pill.png

Pill

Theme C - Interaction &  Interdependence

direct-hit.png

Direct Hit

Theme A - Unity & Diversity

page-facing-up.png

Page Facing Up

Theme B - Form & Function

keycap-digit-one.png

Keycap Digit One

Theme D - Continuity & Change

<ul>
	<li>🎤 Quorum Sensing: It&#39;s like a bacterial group chat!</li>
	<li>Quorum: Minimum number of members needed for a decision.
	<ul>
		<li>Example: 2/3 of UN Security Council members needed for a meeting.</li>
	</ul>
	</li>
	<li>🦠 Bacteria&#39;s version of a quorum: Quorum Sensing.</li>
</ul>

<ul>
	<li>Bacterial Signals
	<ul>
		<li>Bacteria release signalling molecules.</li>
		<li>Think of it as the bacteria sending text messages 📱.</li>
	</ul>
	</li>
	<li>Reading the Message
	<ul>
		<li>These molecules drift and bind to receptors in other cells.</li>
		<li>Like reading a notification on your phone.</li>
	</ul>
	</li>
	<li>Response to the Group Chat
	<ul>
		<li>When enough signals are received, the cell&#39;s gene expression changes.</li>
		<li>It&#39;s like getting many likes on a post and deciding to post more.</li>
	</ul>
	</li>
	<li>Counting the Group Size
	<ul>
		<li>As bacterial population increases, more signalling happens.</li>
		<li>When enough bacteria agree, they collectively change their activity.</li>
		<li>&quot;Hey, there&#39;s enough of us here. Let&#39;s do something cool!&quot;</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Bacteria rely on each other for certain tasks. They are the ultimate team players 🤝.</li>
	<li>Example 1: Dental Bacteria
	<ul>
		<li>High numbers ➡️ they secrete a glue-like substance.</li>
		<li>Creates a biofilm layer on teeth (this is why you should brush!).</li>
	</ul>
	</li>
	<li>Example 2: Bioluminescence
	<ul>
		<li>Bacteria glow in the dark, but only when they&#39;re in a crowd.</li>
		<li>Imagine lighting up only when everyone brings their own torch!</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Fun Fact: Vibrio Fischeri was the first bacteria known to use quorum sensing for bioluminescence.</li>
	<li>The Process
	<ul>
		<li>Signal Release: Produces an autoinducer signal.</li>
		<li>Signal Reception: Signal binds to the LuxR protein inside the cell.</li>
		<li>Bright Idea: This binding tells the bacteria to produce an enzyme called luciferase.</li>
		<li>Let There Be Light!: Luciferase releases energy, producing a greenish-blue glow.</li>
	</ul>
	</li>
	<li>In the Wild
	<ul>
		<li>Free living V. Fischeri don&#39;t light up; it&#39;d waste energy.</li>
		<li>In partnership with the bobtail squid, they glow.
		<ul>
			<li>Inside the squid&#39;s light organ, there are many bacteria, so they &quot;sense&quot; a quorum and light up.</li>
			<li>This light helps the squid camouflage 🦑💡.</li>
			<li>In return, the squid provides food for the bacteria. Mutual benefits!</li>
		</ul>
		</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Bacteria use quorum sensing to make collective decisions.</li>
	<li>This is vital for tasks that require many bacteria, like forming biofilms or glowing.</li>
	<li>Vibrio Fischeri is a cool example: they light up when together, and help squids camouflage in return for food.</li>
</ul>

Study Tip: Think of quorum sensing like group chats or social media. Bacteria &quot;post&quot; signals and &quot;like&quot; or &quot;share&quot; by receiving them. If a &quot;post&quot; gets enough &quot;likes&quot;, they start a new activity!

Theme C - Interaction & Interdependence

Unlocking Quorum Sensing Bacteria’s Secret Communication

Table of content

Introduction

What's quorum sensing?

Why Is this interaction important?