examples of passive transport
Education

What Are The Examples Of Passive Transport? 

In school, you might have heard of examples of passive transport. Here we will polish the concept of passive transport and explore its examples in a very appropriate way. Passive transport is a term that denotes the process of transporting molecules from one side of the membrane to the other without any energy requirements. But, the question is where this transportation will happen. It happens inside the cell. The material across the cell membrane is necessary to uphold cellular homeostasis. It is required to balance the pH, accumulation, and volume of nutrients for protein synthesis and cell metabolism for organisms to thrive. Let’s explore some examples of passive transport. 

What Is Passive Transport? 

Well, passive transport is not a very complex process, but it is a very essential process in plants. You may know that there is gravity that attracts everything towards itself. Then how the plants carry water from the soil to their leaves. Plant violates the law of gravity and carries water to make food by photosynthesis. It is due to the process of osmosis. 

The cell membrane in the plant is composed of lipids, proteins, carbohydrates, and sterols that interact with each other to facilitate hydrophilic transmembranes. One cell absorbs water and its area increases, leading to insert pressure on the neighboring cells. Due to increased pressure water gets transferred to the next cell and the process continues until the water reaches the leaves. 

4 Examples Of Passive Transport? 

While reading the given list of examples of passive transport, you may get an idea about how passive transport practically works. First of all, have a look at the list of examples of passive transport. 

  1. Simple Diffusion 
  2. Facilitated Diffusion 
  3. Filtration 
  4. Osmosis 

What Are Examples Of Passive Transport? 

Here are some examples of passive transport that you should know about. Animals, plants, and even humans utilize different means of transporting materials from one place to another. This unique transportation network circulates food, hormones, oxygen, minerals, carbon dioxide, waste products, etc. let’s have a look at the examples of passive transport in biology.

1. Simple Diffusion 

Simple is as simple as its name, in which the movement of materials such as water, nutrients, hormones, etc, from an area of high concentration to that of low concentration until the concentration is equal on both sides. Does passive transport require energy? So, the Diffusion passive transport requires no energy and expenses, instead, the concentration gradient is created and utilized during the transport of molecules.

In the simple diffusion process of passive transportation, molecules or solute particles move in random Brownian motion. And, the flux across the membrane can be calculated using an equation proposed by Torrell in 1953. Which is, Flux = Mobility x Concentration x Driving Force.

Simple diffusion occurs only in liquids and gases because of the random movements of their particles from one place to another. Examples of molecules transported by simple diffusion include oxygen, carbon dioxide, and ethanol. It is also used to carry water and nutrients in prokaryotes like bacteria.

2. Facilitated Diffusion 

Facilitated diffusion is one examples of passive transport in a cell. In facilitated diffusion, some molecules, such as carbon dioxide and oxygen, can diffuse across the plasma membrane directly, but others need help to cross its hydrophobic core. The molecules diffuse across the plasma membrane with the help of membrane proteins, such as channels and carriers.

A concentration gradient exists for these molecules, so they have the potential to diffuse out of or into the cell by moving down it. Well, because they are charged or polar, they can not cross the phospholipid part of the membrane without help. The facilitated passive transportation process carries the proteins shield from the hydrophobic core of the membrane, providing a route by which they can cross. Two main types of facilitated diffusion are channels and carrier proteins.

3. Filtration 

What is filtration in passive transport? Filtration passive transportation is the process of isolating solids from liquids and gases. It does not require energy expenditure and takes place along the concentration gradient. Examples of filtration include the selective absorption of nutrients in the human body. In the kidney, the glomerulus filters the blood, and the body reabsorbs the necessary molecules. Filtration is involved in the transfer of certain molecules across biological membranes based on concentration gradient and without any energy expenditure.

4. Osmosis

Osmosis is one of the very important passive transport examples, you might have heard of it. It is the process of transporting solvent molecules from an area of high water potential to lower water potential through a selectively permeable membrane. All types of gases and supercritical liquids like CO2 can cross the membrane or any other system through the process of osmosis.

You know, the water in the oceans is very salty. But, the interesting thing is that, by using reverse osmosis, you can filter this water and make it drinkable. You may have RO in your home for water filtration, it also uses the process of reverse osmosis.

The osmotic solutions are of three types namely hypotonic, hypertonic, and isotonic. In hypotonic, higher solute concentration is present inside the cell than outside. In hypertonic, the solution has a higher solute concentration outside the cell than inside. In isotonic, the concentration of the solution is equal on both sides of the cell.

Now, you know more than 3 types of passive transport. Like passive transport, there is also active transport and the 3 types of active transport are antiport pumps, symport pumps, and exocytosis.

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FAQ

What Is A Good Example Of Passive Transport?

One example of passive transport is diffusion, when molecules move from an area of high concentration (large amount) to an area of low concentration (low amount). Molecules are said to naturally flow down their concentration gradient. This type of diffusion proceeds without an input of energy.

What Are 2 Passive Transport?

A substance diffuses over a membrane by passive transport as it diffuses along its concentration gradient without requiring any energy from the cell. The two types of passive transport are : Simple diffusion and facilitated diffusion .

What Is The Simplest Passive Transport?

So, diffusion is a type of passive transport as particles move down their concentration gradient. Passive diffusion is the simplest pathway for molecules to cross the plasma membrane.

What Is Passive Transport In A Cell?

Passive transport is defined as movement of a solute from a region of high electrochemical potential on one side of the cell membrane to a region of lower electrochemical potential on the opposite side.

Conclusion 

After reading the article you got to know all the types of transport across cell membranes in detail. Now, you know all examples of active transport and passive transport. If someone asks you what are two examples of passive transport, then without a second delay you may give an answer. Overall, passive transport is a physiological mechanism of transporting molecules across the membrane that favors the concentration gradient. Without any external pressure and expenditure of energy, the process transfers essential molecules, water, gases, and nutrients to the organism’s body required for their living. So, this was all about the examples of passive transport.