Section 2: Biological Molecules Flashcards
enzymes, biological molecules, food tests
What elements are present in Carbohydrates
Carbon, hydrogen and oxygen
What elements are present in proteins
Carbon, nitrogen, hydrogen and oxygen
What elements are present in lipids
Carbon, hydrogen and oxygen
What are the complex carbohydrates
Starch and glycogen
What is the structure of complex carbohydrates and what are they made of
Polymers made up of simple sugars
What is the structure of proteins and what is it made of
Polymers made up of amino acid
What is the structure of lipids and what is it made of
1 glycerol and 3 fatty acids
What does a positive result look like for starch
blue-black
What does a positive result look like for glucose
small amount - green
large amount - brick red
What does a positive result look like for protein
purple
What does a positive result look like for lipids
White cloudy suspension
What is the role of starch in plants
to store energy
where is glycogen stored
Stored in muscles cells and liver
How do you carry out a test for starch
- Put iodine in each dimple of a spotting tile
- Add a drop of food sample into each solution.
- Observe results
What is the name of the glucose(simple sugars) test and how do you carry it out
Benedicts test
1. Add equal parts benedicts solution and food sample to test tube
2. Put test tube in water bath at 80 degrees for 3 mins
3. Observe results
What colour is iodine
orange/yellow
What colour is benedicts solution
blue
What is the name of the protein test and how do you carry it out
Biurets test
1. Add equal parts food sample and biurets solution to a test tube
2. observe results
What is the name of the lipids test and how do you carry it out
ethanol test
1. Place 1ml of food sample into a test tube
2. Add two ml of water- mix
3. Add 1ml of ethanol and shake
4. Observe results
What is an enzyme
enzymes are a type of protein that is a biological catalyst
What enzyme is added to starch to change it from polymer to monomer
starch + AMYLASE = glucose
What enzyme is added to glycogen to change it from polymer to monomer
glycogen + GLUCAGON = glucose
What enzyme is added to protein to change it from polymer to monomer
protein + PROTEASE = amino acids
What enzyme is added to lipids to change it from polymer to monomer
lipids + LIPASE = glycerol and fatty acids
What is the lock and key theory
- Enzyme and substrate collide
- Complimentary substrate binds with the enzymes active site to form an enzyme substrate complex
- Enzyme product complex is formed
- Products are released from the enzymes active site
How does temperature effect enzymes
changing temperature effects the rate of enzyme - catalysed reaction
What happens to the enzyme when temperature is increased and why
At first when temperature is increased the rate of enzyme-catalysed reaction is increased, because a higher temperature increases the kinetic energy in the enzyme and substrate so there are more collisions leading to a higher reaction rate
what is optimum temperature
Optimum temperature is when the reaction rate is at its highest
What happens to the enzyme when temperature is too high
the enzymes denatures
What is denaturing
Denaturing is when the active site changes shape, denaturing is irreversible
Why does an enzyme denature
When temperature is too high the bonds holding the enzyme together will break
What happens to the reaction rate when denaturing occurs and why
Reaction rate rapidly decreases because the substrate no longer fits into the active
What happens to enzyme if temperature is too low
If t6emperature is too low the reaction rate will slow down because there is a lack of kinetic energy but will NOT denature
How does pH effect enzymes
If enzyme is too high or too low enzyme will denature. Enzymes works at optimum pH
What is the optimum pH
7
What is optimum temperature
37-40 degrees
