notes for test 3 - Test 3 Notes The cell membrane is also...

Info icon This preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Test 3 Notes The cell membrane is also called the plasma membrane, plasmalemma.  It’s a  phospholipid bilayer and is 8 nanometers thick and is semipermeable  Transmembrane proteins(integral proteins) are inside the cell membrane Glycolipid and glycoproteins are part of the cell membrane and the sugar  components always face outwards.  They function in cell recognition and cell  adhesion.  Cholesterol molecules regulate the fluidity of the membrane; meaning is it more  watery or more solid Network of supporting fibers in the cell Semipermeable means that the membrane is selective on what it allows to enter and  leave the membrane Transport proteins are specifically designed to transport materials and will only  transport one material How substances move: Diffusion is the tendency for molecules to spread into an available space.  This  happens because all atoms have kinetic energy. Diffusion occurs down a  constant gradient for a given molecule, meaning molecules move from high to  low.  Diffusion only occurs when you have net movement and equilibrium is  reached when molecules move in equal numbers from left to right and right to  left.  Equilibrium occurs spontaneously.
Image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Net movement or overall movement – although we can not predict the  movement of an individual molecule, we can predict the movement of an  entire population. A cell maintains its own concentration gradient and during any one moment  more oxygen molecules move in than out, whereas CO 2  moves out and not in Diffusion is sometimes referred to as passive transport meaning the cell does  not expend energy for it to occur. The Rate of Diffusion is controlled by:  The size of the molecules involved- smaller molecules diffuse faster Temperature- the high the temperature the faster the rate of diffusion. Permeability of the cell membrane Osmosis is a special kind of diffusion, or the diffusion of water across a  semipermeable membrane.  Aquaporins are protein tunnels that are just large  enough for water molecules to pass through and make membranes permeable to  water but to nothing else. Osmotic pressure is the tendency for a solution to take up water when  separated from pure water by a selectively permeable membrane. Water balance and marine invertebrates- under normal circumstances some  of them have no net intake or outtake of water. In terrestrial animals water  balance is kept within 3 main compartments where water is localized:  Heart and blood vessels (plasma)- 8% total (compartment 1)
Image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern