Biology: Organic vs. Inorganic and Macromolecules

Organic vs. Inorganic / Abiotic vs Biotic

• Organic compounds contain carbon and are often found in living things (e.g., carbohydrates, proteins, lipids, nucleic acids).
• Inorganic compounds lack carbon-hydrogen bonds (e.g., water, salts, minerals).
• Abiotic factors are non-living environmental components (e.g., temperature, water, sunlight).
• Biotic factors are living parts of an environment (all organisms).

Macromolecules of Life

Carbohydrates

• Building blocks: monosaccharides (simple sugars like glucose, fructose).
• Structure: carbon, hydrogen, and oxygen atoms arranged in ring or chain structures.
• Examples: starch (plant energy storage), glycogen (animal energy storage), cellulose (plant structure).

Proteins

• Building blocks: amino acids.
• Structure: amino group (-NH₂), carboxyl group (-COOH), and a variable R-group.
• Examples: hemoglobin, enzymes, antibodies, collagen.

Lipids

• Building blocks: fatty acids and glycerol.
• Structure: long hydrocarbon chains, can form triglycerides (fats) or phospholipids (cell membranes).
• Examples: fats, oils, phospholipids, steroids.

Nucleic Acids

• Building blocks: nucleotides (sugar, phosphate, nitrogenous base).
• Structure: DNA (double helix), RNA (single-stranded).
• Examples: DNA (genetic information), RNA (protein synthesis).

Eukaryotic vs. Prokaryotic Cells

• Eukaryotic cells have a nucleus and membrane-bound organelles (e.g., animal cells, plant cells, fungi, protists).
• Prokaryotic cells lack a nucleus and membrane-bound organelles (e.g., bacteria, archaea).

Cell Parts and Functions

• Nucleus: houses the cell's DNA and controls activities.
• Mitochondria: the cell's power plant, produces ATP via cellular respiration.
• Ribosomes: synthesize proteins.
• Endoplasmic Reticulum (ER): rough ER (with ribosomes) makes proteins; smooth ER makes lipids.
• Golgi Apparatus: modifies and packages proteins for transport.
• Lysosomes: contain digestive enzymes for waste breakdown.
• Chloroplasts (plant cells): site of photosynthesis.
• Cell Membrane: controls what enters and exits the cell.

Apoptosis (Programmed Cell Death)

• A regulated cell death process crucial for maintaining cellular health and development.
• Involves signaling pathways to dismantle the cell without affecting surrounding cells.

Endosymbiotic Theory

• Theory proposing that some organelles (mitochondria, chloroplasts) were once free-living prokaryotes that merged into a host cell.

SA:V (Surface Area to Volume Ratio)

• Affects cellular process efficiency.
• High SA:V is beneficial for nutrient and waste exchange.
• As cell size increases, SA:V decreases, limiting efficiency.

Membrane Structure & Function

• Structure: phospholipid bilayer with embedded proteins; selectively permeable.
• Function: transport, signaling, cell recognition, homeostasis maintenance.

Diffusion

• Movement from high to low concentration.
• Facilitated diffusion: uses membrane proteins without energy input.

Hypertonic vs. Hypotonic

• Hypertonic: higher solute concentration outside the cell; water moves out, cell shrinks.
• Hypotonic: lower solute concentration outside the cell; water moves in, cell swells.

Energy Types

• Exergonic reactions: release energy (e.g., cellular respiration).
• Endergonic reactions: require energy input (e.g., photosynthesis).
• Activation energy: energy needed to start a reaction.

Enzymes

• Speed up reactions by lowering activation energy.
• Factors affecting enzymes: temperature, pH, substrate concentration, inhibitors.

Insulin and Diabetes

• Insulin: regulates blood sugar levels.
• Type 1 Diabetes: immune system attacks insulin-producing cells.
• Type 2 Diabetes: cells become resistant to insulin.

Factors Affecting the Immune System

• Age, nutrition, exercise, stress, disease affect immune function.
• Vaccines train the immune system to recognize pathogens.

Cellular Respiration

• Aerobic respiration: requires oxygen, produces 36-38 ATP per glucose.
• Anaerobic respiration: occurs without oxygen, produces 2 ATP per glucose (lactic acid fermentation, alcoholic fermentation).

Photosynthesis

• Light-dependent reactions: occur in thylakoid membranes, convert light to chemical energy (ATP, NADPH).
• Light-independent reactions (Calvin Cycle): use ATP and NADPH to convert CO2 to glucose.

Chemiosmosis & ETC (Electron Transport Chain)

• Chemiosmosis: ATP production using a proton gradient.
• ETC (Electron Transport Chain): generates a proton gradient for ATP production using proteins in membranes (mitochondria, chloroplasts).

Cell Cycle and Cancer

• Cell Cycle: interphase (G1, S, G2), and mitosis/cytokinesis.
• Cancer: uncontrolled cell division due to mutations in cell cycle regulatory genes (proto-oncogenes, tumor suppressor genes).

Meiosis vs Mitosis

• Mitosis: produces two identical diploid daughter cells.
• Meiosis: produces four non-identical haploid gametes, reducing chromosome number.

Probability in Genetics

• Punnett Squares: predict offspring genotypes and phenotypes.
• Multiplication rule: probability of independent events occurring together.

Mendelian Genetics

• Genotype: genetic makeup (homozygous, heterozygous).
• Phenotype: physical traits expressed by genes (dominant, recessive).
• Codominance: both alleles are expressed (e.g., AB blood type).
• Incomplete dominance: blended expression (e.g., pink flowers from red and white).

Structure of Chromosomes

• Chromosomes: DNA wrapped around histone proteins.
• Homologous chromosomes: similar shape, size, and genetic content.

Linked and Sex-Linked Genes

• Linked genes: located close on the same chromosome, inherited together.
• Sex-linked genes: located on sex chromosomes (X, Y), often with different effects in males and females.

Pedigree Charts

• Track traits across generations, showing phenotypes and relationships.

DNA Replication

• Process of unwinding DNA and adding new nucleotides to create two identical DNA molecules.

Cell Respiration Lab

• Investigates cellular respiration, often measuring CO2 or O2 as metabolic indicators.

Chi-Square (X²) Lab

• Statistical test to compare observed and expected genetic ratios.
• Formula: X² = Σ [(O - E)² / E]. (O = observed, E = expected)