Quiz 2

• Passive Transport


  The movement of substances across membranes without the use of energy
• Passive Transport


  • Diffusion - net movement of solute substances from an area of higher concentration to an area of lower concentration (down the concentration gradient)
  • Osmosis - the diffusion of water molecules across a selectively permeable membrane. Water moves from a region of less concentrated solution (hypotonic solution) to a region of more concentrated solution (hypertonic solution)
• Tonicity of Solutions


  • Cell in a Hypotonic Solution - The solute concentration outside the cell is lower than that inside the cell. Water from the environment enters the cell, causing it to bulge or even burst.
  • Cell in a Hypertonic Solution - The solute concentration outside the cell is higher than that inside the cell. Water in the cell leaves the cell, causing it to shrivel and die.
  • Cell in a Isotonic Solution - The solute concentration outside the cell is equal to that inside the cell. No water will flow from one side of the membrane to the other.
• Tonicity of Solutions


  • RBC in hypertonic, isotonic and hypotonic solutions
  • Plant cell in hypertonic, isotonic and hypotonic solutions
  • Fish rubbed with salt to prolong shelf life
  • Vegetable soaked in saltwater
  • Fruits dried by sugar
  • Fishes living in salt/freshwater environment
• Facilitated Diffusion


  Movement of solutes through protein channels down the concentration gradient without energy expenditure. Water and certain hydrophilic solutes cross the membrane.
• Facilitated Diffusion


  • Channel proteins - open or close as they respond to stimuli.
  • Carrier proteins - change in shape
• Active Transport


  Uses energy in moving solutes across a membrane by moving up the concentration gradient. Requires the use of energy through carrier proteins. Movement of molecules: unidirectional
• Matter


  Anything that occupies space and has mass (solid, liquid, gas, plasma and bose-einstein condensate)
• Bulk Transport


  Occurs when large molecules, such as proteins and polysaccharides cross membranes in bulk through the processes of exocytosis and endocytosis.
• Despite the complexity of living systems, their biochemistry can be simplified by examining their basic composition
• Objects


  Can be composed of either a single or more than one materials
• Exocytosis


  Process of removing materials from the cell through the vesicles that fuse with plasma membrane.
• Elements


  Pure substances that cannot be broken down further into another substance
• Exocytosis


  • Secretion of digestive enzymes from the epithelial cells of digestive organs to the food passing through the digestive system.
• Elements in the periodic table

  • 118 (naturally/synthetically occurring)
• Endocytosis


  Reverse process of exocytosis, cells engulf materials. Engulfed substance enters the cytoplasm while enclosed with a vesicle.
• Elements


  • Oxygen, hydrogen, nitrogen, carbon, phosphorus
• Phagocytosis


  Cellular eating. Occurs when an undissolved materials enter the cell.
• Compounds


  Substances that are made up of one or more elements chemically joined together
• Phagocytosis


  • White blood cells engulf bacteria
  • Capturing of food by single-celled protists
• Compounds


  • Water (H2O), carbon dioxide (CO2), methane (CH4), carbon monoxide (CO)
• Pinocytosis


  Cellular drinking. Occurs when dissolved substances enter the cell.
• Seven major elements in living systems

  • Carbon (C) - main composition of organic compounds
  • Hydrogen (H) - major source of fuel in the production of energy
  • Oxygen (O) - essential part of water molecule and organic compounds
  • Nitrogen (N) - key element in protein
  • Phosphorus - major component of nucleic acids and energy-rich compounds
  • Sulfur - part of some amino acids and vitamins
  • Calcium - for the bones
• Trace elements/minerals


  Elements that are present in small amounts in the body
• Pinocytosis


  • Human egg cell's uptake of nutrients
• Deficiency in trace elements

  May lead to micronutrient deficiency
• Trace element deficiencies


  • Iron deficiency - anemia
  • Iodine deficiency - goiter
• Trace elements in living systems


  • Sodium and potassium - essential for nerve function
  • Iodine - acts as thermostat to regulate body temperature
  • Molybdenum - needed by plants to incorporate nitrogen in a biologically useful substance
  • Magnesium - important component of bones, teeth and chlorophyll
  • Iron - carrier of oxygen in the blood
• Atoms


  Smallest unit of matter
• Elements differ from one another (unique)
• Subatomic particles of atoms


  • Proton - positively charged
  • Electron - negatively charged
  • Neutron - neutral or uncharged particle
• Both proton and neutron are located inside the nucleus, while electrons are in the orbit
• Chemical bonding


  The process of chemical transferring or sharing of electrons to fill their outermost electron orbit
• Examples of chemical bonding


  • Ionic bonding
  • Covalent bonding
• Ionic bonding


  Attractions between ions of opposite charges, bonding between a metal and non-metal, transferring of electrons
• Example of ionic bonding


  • Sodium chloride bonding
• Covalent bonding


  Attractions between ions of same charges, bonding between two non-metals resulting to the process of sharing electrons between two non-metals, strongest bond
• Types of compounds


  • Inorganic compounds - those present without carbon (salt, carbon dioxide, carbon monoxide)
  • Organic compounds - compounds that are containing carbons (methane, glucose)