Organisation Flashcards
What is the name of the process where cells become specialised for different jobs?
Differentiation
What are the stages of organisation?
Cells -> tissues -> organs -> organ systems
When does differentiation occur?
During the development of a multicellular organism
What is a tissue?
A group of similar cells that work together to carry out a particular function. It can include more than one type of cell. E.g. muscular tissue
What is an organ?
A group of different tissues that work together to perform a certain function. E.g. the stomach.
What is an organ system?
A group of organs working together to perform a particular function. E.g. the digestive system.
What are enzymes?
biological catalysts produced by living things. They are large proteins made up of chains of amino acids.
What do enzymes do?
Speed up the useful chemical reaction in the body and control them in order to get the right amount of substances
What is a catalyst?
A substance which increases the speed of a reaction, without being changed or used up in the reaction
What is the lock and key theory?
Every enzyme has an active site with a unique shape that only fits onto the substance involved in its reaction. If they enzyme and substrate don’t fit, the reaction won’t be catalysed.
How does temperature affect enzymes
Enzymes have optimum temperatures. Higher temperatures increased reactions at first but if it gets too hot the enzymes are denatured, changing the shape of the active site as the bonds holding them together break.
How does pH affect enzymes?
All enzymes have an optimum pH. Normally neutral at 7. If its too high or too low it affects the bonds holding the enzyme together which denatures it, changing the shape of its active site.
How do you investigate the effect of pH on enzyme activity?
- fill a spotting tile with drops of iodine solution
- heat a beaker of water inside it to 35 degrees Celsius using a Bunsen burner, keep this constant
- Add 1cm^3 of amylase solution and 1cm^3 of buffer solution with pH 5 to a boiling tube and put it into the hot water.
- Add 5cm^3 of starch solution and mix
-start a stop watch - Time how low long it takes for the starch to be broken down by put a sample of the boiling tube solution into the spotting tile every 30 seconds
-starch is present if the iodine changes colour to dark blue - Repeat the experiment with different pH values each to to see how the results change
What is the formula for rate of reactions in the experiment to test the efficency of enzymes ?
Rate = 1000/time
What happens when a molecule like starch proteins and fat are too big to travel down the digestive system?
Enzymes break them down into smaller ones like sugars, amino acids, glycerol and fatty acids
Protease breaks down proteins. Where is it made?
In the stomach, pancreas and small intestine
Amylase breaks down carbohydrates. Where is it made?
In the salivary glands, pancreas, and small intestine
Lipase breaks down lipids. Where is it made?
The pancreas and small intestine
Where is bile produced, stored and released?
Produced in the liver, stored in the gall bladder, and released into the small intestine.
What does bile do?
Neutralises stomach acid and, making condition alkaline to stop enzymes from denaturing. It emulsifies fat to give it a bigger surface area
What is the thorax?
The top part of your body
How does air get into the blood?
Thorax -> bronchi -> bronchioles -> alveoli where gas exchange takes place
How do the alveoli carry out gaseous exchange?
They are surrounded by blood capillaries. Oxygen diffuses out of the alveoli into the blood and carbon dioxide diffuses out of the blood and into the alveoli
How does oxygen get from the blood to the body cells?
When blood gets to the body cells oxygen diffuses out of the red blood cells and into the blood and carbon dioxide diffuses out of the cells and into the red blood cells to be taken back to the lungs
How does the first human circulatory system work?
Right ventricle pumps deoxygenated blood to the lungs to take in oxygen and then it goes back to the heart.
How does the second human circulatory system work?
The left ventricle pumps oxygenated blood around the body where it gives oxygen to the cells and returns to the heart as deoxygenated blood