Organisation Flashcards
What are specialised cells?
Cells that differentiate to form different type of cells.
What happens as a cell differentiates?
As a cell differentiates:
It may change shape.
different sub-cellular structures develop to let it carry out a specific function.
How is a sperm cell specialised?
Tail: To push the sperm to fertilise the egg.
Mitochondria: Provides energy for the journey.
Nucleus: Contains only one set of genetic material.
Acrosome: Contains enzymes to allow the sperm to penetrate the outer layer of the egg.
How is a Xylem specialised?
They are arranged end to end but then the end walls break down to form hollow tubes.
The cell wall is strengthened with lignin.
How is the phloem specialised?
The end walls of the cells allow sugars through but support the tubes.
They are arranged end to end.
How is a root hair cell specialised?
Lots of mitochondria for active transport of minerals.
Long projection to increase the surface area to absorb water and minerals.
What is a tissue?
A tissue is a group of cells with a similar structure and function, which all work together to do a job.
What does a muscle tissue do?
It contracts to produce movement.
What are organs?
Organs are groups of different tissues, which all work together to preform a specific job.
What does the muscle tissue do in the stomach?
It contracts to churn the contents.
What is an organ system?
An Organ system is groups of organs working together to do a particular job.
What is the lock and key theory?
It is a model used to explain how enzymes work. The key is the substrate and the lock is the active site.
How are digestive enzymes produced?
They are produced by specialised cells and in the lining of the guts:
1) The enzyme pass out of the cells into the digestive system.
2) They come in contact with the food molecules.
3) They catalyse the breakdown of large insoluble food molecules into smaller soluble molecules.
How to test for sugars, starch and proteins?
1) To test for sugars, add benedict reagent and heat in a water bath for 2 minutes. If it turns red then sugar is present
2) To test for starch, add iodine solution. If starch is present, it will turn blue-black.
3)To test for protein add biuret reagent. If protein is present it will turn purple.
Amalyse
Produced in the salivary glands and the pancreas.
Is a carbohydrase that breaks down into sugar (maltose)
Starch to maltose
Protease
Is produced in the stomach, pancreas and small intestine
Breaks down proteins into amino acids.
Protein to peptides or amino acids.
Lipase
Is produced in the pancreas and small intestine
Breaks down lipids into fatty acids and glycerol
Fats to fatty acids + glycerol.
What is bile? Where is it made and where is it stored?
Bile is a liquid made in the liver and stored in the gall bladder.
What does bile do?
-Neutralises the HCl in the stomach.
-Emulsifies the fat to form small droplets increasing the surface area for enzymes to act on.
-It increases the rate at which fat is broken down by lipase.
What is the practical for the effect of ph on the rate of reaction of amalyse enzyme?
1) Put a test tube containing starch solution and a test tube containing amalyse into a water bath at 37 degrees.
2) After 5 minutes add the amalyse solution to the starch.
3) Every 30 seconds take a drop from the mixture and test it for starch using iodine solution.
4) Record how long it takes for the starch to completely be digested.
What is the practical for the effect of ph on the rate of reaction of amalyse enzyme?
1) Put a test tube containing starch solution and a test tube containing amalyse into a water bath at 37 degrees.
2) After 5 minutes add the amalyse solution to the starch.
3) Every 30 seconds take a drop from the mixture and test it for starch using iodine solution.
4) Record how long it takes for the starch to completely be digested.
5) Repeat the experiment at different ph values using different buffer solutions.
