Human Anatomy

• This is an extreme pliable structure composed primarily of back to back phospolipids (bilayer)

  Cell Membrane
• Cholesterol is also present, which contributes to the fluidity of the membrane, and there are various proteins embedded within the membrane that have a variety of functions.
• A single phospolipid molecule has a phosphate group on one end, called the head, and two side by side chains called fatty acids that make up the lipid tail
• Region of a molecule that is attracted to water.

  Hydrophilic
• A type of molecule that repels and is repelled by water

  Hydrophobic
• This molecule contains both hydrophilic and hydrophobic region

  Amphiphatic
• These molecules contain both hydrophilic and hydrophobic regions.
• The hydrophilic portions of these molecules will be exposed to the extracellular environment while the hydrophobic portions will face into the cell.
• The hydrophilic portion of this molecule will be exposed to the extracellular environment while the hydrophobic portion will face into the cell.
• Both sides of the bilayer consist of nonpolar tails facing each other with polar heads facing outside.
• The hydrophilic portion of these molecules faces outward towards the surrounding water while the hydrophobic portions face inwards toward other similar molecules.
• Phospholipids form bilayers when placed into an aqueous environment due to their amphiphatic nature.
• intracellular fluid is the fluid interior of the cell
• The fluid environment outside the enclosure of the cell membrane

  Extracellular Fluid
• It is the given term to ECF referring to not contained within the blood vessels

  Interstitial Fluid
• What are the two types of proteins that are commonly associated with cell membrane

  Integral and Peripheral
• Integral Protein - embedded in the lipid bilayer, cannot be removed by washing or centrifugation
• Glycoproteins - contain carbohydrates covalently bonded to polypeptide chains
• Glycoproteins - has carbohydrate molecules attached, which extends into extracellular matrix. containing proteins found on the surface of cells
• Peripheral protein - attached to integral proteins on one side of the membrane
• Enzymes - catalysts involved in metabolic reactions
• Peripheral protein - attached to integral proteins on one side of the membrane or to phospholipids on both sides of the membrane
• Type of movement that transport without the expenditure of cellular energy

  Passive Transport
• Active Transport is a movement with energy in the form of ATP (Adenosine Triphosphate)
• Diffusion is the process by which substances move from an area of higher concentration to lower concentration across a semipermeable membrane.
• What is the specialized carrier protein that helps to facilitate inward diffusion?

  Glucose transporter
• • Less selective
  • Mildly discriminate between their cargo based on size and shape

  Channel Protein
• • More selective
  • Only allows one particular type

  Carrier Protein
• Osmosis is the diffusion of water through a semi-permeable membrane down its concentration gradient
• The cellular environment can be divided into two parts, intracellular fluid (ICF) and extracellular fluid (ECF).
• Intracellular Fluid (ICF): The fluid inside cells; also called cytosol or cytoplasm
• Extracellular Fluid (ECF): All fluids outside of cells; includes interstitial fluid, lymphatic fluid, plasma, cerebrospinal fluid, synovial fluid, and aqueous humor
• Has higher concentration of solute than another solution

  • Water leaves the cell, causing it to shrivel

  Hypertonic
• Solution that has lower concentration than another solution

  • Causing cell to expand even burst

  Hypotonic
• Concentration of solutes are the same

  • Cells maintain its shape and function

  Isotonic
• Active transport in the form of ATP is require to move substance across cell membrane often with help of protein carrier, usually against concentration gradient
• Transport sodium out while moving potassium into the cell

  • Na+/K+ are abundant in nerve cells to maintain electrical gradient across the cell membrane

  Sodium Potassium Pump
• It is the difference in the electrical charges across a space

  Electrical gradient
• • Cell eating
  • Endocytosis of large particles
  • Process by which immune cells engulf and destroy bacteria

  Phagocytosis
• • Cell drinking
  • Brings fluid containing dissolved intro a cell through membrane vesicle

  Pinocytosis