<h2 class="section-header"><strong class="title">Introduction to the Chemistry of Life</strong></h2>
<p class="para">In this lesson and the next few, we will study the molecular structure and biological functions of key molecules important to life. We will study the chemistry of proteins, carbohydrates, lipids, vitamins and <a data-lesson="nucleic-acids-2" data-subject="biology" data-tutorial="biology-foundations" href="https://app.ulearngo.com/biology/biology-foundations/nucleic-acids-2">nucleic acids</a> and will learn the role of each nutrient class in plant and animal life. We will also learn how our diet allows us to obtain sufficient quantities of each of these nutrients.</p>
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<li class="item">Organic molecules always contain <a data-lesson="carbon-cycle" data-subject="biology" data-tutorial="ecology-overview" href="https://app.ulearngo.com/biology/ecology-overview/carbon-cycle">carbon</a> (C), and usually also contain hydrogen (H) and oxygen (O). Some important organic molecules also contain nitrogen (N), phosphorous (P), sulfur (S), iron (Fe) and other elements.</li>
<li class="item">Water (H<sub>2</sub>O<span style="white-space: nowrap;">)</span> is an inorganic compound made up of two H and one O. Water helps with temperature regulation, form and support, <a data-lesson="secondary-active-transport" data-subject="biology" data-tutorial="cell-transport" href="https://app.ulearngo.com/biology/cell-transport/secondary-active-transport">transport</a> and lubrication and is a medium for chemical reactions.</li>
<li class="item">Minerals are required as part of a healthy diet. A deficit in essential <a data-lesson="minerals" data-subject="biology" data-tutorial="chemistry-of-life-intro" href="https://app.ulearngo.com/biology/chemistry-of-life-intro/minerals">minerals</a> results in deficiency <a data-lesson="emerging-and-re-emerging-diseases" data-subject="biology" data-tutorial="prokaryotes-bacteria-archaea" href="https://app.ulearngo.com/biology/prokaryotes-bacteria-archaea/emerging-and-re-emerging-diseases">diseases</a> in plants and animals.</li>
<li class="item">Fertilizers are a way that <a data-lesson="essential-nutrients" data-subject="biology" data-tutorial="soil-plant-nutrition" href="https://app.ulearngo.com/biology/soil-plant-nutrition/essential-nutrients">essential nutrients</a> can be added to the soil to improve plant growth.</li>
<li class="item">Carbohydrates are made up of C, H and O. They can be in the form of <a data-lesson="introducing-carbohydrates-monosaccharides" data-subject="biology" data-tutorial="biological-macromolecules" href="https://app.ulearngo.com/biology/biological-macromolecules/introducing-carbohydrates-monosaccharides">monosaccharides</a> (single sugars), disaccharides (double sugars) or polysaccharides (many sugars), and are an important <a data-lesson="biology-203-glossary-9" data-subject="biology" data-tutorial="cell-metabolism" href="https://app.ulearngo.com/biology/cell-metabolism/biology-203-glossary-9">energy</a> source for plants and animals.</li>
<li class="item">Lipids are made up of C, H and O. Triglycerides are a type of lipid that contains glycerol and three fatty acid chains. Cholesterol, another type of lipid, can increase the risk of <a data-lesson="heart" data-subject="biology" data-tutorial="human-biology" href="https://app.ulearngo.com/biology/human-biology/heart">heart</a> disease.</li>
<li class="item">Proteins are made up of C, H, O, N, and some have P, S and Fe. Proteins consist of a long chain of <a data-lesson="amino-acids" data-subject="biology" data-tutorial="biological-macromolecules" href="https://app.ulearngo.com/biology/biological-macromolecules/amino-acids">amino acids</a> that fold into a very specific three-dimensional structure. Proteins are an important building block in plants and animals and play a role in the <a data-lesson="disruptions-in-the-immune-system" data-subject="biology" data-tutorial="immune-system" href="https://app.ulearngo.com/biology/immune-system/disruptions-in-the-immune-system">immune</a> system and in cell communication.</li>
<li class="item">Enzymes are a type of protein that act as a biological catalyst to speed up reactions. They work by a "lock and key" mechanism and are affected by temperature and pH.</li>
<li class="item">Nucleic acids such as DNA and <a href="https://app.ulearngo.com/tutorials/introducing-genetics/rna">RNA</a> are made of C, H, O, N and P. DNA contains the genetic information for heredity, and RNA has the instructions on how to make protein.</li>
<li class="item">Vitamins are important organic molecules that must be obtained in the diet. They often help <a data-lesson="enzymes-2" data-subject="biology" data-tutorial="biology-foundations" href="https://app.ulearngo.com/biology/biology-foundations/enzymes-2">enzymes</a> to work properly, or act in <a data-lesson="population-growth-patterns" data-subject="biology" data-tutorial="ecology-overview" href="https://app.ulearngo.com/biology/ecology-overview/population-growth-patterns">growth</a> or differentiation.</li>
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<p class="para">In order to understand the chemistry of living systems, it is important to understand how all living systems are arranged from the smallest unit (atomic scale) to the largest unit (ecosystems). A simple way to describe the levels of organisation of livings things can be given as follows:</p>
<p class="para">atom \(→\) <em class="emphasis">molecule </em>\(→\) cell \(→\) tissue \(→\) organ \(→\) organism \(→\) ecosystem</p>
<p>The video below describes the levels of organisation of livings things.</p>
<h2>Video: Biological Levels</h2>
<p>The <a href="http://www.amoebasisters.com/">Amoeba Sisters</a> video below takes you through the biological levels of organization: cells, tissues, organs, organ systems, organism, population, community, ecosystem, biome, biosphere.</p>
<p><iframe allowfullscreen="allowfullscreen" frameborder="0" height="360" src="https://www.youtube.com/embed/EtWknf1gzKo?rel=0&amp;modestbranding=1&amp;cc_lang_pref=en&amp;cc_load_policy=1" width="640"></iframe></p>

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The Chemistry of Life

Biology studies life and living organisms. Biology can be divided into different sections that cover the morphology, physiology, anatomy, behavior, and so on of living organisms.

Biology

Discover the fundamental role of chemistry in life, explore the importance of molecules such as water, minerals, and nutrients for plant growth, and learn about the essential organic compounds, such as carbohydrates, lipids, and proteins, as well as enzymes, nucleic acids, and vitamins, and the recommended dietary allowance.


The Chemistry of Life

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