This set of questions and topics aligns closely with the foundational principles of biochemistry and macromolecules covered in Unit 1 of AP Biology. Below, I’ve provided concise answers and explanations to help address these questions systematically:

Key Concepts:

Water and Hydrogen Bonds

1. What is a hydrogen bond?
   A weak bond formed between a hydrogen atom in one molecule and an electronegative atom (like oxygen or nitrogen) in another molecule.

2. Where are hydrogen bonds found in water?
   Between the partially positive hydrogen of one water molecule and the partially negative oxygen of another.

3. Where are hydrogen bonds found in DNA?
   Between the nitrogenous bases of complementary strands (e.g., adenine-thymine, cytosine-guanine).

4. How many hydrogen bonds are found between each complementary base pairing?

   • Adenine-Thymine (A-T): 2 hydrogen bonds

   • Cytosine-Guanine (C-G): 3 hydrogen bonds

Amino Acids and Proteins

5. What is the structure of an amino acid?
   Central carbon (C) bonded to:

   • An amino group (-NH₂)

   • A carboxyl group (-COOH)

   • A hydrogen atom (-H)

   • A variable R group (side chain).

6. What are the three types of R groups?

   • Nonpolar (hydrophobic)

   • Polar (hydrophilic)

   • Charged (acidic or basic).

7. For each R group option, describe the polarity and justify your response:

   • Nonpolar: Hydrophobic; does not interact with water.

   • Polar: Hydrophilic; can form hydrogen bonds with water.

   • Charged: Either positively or negatively charged; interacts with water and ions.

Properties of Water

8. What are three properties of water?

   • Cohesion: Water molecules stick together (e.g., surface tension).

   • Adhesion: Water molecules stick to other surfaces (e.g., capillary action).

   • High specific heat: Water resists temperature changes.

9. How did hydrogen bonding allow for each property?

   • Cohesion: Hydrogen bonds create a network that holds water molecules together.

   • Adhesion: Hydrogen bonds interact with polar surfaces.

   • High specific heat: Hydrogen bonds absorb heat, requiring more energy to break.

10. Why is water considered a polar molecule?
    The oxygen atom is more electronegative, creating partial charges:

• Oxygen: Partial negative (δ-)

• Hydrogen: Partial positive (δ+).

11. Using the properties of water, describe how water can move up a capillary tube from roots to leaves:
    Adhesion to the tube walls and cohesion between water molecules allow for capillary action.

12. Using the properties of water, describe how a water strider can walk on water:
    Surface tension from cohesive hydrogen bonds creates a strong "skin" on the water surface.

Macromolecules

13. What are the four macromolecules?

    • Carbohydrates

    • Proteins

    • Nucleic acids

    • Lipids

14. What are the elements found in a carbohydrate?
    Carbon (C), Hydrogen (H), Oxygen (O)

15. What are three functions of carbohydrates in living organisms?

    • Energy storage (e.g., starch, glycogen).

    • Structural support (e.g., cellulose, chitin).

    • Cellular recognition (e.g., glycoproteins).

16. What are the elements found in a protein?
    Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), sometimes Sulfur (S).

17. What are the functional groups found in all amino acids?

    • Amino group (-NH₂)

    • Carboxyl group (-COOH).

18. What are three functions of proteins in living organisms?

    • Enzymes (catalysts for reactions).

    • Structural components (e.g., keratin).

    • Transport (e.g., hemoglobin).

19. What are the elements found in nucleic acids?
    Carbon (C), Hydrogen (H), Oxygen (O), Nitrogen (N), Phosphorus (P).

20. What are parts found in all nucleotides?

    • A phosphate group

    • A pentose sugar (deoxyribose or ribose)

    • A nitrogenous base (A, T, G, C, U).

21. What are three functions of nucleic acids in living organisms?

    • Store genetic information (DNA).

    • Transmit genetic information (RNA).

    • Catalyze biochemical reactions (ribozymes).

22. What are the elements found in a lipid?
    Carbon (C), Hydrogen (H), Oxygen (O), sometimes Phosphorus (P).

23. How are the three different types of lipids different?

    • Fats (triglycerides): Glycerol + 3 fatty acids.

    • Phospholipids: Glycerol + 2 fatty acids + phosphate group.

    • Steroids: Four fused carbon rings.

24. What are three functions of lipids in living organisms?

    • Energy storage.

    • Membrane structure (phospholipids).

    • Hormone signaling (steroids).

25. Which macromolecule(s) contain nitrogen?
    Proteins, Nucleic acids.

26. Which macromolecule(s) contain phosphorus?
    Nucleic acids, some lipids (e.g., phospholipids).

27. Which macromolecule(s) contain sulfur?
    Some proteins (e.g., those with sulfur-containing R groups like cysteine).

Chemical Reactions

28. What is hydrolysis?
    A reaction where water is used to break bonds between monomers (e.g., breaking a disaccharide into monosaccharides).

29. What is dehydration?
    A reaction where water is removed to form bonds between monomers (e.g., forming a peptide bond in proteins).

Bond Types in Macromolecules

30. Carbohydrates: Glycosidic bonds between monosaccharides.

31. Proteins: Peptide bonds between amino acids.

32. Nucleic Acids: Phosphodiester bonds between nucleotides.

Let me know if you'd like any of these sections further elaborated!