5. Enzymes Flashcards
Describe the structure of DNA
- Two strands coiled together to form a double helix.
- Each strand contains a protein called bases.
- Crosslinks between strands are formed by pairs between bases.
What are the four types of bases
1) Adenine
2) Thymine
3) Guanine
4) Cytosine
What is the method for testing for reducing sugars
1) Crush and grind to make extract.
2) Add benedict’s solution
3) Gently heat the mixture
What are the results from a reducing sugars test
If present: Mixture turns from blue to yellow to green to orange to brick-red
If absent: Mixture remains blue
What are the methods to test for starch
- Crush and grind to make extract
- Add iodine solution
What are the results from a starch test
If present- Turns blue black
If absent - Remains yellow or light brown
What are the methods to test for proteins
- Crush and grind to make extract
- Add biuret solution ( or add equal amounts of copper sulfate and hydrogen peroxide)
What are the results from a test for proteins
If present: Solution turns purple/ mauve/lilac
If absent: Solution remains blue
What are the methods to test for fats
Crush and grind to make extract
Add ethanol to extract
Add distilled water
Shake it up
What are the results from a test for fats
If present: Solution turns milky white/ a white emulsion appears
If absent: Remains the same
What are the methods to test for Vitamin C
-Crush or grind to make extract
- Add DCPIP
- Add the liquid one drop at a time
What are the results of a vitamin C test
If present: Turns colorless
If absent: Blue color persists
What are enzymes
Biological catalysts that speed up the rate of reactions while remaining unchanged
What are catalysts
A substance that speeds up a chemical reaction and remains unchanged
Factors affecting the rate of enzyme activity
Temperature and pH
