1. In cell membrane the hydrocarbon chains for hydrophilic phase and the polar heads form hydrophobic phase.
a) True
b) False
Explanation: Hydrocarbon chains are oriented inwards to form hydrophobic phase and their polar heads are oriented to form the outer hydrophilic boundaries of the cell membrane, it surrounds the aqueous environment.
2. Proteins interact with which part of the cell membrane?
a) Hydrophobic tail
b) Polar head
c) Non polar head
d) Hydrophilic tail
Explanation: Proteins are always bonded to the polar head part of the cell membrane, which is usually hydrophilic in nature. It is known that the heads are always polar and the tails are nonpolar, i.e hydrophobic in nature.
3. Which part of the membrane is responsible for the relative impermeability of polar molecules in and out of the cell?
a) Polar head
b) Hydrophobic head
c) Hydrophobic core
d) Non polar head
Explanation: Hydrophobic core don’t bind to any polar compound being hydrophobic, thus it doesn’t allow polar compounds to pass through the membranes easily. Heads of phospholipid bi-layer in cell membrane are always polar and tails are non-polar in nature
4. What helps in the passing of inorganic ions?
a) Ion channels
b) Voltage gated channels
c) Aqueous filled pores
d) Diffusion
Explanation: Aqueous filled pores of diameter ranging from 4 to 10 Å helps to pass small organic water-soluble molecules and inorganic ions. These pores have polar amino acid on the inner side of the pore which helps the water-soluble molecules to easily pass through them.
5. The cell membrane is ___________
a) Impermeable
b) Semipermeable
c) Permeable
d) Permeable to only gases
Explanation: A cell membrane is always semi permeable that is it permits rapid and limited passage of some of the compounds and restricts other compounds.
6. What is the most important characteristic of a drug to be absorbed after oral administration?
a) Dissolved in HCL
b) Dissolved in alkaline solution
c) Can pass through the cell membrane
d) Form aggregate and settle down
Explanation: A drug should not get destroyed by either of acidic or alkaline medium. It must first pass through the biological barrier of cell membrane. Formation of aggregation will decrease its molecular activity.
7. Cell membrane can pass easily Oxygen and Carbon dioxide.
a) False
b) True
Explanation: Oxygen being small and nonpolar can easily pass through the membrane and carbondioxide is also small enough to easily diffuse in and out of the cell. Small hydrophobic molecules and small uncharged polar molecules can easily pass through the cell membrane. Larger uncharged polar molecules and ions find it difficult to cross the cell membrane.
8. Which one of these is an example of Enteral Route?
a) Skin
b) IV
c) Gastrointestinal
d) Inhalation
Explanation: Enteral routes include oral routes. Thus, the common examples are GI, sublingual/buccal, rectal. IV comes under the parenteral route. Skin and Inhalation are examples of the Topical route
9. Gastrointestinal route is an example of which of the major drug delivery routes?
a) The enteral route
b) The parenteral route
c) The topical route
d) The intravenous route
Explanation: The enteral route includes delivery peroral. The parenteral route involves routes of administration through skin or under layers of skin. The topical route involves eyes, skins, nose, or other membranes
10. Which is the major process of absorption for more than 90% of drugs?
a) Facilitated diffusion
b) Active transport
c) Endocytosis
d) Passive diffusion
Explanation: Passive diffusion is also known as non-ionic diffusion. It is the major process through which 90% of the drugs get absorbed. The driving force for passive diffusion is the concentration gradient and electrochemical gradient.