M2

• This is the study of the processes and functions of the body
• The study of the structures of the body
• The condition in which body functions, body fluids, and other factors of the internal environment are maintained within a range of values suitable to support life
• Cells


  The basic living unit of all organisms; each cell is a highly organized unit
• Organelles


  Specialized structures in cells that perform specific functions
• Cytoplasm


  Jelly-like substance that holds organelles and is enclosed by cell membrane (aka plasma membrane)
• Organelles in the human cell

  • Nucleus
  • Nucleolus
  • Nucleoplasm
  • Cell membrane
  • Rough endoplasmic reticulum
  • Smooth endoplasmic reticulum
  • Golgi apparatus
  • Secretory vesicles
  • Lysosome
  • Mitochondrion
  • Ribosomes
  • Cytoplasm
  • Centrioles
  • Cilia
  • Microvilli
  • Phagocytic vesicle
  • Centrosome
  • Peroxisome
  • Microtubule
• Cell membrane/plasma membrane


  • It is the outermost component of the cell that forms a selective barrier between intracellular (materials inside the cell) and extracellular substances (materials outside the cells)
• Major molecules in cell membrane

  • Phospholipids
  • Protein
  • Cholesterol
  • Carbohydrates
• Phospholipids

  Form a double layer that contains 2 regions: 1) Polar Region - "heads", exposed to H2O (hydrophilic) 2) Nonpolar Region - "tails", away from H2O (hydrophobic)
• Proteins


  Float among the phospholipid molecules and in some, extend from inner to the outer surface of cell membrane. Function as membrane channels, carrier molecules, receptor molecules, enzymes, or structural supports in membrane
• Cholesterol


  Provide added strength & stability by limiting the amount of movement of phospholipids
• Carbohydrates


  May be bound to some CHON molecules, modifying their functions
• Functions of the cell

  • Cell metabolism and energy use
  • Synthesis of molecules
  • Communication
  • Reproduction and inheritance
• Organelles and their functions

  • Nucleus - Contains genetic material of cell (DNA) and nucleoli; Site of RNA synthesis & ribosomal subunit assembly
  • Ribosomes - Site of protein synthesis
  • Rough Endoplasmic Reticulum - Site of protein synthesis
  • Smooth Endoplasmic Reticulum - Site of lipid synthesis; Participates in detoxification
  • Golgi Apparatus - Modifies CHON structure & packages CHON in secretory vesicles
  • Secretory Vesicle - Contains materials produced in cell; Secreted by exocytosis
  • Lysosome - Contains enzymes that digest material taken into the cell; Breaks down fatty acids, amino acids, and hydrogen peroxide
  • Peroxisome - Site of aerobic respiration and the major site of ATP synthesis
  • Microtubule - Supports cytoplasm; Assists in cell division and forms components of cilia & flagella
  • Centrioles - Facilitate the movement of chromosomes during cell division
  • Cilia - Located on cell surface that move substances over surfaces of certain cells
  • Flagella - Proper sperm cells
  • Microvilli - Increase surface area of certain cells
• Passive Membrane Transport


  Does not require the cell to expend energy. Includes diffusion, osmosis, and facilitated diffusion
• Active Membrane Transport


  Does require the cell to expend energy, usually in the form of ATP. Includes active transport, secondary active transport, endocytosis, and exocytosis
• Adenosine triphosphate (ATP)


  Considered the universal energy currency for metabolism
• Diffusion


  The movement of a solute from an area of higher concentration to an area of lower concentration within a solvent. At equilibrium, the distribution of molecules is uniform
• Concentration gradient


  The concentration of a solute at one point in a solvent minus the concentration of that solute at another point in the solvent divided by the distance between the points
• Osmosis


  The diffusion of water across a selectively permeable membrane. Osmotic pressure is the force required to prevent movement of water across a selectively permeable membrane
• Types of osmotic solutions

  • Hypotonic solution
  • Isotonic solution
  • Hypertonic solution
• A hypotonic solution causes a cell to swell, whereas a hypertonic solution causes a cell to shrink
• Facilitated Diffusion


  Moves substances from a higher to lower concentration and does not require energy in the form of ATP
• Carrier-Mediated Transport


  The movement of a substance across a membrane by means of a carrier molecule. The substances transported tend to be large, water-soluble molecules or ions
• Active Transport


  Moves substances from a lower to a higher concentration and requires ATP
• Secondary Active Transport


  Uses the energy of one substance moving down its concentration gradient to move another substance across the cell membrane. In co-transport, both substances move in the same direction; in counter-transport, they move in opposite directions
• Endocytosis


  Movement of materials into cells by the formation of a vesicle
• Receptor-Mediated Endocytosis


  Involves cell receptors attaching to molecules
• Phagocytosis


  Movement of solid material into cells (cell-eating)
• Pinocytosis


  The materials ingested is much smaller and is in solution (cell-drinking)
• Exocytosis


  The secretion of materials from cells by vesicle formation
• Cytoskeleton


  A cell's framework. This is vital for providing support, holding organelles in place and enabling the cell to change shape
• Types of cytoskeleton

  • Microtubules - largest diameter; provide structural support, assist in cell division, forming essential components of certain organelles (cilia and flagella)
  • Intermediate Filaments - medium diameter; maintain cell shape
  • Microfilaments - smallest diameter; determine cell shape and involved in cell movement
• Deoxyribonucleic Acid (DNA)


  A double helix in the nucleus, composed of nucleotides, and contains five carbon sugar (deoxyribose), nitrogen base, & phosphate
• Gene Expression is a process that converts the information in DNA into the structures and functions of a cell
• Hypotonic Solution: A solution with a lower solute concentration or lower osmotic pressure across a semipermeable membrane
• Hypertonic Solution: A hypertonic solution contains a higher concentration of solutes compared to another solution.