Preview

Reoprt

Good Essays
Open Document
Open Document
630 Words
Grammar
Grammar
Plagiarism
Plagiarism
Writing
Writing
Score
Score
Reoprt
Cell Membrane

Simple diffusion is when a small, non-polar molecule passes through a lipid bilayer.
It is classified as a means of passive transport. In simple diffusion, a hydrophobic molecule can move into the hydrophobic region of the membrane without getting rejected. Simple diffusion does not involve a protein. An example of simple diffusion is osmosis. Hydrophilic molecules cannot participate in simple diffusion because they would move into the hydrophobic region of the membrane and be rejected.

Facilitated diffusion is a type of passive transport that is dependent on single transport protein carriers. These protein carriers operate on a bind, flip, and release mechanism. Facilitated diffusion is non-diffusional because the molecule moves along with the carrier. Saturation occurs in facilitated diffusion because not enough carriers may be available to handle all the free solute molecules. The rate of movement may reach a maximum.

Active Transport There are numerous situations in living organisms when molecules move across cell membranes from an area of lower concentration toward an area of higher concentration. This is counter to what would be expected and is labeled "active transport". Many crucial processes in the life of cells depend upon active transport. Active transport mechanisms may draw their energy from the hydrolysis of ATP, the absorbance of light, the transport of electrons, or coupling with other processes that are moving particles down their concentration gradients. A vital active transport process that occurs in the electron transport process in the membranes of both mitochondria and chloroplasts is the transport of protons to produce a proton gradient. This proton gradient powers the phosphorylation of ATP associated with ATP synthase. Osmosis Osmosis is a special example of diffusion. It is the diffusion of water through a partially permeable membrane from a more dilute solution to a more

You May Also Find These Documents Helpful

  • Good Essays

    BSC2085L Anatomy Quiz 1

    • 550 Words
    • 3 Pages

    Osmosis is the net diffusion of water across a membrane from a region of high concentration to low…

    • 550 Words
    • 3 Pages
    Good Essays
  • Good Essays

    Mg2 Unit 9 Study Guide

    • 1084 Words
    • 5 Pages

    b) Active transport moves molecules up the concentration gradient, low to high concentration. Diffusion goes down the concentration gradient, high to low concentration.…

    • 1084 Words
    • 5 Pages
    Good Essays
  • Satisfactory Essays

    Pe 220 Notes Exam 2

    • 1246 Words
    • 5 Pages

    In facilitated diffusion, the carrier protein has equal affinity for the molecule being transported on both sides of the membrane.…

    • 1246 Words
    • 5 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Passive transport is moving biochemical and atomic or molecular substances across the cell membrane but unlike active transport it does not involve chemical energy. Active transport is transporting things from a region of lower concentration to higher concentration, and it uses energy. Depending on whether it needs energy and the transports or places that it goes through will depend on whether it will use active or passive.…

    • 376 Words
    • 2 Pages
    Satisfactory Essays
  • Powerful Essays

    Cell Transport Mechanisms and Permeability 1 EXERCISE 1 OBJECTIVES 1. To define the following terms: differential permeability, passive and active processes of transport, diffusion (simple diffusion, facilitated dif- fusion, and osmosis), solute pump, pinocytosis, and phagocytosis. 2. To describe the processes that account for the movement of sub- stances across the plasma membrane, and to indicate the driving force for each. 3.…

    • 4065 Words
    • 27 Pages
    Powerful Essays
  • Powerful Essays

    BIO 104 Chapter 3

    • 7229 Words
    • 29 Pages

    Others, including penicillin and streptomycin, require the assistance of transport proteins. Transport proteins can move substances either up or down a concentration gradient. When a substance uses a transport protein to move down a concentration gradient, the process is called facilitated diffusion. Like simple diffusion, facilitated diffusion requires no energy CHAPTER 3: CELL FUNCTION AND STRUCTURE 3620001C03.indd 49 49 1/27/11 10:14 AM INFOGRAPHIC 3.7 Molecules Move across the Cell Membrane Simple diffusion…

    • 7229 Words
    • 29 Pages
    Powerful Essays
  • Satisfactory Essays

    303 Bio Study Guide

    • 287 Words
    • 2 Pages

    When an ion crosses the membrane and binds to a protein to accomplish this feat, it is using active transport and facilitated diffusion.…

    • 287 Words
    • 2 Pages
    Satisfactory Essays
  • Satisfactory Essays

    Associated with symptoms that result from cell shrinkage as water is pulled into vascular system…

    • 1353 Words
    • 6 Pages
    Satisfactory Essays
  • Good Essays

    Define osmosis: Osmosis can be defined as the movement of solvent molecules across a semipermeable or selectively permeable membrane ,from a region of lower concentration of the solute to that of a higher concentration till equilibrium is attained.…

    • 661 Words
    • 3 Pages
    Good Essays
  • Good Essays

    C. facilitated diffusion, active transport Active transport is where a cell uses energy to move molecules. Facilitated diffusion is the same as diffusion, just when they pass through integral proteins.…

    • 602 Words
    • 3 Pages
    Good Essays
  • Satisfactory Essays

    Physilogy

    • 266 Words
    • 1 Page

    Both facilitated diffusion and simple diffusion transport molecules from hi to low concentration of solute without the use of energy (ATP) , the difference is that facilitated diffusion requires a protein (channel) while simple diffusion doesn’t need the aid of a carrier.…

    • 266 Words
    • 1 Page
    Satisfactory Essays
  • Powerful Essays

    Anantomy help

    • 1420 Words
    • 6 Pages

    What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane? - In facilitated diffusion, molecules only move with the aid of a protein in the membrane.…

    • 1420 Words
    • 6 Pages
    Powerful Essays
  • Good Essays

    egg lab

    • 358 Words
    • 2 Pages

    Diffusion is the simplest form of passive transport. Using its own energy molecule will move from areas of higher solute concentrations to areas of lower concentrations until a balance is reached. Osmosis is also a form of passive transport.Osmosis occurs when water molecules diffuse across the cell membrane from an area of higher solute concentration to an area of lower solute concentration.…

    • 358 Words
    • 2 Pages
    Good Essays
  • Better Essays

    Oxford Tutorial

    • 1838 Words
    • 8 Pages

    Carrier proteins are saturated throughout the cell membrane, and can facilitate movement by carrying small molecules, such as amino acids, across the cell membrane. Carrier proteins do not require energy because they facilitate movement from an area of high concentration to an area of lower concentration. Many carrier proteins can facilitate movement in both directions, and allow molecules to enter or exit. Direction is based on concentration gradient. For example, if the concentration is higher outside the cell, molecules would naturally move to na area of lower concentration. That is, they would enter the cell.…

    • 1838 Words
    • 8 Pages
    Better Essays
  • Good Essays

    9th grade bio

    • 536 Words
    • 3 Pages

    2. Facilitated Transport (a.k.a facilitated diffusion)- Diffusion, uses a channel protein, large or charged particles…

    • 536 Words
    • 3 Pages
    Good Essays