BIOLOGY

• Biology


  The branch of natural science that deals with the study of all living things including their origin, structure, function, evolution, and taxonomy
• BIOLOGICAL MOLECULES


  • Carbohydrates
  • Proteins
  • Lipids
  • Nucleic Acids
• Monomers


  Smaller units that can link together to form macromolecules
• Carbohydrates


  • Major source of energy
  • Monomer: Monosaccharide
  • Type of bond: Glycosidic bond
  • Link together: Disaccharide, Oligosaccharides & Polysaccharides (Starch, Cellulose, etc.)
  • Structure: Carbon, Hydrogen, Oxygen (CHO)
• Lipids


  • Energy storage
  • Monomer: Fatty acid and Glycerol
  • Type of bond: Ester Bond
  • Link together: Fats and Phospholipids
  • Structure: Carbon, Hydrogen, Oxygen (CHO)
• Proteins


  • Involved in a range of biological processes
  • Monomer: amino acid
  • Type of bond: Peptide bond
  • Classification based on structure: Primary, Secondary, Tertiary, Quaternary
  • Classification based on function: Structural, Defense, Enzyme, Transport
  • Link together: Polypeptide
  • Structure: Carbon, Hydrogen, Oxygen, Nitrogen (CHON)
• Nucleic acid


  • Long chain of molecules that carry genetic information
  • Monomer: Nucleotide
  • Type of bond: Phosphodiester Bond
  • Link together: DNA and RNA
  • Structure: Carbon, Hydrogen, Oxygen, Nitrogen, Phosphorus (CHONP)
• History of Cell Theory

  1. 1663 - Robert Hooke discovered cells in cork

  2. Anton Van Leeuwenhoek observed bacteria and protozoa

  3. Matthias Schleiden studied plant cells and suggested cell as basic unit of life in plants

  4. Theodore Schwann studied animal cells and suggested cell as basic unit of life in animals

  5. Rudolph Virchow added correct interpretation of cell formation by cell division
• Cell Theory


  1. The cell is the unit structure, physiology, and organization of all living things
  2. Cell is the building block in the construction of an organism
  3. Cells are formed by free-cell formation (Spontaneous generation) similar to the formation of crystals
• Modern Cell Theory


  1. All known living things are made up of cells
  2. The cell is the structural and functional unit of all living things
  3. Cells came from pre-existing cells by cell division
  4. Cells contain hereditary material which is passed from cell to cell during cell division
  5. All cells are basically the same in chemical composition
  6. All energy flows (metabolism and biochemistry) of life occur within cells
• Prokaryotic Cells


  Lack membrane-bound structures (organelles)

  Carry hereditary material (DNA) in a circular form called nucleoid

  Generally smaller than eukaryotic cells, with an average size of 1-5 micrometers

  Have a single, circular chromosome that is not enclosed in a nucleus

  Have ribosomes for protein synthesis, which are smaller than eukaryotic cells

  Have a cell wall called peptidoglycan

  Reproduce by binary fission

  Have a wide range of metabolic capabilities
• Eukaryotic Cells


  Characterized by their complex structure and the presence of a nucleus and membrane-bound organelles

  Generally larger than prokaryotic cells, with an average size of 10-100 micrometers

  Nucleus contains the cell's genetic material in the form of chromosomes, surrounded by a double membrane

  Have membrane-bound organelles such as mitochondria, chloroplasts, endoplasmic reticulum, Golgi apparatus, lysosomes, and peroxisomes

  Have a cytoskeleton that provides support and helps maintain the cell's shape

  Reproduce by mitosis and cytokinesis

  Have a wide range of metabolic capabilities including aerobic respiration, anaerobic respiration, and photosynthesis (in plants)
• Basic Parts of a Prokaryotic Cell

  • Nucleoid

  Plasmid DNA

  Pili

  Cell membrane

  Cell wall
• Basic Parts of a Eukaryotic Cell

  • Cell membrane

  Mitochondria

  Cell wall (plant cells)

  Endoplasmic reticulum

  Rough ER

  Smooth ER

  Golgi apparatus

  Lysosomes

  Cytoskeleton

  Plasma membrane
• Cell Division


  Mitosis - Involves somatic cells, produces two identical daughter cells

  Meiosis - Involves the division of reproductive cells, produces four genetically distinct daughter cells
• Endoplasmic reticulum


  Lacks ribosomes on its surface, functions in several metabolic processes, including synthesis of lipids, metabolism of carbohydrates and calcium concentration, drug detoxification, and attachment of receptors on cell membrane proteins
• Golgi apparatus


  Responsible for modifying, sorting, and packaging proteins and lipids for transport to other parts of the cell or secretion outside the cell
• Lysosomes


  Contain digestive enzymes and break down old or damaged organelles and other materials in the cell
• Cytoskeleton


  Helps to maintain the cell's shape and involved in cell movement and division
• Plasma membrane


  A phospholipid bilayer that surrounds the cell and controls what enters and leaves the cell
• Ribosomes


  Responsible for synthesizing proteins using the genetic information stored in the cell's DNA
• Vacuoles


  Store water, nutrients, and waste products
• Chloroplast


  Carry out photosynthesis
• Cell Division


  1. Mitosis - Produces two (2) identical daughter cells with the same genetic material as the parent cell

  2. Meiosis - Involves the division of gametes, a diploid parent cell produces four (4) haploid daughter cells
• Cell Cycle


  1. G0 - Cell rest, and prepares for division

  2. G1 (Gap 1) Stage - Cells engaged in growth, metabolism and production of proteins required for DNA replication and cell division

  3. S (Synthesis) Stage - DNA synthesis occurs

  4. G2 (Gap 2) Stage - Cell continues to grow and prepares for the cell division, significant biosynthesis occurs

  5. M (Mitotic) Stage - Cell divides forming 2 new daughter cells
• Mitosis


  1. Prophase - Chromatin condenses, nuclear envelope disintegrates

  2. Metaphase - Chromosomes align at the metaphase plate

  3. Anaphase - Sister chromatids separate and move to opposite poles

  4. Telophase - Nuclear envelope reforms, chromosomes decondense
• Meiosis I


  1. Prophase I - Homologous chromosomes pair up, crossing over occurs

  2. Metaphase I - Homologous pairs move to the equator

  3. Anaphase I - Homologous chromosomes separate

  4. Telophase I - Nuclear envelope reforms, chromosomes decondense
• Meiosis II


  1. Prophase II - Centrioles move to poles, spindle fibers form

  2. Metaphase II - Centromeres attach to spindle fibers

  3. Anaphase II - Sister chromatids separate

  4. Telophase II - Nuclear envelope reforms, cell division produces 4 haploid cells
• Spermatogenesis


  Production of sperm cells, occurs in testes, a continuous process that produces motile gametes
• Oogenesis


  Production of egg cells, occurs in ovary, a discontinuous process that produces non-motile gametes