Cell Membrane

• The Cell membrane controls what can enter and leave the cell.
• Function of the Cell Membrane:

  The cell membrane, or plasma membrane, is important for maintaining equilibrium inside the cell.

  • needs to keep this equilibrium while allowing some substances in and keeping others out
  • Selectively permeable or semi-permeable
  • The passage of materials through the cell membrane is determined by the size of the molecules, their charge, and whether they are soluble in lipids
• Particle Model of Matter:

  • All matter is made of particles but the particles indifferent substances may be different in size and composition.
  • The particles of matter are constantly moving or vibrating; particles move least in solids and most in gases. Adding or taking away energy will affect the movement of particles.
  • The particles of matter are attracted o one another or are bonded together.
  • Particles have spaces between them that are smallest in solids, except for ice, and greatest in gases. The spaces may be occupied by the particles of other substances.
• The difference in the concentration of a substance between two areas is called concentration gradient.

  • High to low concentration to reach equilibrium
• Manipulated: the variable that is being change in an experiment
• Responding: the variable that will change in response to the change in manipulated variable
• Controlled: variable that remains constant