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.
Invasive species. Native grasses have evolved with the normally-occurring grazing organisms to achieve a level of reproduction which sustains the grasses despite the grazing. An invasive species disrupts this ecological balance that took millions of years to develop by eating the grass at a rate that exceeds the rate for the grass to re-seed itself and maintain its own population. The invasive species easily decimates the grass population.
Se produce en la mitocondria. La respiración celular, como componente del metabolismo, es un proceso catabólico, en el cual la energía contenida en los sustratos usados como combustible es liberada de manera controlada.
