Question

Homeostasis and Cell Transport 1. What does selective transport or selectively permeable mean? 2. What types of organic molecules make up a cell membrane? 3. What is the function of the cell membrane? 4. What is diffusion? 5. What is facilitated diffusion? 6. What is equilibrium? Give exam​

Answer 1

1. Selective transport or selectively permeable means that a cell membrane only allows certain substances to pass through it. This allows the cell to control what enters and leaves the cell, ensuring that the cell maintains a stable internal environment, also known as homeostasis.
   
2. The cell membrane is composed of a phospholipid bilayer, which is a double layer of phospholipid molecules. These molecules have a hydrophilic (water-loving) head and a hydrophobic (water-fearing) tail. The hydrophobic tails face each other, forming a barrier that only allows certain molecules to pass through.
   
3. The main function of the cell membrane is to protect the cell from the external environment and to maintain the cell's internal environment. The cell membrane also plays a role in cell signaling and communication, as well as in the movement of substances in and out of the cell.
   
4. Diffusion is the movement of molecules from an area of high concentration to an area of low concentration. This movement occurs without the input of energy, and it helps to distribute molecules evenly throughout a system.
   
5. Facilitated diffusion is a type of passive transport that uses proteins in the cell membrane to help molecules move across the membrane. These proteins, called transmembrane proteins, provide a channel or carrier through which molecules can pass. Unlike diffusion, facilitated diffusion requires the input of energy to move molecules across the membrane.
   
6. Equilibrium is the state of a system in which the concentration of molecules is equal on both sides of a barrier. In the context of cell transport, equilibrium occurs when the concentration of molecules inside and outside of the cell is the same, and there is no net movement of molecules across the cell membrane. This state is also known as dynamic equilibrium.