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Last Updated: 22nd July 2023

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Pathogen Life Cycle

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Pathogen, life cycle, lytic, antibiotics, lysogenic, replication, host cell, linking DNA.

Introduction

The life cycle of a pathogen is short, especially if we combat it with antibiotics. By now, you should know what a pathogen is, but for the sake of it, you can click on the link and read up on it.

Two Types of Life Cycle

That's right, there's two type of life cycle that a pathogen can take. They get to choose, by either taking the red pill, or the blue pill. No, wait, that's the Matrix. But they do have two life cycles.

So what are they? They are the Lytic cycle, and the Lysogenic cycle. Let's look at both:

The Lytic Cycle

In the lytic cycle, the pathogen is impatient, and hijacks the cell's genetic machinery to replicate quickly and then breaks up the original host cell.

Replication comes at a rate of knots, as the cell uses the machinery to quickly process through the stages it needs to make new cells. This is all done within the host cell, and it can make several copies of the pathogen inside it before it bursts open through overuse and the inability to expand any further. It would be like filling a balloon with water so much so that it bursts.

This process is called Lysis, and the broken-free viral cells can then attach to more host cells.

The Lysogenic Cycle

In a lysogenic cycle, there may not be as many host cells available for the pathogen to replicate inside. Instead of replicating inside the host cell and destroying it, the pathogen becomes a part of the host cell, linking up its DNA with the host cell.

Because it becomes linked with the original cell, it does not notice, and so replicates itself naturally as it would do to make more cells, giving the pathogen more cells that it inhabits.

When the host cell realises it has an error (that being the pathogen), it then releases it. It does this, and then the pathogen follows the same rules as the lytic cycle.

Interesting fact: a virus needs a host in order to reproduce. This is because it does not have the organelles inside them to help them replicate. Instead, they replicate using host cells, which are later destroyed.

A virus cannot be treated with antibiotics. Instead, another form of medication can be used to treat them. This is because antibiotics combat bacteria, a living infection, where a virus is non-living.

You can see all this information in the following YouTube video from Fuse Schools:


Too Long; Didn't Read

A pathogen has a life cycle, much like our regular cells do. There are two types of cycle that they have - lytic, which replicates using a host cell to quickly reproduce it's own DNA and destroying the original cell once it's no longer needed, and the lysogenic cycle, where it replicates within a host cell, but is fully linked with the DNA of the host cell. It goes uninterrupted until possibly too late, when the host cell then ejects the pathogen from it to lay dormant or find a new host.

Viruses use both methods to infect someone, and unfortunately can't be treated by antibiotics, whereas a bacterial pathogen can.

Suitability

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Related Pages

DNA iconDNA & RNA

Diseases iconCommunicable Diseases

DNA iconProkaryotic Cells - A Closer Look

Diseases iconAntibiotics

Resources

These are the following resources that I recommend to use. You don't have to use them, but I have found them to be useful when presenting this lesson.

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