Please answer number 3, 4 and 6 Label the structures in the membrane above marke
ID: 93182 • Letter: P
Question
Please answer number 3, 4 and 6
Label the structures in the membrane above marked by letters. The top of the page is outside the cell while below the membrane is inside the cell. Which types of organisms use a cell membrane on their cells? Why are the phospholipids arranged like they are in the cell membrane? Why is the membrane described as "fluid"? What is the probable function of part G? What is the purpose of cholesterol in the cell membrane? What types of molecules would be able to pass through the membrane freely and what types of molecules would need special help?Explanation / Answer
A1 -hydrophilic head of phospholipid, A2- Tail of phospholipid(hydrophobic)
B-phospholipids
C-SUgar
D-Sugar side chain
E.C holesterol
G. Integral or transmembrane protein
E-Sterol
H-Outer face of the cell membrane
I-Inner face of the membrane
1.The cell membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells.
2.The phospholipids in the plasma membrane are arranged in two layers, called a phospholipid bilayer . Each phospholipid molecule has a head and two tails. The head “loves” water (hydrophilic) and the tails “hate” water (hydrophobic). The water-hating tails are on the interior of the membrane, whereas the water-loving heads point outwards, toward either the cytoplasm or the fluid that surrounds the cell.
3.The 'Fluid' part represents how some parts of the membranecan move around freely, if they are not attached to other parts of the cell.
4.A transmembrane protein (TP) is a type of integral membrane protein that spans the entirety of the biological membrane to which it is permanently attached. Manytransmembrane proteins function as gateways to permit the transport of specific substances across the biological membrane.
5.cholesterol helps to immobilize some of the lipid molecules around them. This extra rigidity makes the cell membrane stronger and makes it harder for small molecules to pass through the membrane. The presence of cholesterol allows the cell membrane to be strong enough to hold the cell together and to serve as an effective barrier to ions.
6.Nonpolar and small polar molecules can pass through the cell membrane, so they diffuse across it in response to concentration gradients. Carbon dioxide andoxygen are two molecules that undergo this simple diffusion through the membrane. The simple diffusion of water is known as osmosis.
Those substances which are large and charged need special help in their movement across a membrane.