B2 - Organisation Flashcards
What are:
- cells
- tissues
- organs
- organ systems
Basic building blocks of all living organisms
A tissue is a group of cells with a similar structure and function.
Organs are aggregations of tissues performing specific functions.
Organs are organised into organ systems, which work together to form organisms
Define catalyst
substance which increases speed of reaction by providing an alternate pathway without being changed or used up in the reaction
What is an enzyme
Chemical which speeds up the rate of reaction
Is a protein
Explain the lock and key theory (3 marks)
Enzyme is the lock, substrate is the key
Every enzyme has an active site with a unique shape that fits onto the substance involved in a reaction
For an enzyme to work, substrate has to fit into its active site
Vice Versa
Formula for rate of reaction
1000/time
What does change equal to
Other equation
amount of product formed
Change/time
What is the digestive system
An example of an organ system in which
several organs work together to digest and absorb food.
Explain how temperature and affect enzymes (4 marks)
Changing temperature changes the rate of an enzyme-catalysed reaction
As temp increase, rate increases up until a point
If it gets to hot, some of the bonds holding the enzyme together will break - changes shape of enzymes active site, substrate won’t fit anymore - denatured
Explain how pH affects enzymes ( 3 marks)
If pH gets too high or too low, pH interferes with the bonds holding enzymes together - changes the shape of the active site - denatures
What pH do enzymes work at
But what is the name of the other enzyme used to break down proteins in the stomach and what is its optimum pH
7
Pepsin - pH2
How to investigate effect of pH on Enzyme activity (6 marks)
Put a drop of iodine solution in a spotting file
Place Bunsen burner on a heat proof mat, and place tripod and gauze over it
Using a Bunsen burner, heat up a beaker of water to 35 degrees - keep constant
Using a syringe add 1cm^3 of amylase solution and 1mc^3 of buffer solution pH5 to the boiling tub. Put this boiling tube into the beaker of water and wait 5 minutes
After 5 minutes, add 1cm^3 of starch solution to the boiling tube using a different syringe
Immediately mix the contents and start a stopwatch
Every 10 seconds, put a drop from the boiling tube into a spotting file using a pipette
When the iodine solution remains brown-orange, there is no more starch present
Repeat with different pH of buffer solution to see how pH affects rate of reaction
Keep concentration and volume of amylase solution constant throughout the experiment
Where is Amylase found
Converts what to what
Salivary glands pancreas s.i
Carbohydrates into maltose
Amylase is an example of ..
carbohydrases
Where is protease found
Converts what to what
Stomach Pancreas S.I
Proteins into amino acids
Where is lipase found
Converts what to what
Pancreas S.I
Lipids into glycerol and fatty acids
