Chem of Life

Characteristics of Life
- Organization: Living organisms exhibit structured complexity.
- Energy Requirement: Life necessitates energy to maintain processes.
- Homeostasis: Stability within organisms is essential for survival.
- Reproduction: Organisms reproduce to ensure the continuation of their species.
- Adaptation & Evolution: Ability to adjust to changes in the environment is crucial.
Three Domains of Life
- Bacteria: Prokaryotic organisms that lack a nucleus.
- Archaea: Single-celled microorganisms distinct from bacteria, often found in extreme environments.
- Eukarya: Organisms whose cells contain a nucleus, including animals, plants, fungi, and protists.
Scientific Method
- A systematic approach using evidence to answer questions and test hypotheses.

Influence of Chemical Bonds
- The type of bond (covalent, ionic, hydrogen) affects the properties and reactions of biological molecules.

Biological Importance of Water
- Cohesion: Molecules attract each other, contributing to surface tension.
- Adhesion: Water molecules form hydrogen bonds with other substances.

Four Main Types of Organic Molecules:
- Carbohydrates: Energy sources and structural components.
- Lipids: Fats that store energy and form cell membranes.
- Proteins: Perform a vast range of functions, including structure, transport, and defense.
- Nucleic Acids: Store and transmit genetic information (DNA and RNA).

Definitions and Examples:
- Organelle: Membrane-bounded structure with a specific function (e.g., chloroplast).
- Molecule: Group of joined atoms (e.g., DNA).
- Atom: Smallest unit of a pure substance (e.g., carbon atom).
- Cell: Fundamental unit of life (e.g., leaf cell).
- Organism: Single living individual (e.g., acacia tree).
- Tissue: Collection of specialized cells functioning together (e.g., leaf epidermis).
- Organ: Structure of tissues organized to carry out functions (e.g., leaf).
- Population: Same species living in the same area (e.g., multiple acacia trees).
- Organ System: Organs connected functioning together (e.g., aboveground part of a plant).
- Community: All populations in the same region (e.g., savanna populations).
- Ecosystem: Living and nonliving components of an area (e.g., savanna ecosystem).
- Biosphere: Global ecosystem; regions of the planet where life is possible.

Definition of an Atom:
- Smallest unit of an element, retaining its properties.
Subatomic Particles:
- Protons: Positively charged particles.
- Neutrons: Neutral particles found in the nucleus.
- Electrons: Negatively charged particles orbiting the nucleus.
Important Atomic Properties:
- Atomic Number: Number of protons in an atom.
Mass Number: Total number of protons and neutrons in the atom's nucleus.
Atomic Mass: Approximate mass number expressed in atomic mass units.

Structure of the Periodic Table:
- Groups and periods classify elements based on shared properties.
- Example: Hydrogen (H), Atomic Number: 1, Atomic Mass: 1.0079

Types of Chemical Bonds:
- Covalent Bonds: Electrons are shared between atoms.
- Polar covalent bonds: Electrons are shared unequally.
- Non-polar covalent bonds: Electrons are shared equally.
- Ionic Bonds: One atom donates an electron to another, resulting in charges that attract.
- Hydrogen Bonds: Weak attractions between polar molecules due to charges from polar covalent bonds.

Importance for Life:
- Stronger bonds are important for structural functions, while weaker bonds facilitate metabolic processes because they're easily broken.

Properties of Water:
- High cohesion and adhesion enabling various biological processes.
- Acts as an excellent solvent, facilitating biochemical reactions.
- Hydrophilic vs. Hydrophobic:
- Hydrophilic: Water-attracting substances.
- Hydrophobic: Water-repelling substances.
Temperature Regulation:
- Water can absorb heat and reduce temperature fluctuations.
pH Influences:
- Water dissociates into H+ and OH- ions affecting its pH range, which crucially influences biological processes and organism survival.

Definitions of Organic Molecules:
- Compounds primarily containing carbon and hydrogen.
- Most are polymers made of repeating monomer units.
Types of Organic Molecules:
- Carbohydrates: Sugars that serve as energy sources (simple sugars: monosaccharides and disaccharides; complex carbohydrates: polysaccharides).
- Lipids: Non-polymeric molecules, primarily hydrophobic (e.g., triglycerides, waxes, phospholipids).
- Proteins: Polymers made of amino acids serving various functions (structure, transport, signaling).
- Nucleic Acids: Polymers of nucleotides storing genetic information (e.g., DNA and RNA).

Composition of Amino Acids:
- Central carbon, amino group, carboxyl group, and varying R groups which determine their properties.
Protein Structure Levels:
- Primary Structure (1º): Sequence of amino acids.
- Secondary Structure (2º): Coils and loops formed through hydrogen bonding.
- Tertiary Structure (3º): Overall 3D shape determined by interactions of R groups.
- Quaternary Structure (4º): Interaction between multiple polypeptide chains.
Denaturation and Misfolding:
- Denaturation alters protein structure, impacting function, stressors include heat and pH.

Functions:
- DNA stores genetic information.
- RNA enables protein synthesis from the genetic blueprint.
Structure of Nucleic Acids:
- Composed of nucleotides, each having a phosphate group, a sugar, and a nitrogenous base (A, T/U, G, C).

Summary of Key Questions:
- How do chemical bonds influence biological reactions?
- What are the biologically important properties of water?
- What are the primary organic molecules?
- What factors influence protein function?