Membrane diffusion through the plasma membrane

Info icon This preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: n through the plasma membrane Membranes often porous to solvent (water, via aquaporins) but not solutes Plasma Membranes Membrane are selectively permeable to solutes K+, Na+, Cl, proteins, etc. How are these concentrations maintained against the diffusion gradient? Filtration Active transport (primary and secondary) Vesicular Ex. The Na+/K+ pump Operation of the sodiumpotassium pump K+ high inside Na+ high outside Secondary active transport Stored energy from the active transport of molecules can be used to power further systems Taking in, and getting rid of, particles Exocytosis Removal of products Endocytosis Absorption of products phagocytosis: pseudopods engulf particles bulk phase: nonselective absorption of extracellular fluids and molecules receptor mediated: absorption of specific molecules Exocytosis Types of endocytosis Types of endocytosis Types of endocytosis Membrane potentials and cell polarity Caused by the selective permeability of ions Inside of cells more negative than outside creates a resting membrane potential (20 to 200mV) Ions move in relation to the electrochemical gradient rather than just the concentration Summary of forces that generate and maintain membrane potentials How do cells communicate? Contact signaling Electrical signaling Chemical signaling Ligands: chemicals that bind to specific receptors Model of the...
View Full 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