Biology Lecture Notes

Introduction

• Discussion about creating a recap video for their biology playlist
• Importance of scientific names over common names
• Idea of a TL;DR video summarizing key points

Characteristics of Life

• Life is difficult to define; there are exceptions
• Characteristics of life may differ
• Importance of understanding biological levels of organization
  • Smallest living unit is the cell
  • Cells make up tissues, organs, organ systems, and organisms
  • Levels of organization: population, community, ecosystem, biome, biosphere

Biomolecules

• Four major macromolecules: carbohydrates, lipids, proteins, nucleic acids
• Building blocks: monosaccharides, fatty acids & glycerol, amino acids, nucleotides
• Enzymes are mostly proteins
  • Enzymes have active sites where substrates bind
  • Specific temperature and pH ranges are needed for enzyme activity
  • Denaturation occurs outside of these ranges

Cells

• Prokaryotic vs. Eukaryotic cells
  • "Pro" rhymes with no (nucleus), "eu" rhymes with do (nucleus)
  • Prokaryotes: bacteria, archaea
  • Eukaryotes: plants, animals, protists, fungi
• Membrane-bound organelles in eukaryotes
• Cell membranes control homeostasis
  • Phospholipids: polar heads, nonpolar tails
  • Passive vs. active transport
  • Osmosis in water movement

Cellular Processes

• Mitochondria (cellular respiration) vs. Chloroplasts (photosynthesis)
  • Photosynthesis and cellular respiration have switched reactants/products
• DNA structure and function
  • DNA replication involves enzymes like helicase, primase, DNA Polymerase, ligase
• Cell cycle phases: G1, S, G2, M (mitosis, cytokinesis)
  • Checkpoints and apoptosis
  • Cancer cells bypass checkpoints

Genetic Concepts

• Mitosis vs. Meiosis
  • Mitosis for growth and repair, producing identical cells
  • Meiosis for gametes, involving crossing over and independent assortment
• Alleles and Mendelian inheritance
  • Dominant/recessive traits
  • Inheritance patterns: monohybrid, dihybrid crosses
  • Non-Mendelian genetics: incomplete dominance, codominance
• Pedigrees for tracking traits

Protein Synthesis

• Transcription in the nucleus creates mRNA
• Translation in ribosomes forms polypeptides
• Codons and anticodons in mRNA/tRNA
• Mutations: gene mutations (substitution, deletion, insertion), frameshift potential

Natural Selection and Genetic Drift

• Natural selection and fitness
• Genetic drift: chance events
• Examples: antibiotic resistance in bacteria

Bacteria and Viruses

• Bacteria: unicellular prokaryotes, roles in health and environment
• Viruses: non-living, require hosts, lytic/lysogenic cycles
• Classification into three domains: Bacteria, Archaea, Eukarya

Plant Biology

• Autotrophs: photosynthesis, water uptake through osmosis or vascular tissue
• Flower reproduction: pollination, fertilization
• Food chains and webs: energy flow and trophic levels

Ecology

• Ecological succession: primary vs. secondary
• Carbon and nitrogen cycles
• Symbiotic relationships: commensalism, parasitism, mutualism

Human Body Systems

• Overview of 11 systems and their basic functions
• Importance of systems working together

Conclusion

• Importance of understanding biology's interconnectedness
• Suggestions for further exploration based on personal interest and study needs