Glucose is an important biomolecule. Which of these statements is true regarding the movement of glucose into and out of cells?
A) Glucose, a small molecule, can diffuse between the phospholipids. B) Glucose requires both a membrane protein and ATP energy in order to enter or exit a cell. C) Glucose, a nonpolar molecule, can pass freely across the phospholipid bilayer from high to low concentration. D) Glucose is a large, hydrophilic molecule and must use a channel protein to enter or exit a cell, but does not require energy.
D) Glucose is a large, hydrophilic molecule and must use a channel protein to enter or exit a cell, but does not require energy.
Explanation:
Glucose is a polar, large, and hydrophilic molecule that cannot easily diffuse the cell membrane. It moves across the membrane through a mechanism known as <u>facilitated diffusion</u>. In this process, a carrier protein attaches itself to glucose molecule and transport it without any use of ATP. Instead, the movement is driven by concentration gradient. An example is the diffusion of glucose in red blood cells.
Cholesterols are amphiphatic molecules. This property allow cholesterol to insert themselves into cell membranes by interacting with phospholipids which are also amphiphatic in nature. A molecule is said to be ampiphatic if it has both polar and non polar regions.
An ohmmeter is an electrical instrument that measures electrical resistance, the opposition to an electric current. Micro-ohmmeters make low resistance measurements. Megohmmeters measure large values of resistance. The unit of measurement for resistance is ohms
