The Corn Collection: Current Curriculum Containing Corn Science

The Story of Corn and the Factory Within

The Iowa Corn Challenge-A World Without Corn

The High Fructose Corn Syrup Debate

Genetically Modified Corn

Ethanol-A Fuel from the past in today’s News

Corn, Corn Products or No Corn

YERTpod14: Challenging Corn in Iowa

The Great Corn Adventure

http://www.urbanext.uiuc.edu/corn/03static.html

• The mother grain of the Americas hardly needs describing - it is so familiar a plant that every child knows it. And it can hardly be overlooked. Corn is a giant among the grasses - growing over 2m high, it covers vast stretches of land and dominates many rural landscapes. The sturdy, fibrous stalk with its characteristic broad angularly bent over leaves is a familiar sight. The ears develop in the leaf axils though they are so well covered by the outer sheathing (husks) that they can barely be seen, were it not for the tuft of hair, the stigma that protrudes from the top of the cobs.

http://www.sacredearth.com/ethnobotany/plantprofiles/corn.php

• The endosperm accounts for about 82 percent of the kernel’s dry weight and is the source of energy (starch) and protein for the germinating seed. Starch is the most widely used part of the kernel and is used as a starch in foods—or as the key component in fuel, sweeteners, bioplastics and other products.

•The pericarp is the outer covering thatprotects the kernel and preserves thenutrient value inside. It resists waterand water vapor—and is undesirableto insects and microorganisms.

• The germ is the only living part of thecorn kernel. The germ contains theessential genetic information, enzymes,vitamins and minerals for the kernelto grow into a corn plant. About 25percent of the germ is corn oil—themost valuable part of the kernel,which is high in polyunsaturated fatsand has a mild taste.

• The tip cap is the attachment point of the kernel to the cob, throughwhich water and nutrients flow—and is the only area of the kernel notcovered by the pericarp.

Anatomy of a Corn Kernel

http://www.ncga.com/worldofcorn/2007/kernel.asp

From One Bushel of Corn

• A typical bushel of corn weighs 56 pounds/25.4 kilograms and

contains 72,800 kernels.

What can be extracted from a bushel of corn? 

• 32 lbs/14.53 kg of starch / 32 regular 500 gram boxes• or 33 lbs / 14.97 kg of sweetener• or 2.5 gal / 11.37 litres of fuel ethanol • and 11.4 lbs / 5.17 kg of Gluten Feed*Source Corn industry sources **20% Gluten Feed• and 3 lbs / 1.36 kg of Gluten ** 60% Gluten Meal

http://www.ontariocorn.org/classroom/bushel022405.htm

• There are five basic types of corn with many varieties representative of each: DENT Corn (white to yellow), FLINT Corn (all colors; shrinks on drying), POPCORN (hard grain), SWEET or VEGETABLE Corn (high sugar content), WAXY Corn (starchy with a waxy appearance). Flint and Dent corn are used for Oil, Cereal, Flour, and Animal feed. Waxy Corn is used mainly in the Far East for its tapioca-like starch.

http://earthnotes.tripod.com/corn.htm

Popcorn varieties and hybrids

• There are several commercial classifications of corn. Field corn (also called dent corn or cow corn) is fed to animals. Flour corn is mostly starchy center with a soft hull that allows it to be easily ground into flour. Sweet corn is the kind we eat at the dinner table. Flint corn is usually called Indian corn; its colorful kernels make it highly attractive, and it is used for decoration because it is tough and tasteless. Pod corn is also only used for decoration because each of its kernels has its own separate husk.

• Popcorn, also a collection of varieties of Zea mays, is the only corn that pops; it is not dried kernels of sweet corn. There are several

http://www.madehow.com/Volume-5/Popcorn.html

Popcorn Classification

• Kingdom• Plantae plant

Phylum• Anthophyta produces flowers

Class• Monocotyledonae each seed produces a single leaf

Order• Commelinales the leaves are fibrous

Family• Poaceae has blade-shaped leaves, like grass

Genus• Zea mays produces fleshy, one-seeded fruits

Species• mays"corn

The Popcorn Secret• A popcorn kernel is actually a seed. Like other seeds, inside it has a

tiny plant embryo (a life form in its earliest phase). The embryo is surrounded by soft, starchy material that would give the embryo energy for growing into a plant. A hard, glossy shell protects the outside of the seed.

• The soft, starchy material holds some water. When the kernel is heated to a high heat (400 degrees F), the water inside the kernel turns into steam. The pressure from the steam causes the kernel to explode. The soft starch inside bursts out at about 40 times its original size, turning the kernel inside out. This creates the fluffy white area of a popped kernel.

