BIO311C Final Exam Study Guide: Structure Relates to Function, Energy, and Genetic Information in Biology

Study Guide - Smart Notes

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Big Idea I: Structure Relates to Function

Biological Hierarchy: Organization of Life

Biological systems are structured at many interrelated levels, from molecules to ecosystems. Understanding this hierarchy is essential for grasping how structure relates to function in living organisms.

Hierarchy Levels: Molecule, Organelle, Cell, Tissue, Organ, Organ System, Organism, Population, Community, Ecosystem, Biosphere.
Emergent Properties: New properties arise at each level due to interactions among components.
Example: The heart is made of muscle cells, but its ability to pump blood emerges only when all cells work together.

Scientific Method and Hypothesis Testing

The scientific method is a systematic approach to understanding natural phenomena through observation, hypothesis formation, experimentation, and analysis.

Steps: Observation, Question, Hypothesis, Prediction, Experiment, Analysis, Conclusion.
Hypothesis: A testable explanation for an observation.
Example: Testing whether light affects plant growth by growing plants under different light conditions.

Big Idea II: The Chemical Context of Life

Chemistry for Biology: Structure and Properties of Chemicals

Chemical properties of atoms and molecules determine biological structure and function. Water's unique properties are central to life.

Atomic Structure: Atoms consist of protons, neutrons, and electrons. Atomic number = number of protons.
Bonding: Covalent (sharing electrons), Ionic (transfer of electrons), Hydrogen bonds (weak attractions between polar molecules).
Water: Polar molecule, forms hydrogen bonds, high specific heat, cohesion, adhesion, solvent properties.
pH:
Buffers: Substances that minimize changes in pH.

Biological Molecules: Carbon and Molecular Diversity

Carbon's ability to form four covalent bonds allows for a diversity of organic molecules essential for life.

Macromolecules: Carbohydrates, Lipids, Proteins, Nucleic Acids.
Monomers and Polymers: Monomers are building blocks; polymers are chains of monomers.
Functional Groups: Groups of atoms that confer specific chemical properties (e.g., hydroxyl, carboxyl, amino, phosphate).
Example: Glucose (a carbohydrate monomer) forms starch (a polymer).

Big Idea III: Cell Structure and Function

Cell Theory and Cell Types

All living things are composed of cells, which are the basic units of life. Cells can be prokaryotic or eukaryotic.

Prokaryotes: No nucleus, simple structure (e.g., bacteria, archaea).
Eukaryotes: Nucleus, membrane-bound organelles (e.g., plants, animals, fungi).
Organelles: Nucleus, mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, cytoskeleton.
Endosymbiotic Theory: Mitochondria and chloroplasts originated from symbiotic bacteria.

Membrane Structure and Transport

Cell membranes are selectively permeable barriers composed of a phospholipid bilayer with embedded proteins.

Fluid Mosaic Model: Membranes are dynamic, with proteins and lipids moving laterally.
Transport: Passive (diffusion, osmosis, facilitated diffusion) and active (requires energy, e.g., pumps).
Osmosis: Movement of water across a membrane from low solute to high solute concentration.
Example: Sodium-potassium pump ( out, in, uses ATP).

Big Idea IV: Cell Communication and Signaling

Cell Communication

Cells communicate via chemical signals that bind to receptors, triggering signal transduction pathways and cellular responses.

Types of Signaling: Paracrine, autocrine, endocrine, synaptic.
Signal Transduction: Series of molecular events converting a signal to a response.
Second Messengers: cAMP, Ca2+, IP3.
Example: Epinephrine signaling pathway activates glycogen breakdown in muscle cells.

Big Idea V: Energy in Living Systems

Metabolism: Energy Transfer and Transformation

Metabolism encompasses all chemical reactions in cells, including catabolic (breakdown) and anabolic (synthesis) pathways.

Thermodynamics: Laws govern energy transfer; energy cannot be created or destroyed.
ATP: Main energy currency; hydrolysis releases energy ().
Enzymes: Biological catalysts that lower activation energy.
Example: Cellular respiration converts glucose to ATP.

Cellular Respiration and Fermentation

Cells extract energy from organic molecules via cellular respiration (aerobic) or fermentation (anaerobic).

Stages of Cellular Respiration: Glycolysis, Pyruvate Oxidation, Citric Acid Cycle, Electron Transport Chain.
Equation:
Fermentation: Produces ATP without oxygen; yields less energy.

Photosynthesis

Photosynthesis converts light energy into chemical energy in plants, algae, and some bacteria.

Equation:
Stages: Light reactions (produce ATP and NADPH), Calvin cycle (fixes CO2 into sugars).
Chloroplasts: Organelles where photosynthesis occurs.

Big Idea VI: Genetic Information

Cell Cycle and Mitosis

The cell cycle is the series of events leading to cell division and replication. Mitosis produces genetically identical daughter cells.

Phases: G1, S, G2, M (mitosis), C (cytokinesis).
Mitosis Stages: Prophase, Metaphase, Anaphase, Telophase.
Checkpoints: Control progression; errors can lead to cancer.

Meiosis and Sexual Life Cycles

Meiosis reduces chromosome number by half, producing gametes for sexual reproduction and increasing genetic diversity.

Phases: Meiosis I (homologous chromosomes separate), Meiosis II (sister chromatids separate).
Genetic Variation: Crossing over, independent assortment.

Mendelian Genetics and Inheritance

Mendel's laws explain patterns of inheritance for traits.

Law of Segregation: Alleles separate during gamete formation.
Law of Independent Assortment: Genes on different chromosomes assort independently.
Punnett Square: Tool for predicting genotype and phenotype ratios.

Molecular Basis of Inheritance

DNA is the hereditary molecule; its structure and replication are central to genetics.

Double Helix: Two strands held by hydrogen bonds between complementary bases (A-T, G-C).
Replication: Semi-conservative; each new DNA has one old and one new strand.
Central Dogma: DNA → RNA → Protein.

Gene Expression and Regulation

Gene expression involves transcription (DNA to RNA) and translation (RNA to protein). Regulation ensures proper timing and amount of protein production.

Transcription: RNA polymerase synthesizes RNA from DNA template.
Translation: Ribosomes synthesize proteins using mRNA, tRNA, and rRNA.
Regulation: Operons in prokaryotes, enhancers/silencers in eukaryotes, epigenetic modifications (acetylation, methylation).

Big Idea VII: Evolution and Diversity

Origin of Life and Evolution

Life originated through chemical evolution, and biological diversity arose through evolutionary processes.

Natural Selection: Mechanism for evolution; organisms with advantageous traits survive and reproduce.
Phylogeny: Evolutionary relationships among species.
Domains of Life: Bacteria, Archaea, Eukarya.

Sample Table: Comparison of Cell Types

Feature	Prokaryotic Cell	Eukaryotic Cell
Nucleus	Absent	Present
Organelles	Absent	Present (mitochondria, ER, etc.)
Size	Small (1-10 μm)	Larger (10-100 μm)
Examples	Bacteria, Archaea	Plants, Animals, Fungi

Additional info:

These notes are based on a comprehensive final exam study guide for a General Biology course, covering all major topics from molecular biology to evolution.
Textbook graphs and figures referenced in the original notes are not included but can be found in standard biology textbooks.