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Pill

Theme C - Interaction &  Interdependence

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Direct Hit

Theme A - Unity & diversity

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Page Facing Up

Theme B - Form & Function

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Keycap Digit One

Theme D - Continuity & Change

It&#39;s the process by which cells produce energy without using oxygen. Instead of oxygen, other molecules play a role in generating energy.

<ul>
	<li>Yeast is a one-celled fungus. It&#39;s like that friend who&#39;s up for anything - a &#39;facultative anaerobe&#39;. This means yeast can work with or without oxygen. Cool, right?</li>
	<li>Fun fact: Yeast is naturally found chilling on the surfaces of fruits.</li>
</ul>

<ul>
	<li>Instead of producing lactate like our muscles do without oxygen, yeast makes ethanol and carbon dioxide.</li>
	<li>Process
	<ul>
		<li>Carbon dioxide is removed from pyruvate to form ethanal.</li>
		<li>Hydrogens are added to ethanal to form ethanol.</li>
	</ul>
	</li>
</ul>

<ul>
	<li>Making bread? You&rsquo;ll often find yeast in the mix.</li>
	<li>Role of yeast in bread-making
	<ul>
		<li>Initially, yeast breathes with oxygen present in the dough.</li>
		<li>Once the oxygen&#39;s gone, it&#39;s anaerobic party time.</li>
		<li>The CO₂ produced can&#39;t escape the sticky dough, so it creates bubbles making the dough rise!</li>
		<li>Ethanol? It&#39;s there but disappears when baking because it evaporates.</li>
	</ul>
	</li>
</ul>

Real-world example: Ever made a pizza? That fluffy crust is thanks to the bubbles formed by yeast fermentation!

<ul>
	<li>Beer &amp; wine, they owe a lot to our yeasty friends.</li>
	<li>Wine is from grape juice (high in sugar).</li>
	<li>Beer uses barley grains (low in sugar but high in starch). Yeasts need amylase to convert starch to sugar because they can&#39;t eat starch.</li>
	<li>In big tanks, oxygen is used up quickly. Yeasts then start producing ethanol. But, most of the CO₂ just bubbles away.</li>
</ul>

Real-world example: Ever noticed the bubbles in champagne or carbonated drinks? That&#39;s CO₂ in action!

Too much of a good thing isn&#39;t always great. For yeast, when the ethanol concentration hits around 15%, it&#39;s party over. The environment becomes toxic for them.

<ul>
	<li>Remember ethanol? It&#39;s not just for drinks. It&rsquo;s also a renewable energy source.</li>
	<li>Source: Any plant matter. However, sugar cane and corn are MVPs.</li>
	<li>Here&#39;s the drill: Sugars are turned into ethanol with yeast&#39;s help in large fermenters. This ethanol is then distilled and used as fuel.</li>
</ul>

Real-world example: Some cars use a mix of gasoline and ethanol or just pure ethanol. If you&rsquo;ve heard of E10 or E85 fuels, that&rsquo;s bioethanol in action!

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Remember, whether it&#39;s making bread rise or fueling your car, tiny yeasts have a big role to play! So next time you munch on a sandwich or fill up your tank, give a nod to these amazing microorganisms. 🍞🚗

Theme C - Interaction & Interdependence

Unlock Yeast's Brewing & Baking Secrets!

Table of content

What is anaerobic cell respiration?

What’s up with yeast?

Anaerobic respiration in yeast

Yeast in baking 🍞

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