• The ideal popcorn kernel contains about 14 percent moisture. If the popcorn is much drier, it will not pop. Popcorn kernels should be kept in a tightly sealed jar so that they will not dry out.

http://www.factmonster.com/spot/popcorn1.html

Resources for Corn Education

• National Corn Grower’s Association• http://www.ncga.com/education/unit1/u1l2.html• Science

UNIT 1, LESSON 1: Tour a Power PlantUNIT 2, LESSON 2: Corn Eats Lunch UNIT 2, LESSON 3: Topsoil DessertUNIT 3,LESSON 2: Weather or Not to Act UNIT 3,LESSON 3: Prolegs, Head Capsules & Warts UNIT 3,LESSON 4: Give Me an "I" "P" "M" UNIT 4, LESSON 2: Genes-R-UsUNIT 4, LESSON 4: Farm or Pharmacy? Jr. & Sr. High StudentsUNIT 5, LESSON 3: Satellite ScienceUNIT 6, LESSON 1: A Food Pyramid Built From Corn UNIT 7, LESSON 4: Corn that Bounces & Stretches UNIT 9, LESSON 2: Kernel Surgery UNIT 9, LESSON 3: Starch Your Day Right!

• Alcohol Can Be A Gas by David Blume• http://www.alcoholcanbeagas.com/?bid=2&aid=CD99&opt=• Blume systematically and entertainingly builds his case for individual responsibility

and activism in dealing with the nation’s domestic-energy challenges, and he excludes no one in preaching his gospel of alcohol-fuel independence. For the novice, Blume tells the story of alcohol production’s rich history in America, from the Civil War to today, and effectively demystifies the thorny pros and cons of the current national energy-policy debate regarding ethanol. This education alone is worth the cover price.

Corn Legends-Literature Connection

• Corn was so much a part of the lives of the Native Americans that they often told stories of how it was first obtained.  A good book to read about corn is called Corn Is Maize by Aliki.

http://www.american.edu/edtech/harmon/LEGENDS.HTML

• Creating a Three Sisters Garden Discovering A Native Trio

• Native peoples from different parts of North America have used a wide range of agricultural techniques. Perhaps the best known is the inter planting of corn, beans, and squash together – a trio often referred to as the "three sisters."

• In a three sisters planting, the three partners benefit one another. Corn provides support for beans. Beans, like other legumes, have bacteria living on their roots that help them absorb nitrogen from the air and convert it to a form that plants can use. (Corn, which requires a lot of nitrogen to grow, benefits most.) The large, prickly squash leaves shade the soil, preventing weed growth, and deter animal pests. The three sisters also complement each other nutritionally.

Copyright© 2002 National Gardening Association

http://www.usatoday.com/tech/columnist/aprilholladay/2006-07-17

http://reta.nmsu.edu/sacred/lesson/agriculture/cornquiz/corn_quiz.html#top

• An assortment of corn (Zea mays), including strawberry corn, popping corn, Indian corn and pod corn. Many botanical authorities believe that all of these amazing varieties were developed from a Mexican grass called teosinte, known as "madre de maíz" in the regions where it grows wild. In the two ears at far left (called pod corn), the individual grains are enclosed in papery bracts called glumes. Glumes are present is most native grasses, but have been selected against in modern edible corn for obvious reasons. http://waynesword.palomar.edu/plapr99.htm

• Popping corn, one of the many varieties of Zea mays. The small, upper left ear is called strawberry popcorn. When the grains are heated, water contained within the starchy endosperm expands as steam, and the hard-shelled grains literally explode. Grains of some of the earliest known forms of corn, such as teosinte, were hard, thick-shelled popping corns. So the next time you enjoy freshly-popped corn, remember that you are primarily eating hot, exploded endosperm.

http://waynesword.palomar.edu/plapr99.htm

The Power of Green

http://photoscience.la.asu.edu/photosyn/education/learn.html

The majority of plants we see around us are eukaryotes. Eukaryotes are trees and corn and wheat. They are seaweed and lily pads, grass and dandelions. Eukaryotic plants are made of billions of cells all working towards shared goals. Each cell includes a nucleus and a slew of other internal machinery called organelles.

