Answer:
Each one has two fatty acid chains and the glycerol backbone is bonded to a small polar group.
Explanation:
Phospholipid is a unique form of lipid. The bonding of the glycerol backbone to the polar phosphate group makes phospholipid to have dual solubility unlike general triglycerides.
The polar head is said to be hydrophillic that is <u>water loving,</u> while the two carbon chains that retained lipid features are hydrophobic <u>water hating.</u>
Therefore if a phopholipid is placed in water, in relation to its functions as component of cell membrane, it forms a bi-layer in which the water loving portion hydrophilic head points into the surrounding watery medium, while the hydrophobic layer points inwards far away from the watery medium into the internal cellular layer to form an impermeable barrier to hydrophilic (polar) substances.
This forms the basis of the phospholipd bilayer of the cell membrane. And it controls the permeability of the cell membrane to influx substances into the cells.
Secondary structures are dependent upon hydrogen bonding. The two main types of secondary structure are the a-helix and the B-sheet. The a-helix is a right-handed coiled strand.
Answer:
The answer is b. Both of them are characterized by selective permeability.
Explanation:
- Option a. states that both, the nuclear and the cell membrane have two layers. This is only true for the nuclear membrane that consists of two lipid bilayers whereas the plasma membrane only contains one layer.
- c. Only the nuclear membrane has nuclear pores that connect the two bilayers. The pores act as protein channels or passages that allow transport of materials. The cell membrane does contain channel proteins or transmembrane proteins but not protein channels.
- d. The nuclear membrane separates nuclear contents from the cytoplasm whereas the cell membrane separates cellular contents from the extracellular environment.
