Biology Q3 Test Review

Organic Compounds

1. What is an organic compound?

   • A compound that contains carbon and usually hydrogen.

   • Example: Glucose (C₆H₁₂O₆)

2. What is NOT considered an organic compound?

   • Example: Carbon dioxide (CO₂)

Isomers

3. What is an isomer?

   • Compounds with the same chemical formula but different structural arrangements.

   • Examples: Glucose and fructose

Functional Groups

4. Identify the functional groups:

   • Hydroxyl (OH)

   • Amino (NH₂)

   • Carbonyl (C=O)

   • Carboxyl (C=O-OH)

   • Phosphate (PO₄)

   • Methyl (CH₃)

Macromolecules

5. What are the four macromolecule groups?

   • Carbohydrates

   • Lipids

   • Proteins

   • Nucleic Acids

Carbohydrates

6. What elements make up carbohydrates?

   • Carbon, Hydrogen, Oxygen (1:2:1 ratio)

7. What is the simplest form of a carbohydrate?

   • Monosaccharide (Example: Glucose)

8. What is an example of a disaccharide?

   • Sucrose (Made by linking two monosaccharides via dehydration reaction)

9. What is an example of a polysaccharide?

   • Storage carbohydrates:

     • Plants: Starch

     • Animals: Glycogen

   • Structural carbohydrates:

     • Plants: Cellulose (fiber)

     • Insects/crustaceans: Chitin

Reactions

10. What is hydrolysis?

    • The breaking of molecules using water.

11. What is a dehydration reaction?

    • The joining of molecules by removing water.

Enzymes

12. How can you recognize enzymes?

    • Most enzyme names end in "-ase"

    • Most carbohydrate names end in "-ose"

Lipids

13. What are lipids made of?

    • Carbon, Hydrogen, Oxygen

14. What makes up a fat molecule?

    • 1 glycerol + 3 fatty acids

15. What are the two types of fats?

    • Saturated fats: No double bonds between carbons

    • Unsaturated fats: At least one double bond

16. What is hydrogenation?

    • The process of converting unsaturated fats into saturated fats by adding hydrogen.

17. What is a trans fat?

    • A partially hydrogenated fat that is unhealthy.

18. Why do fats float on water?

    • They are hydrophobic and less dense than water.

19. What are phospholipids?

    • Lipids that form cell membranes.

    • Parts:

      • Hydrophilic head

      • Hydrophobic tails

20. What is the phospholipid bilayer?

    • A double-layer structure that forms cell membranes.

21. What are steroids?

    • Lipids that act as messenger molecules (hormones).

    • Base molecule: Cholesterol

    • Examples: Testosterone, Estrogen

Proteins

22. What are proteins made of?

    • Amino acids (There are 20 important ones)

23. What are the four levels of protein structure?

    • Primary: Chain of amino acids

    • Secondary: Pleated sheets or helices (formed by hydrogen bonds)

    • Tertiary: 3D structure (formed by R-group interactions)

    • Quaternary: Multiple polypeptides combined (e.g., Hemoglobin)

24. What is a peptide bond?

    • The bond that links amino acids together in proteins.

25. What can denature a protein?

    • Heat, pH changes, salt concentration

Nucleic Acids

26. What are the two types of nucleic acids?

    • DNA and RNA

27. What are the three parts of a nucleotide?

    • Five-carbon sugar, Phosphate, Nitrogenous base

28. What are the nitrogenous bases in DNA?

    • Adenine (A), Thymine (T), Guanine (G), Cytosine (C)

29. What replaces thymine in RNA?

    • Uracil (U)

30. What are the base-pairing rules in DNA?

    • A-T and C-G