Concept explainers
To access:
Transport proteins are needed to move certain substances against a membrane.
Introduction:
The cell membrane is the outer boundary of the cell and helps to regulate the entry and exit of molecules, ions or solutes. It is selectively permeable and so it lets some substance to pass through more rapidly and other substances more slowly.
Explanation of Solution
As the cell membrane is a selectively permeable membrane, it checks the influx and out flux of substances or molecules. Small molecules such as water, oxygen and carbon dioxide can pass directly through the lipid bilayer in the cell membrane. In case of larger molecules, charged molecules for example, glucose, a specific transport protein facilitates the movement.
A concentration gradient exists which allow the larger molecules to diffuse into the cells but these materials are repelled by the hydrophobic parts of the cell membrane. The transport protein allows them to diffuse by carrying these materials to the interior of the cell.
The transport protein act as either channels or carriers for the material which may be regulated or unregulated.
In addition to the water molecules, ions, the cell requires some other molecules like glucose, to carry out vital activities. The large molecules do not readily move inside the cell but they require special transporters.
Chapter 7 Solutions
Biology Illinois Edition (Glencoe Science)
Additional Science Textbook Solutions
Anatomy & Physiology (6th Edition)
Human Biology: Concepts and Current Issues
Biology: Life on Earth (11th Edition)
Human Anatomy & Physiology (11th Edition)
Campbell Biology in Focus (2nd Edition)
Microbiology with Diseases by Body System (5th Edition)
- Human Anatomy & Physiology (11th Edition)BiologyISBN:9780134580999Author:Elaine N. Marieb, Katja N. HoehnPublisher:PEARSONBiology 2eBiologyISBN:9781947172517Author:Matthew Douglas, Jung Choi, Mary Ann ClarkPublisher:OpenStaxAnatomy & PhysiologyBiologyISBN:9781259398629Author:McKinley, Michael P., O'loughlin, Valerie Dean, Bidle, Theresa StouterPublisher:Mcgraw Hill Education,
- Molecular Biology of the Cell (Sixth Edition)BiologyISBN:9780815344322Author:Bruce Alberts, Alexander D. Johnson, Julian Lewis, David Morgan, Martin Raff, Keith Roberts, Peter WalterPublisher:W. W. Norton & CompanyLaboratory Manual For Human Anatomy & PhysiologyBiologyISBN:9781260159363Author:Martin, Terry R., Prentice-craver, CynthiaPublisher:McGraw-Hill Publishing Co.Inquiry Into Life (16th Edition)BiologyISBN:9781260231700Author:Sylvia S. Mader, Michael WindelspechtPublisher:McGraw Hill Education