THE MOLECULES OF CELLS

WHAT IS LACTOSE INTOLERANCE?

• Prevalence: 80% of African Americans and Native Americans are lactase-deficient by teenage years.

• Symptoms: Cramps, bloating, diarrhea.

• Graph Representation: Lactose intolerance varies across populations (0-100%).

CARBON COMPOUNDS

Importance of Carbon

• Carbon-containing molecules = organic compounds.

• Carbon has 4 electrons in its outer shell, allowing the formation of diverse organic molecules.

Hydrocarbons & Carbon Skeletons

• Hydrocarbons: Compounds mainly consisting of carbon and hydrogen.

• Carbon Skeletons: Vary in length and structure, including:

  • Isomers: Compounds with the same formula but different structural arrangements (e.g., Ethane, Propane).

  • Double Bonds: Exist in carbon skeletons (e.g., 1-Butene, 2-Butene).

  • Rings: Carbon atoms can be arranged in circular structures.

FUNCTIONAL GROUPS OF ORGANIC COMPOUNDS

Chemical Functional Groups

• Importance: Functional groups such as hydroxyl, carbonyl, and amino carry distinct chemical properties, affecting how molecules interact.

• Hydrophilic: Water-loving (polar), example: hydroxyl group.

MACROMOLECULES

Definitions

• Macromolecule: A large complex molecule, typically formed from smaller building blocks.

• Polymer: A long molecule consisting of many similar or identical monomers linked together.

• Monomer: The individual subunits that make up polymers.

DEHYDRATION REACTION

• Process: Links monomers by removing a water molecule, forming a new bond and yielding longer polymers.

HYDROLYSIS REACTION

• Process: Breaks bonds by adding water, effectively dividing a polymer into monomers.

DIVERSITY OF POLYMERS

• Proteins: Composed of 20 different amino acids; sequence variation leads to diverse forms and functions.

• DNA: Built from 4 nucleotides, allowing various arrangements.

SACCHARIDES (CARBOHYDRATES)

Monosaccharides

• Definition: Simplest form of carbohydrates; examples include glucose and fructose (aldoses and ketoses) with the formula Cn(H2O)n.

DISACCHARIDES

• Formation: Composed of two monosaccharides; example: maltose formed from two glucose molecules by dehydration.

POLYSACCHARIDES

Major Types

• Starch: A polysaccharide in plants for energy storage; can be branched or unbranched.

• Glycogen: The animal equivalent of starch for energy storage found in liver and muscles.

• Cellulose/Chitin: Structural polysaccharides found in plant cell walls and fungal cell walls, respectively.

LIPIDS

• Characteristic: Hydrophobic (do not mix well with water) and not classified as macromolecules.

• Types: Include fats, phospholipids, and steroids.

• Fatty Acids: Can be saturated or unsaturated.

PHOSPHOLIPIDS

• Structure: Composed of glycerol, two fatty acids, and a phosphate group; forms cell membranes with hydrophilic heads and hydrophobic tails.

CHOLESTEROL AND STEROIDS

• Cholesterol: Associated with cardiovascular diseases.

• Anabolic steroids: Synthetic versions of testosterone; can lead to side effects like mood swings and liver damage.

PROTEINS

Structure

• Polypeptide: Minimum of 100 amino acids in a specific sequence, folded into a 3D shape.

Functions

• Roles: Enzymatic, structural, transport, signaling, immune protection, storage.

• Denaturation: Altered protein shape due to environmental changes, affecting functionality.

PROTEIN STRUCTURE

Levels

1. Primary: Sequence of amino acids.

2. Secondary: Alpha helix and beta sheets formed by hydrogen bonding.

3. Tertiary: 3D shape from R group interactions.

4. Quaternary: Multiple polypeptides association.

NUCLEIC ACIDS

• Types: DNA (deoxyribonucleic acid) and RNA (ribonucleic acid).

• Nucleotides: Comprised of a sugar, phosphate group, and nitrogenous base.

• DNA Structure: Two polynucleotide strands forming a double helix; A pairs with T, and C pairs with G in base pairing.

I'm unable to add pictures directly to text notes. However, here are some suggestions for types of images that would enhance the content of your notes on molecules and cells:

1. Diagram of Lactose Intolerance: An illustration showing the prevalence of lactose intolerance across various populations.

2. Carbon Compound Structures: Visual representations of hydrocarbons, carbon skeletons, and examples of isomers such as ethane and propane.

3. Functional Groups: A chart displaying different functional groups, including hydroxyl, carbonyl, and amino groups, along with their hydrophilic properties.

4. Macromolecule Structure: Graphics that illustrate the structures of proteins, lipids, carbohydrates, and nucleic acids (DNA and RNA).

5. Dehydration and Hydrolysis Reactions: Diagrams explaining these chemical reactions with visual representations of the before and after scenarios.

6. Protein Structure Levels: Images showcasing the primary, secondary, tertiary, and quaternary structures of proteins.

7. Nucleotide Structure: Infographics detailing the basic components of nucleotides, including sugar, phosphate group, and nitrogenous base.