Biology Chapter 1 & 2

Chapter 1

• Theory is a hypothesis that has never been disproved.
• Evidence types: anecdotal and scientific.
• Independent variable: factor changed in the experimental group.
• Dependent variable: measured result of the experiment.
• Epidemiology: study of patterns of disease in a population.
• Correlation does not prove causation.
• Evaluating scientific information: consider study size, bias, model systems, replication, funding source, publication reputation, and avoid hyped language.
• A p-value less than 0.5 indicates statistical significance.

Chapter 2

• Living organisms grow, reproduce, sense stimuli, maintain homeostasis, and obtain and use energy.
• All life evolved from a common ancestor.
• Eukaryotes (protists, fungi, plants, animals) and prokaryotes (archaea, bacteria).
• Matter is made of elements which are made of atoms.
• Atoms have protons, neutrons, and electrons.
• Isotopes have different numbers of neutrons.
• Atoms combine to form molecules.
• Different atoms form compounds.
• Atoms bond to form molecules (ionic or covalent).
• Polar molecules: unequal sharing of electrons.
• Nonpolar molecules: equal sharing of electrons.
• Polar molecules exhibit cohesion and adhesion.
• Cohesion occurs when water molecules stick together.
• Adhesion happens when water molecules stick to other polar substances.
• Water’s properties allow it to form a meniscus.

Chapter 3

• Cell theory: cells are the fundamental units of life, all living things are composed of cells, all cells come from pre-existing cells, and all cells come from a common ancestor.
• Prokaryotic cells (bacteria) lack internal membrane-bound organelles.
• Eukaryotic cells (animals, plants) have membrane-bound organelles, including a nucleus and are larger.
• Eukaryotic cells: contain organelles and DNA in the nucleus, plant cells also have cell walls and chloroplasts, animal cells have lysosomes.
• Nucleus: contains DNA, surrounded by a double membrane.
• Endoplasmic Reticulum (ER) : network of membrane pipes for protein and lipid synthesis.
• Rough ER: contains ribosomes (protein synthesis).
• Smooth ER: lipid production.
• Golgi Apparatus: packages and modifies proteins.
• Mitochondria: converts food energy into usable energy for the cell, bean shaped.
• Chloroplasts: site of photosynthesis in plants and algae, found in plants and algae.
• Lysosomes: digestive and recycling centers.
• Cytoskeleton: network of protein fibers that provide support and movement.
• Cell membrane: all cells have a phospholipid bilayer with embedded proteins, a boundary.
  • Hydrophilic heads and hydrophobic tails.
• Osmosis: water movement across a semipermeable membrane from an area of low solute concentration to high.
• Hypotonic solution: lower solute concentration than the cell (water moves into the cell, cell swells).
• Hypertonic solution: higher solute concentration than the cell (water moves out of the cell, cell shrinks).
• Isotonic solution: same solute concentration as the cell (no net movement and cell stays at the same size).

Chapter 4

• Macronutrients: carbohydrates, proteins, and lipids (fats).
• Carbohydrates are broken down into simple sugars.
• Proteins are broken down into amino acids.
• Lipids are broken down into fatty acids and glycerol.
• Micronutrients: minerals (inorganic elements) and vitamins (organic molecules).
• Metabolism: all chemical reactions in the body (catabolic and anabolic).
• ATP is the energy currency of cells (chemical-work, transport-work, mechanical work).

Chapter 5

• Heat transfer: thermal energy from one body to another.
• Autotrophs (like plants) capture energy from sunlight.
• Heterotrophs (animals) get energy from consuming other organisms.
• Photosynthesis: light energy converts water and carbon dioxide into glucose and oxygen.
• Photosynthesis occurs in the chloroplast.
• Chlorophyll absorbs photons and excites electrons.
• ATP and NADPH used in the Calvin Cycle to form glucose.
• Atmosphere composition: nitrogen, oxygen, argon, carbon dioxide.
• Ocean acidification: CO2 reacting with water to form carbonic acid.

Chapter 6

• Calorie: unit of energy; amount of energy to increase the temperature of 1g of water by 1°C.
• Glycogen: short-term energy storage in muscle and liver cells.
• Triglycerides: long-term energy storage.
• Aerobic respiration (glucose + oxygen → ATP + water + carbon dioxide).
• Stages: glycolysis, Citric Acid Cycle, and electron transport chain.
• Glycolysis: occurs in the cytoplasm breaks sugar into pyruvate molecules.
• Citric Acid Cycle (Krebs cycle): occurs in mitochondria, pyruvates modified and enter the cycle, release carbon dioxide.
• Electron Transport Chain: in mitochondria (electrons passed along a chain, oxygen receives electrons and water forms).
• Fermentation: anaerobic respiration (occurs in cytoplasm, less ATP produced).

Chapter 7

• Helicase: enzyme unwinds DNA for replication.
• RNA doesn’t contain thymine.