Lecture Notes: Chapter 2 - Chemistry Overview
Introduction to Chemistry
- Definition: Chemistry involves all elements and how they interact with the world.
- Focus: Understanding the periodic table and matter interactions.
Basic Concepts
Matter
- Definition: Anything with mass that takes up space.
- Forms of Matter: Solid, Liquid, Gas.
- Atoms: Basic unit of matter.
- In class, atoms and elements are interchangeable.
Molecules and Compounds
- Molecule: Two or more of the same atom bound together.
- Compound: Two or more different atoms bound together (e.g., H2O).
Elements
Major Elements
- Six Major Elements: Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, Sulfur.
- Make up 90-95% of living organisms.
- Carbon and hydrogen are essential for organic molecules.
Minor Elements
- Examples include sodium, potassium, calcium, iron, iodine, chlorine.
Atomic Structure
- Protons: Positive charge, 1 atomic mass unit, in nucleus.
- Neutrons: No charge, 1 atomic mass unit, in nucleus.
- Electrons: Negative charge, 0 atomic mass units, in shells.
- Nucleus: Center of atom where protons and neutrons are located.
Bonding
Ionic Bonds
- Involves donation/acceptance of electrons (e.g., formation of NaCl).
Covalent Bonds
- Non-polar: Equal sharing of electrons.
- Polar: Unequal sharing of electrons (e.g., water).
Hydrogen Bonds
- Between an electropositive hydrogen and an electronegative atom.
Properties of Water
- Polar Solvent: Dissolves substances like salt.
- Cohesive and Adhesive: Water binds to itself and other surfaces.
- High Surface Tension: Due to hydrogen bonds.
- High Heat Capacity: Takes a lot of energy to heat.
- High Heat of Vaporization: Requires breaking bonds to vaporize.
- Solid Water (Ice) is Less Dense: Ice floats on water.
Chemical Reactions
- Reactants: Starting substances.
- Products: Resulting substances.
- Anabolic vs Catabolic: Builds vs breaks down.
- Exergonic vs Endergonic: Releases vs requires energy.
Enzymes
- Catalysts: Increase reaction speed by lowering activation energy.
- Not Consumed: Reusable in reactions.
- Enzyme Specificity: Specific to their substrates.
Enzyme Structures
- Active Site: Where substrate binds.
- Allosteric Site: Other binding site influencing enzymatic activity.
Factors Affecting Enzymes
- Temperature: Optimal for enzyme activity.
- pH: Optimal range necessary for enzyme activity.
- Concentration: Saturation point of enzymes.
Acids, Bases, and pH
- Acids: Release hydrogen ions (H+).
- Bases: Release hydroxide ions (OH-).
- pH Scale: Ranges from 1 (acidic) to 14 (alkaline), with 7 as neutral.
Macromolecules
Carbohydrates
- Used for short-term energy and building blocks.
- Monosaccharides: Simple sugars like glucose.
- Disaccharides: Two sugars like sucrose.
- Polysaccharides: Many sugars like glycogen.
Lipids
- Simple Lipids: Fatty acids and glycerol.
- Saturated Fats: No double bonds, solid at room temperature.
- Unsaturated Fats: Have double bonds, liquid at room temperature.
- Trans Fats: Unsaturated fat converted to saturated fat.
- Complex Lipids: Include extra elements like phosphorus.
- Steroids: Four-ring structure with a hydroxy group.
Proteins
- Made of amino acids.
- Functions: General cellular functions.
Nucleic Acids
- DNA/RNA: Genetic material and protein synthesis.
- Structure: 5-carbon sugar, phosphate, nitrogenous base.
ATP
- Adenosine Triphosphate: Energy currency of the cell.
- Conversion of ADP + inorganic phosphate with energy into ATP.
These notes cover the fundamental concepts discussed in the chemistry chapter, providing a comprehensive overview of the material covered in the lecture.