Small intestine
What are carbohydrates converted into by amylase?
Sugar molecules and Maltose
What are proteins broken down into by protease?
Amino acids
What are fats broken into down by lipase?
Fatty acids and Glycerol
What is bile?
A green substance produced by the liver
Where is bile stored?
Gall bladder before it is released into the small intestine when being used
Why do we need bile?
The hydrochloric acid makes the pH too acidic for enzymes in the small intestine to work properly. Bile is alkaline - it neutralises the acid and makes conditions alkaline
What does bile do?
It emulsifies fat and breaks them into tiny droplets which gives a bigger surface area of fat for the enzyme lipase to work on (making digestion faster)
Name in order all the organs in the digestive system
1) Mouth
2) Salivary Glands
3) Oesophagus
4) Stomach
5) Pancreas
6) Liver
7) Gall bladder
8) Small intestine (duodenum and ileum)
9) Large Intestine (colon and rectum)
10) Rectum
11) Anus
Mouth
Where food enters the alimentary canal and digestion begins
Salivary glands
Produce saliva containing amylase
Oesophagus
Muscular tube which moves ingested food to the stomach
Stomach
Muscular organ where digestion continues
Pancreas
Produces digestive enzymes
Liver
Produces bile
Gall bladder
Stores bile before releasing it into the duodenum
Small intestine - duodenum
Where food is mixed with digestive enzymes and bile
Small intestine - ileum
Where digested food is absorbed into the blood and lymph
Large intestine - colon
Where water is reabsorbed
Large intestine - rectum
Where faeces are stored
Large intestine - anus
Where faeces leave the alimentary canal
What test should you use to test for sugars?
Benedict’s Test
Benedict’s Test method
Add Benedict’s reagent to the food and boil in a water bath.
What should you use to test for starch?
Iodine
Iodine test method
Add iodine reagent to the food.
What should you use to test for proteins?
Biuret (a mixture of sodium hydroxide and copper sulfate)
Protein test method
Add Biuret reagent to the food.
What should you use to test for fats?
Ethanol/cooking paper
Lipid test method
Add ethanol to the food to dissolve the fat then add water.
Sugar test colours
i: blue
p: red