English Deutsch Français Italiano Español Português 繁體中文 Bahasa Indonesia Tiếng Việt ภาษาไทย
All categories

just give me informations about this topic...

2006-12-25 20:23:12 · 3 answers · asked by FiLipina Lass^^ 2 in Science & Mathematics Biology

3 answers

I never heard of this before.Where did you?I think it's the way the cell transpots inside and outside of it the nutrients. If you agree,do you want to e-mail me? dragoianamaria@yahoo.com

2006-12-25 20:46:01 · answer #1 · answered by Ana 3 · 0 0

Materials are transported into and out of the cell by two basic methods. Passive transport doesn't require the cell to use any energy to make it happen. Materials go from high to low concentration. Some molecules with the right solubility, charge, and size can just diffuse randomly between the phospholipids that make up the plasma membrane. Others must diffuse through special proteins in the membrane that act like channels or tubes. Passive transport also includes facilitated transport in which molecules are carried through proteins that change shape to help the molecules go through. It still doesn't take energy.

Active transport requires the cell to use energy to move materials from low to high concentration. Usually a protein in the plasma membrane "grabs" a molecule on the low concentration side, and the cell uses ATP energy to change the protein's shape and release the molecule on the high concentration side of the membrane.

Bulk transport is one way that cells take in or put out larger particles. Two kinds of bulk transport: endocytosis and exocytosis. In endocytosis, the plasma membrane wraps around and encloses a large particle forming a vacuole - a little bubble of plasma membrane - that pinches off and contains the particle inside the cell. The reverse process is exocytosis.

2006-12-26 11:58:45 · answer #2 · answered by ecolink 7 · 0 1

cell transport system is a mechanism in which cells carries nutrients in and out of the cell. there are different types of cell transport. Active transport , passive transport, diffussion, and osmosis..

2006-12-26 06:48:05 · answer #3 · answered by water nixie 2 · 0 1

fedest.com, questions and answers