Study Notes on Scientific Method, Cell Biology, and Protein Synthesis

Scientific Method

  • Step of Scientific Method
    • Parts of Lab Report
    • Title
    • Abstract
    • Introduction
    • Methods
    • Results
    • Discussion
    • Conclusion
    • References
    • Negative Control: Shows there is no contamination; known to produce no result.
    • Positive Control: Known to produce a positive result; verifies that the test works.

Microscopy

  • Types of Microscopes
    • Eyepiece (Ocular)
    • Objective Lenses (4x, 10x, 40x)

Cell Biology

Basic Cell Structures

  1. Nucleus
    • Stores DNA.
  2. Nucleolus
    • RNA Synthesis.
  3. Ribosomes
    • Protein Synthesis.
  4. Mitochondria
    • ATP Production.
  5. Rough Endoplasmic Reticulum (RER)
    • Protein Synthesis.
  6. Smooth Endoplasmic Reticulum (SER)
    • Lipid Synthesis; detoxification.
  7. Golgi Apparatus
    • Packaging and modifying proteins.
  8. Lysosomes
    • Digestion.
  9. Peroxisomes
    • Detoxification and H2O2 breakdown.
  10. Plasma Membrane
    • Selective barrier.
  11. Cytoplasm/Cytoskeleton
    • Multiple types of RNA (mRNA, rRNA, tRNA) used in protein synthesis; structure and transport.
  12. Chloroplasts (present in plant cells)

Genetic Material

  • DNA
    • Double-stranded.
    • Deoxyribose sugar.
    • Contains Thymine.
    • Stores genetic information.
  • RNA
    • Single-stranded.
    • Ribose sugar.
    • Contains Uracil (u) instead of Thymine (T).

Protein Synthesis

  • Stages:
    • Transcription
    • DNA -> pre-mRNA by RNA polymerase.
    • mRNA is processed to become mature mRNA.
    • Promoter: transcription starts.
    • Termination: marks the end of transcription.
    • Translation
    • Occurs at the ribosome; codons are translated to amino acids.
    • Start codon: AUG (Methionine).
    • Stop codons: UAA, UAG, UGA.
    • Amino acids are joined by peptide bonds, facilitated by tRNA (anticodons match codons on mRNA).

Cell Division

Mitosis vs. Meiosis

  • Mitosis
    • One division resulting in identical diploid cells.
    • Stages: Prophase, Metaphase, Anaphase, Telophase (+ Cytokinesis).
  • Meiosis
    • Two divisions resulting in four non-identical haploid gametes.
    • Meiosis I: Homologous chromosomes separate; includes crossing over in Prophase I.
    • Meiosis II: Separating sister chromatids.
    • Reduces chromosome number for gametes.

Conclusion

  • Understanding these cellular components and processes is crucial in numerous biological fields, including genetics, molecular biology, and biotechnology. The ability to differentiate between mitosis and meiosis is fundamental in genetics, as they serve different functions in the life cycle of organisms.