CBSE Class 9 Answered
what materials does cell memberane allow ?
can cell memberane allow all small substances or particles which obey law of diffusion. because cell memberane only allows small particles or substances to move across through passive process?
Asked by Saurabh Vyas | 13 Sep, 2010, 12:00: AM
Expert Answer
A few substances can diffuse directly through the lipid bilayer part of the membrane. The only substances that can do this are lipid-soluble molecules such as steroids, or very small molecules, such as H2O, O2 and CO2.
Water molecules can diffuse freely across a membrane, but always down their concentration gradient.
Facilitated diffusion allows certain ions and glucose to diffuse through the cell membrane.
Active transport uses energy and transports materials against their concentration gradient. A very important active transport system in all animals is the one that maintains sidium and potassium gradients between cells and the surrounding extracellular fluid.
Large molecules (such as proteins, polysaccharides and nucleotides) and even whole cells are moved in and out of cells by using membrane vesicles.
Answered by | 14 Sep, 2010, 03:09: PM
Application Videos
-
Cell Organelles- Vacuoles
This video talks about the vacuoles. -
Cell Organelles- Smooth endoplasmic reticulum ...
This video talks about the smooth endoplasmic reticulum. -
Cell Organelles- Plastids, Mitochondria ...
This video highlights the comparison between plastids and mitochondria. -
Osmosis
This video explains the practical application of osmosis. -
Osmosis
This video explains the practical application of osmosis.
Concept Videos
-
Cell - The Fundamental Unit of Life
Discusses the discovery of Cell,Cell theory,Various shapes and sizes of ...
-
Cell - The Fundamental Unit of Life
Discuss the structure of a generalized cell, Unicellular and multicellular... -
Cell - The Fundamental Unit of Life
Cell organelles-I -
Processes involved in Transport of Materials
Understand the various phenomena responsible for transporting the substance... -
Cell - The Fundamental Unit of Life
Discusses the discovery of Cell,Cell theory,Various shapes and sizes of cel...
CBSE 9 - Biology
Asked by afiyamallick12 | 29 Mar, 2024, 01:03: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by manishsingh75352335 | 28 Mar, 2024, 06:06: AM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by nandinikallimani | 04 Mar, 2024, 07:11: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by kamblesangeeta537 | 24 Jan, 2024, 04:59: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by ujjwalgamerz067 | 02 Oct, 2023, 08:37: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by irampathan554 | 13 Sep, 2023, 06:49: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by ramulachandana057 | 12 Jul, 2023, 06:30: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by preranshtiwari.anshul | 07 Jul, 2023, 06:59: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by nandhithar2010 | 19 Jun, 2023, 07:28: PM
ANSWERED BY EXPERTCBSE 9 - Biology
Asked by saniyakhan4816 | 07 Jun, 2023, 03:46: PM
ANSWERED BY EXPERT
