Biology Overview and Lab Equipment

Biology Notes

• Biology is the study of life, encompassing diverse branches like biochemistry, cell biology, genetics, evolutionary theory, microbiology, botany, and zoology.

Characteristics of Living Organisms

• Living things are composed of cells.
• Living things acquire and utilize energy.
• Living things grow and develop.
• Living things reproduce.
• Living things respond and adapt to their environment.
• Living things eliminate waste.

Lab Equipment (Glassware)

• Erlenmeyer Flask
• Griffin Beaker
• Graduated Cylinder
• Graduated Pipet

Homeostasis

• Homeostasis is crucial for maintaining a stable internal environment in organisms, particularly higher vertebrates.
• Homeostasis helps establish optimal conditions for organisms.

Metric Conversions

• A table detailing the conversion factors between metric units is provided.

Theory vs. Law

• A law is a widely accepted idea about a phenomenon that does not change.
• An example is the Law of Conservation of Mass.
• A theory is a broad explanatory idea supported by multiple experiments and potentially changes with advances in technology.
• An example is the Cell Theory.

Scientific Method

• Hypothesis: A proposed explanation for observations, must be testable and falsifiable.
• Experiment: Tests a hypothesis, gathering data.
• (Controlled experiments test only one variable at a time.)
• Results: Data reported using the universal metric system.

Independent and Dependent Variables

• Independent variable: The variable changed by the scientist in the experiment, graphed on the x-axis.
• Dependent variable: The variable measured in the experiment, graphed on the y-axis.

Chemistry

• Atoms consist of protons, neutrons, and electrons.
• The atomic number is the number of protons in the atom's nucleus.
• Atomic mass is the sum of protons and neutrons.
• Isotopes are atoms of the same element with the same number of protons but differing numbers of neutrons.

Chemical Bonds

• Covalent Bonds: Elements share valence electrons.
• Ionic Bonds: Transfer of electrons creates positive (lost electron) and negative (gained electron) ions.
• Hydrogen Bonds: Weak bonds between polar molecules.

Water Properties

• Water is a polar molecule (hydrogen slightly positive, oxygen slightly negative).
• Adhesion: Water attraction to surfaces.
• Cohesion: Water molecules' attraction to each other.

Solutions

• A solution is a homogenous mixture of two or more substances at the molecular level.
• Homogeneous means the particles are evenly distributed.
• When a substance like salt dissolves in water, water is the solvent, and the salt is the solute.

Organic Molecules

• Polymer categories (carbohydrates, lipids, nucleic acids, proteins) are linked to their monomers.
• The monomers of these key macromolecules contribute to their respective roles.

Functional Groups of Amino Acids

• Amino acids have specific functional groups like an amino group (NH2) and a carboxyl group (COOH), along with their side chain (R group).

Tests for Biomolecules

• Tests to detect the presence of specific biological molecules: Biurets test (Protein), Lugol's iodine (Complex Carbohydrates), Benedict's test Simple Sugar (Glucose), Sudan III (Lipids)

Membrane Transport

• Passive transport (does not require energy): Movement of substances down a concentration gradient (high to low concentration).
• Facilitated diffusion: Passive transport using carrier proteins.
• Active transport (requires energy): Movement of substances against a concentration gradient (low to high concentration)
• Example: Sodium potassium pump and calcium pump in muscles, pyruvate in mitochondrial membrane.

Cell Roles

• Cells performing essential functions are involved in processes like muscle contraction (calcium role), and cell transport.

Cellular Processes

• Endocytosis and exocytosis: Bulk movement of substance in and out of cells.

Cell Theory

• All organisms are composed of one or more cells.
• The cell is the basic unit of all living things.
• All cells arise from preexisting cells.

Cell Types

• Prokaryotes: Bacteria, unicellular, lack a nucleus.
• Eukaryotes: Diverse organisms (animals, plants, fungi, protists): have a nucleus.

Cell Organelles

• Cytoplasm: Gel-like substance surrounding cell organelles.
• Mitochondria: Cellular respiration, breaking down food substances.
• Cell Membrane: Environmental boundary, regulates substance exchange in and out of the cell.
• Lysosomes: Contain enzymes digesting old organelles, food particles, and unwanted substances.
• Cell Wall: Provides support and protection.
• Ribosomes: Make proteins.
• Chloroplast: Site of photosynthesis.
• Nucleus: Stores DNA, genetic material, and controls cellular processes.

Plant vs Animal Cells

• Plant cells have chloroplasts and cell walls; animal cells have centrioles.

Photosynthesis

• Photosynthesis formula: 6CO2 + 6H2O + light energy → C6H12O6 + 6O2.
• Takes place in the chloroplast.
• Performed by autotrophs.
• Two stages: light reactions and Calvin cycle.

Cellular Respiration

• Cellular respiration formula: C6H12O6 + 6O2 → 6H2O + 6CO2 + 36ATP.
• Occurs in the cytoplasm and mitochondria.
• Produces ATP (energy). Stages: glycolysis, Krebs cycle, and electron transport chain.

Autotrophs vs Heterotrophs

• Autotrophs make their own food (e.g., plants).
• Heterotrophs consume food (e.g., animals).

Relationship Between Photosynthesis and Respiration

• Products of photosynthesis are the reactants of cellular respiration. This cycle is fundamental to the flow of energy in ecosystems.