bio 1

• Life


  An organized genetic unit capable of metabolism, reproduction and evolution
• A virus does not fit the definition of life
• A virus requires a living cell to perform life's processes
• Chemical bonds in biological systems

  • Covalent bond
  • Ionic bond
  • Hydrogen bond
  • van der Waals forces
• Elements essential to life

  • Major elements: carbon, hydrogen, oxygen and nitrogen
  • Trace elements: required in small quantities for proper functioning of an organism
• Homeostasis


  Internal balance
• Water


  • Polar molecule that can form H bonds
  • High specific heat capacity
  • High surface tension
  • High heat of vaporization
• pH


  Measure of acidity or alkalinity of a biological solution depending on the amount of H+ present
• Macromolecules of life


  • Carbohydrates
  • Fats or lipids
  • Nucleic acids
  • Proteins
• Types of carbohydrates


  • Monosaccharide
  • Disaccharide
  • Oligosaccharides
  • Polysaccharide
• Triglyceride or neutral fat

  Glycerol + 3 fatty acids
• Saturated fat or animal fat


  Stays solid at room temperature
• Unsaturated or vegetable fat

  Liquid at room temperature
• Nucleotide


  Contains a pentose (5-C) sugar, a nitrogenous base (pyrimidine and purine) and a phosphate group

  
• Nitrogenous bases


  • Purine: adenine (A) and guanine
  • Pyrimidine: cytosine (C), thymine (T) and uracil (U)
• DNA has two antiparallel strands, each running in opposite directions. Its polarity is established by the 5' → 3' ends. One strand is complementary to the other strand.
• Biologically important proteins found in animals

  • Structural support: collagen, elastin, keratin
  • Protection: toxin, antibodies
  • Contraction: actin, myosin
  • Chemical messengers: hormones (ex. insulin)
  • Transport: lipoprotein, hemoglobin
  • Catalyst of biological reactions: enzymes
  • Identification of self cells: major histocompatibility proteins (MHCs)
  • Storage: albumen
• Levels of organization of life

  • Atoms
  • Molecules
  • Organelles
  • Cells
  • Tissues
  • Organ-Systems
  • Organism
• Cell


  Basic structural and functional unit of life capable of semi-autonomous existence
• Types of cells


  • Prokaryotic cell
  • Eukaryotic cell
• Prokaryotic cell


  • Has no nucleus and membrane-bound organelles
  • DNA is circular and located in a nucleoid region
  • Divide by binary fission
• Eukaryotic cell


  • With a nucleus and membrane-bound organelles
  • DNA is linear and found inside the nucleus
  • Divide by mitosis or meiosis
• Plasma membrane


  Outermost membrane enclosing the protoplasm of the animal cell, depicted by the Singer-Nicolson (1972) Fluid Mosaic Model, semi-permeable

  
• Membrane-bound organelles


  • Rough endoplasmic reticulum
  • Smooth endoplasmic reticulum
  • Golgi complex
  • Lysosome
  • Peroxisome
  • Mitochondria

  
• Non membrane-bound structures


  • Ribosome
  • Centrioles
  • Cytoskeleton
• Plant cell structures not found in animal cells

  • Cell wall
  • Plastids (with pigments)
  • Vacuoles
• Nucleus


  Contains the hereditary material DNA that are associated with protein histones to form chromatin, bounded by a double membrane with nuclear pores

  
• Movements across the plasma membrane

  • Diffusion
  • Osmosis
  • Active transport
• Types of cells


  • Somatic cell
  • Sex cell or gamete
• Stages of the cell cycle

  • Cell division
  • Interphase
• Parts of a chromosome

  • Chromatids
  • Centromere
  • Kinetochore
• Events occurring during interphase

  • Replication
  • Transcription
  • Translation
• Retroviruses


  Unusual because they have RNA as genetic material, use reverse transcriptase to form DNA from their RNA
• Examples of mutations


  • Sickle-cell anemia
  • Porphyria
  • Albinism
• Stages of mitosis


  • Prophase
  • Metaphase
  • Anaphase
  • Telophase
• Sickle cell anemia


  Genetic disease where glutamic acid is replaced by valine in the hemoglobin molecule
• Porphyria


  Genetic disease involving the globin synthesis of RBCs, caused by the absence of an enzyme that will complete the globin synthesis
• People with porphyria are inadvertently referred to as vampires
• Albinism


  Inability to synthesize the pigment melanin, due to defective or absent enzyme that converts tyrosine to melanin
• Mitosis


  1. Prophase

  2. Metaphase

  3. Anaphase

  4. Telophase