Properties of Life and Biological Organization

Properties of Life

• Life exhibits order in its structure and function.
• Reproduction ensures the continuation of life.
• Growth and development are characteristic of living organisms.
• Energy processing sustains life functions.
• Regulation maintains a stable internal environment.
• Response to the environment allows organisms to adapt and survive.
• Evolutionary adaptation occurs over generations.

Levels of Biological Organization

• Biosphere: The entire Earth inhabited by life (e.g., Florida).
• Ecosystem: A specific environment with interacting organisms and physical components (e.g., Florida Everglades).
• Community: All the interacting populations of organisms within an ecosystem.
• Population: A group of individuals of the same species living in a specific area (e.g., all alligators in the wetlands).
• Organism: An individual living being (e.g., an American alligator).
• Organ System: A group of organs working together (e.g., nervous system).
• Organ: A structure composed of different tissues performing a specific function (e.g., brain).
• Tissue: A group of similar cells performing a specific function (e.g., nervous tissue).
• Cell: The basic unit of life (e.g., nerve cell).
• Organelle: A functional component within a cell (e.g., nucleus).
• Molecule: A group of atoms bonded together (e.g., DNA).
• Emergent properties arise from the interactions of components at lower levels.

Taxonomy

• Domain Bacteria: Contains organisms with simple cells.
• Domain Archaea: Contains organisms with simple cells.
• Domain Eukarya: Includes protists, fungi, plants, and animals.
• Kingdom Protista: A diverse group, representing multiple kingdoms.
• Kingdom Plantae: Plants.
• Kingdom Animalia: Animals.
• Kingdom Fungi: Molds, yeasts, and mushrooms.

Scientific Method

• Observation: Noticing a phenomenon (e.g., flashlight doesn't work).
• Question: Posing a question about the observation (e.g., why doesn't the flashlight work?).
• Hypothesis: Proposing a testable explanation (e.g., batteries are dead).
• Experiment: Testing the hypothesis (e.g., replace batteries).
• Results and Conclusions: Analyzing data and determining if the hypothesis is supported or contradicted (e.g., flashlight doesn't work; the hypothesis is contradicted).
• Falsifiability: The possibility that a hypothesis can be shown to be incorrect.

Major Themes of Biology

• Evolution: Insects camouflage adapting to their surroundings as an example.
• Life Depends on the Flow of Information: DNA.
• Structure and Function Are Related: Proteins.
• Life Depends on the Transfer and Transformation of Energy and Matter: Circle of life.
• Life Depends in Interactions Within and Between Systems: Properly assembled bicycle parts.
• Evolution is the unifying theme of biology.

Natural Selection & Evolution

• Natural selection is the mechanism of evolution.
• Evolution is the descent with gradual modification of ancestral species.
• Overproduction leads to competition for survival.
• Limited resources lead to competition.
• Variation exists within populations.
• Heritability: Traits can be passed from parents to offspring.
• Descent with modification: Over time, populations accumulate favorable traits.
• Adaptations moths have to developed to evade bats: Elongated tails interfere with bat echolocation.

Mimicry

• Batesian Mimicry: A non-poisonous species resembles a poisonous species.
• Mullerian Mimicry: Multiple poisonous or foul-tasting species resemble each other.
• Artificial Selection: Humans select for desired traits.

Phylogenetic Trees

• Phylogenetic Trees identify the most recent common ancestor.

Chemistry

Matter and Elements

• Matter: Anything that has mass or takes up space.
• Elements: Pure substance made up of only one type of atom.
• Compounds: Substance of two or more different elements in a fixed ratio.
• Four Most Common Elements: oxygen, carbon, hydrogen, and nitrogen.
• Trace elements are common additives of food and water eg; iodine in iodized salt.

Atoms

• Atoms: The smallest unit of matter that retains the properties of an element.
• Protons: Found in the nucleus; have a positive charge.
• Neutrons: Found in the nucleus; have no charge.
• Electrons: Orbit the nucleus; have a negative charge.
• Atomic number: # of protons in element.
• Atomic mass: mass of the atom roughly equal to number of protons and neutrons.
• Isotopes: same number of protons but different number of neutrons in an element.

Electron Shells

• 1st shell: 2 electrons.
• 2nd shell: 8 electrons.
• 3rd shell+: 8 electrons.
• valence shells & valence electrons.

Chemical Bonds

• Chemical reactions: Breaking existing chemical bonds and forming new ones.
• Reactants: 2 or more separate elements.
• Products: bond elements have formed after the chemical reaction.
• Ionic bond: attractions between ions of of opposite charge resulting in a transfer of electrons formed by giving up an electron.
• Ion: an tom or molecule with an electrical charge resulting from gain o ross of one or more electrons.
• Salt: NaCl Na gives up electron to Cl forming ionic bond (synonym for an ionic compound).
• Covalent bond: Share electrons as opposed to an ionic bond that gives up electrons formed through electron sharing.
• Polar molecule: electrons are pulled closer to the more electronegative atom (e.g., water).
• Non - polar molecule: electrons are shared equally.
• Molecular formula: Formula giving the number of atoms of each of the elements present in one molecule of a specific compound.
• Structural formula: Identify the location of chemical bonds between the atoms of a molecule.
• Single bonds: Chemical bond between two atoms where they share only one pair of electrons.
• Double bonds: A covalent bond between two atoms where two pairs of electrons are shared.

