Part VI. The following questions all deal with the cell membrane and membrane tr
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Question
Part VI. The following questions all deal with the cell membrane and membrane transport. Use the figure below in answering questions 2 and 3. ) The cell membrane a) prevents all molecules from entering/exiting the cell ) contains proteins that are involved in cell signaling c) is comprised of small pieces of ribonucleic acid forms a non-selective barrier to hydrophilic molecules e) all of the above are correct 2) Explain simple diffusion, facilitated diffusion and active tran facilitated diff UlWr isme bindi. Side mnkrare than other 1me on me 3) Explain the main functional difference (right). Would these proteins be synahesized on ER-bound or free- Explain. and protein carriers floating ribosomes? Dat allow protan side and In racelliuler fluids on the ther Carriel bi en Dre ECF Cell membrane ICF Carrier open to IcF Same carrler open to ECF prot themo protzinExplanation / Answer
1. b. contains proteins that are involved in cell signalling
2. Simple diffusion is the movement of solute particles from the region of higher concentration to the region of lower concentration. Simple diffusion does not require energy, it occurs by random motion.
Facilitated diffusion is the passive movement of molecules across the cell membrane with the help of membrane proteins.
Active transport is the movement of molecules across a membrane from a region of their lower concentration to a region of their higher concentration. Active transport involves the use of ATP.
3. Protein carriers are not open to the intracellular and extracellular environments at the same time, however, channel proteins are open to both the environments at the same time.
Carrier proteins have binding sites whereas channel proteins do not have binding sites.
Carrier proteins allows ony 100-1000 molecules to pass through it per second, but channel proteins allows millions of molecules to pass through it.
Carrier proteins are synthesized in the free ribosomes in the cytoplasm. Channel proteins are synthesized in the rough endoplasmic reticulum.