biology

• basic single unit of life - Cell
• Trying to review all of biology in less than 90 minutes is an insane task
• Order of topics covered in the video

  1. Cell and its contents

  2. Reproduction (mitosis and meiosis)

  3. Embryogenesis and fetal circulation

  4. Nervous system (somatic and autonomic, central and peripheral)

  5. Endocrine system

  6. Respiratory system

  7. Cardiovascular system

  8. Immune system

  9. Digestive system

  10. Homeostasis (kidney and skin)

  11. Musculoskeletal system (bone and muscle)

  12. Genetics and evolution
• Cell theory


  1. All living things are composed of cells
  2. Cells are the basic functional unit of life
  3. Cells arise only from pre-existing cells
  4. Cells carry genetic information in the form of DNA
• Prokaryotes


  Cells without a true nucleus, DNA is not protein-bound and is circular
• Eukaryotes


  Cells with a true nucleus bound by a membrane, organelles also bound by membranes, DNA is linear and protein-bound
• Examples of eukaryotes


  • Mammals, including humans
• Cell


  • Has a nucleus, cytoplasm, and is surrounded by a plasma membrane made of phospholipids
• Cytosol


  The fluid inside the cell with no organelles
• Cytoplasm


  The fluid inside the cell including the organelles
• Protoplasm


  The nucleus and cytoplasm together
• Nucleus


  The control center of the cell, contains DNA organized into chromosomes
• Nuclear pores


  Allow entry and exit of materials to and from the nucleus
• Central dogma of molecular biology

  1. DNA replication

  2. Transcription (DNA to RNA)

  3. Translation (RNA to proteins)
• Mitochondria


  • The powerhouse of the cell, provides energy in the form of ATP

  Has its own mitochondrial DNA
• Lysosome


  Organelle that contains hydrolytic enzymes to break down foreign invaders and old/damaged cell components
• Endoplasmic reticulum


  Rough ER - site of protein synthesis

  Smooth ER - site of lipid synthesis and detoxification
• Golgi apparatus


  Modifies, sorts, and directs cellular products for delivery
• Peroxisome


  Organelle that uses hydrogen peroxide to break down fats
• Cytoskeleton


  • Protein network that provides structure, allows movement, and acts as a "railroad" for intracellular transport

  Consists of microfilaments, microtubules, and intermediate filaments
• Cilia and flagella


  Hair-like projections made of microtubules that allow movement
• Types of tissues


  • Epithelial
  • Connective
  • Muscle
  • Nervous
• Epithelial tissue


  Covers surfaces and lines cavities, has a parenchyma (functional cells) and stroma (supportive connective tissue)
• Connective tissue


  Provides support, framework, and structure for the body
• Cell cycle


  1. G0 (resting)

  2. G1 (growth 1)

  3. S (DNA synthesis)

  4. G2 (growth 2)

  5. M (mitosis or meiosis)
• Karyokinesis (nuclear division) and cytokinesis (cell division) occur during the M phase of the cell cycle
• Cell cycle


  1. G0 resting

  2. Growth phase 1

  3. DNA synthesis

  4. Growth phase 2

  5. Mitosis or meiosis M phase
• Somatic cells


  Cells that are not germ cells
• Germ cells


  Cells that give rise to gametes
• DNA replication


  Happens during the S phase of the cell cycle
• Transcription


  Taking the DNA into RNA
• Translation


  Taking the RNA to proteins
• Meiosis


  Everything is a piece of cake
• Cell division


  Karyokinesis (nuclear division) and cytokinesis (cytoplasmic division) take place in the M phase
• Cell types


  • Permanent cells
  • Stable cells
  • Labile cells
• Permanent cells


  • Do not divide under normal circumstances
• Stable cells


  • Do not divide under normal circumstances, but can divide under certain conditions
• Labile cells


  • Always dividing
• If cells are dividing like crazy with no check, this is cancer
• Chemotherapy


  Stops or arrests cell division, killing cancer cells but also some normal rapidly dividing cells like hair and gut cells