Biology Crash Review for End of Course Exam

Introduction

• Targeted at students taking the end-of-course biology exam, typically in 9th or 10th grade.
• Quick review of important content and skills.
• Not comprehensive; aimed at highlighting key areas.
• Reminder to consult other resources for detailed study.

Organic Compounds

• Elements: Matter is made of elements; elements are composed of atoms.
• Organic Compounds: Essential molecules for life, contain carbon:
  • Nucleic Acids: Monomers are nucleotides.
  • Proteins: Monomers are amino acids; enzymes are proteins.
  • Carbohydrates: Monomers are monosaccharides.
  • Lipids: Monomers include fatty acids and glycerol.
• Mnemonics: "Clean Later Party" (Carbohydrates, Lipids, Proteins, Nucleic Acids).

Water and Its Properties

• Universal Solvent: Polar; partly positive and negative.
• Hydrophilic: Water-loving molecules; soluble.
• Hydrophobic: Water-fearing molecules; insoluble.
• Properties:
  • Cohesion: Attraction between water molecules.
  • Adhesion: Attraction to other substances.
  • Capillary Action: Combined effect of cohesion and adhesion.
  • Surface Tension: Allows bugs and leaves to float.

Cells: Basic Units of Life

• Cell Membrane: Phospholipid bilayer.
• Genetic Information: All cells contain DNA.
• Types of Cells:
  • Eukaryotic Cells: Have a nucleus and membrane-bound organelles.
  • Prokaryotic Cells: No nucleus, DNA floating in cytoplasm.
• Plant vs Animal Cells:
  • Plant Cells: Have cell wall, chloroplasts, large vacuole.
  • Animal Cells: No cell wall, smaller vacuoles.

Cell Membrane Transport

• Simple Diffusion: Particles move from high to low concentration without energy.
• Facilitated Diffusion: Requires protein channels, still no energy.
• Active Transport: Requires energy (ATP), moves from low to high concentration.
• Osmosis: Water movement across membranes:
  • Isotonic: Equal concentration, water moves freely.
  • Hypotonic: Water moves into cell.
  • Hypertonic: Water moves out of cell.

Enzymes

• Type of Protein: Function as biological catalysts.
• Factors Affecting Enzymes: Temperature and pH can denature enzymes.

Cellular Respiration and Photosynthesis

• Cellular Respiration: Occurs in mitochondria; glucose + oxygen -> ATP + CO2 + water.
• Photosynthesis: Occurs in chloroplasts; sunlight + CO2 + water -> glucose + oxygen.
• Fermentation: Anaerobic respiration; less efficient, used when oxygen is not present.

DNA and Protein Synthesis

• DNA Structure: Double helix, bases A-T, G-C.
• Replication: Semi-conservative, each new DNA has one old and one new strand.
• Protein Synthesis:
  • Transcription: DNA to mRNA in nucleus.
  • Translation: mRNA to protein at ribosome.
  • RNA: Single-stranded, uracil (U) instead of thymine (T).

Genetics

• Mendel’s Laws: Dominant and recessive traits, homozygous and heterozygous.
• Punnett Squares: Used to predict genotype and phenotype probabilities.
• Genetic Variations: Include incomplete dominance, co-dominance, sex-linked traits.

Evolution

• Natural Selection: Survival of the fittest; evolutionary fitness refers to reproductive success.
• Adaptations: Traits that increase survival and reproduction.
• Evidence for Evolution: Fossil records, DNA, embryology.

Ecology

• Biodiversity: Importance of variety for ecosystem resilience.
• Trophic Levels: Energy decreases as you move up; producers to tertiary consumers.
• Carbon Cycle: Photosynthesis, respiration, decomposition, combustion.

Human Impact on Environment

• Negative Impacts: Pollution, deforestation, climate change.
• Positive Actions: Conservation efforts, recycling, sustainable practices.

Conclusion

• Encouragement to explore more detailed resources for study.
• Reminder of other available resources and support for biology exams.