Cell Transport

• The three major components of the cell are the cell membrane, cytoplasm, and organelles.
• The structure/function of the cell membrane is to form the boundary of the cell.
• The components of the nucleus are the nuclear envelope, nucleolus, and chromosomes.
• The organelles stored within the cytoplasm include the mitchondria, smooth endoplasmic reticulum, ribosomes, golgi apparatus, and lysosomes.
• Functions of organelles:

  Mitochondria - energy production

  Smooth Endoplasmic reticulum - lipid production

  Ribosomes - protein production

  Golgi apparatus - protein modification and export

  Lysosomes - protein destruction
• Active transport requires ATP and moves substances against concentration gradient.

  Passive transport requires no energy and moves substances with concentration gradient.
• 3 Passive mechanisms of cellular transport:

  1. Diffusion - Small and nonpolar molecules move easiest with this diffusion
  2. Facilitated Diffusion - Carrier proteins used to diffuse larger molecules
  3. Filtration
• Osmosis is the passive transport of water and water flows to area with more solute.
• Osmolarity is a measure of total solute concentration.

  Tonicity is the ability of a solution to influence the shape of a cell, the concentration of non-penetrating solutes in a solution.
• Isotonic: solution and cells have equal concentration
• Hypotonic: solution has lower concentration than cells
• Hypertonic: solution has higher concentration than cells
• Active mechanisms of cellular transport:

  1. Facilitated active transport - Uses carriers and ATP to move molecules against concentration gradient
  2. Bulk Transport - movement of large quantities of molecules
• Two types of bulk active transport:

  1. Exocytosis: out of cell
  2. Endocytosis: into cell (two types)

  Two types of endocytosis:

  1. Phagocytosis: cell eating
  2. Pinocytosis: cell drinking