Transportation is the process of movement or distribution of different materials or goods from one place to another. In general, we humans make use of different means of transportation. Similarly, the living system, including plants, animals, and humans has an amazing network of transportation systems, involved in circulating food, minerals, hormones, oxygen, carbon dioxide, waste products, etc. Show
There are two types of transportation in our body- Active and Passive Transport, which help in the transportation of biochemical nutrients like water and oxygen to the cells.
Passive transport is a natural phenomenon, which does not require any external energy. Let us explore more about Passive transport, its types and other related examples. Table of Contents
What is Passive Transport?Passive transport is the fundamental movement of ions and other molecular substances within the cells along the concentration gradient, without any external energy. It is also known as passive diffusion. Passive Transport There are four types of passive transport:
Simple DiffusionTypes of Passive Transport – Simple Diffusion Diffusion is the movement of substances from a region of higher concentration to a lower concentration. The difference in the concentration of the two areas is termed a concentration gradient and the process of diffusion continues until this gradient neutralizes. Diffusion occurs in liquids and gases because their particles move randomly from one place to another. It is an important process in living things required for different life processes. The substances move in and out of the cells by simple diffusion. Also Refer: Diffusion Facilitated DiffusionFacilitated diffusion is the passive transportation of ions or molecules across the cell membrane through specific transmembrane integral proteins. The molecules, which are large and insoluble require a carrier substance for their transportation through the plasma membrane. This process does not require any cellular or external energy. Glucose transporter, ion channels and aquaporins are some examples of facilitated diffusion. The cell membrane is permeable only to a few molecules that are smaller in size and non-polar. Therefore, facilitated diffusion with the help of transmembrane proteins is important. Also Read: Facilitated Diffusion FiltrationFiltration is the process of separating solids from liquids and gases. The selective absorption of nutrients in the body is an example of filtration. This process does not require any energy and takes place along the concentration gradient. The kidneys are an example of a biological filter. The blood is filtered by the glomerulus and the necessary molecules are reabsorbed. In the process of filtration, the cell membrane permits only those substances which are soluble and could easily pass through its pores. OsmosisPassive transport represented by the process of osmosis In the process of osmosis, water and other molecules pass through a selectively permeable membrane in order to balance the concentration of other substances. Osmosis is affected by the concentration gradient and temperature. The greater the concentration gradient, the faster the rate of osmosis. Also, the rate of osmosis increases with the increase in temperature. There is a theory of conflict about the process of osmosis. Few biologists suggest that osmosis is an active transportand not passive transport. Also Read: Osmosis Examples Of Passive TransportFollowing are some examples of passive transport:
Also Read: Difference Between Active And Passive Transport For more information on passive transport, its types and examples, keep visiting BYJU’S website or download BYJU’S app for further reference. Further Reading: Transport across cell membrane An Overview of Water Potential Frequently Asked QuestionsThe simplest plasma membrane transport mechanism is
called passive diffusion. It is the movement of ions and other molecules within the cells along the concentration gradient, without any external energy. Transportation through plasma membrane occurs by simple diffusion, osmosis
and facilitated diffusion. These are passive transport mechanisms. In facilitated diffusion, the transport through plasma membrane occurs with the help of specific transmembrane integral proteins. Large and insoluble molecules require a carrier
substance for their transportation through the plasma membrane. Is the passive transport of material across a membrane by means of transport proteins is called activated diffusion?Passive Transport using Membrane Proteins
These molecules need special transport proteins to help them move across the membrane, a process known as facilitated diffusion.
What is passive transport across a membrane?Passive transport is a type of membrane transport that does not require energy to move substances across cell membranes. Instead of using cellular energy, like active transport, passive transport relies on the second law of thermodynamics to drive the movement of substances across cell membranes.
What are the 3 types of passive transport?There are three main types of passive transport: Simple diffusion – movement of small or lipophilic molecules (e.g. O2, CO2, etc.) Osmosis – movement of water molecules (dependent on solute concentrations) Facilitated diffusion – movement of large or charged molecules via membrane proteins (e.g. ions, sucrose, etc.)
What is transported in passive transport?Not everything enters the cell through passive transport.
Only the smallest molecules like water, carbon dioxide, and oxygen can freely diffuse across cell membranes. Larger molecules or charged molecules often require an input of energy to be transported into the cell.
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