Biological molecules and enzymes Flashcards
What elements make up carbohydrates?
Carbon (C), Hydrogen (H), and Oxygen (O).
What is the simplest form of carbohydrates?
Glucose (simple sugars/monosaccharides).
What are complex forms of carbohydrates?
Starch, glycogen, and cellulose (polysaccharides).
What is the main importance of carbohydrates?
They serve as a source of energy.
What elements make up lipids?
Carbon (C), Hydrogen (H), and Oxygen (O).
What are lipids made of?
One glycerol molecule and three fatty acids.
What are the main functions of lipids?
They provide energy, insulation, and serve as a store of energy.
What elements make up proteins?
Carbon (C), Hydrogen (H), Oxygen (O), and Nitrogen (N).
What are proteins made of?
Amino acids.
What are the main functions of proteins?
They are used for growth, repair of cells, and enzyme formation.
- What test is used for starch?
- What is the positive and negative result for the starch test?
- Iodine solution.
- Positive: blue-black | Negative: yellow (orange).
- How is a reducing sugar (glucose) test conducted?
- What are the possible positive results for a reducing sugar test?
- Add Benedict’s solution and heat in a water bath.
- Green, yellow, orange, or brick-red.
- What test is used for proteins?
- What is the positive and negative result for the protein test?
- Biuret solution.
- Positive: purple (lilac) | Negative: blue.
- How is a lipid test conducted?
- What are the positive and negative results for the lipid test?
- Emulsion test: add ethanol and water to the sample and shake.
- Positive: white | Negative: clear.
What is the definition of an enzyme?
A protein that acts as a biological catalyst, speeding up the rate of chemical reactions without being used up or changed.
How do enzymes work? (Not chemistry)
Each enzyme has a specific shape (active site) that complements a substrate molecule.
How does temperature affect enzyme activity?
- At low temperatures, enzymes are inactive because particles move slowly, leading to fewer collisions with the active site.
- As temperature increases, particles gain kinetic energy and move faster, leading to more collisions.
- At high temperatures, the active site changes shape, and the substrate no longer fits (enzyme denatures).
What happens to enzyme activity at optimum temperature?
The enzyme works at its highest efficiency.
How does pH affect enzyme activity?
Each enzyme has an optimum pH; changing the pH can denature the enzyme.