Hydrogen Bonds

• Hydrogen bond: A weak bond between hydrogen and oxygen through a polar covalent bond.
• In water, when water freezes, each molecule forms a stable bond with its neighbors.
• Water is the universal solvent due to the Polarity of its molecules.
• Solute: A substance that dissolves when water molecules surround them.
• Solution: A liquid of a a uniform mixture of two or more substances.

Unique Properties of Water

• Water is a solvent of life.
• Water is cohesive.
• Moderates temperature.
• pH: Potential of Hydrogen.
• Acidic: higher H+ concentration (anything under 7 on pH scale).
• Basic: higher OH- concentration (anything above 7 on pH scale).
• Neutral: [H+] + [OH-].
• pH scale (logarithmic).
• The increase or decrease on the ph scale is a 10x change.
• Ocean acidification is harmful to coral reefs, the extra hydrogen ions combine with carbonate ions to form bicarbonate ions this reaction reduces the carbonate ion concentration available to corals and other shell building animals.

Biomolecules

Organic & Hydrocarbons

• Organic compound: carbons ability to bond w/ 4 other atoms is the basis for building large and diverse organic compounds.
• Hydrocarbons: are composed of only carbon and hydrogen.
• Isomers: have the same molecular formula but different structures.
• Functional groups: give organic molecules specific chemical properties.
• Hydrophilic: water loving.
• Hydrophobic: water fearing.
• Dehydration Synthesis: builds polymers from monomers.
• Hydrolysis: breaks down polymers into monomers.

Carbohydrates

• Carbohydrates: macromolecule, monomer individual building blocks of macromolecules, polymer monomers that are linked together via covalent bonds.
• Monosaccharides: simple sugars (e.g., honey), formula that is a multiple of CH2O.
• Disaccharides: two monosaccharides bond through a dehydration reaction (e.g., sucrose, maltose, lactose).
• Polysaccharides: Starch and Glycogen storage polysaccharides , Cellulose structure in plant cell walls, Chitin component of insect, crustacean, and fungal cell walls.

Lipids

• Unifying characteristic of all Lipids: All hydrophobic (water - fearing).
• Fats/Triglycerides: consists of glycerol linked to three fatty acids
• Glycerol: liquid molecule that serves as the backbone of lipids.
• Fatty acid: molecule composed of long hydrocarbon chain with a carboxyl group at one end.
• Saturated Fats: (animal fats) fats w/ the maximum number of hydrogens.
• Unsaturated Fats: (plant oils) fatty acids that contain one or more double bonds.
• Trans Fats: unsaturated fats converted to saturated fats through the process of hydrogenation.
• Unsaturated fats are the healthiest while unsaturated and trans fats the unhealthiest.
• Phospholipids: components of cell membranes.
• Steroids: include cholesterol and some hormones.

Proteins

• Monomer: amino acids.
• Polymer: polypeptide/protein.
• Amino acids: monomers linked together in a dehydration reaction.
• “R” group: distinguishes 20 amino acids each with specific properties.
• A peptide bond links amino acids together to polypeptides.
• Polypeptide: bonds that link amino acids together.
• Primary structure: order of amino acids.
• Secondary structure: coiling/folding of polypeptide chain (Alpha Helix coiled/ spring like, Beta Pleated Sheet flat pleated sheets).
• Tertiary structure: 3D shape of polypeptide.
• Quaternary structure: orientation of more than 1 polypeptide.
• An error in the amino acid sequence of a protein can lead to a is folded protein which can affect the way it's intended to perform.
• Denaturation: when a protein unravels, loses its specific shape, and loses its function.
• Enzyme: catalysts that decrease the activation energy needed for a reaction to begin w/o being consumed by the reaction.
• Active site: a pocket or groove on the surface of the enzyme.
• Substrate: fits into a region called the active site.

Nucleic Acids

• Monomer: nucleotides.
• Polymer: nucleic acids.
• Nucleotide: monomers that make up nucleic acids.
• Nitrogenous base: nitrogen containing molecule that forms part of the nucleotide structure.
• Sugar: ribose(in RNA) or deoxyribose(in DNA).
• Phosphate Group: phosphorus atom bonded to four oxygen atoms(backbone of DNA).
• DNA: deoxyribonucleic acid (Double stranded, Sugar deoxyribose, Complementary base pairing A → T / C → G (DNA) A → U/ C → G (RNA).
• RNA: ribonucleic acid (Single stranded, Sugar ribose).
• Flow of genetic information (DNA -> RNA -> Protein).

Exploration of the characteristics defining life: order, reproduction, growth, energy processing, regulation, response, and adaptation. Overview of biological organization levels from biosphere to organ systems, with examples like the Florida Everglades and American alligators.