AP Biology Exam Review Notes

Topic 1.1: Structure of Water and Hydrogen Bonding

Overview of Water in Biological Systems

Systems Interactions: Biological systems interact, and these systems and their interactions exhibit complex properties.

Properties of Water Due to Polarity and Hydrogen Bonding

1.1.A: Explain how the properties of water from its polarity and hydrogen bonding affect its biological function.
   - 1.1.A.1: Living systems depend on the properties of water to sustain life.
     - Polarity of Water: Water molecules have polar covalent bonds between hydrogen and oxygen, leading to overall polarity.
     - Hydrogen Bonds: The polarity allows for hydrogen bonding between water molecules and biological molecules.
     - High Specific Heat Capacity: Water can absorb a lot of heat without a significant change in temperature, helping in temperature regulation (homeostasis) of living organisms.
     - High Heat of Vaporization: Allows water to evaporate and cool the environment; essential for temperature maintenance in organisms.
     - Key Questions:
       - A polar covalent bond is defined as… (elaboration needed).
       - Diagram Requirement: Include a labeled diagram of a water molecule showing polar bonds and partial charges.
       - Water is polar due to…
       - A hydrogen bond is defined as…
       - Locate hydrogen bonds in water.
       - Diagram Requirement: Two water molecules showing hydrogen bonds and polar bonds.
       - Properties of Water: List three properties caused by hydrogen bonding:
         - Cohesion
         - Adhesion
         - Surface tension
       - Specific Heat Capacity: Defined as the amount of heat required to change the temperature…
         - Water has a high specific heat because…
       - Evaporative Cooling: The process by which water absorbs heat from the environment as it changes from liquid to gas…
         - Water facilitates this by…
       - Temperature Maintenance: Organisms maintain body temperatures through mechanisms such as…

Hydrogen Bonds and Their Effects on Water Properties

1.1.A.2: The hydrogen bonds between polar water molecules result in cohesion, adhesion, and surface tension.
   - Key Questions:
     - Describe a hydrogen bond.
     - Identify three properties caused by hydrogen bonds.
     - Compare cohesion and adhesion:
       - Cohesion: Cohesion is…
       - Adhesion: Adhesion is…
     - Surface Tension: Defined as…
       - The properties of water contributing to surface tension include…
     - Capillary Action: Explain how properties of water enable it to move against gravity in plants (capillary tubes).
     - Water Strider: Describe how water striders walk on water due to surface tension.

Topic 1.2: Elements of Life Energetics

Composition of Biological Macromolecules

1.2.A: Describe the composition of macromolecules required by living organisms.
   - 1.2.A.1: Atoms and molecules from the environment are necessary to build new molecules.
     - Key Elements: Carbon, hydrogen, and oxygen are foundational elements in biological macromolecules:
       - Carbohydrates: Composed of…
       - Proteins: Rich in…
       - Lipids: Contain…
       - Nucleic Acids: Made up of…
     - Additional Elements:
       - Sulfur: Found in proteins.
       - Phosphorus: Present in nucleic acids and phospholipids.
       - Nitrogen: Essential for nucleic acids.
     - Key Questions:
       - Identify the four macromolecules and their composition.
       - List elements in carbohydrates, proteins, lipids, and nucleic acids and their functions.

Topic 1.3: Introduction to Macromolecules

Chemical Reactions of Macromolecules

1.3.A: Describe the chemical reactions that build and break biological macromolecules.
   - 1.3.A.1: Hydrolysis involves cleaving covalent bonds and breaking down larger molecules into smaller units:
     - Water (H2O) is added: A hydrogen ion attaches to one monomer and a hydroxyl group to another.
     - Key Questions:
       - What is hydrolysis and the process associated with it?
       - Identify the bond broken during hydrolysis in carbohydrates, proteins, and nucleic acids.
   - 1.3.A.2: Dehydration Synthesis combines smaller molecules via covalent bonding, resulting in the loss of water:
     - A hydrogen ion is removed from one monomer and a hydroxyl group from another.
     - Polymerization: The process of linking many monomers.
     - Key Questions:
       - Describe dehydration synthesis and diagram the reaction involving carbohydrate and nucleic acid monomers.

Topic 1.4: Carbohydrates

Structure and Function of Carbohydrates

1.4.A: Describe the structure and function of carbohydrates.
   - 1.4.A.1: Monosaccharides are the building blocks of complex carbohydrates, which can be linear or branched:
     - Key Questions:
       - Identify the monomer (monosaccharides) of carbohydrates and their components.
       - Diagram the structure of a carbohydrate monomer and a disaccharide.
       - Compare the bonding and structure of starch vs. cellulose.
       - List two functions of carbohydrates.

Topic 1.5: Lipids

Structure and Functions of Lipids

1.5.A: Describe the structure and function of lipids.
   - 1.5.A.1: Lipids are nonpolar, hydrophobic molecules:
     - Fatty acids: Saturated (single bonds) vs. unsaturated (double bonds).
       - More unsaturated implies…
       - Key Questions:
         - What is the property of lipids compared to other macromolecules?
         - Describe saturated vs. unsaturated fatty acids and their room temperature behavior.
   - 1.5.A.2: Functions of lipids:
     - Examples include:
       - Fats: Energy storage, cell support, insulation.
       - Steroids: Hormonal functions.
       - Cholesterol: Membrane stability.
       - Phospholipids: Form cellular membranes.
     - Key Questions:
       - Identify and describe the structure of fat molecules, steroids, and phospholipids.