drawing by Michael Hagelberg

http://www.ftexploring.com/me/photosyn1.html

   In the picture above, the little black lines between atoms represent the chemical bonds which you can think of as sort of like hand holding between the atoms. It's how they hold on to each other. It's not really how

they look. There aren't really little black lines between the atoms. For that matter, there isn't really a little glowing yellow star of energy in the center of each molecule. The stored energy is really in the chemical

bonds. When those bonds are broken the stored energy is released.

http://www.ftexploring.com/me/photosyn1.html

Corn Silk

• A natural insecticide in the silk of some corn lines will deter earworms in the future if ARS scientists succeed in transferring genes that control the production of maysin.

http://www.ars.usda.gov/is/AR/archive/jun97/maysin0697.htm

• There is no such thing as a natural corn syrup pressed directly from corn kernels. Instead, the pulpy middle layer called cornstarch is first separated from the outer husk and the inner germ layers. The cornstarch is then stored in giant vats, where natural enzymes are added to break it down into glucose. It is these sugars which are heated and turned into what we call corn syrup.

• Corn syrup is almost exactly as sweet as the granulated sugar (sucrose) it often replaces in recipes. Corn syrup can be naturally light in color which is often used in candymaking or darker which is usually used for general baking purposes. The light form of corn syrup may have vanilla flavoring added, while the dark corn syrup has a stronger natural flavor. The advantage of corn syrup over sugar is its resistance to crystallization. A candy lollipop made with corn syrup will retain its smooth texture, while a similar treat made from pure sugar may turn into a hardened rock candy. Corn syrup also prohibits crystal formation when sugar is added to a cake or fudge mixture.

http://www.wisegeek.com/what-is-corn-syrup.htm

Corn Syrup

http://www.corn.org/Starch2006.pdf

Corn starch photographedat 3000x.

http://www.corn.org/Starch2006.pdf

Corn Plants produce Oxygen

• There's something corny about oxygen"An average hectare of corn produces enough oxygen per hectare per day in mid summer to meet the respiratory needs of about 325 people. This means that the one million or so hectares of corn grown in Ontario produce enough oxygen for the annual respiratory needs of Ontario's 10 million residents in about 11 summer days!" From: Corn and Photosynthesis

http://photoscience.la.asu.edu/photosyn/education/learn.html

• Some plant species are much more efficient than others in converting carbon dioxide and water into oxygen and organic matter - especially when the atmospheric concentration of carbon dioxide is very low as it has been for the past several hundred million years. These more efficient plants, which include corn, sorghum and a few weed species, have a unique "C4" photosynthetic system which permits carbon dioxide to be converted into organic matter at a faster rate than with the more common photosynthetic system of other plant species.

The Leaf     It's amazing what's inside a leaf. In this top section I'll give an overview of the leaf parts involved in photosynthesis. In the section below, we'll go into more detail.      The whole leaf looks green to us, but most of the cells and cell material are colorless or clear. The green color comes from the chlorphyll molecules in the chloroplasts.      Except for the thylakoid membranes, where the clorophyll molecules reside, the rest of my colors are just there to help you see the parts, and to make pretty pictures.  Leaf Section     Cut out a little section of the leaf. Cut it all the way through. There are many different types of cells, specialized to do different things - all for the good of the tree, of course.      On the top and bottom are the cuticle layer and the epidermal cells.      In the middle, between the epidermis cells on the top and bottom, are the mesophyll cells where the chloroplasts live.     On the bottom only, in most plants, are the stomates which let carbon dioxide in and oxygen out. More on the Leaf Section   Mesophyll Cells     No, it's not a "Mess of Phils". It's a mesophyll.      The chloroplasts, where photosynthesis occurs, are in the mesophyll cells.      There are two kinds of mesophyll cells in our typical leaf.  The ones you see in the leaf section above, packed close together, are in the palisade parenchyma region (I can't say it either - that's biologists for you).  This is where most photosynthesis is done.  The other region is called the spongy parenchyma region.  Here the cells aren't so close.  There are roomy air spaces between them. Jump on down to the leaf section below for the purpose of the air spaces.  

Leaf anatomy of a C3 (top) and C4 (bottom) plant. Images from Purves et al., Life: The Science of Biology,

C3 Leaf

C4 Leaf : Corn and Soybeans

•     Chloroplast Now we're getting to some small plant parts.  But you can still see chloroplasts with a regular microscope. Inside the chloroplasts, in the stoma and the grana, is where photosynthesis happens (see below).     Promise me you will never forget the chloroplasts - fascinating little "organelles" (why not organettes?) with their own genetic material to make more of themselves.      Each chloroplast is a little carbohydrate factory, powered by solar energy, and for which the only raw materials are carbon dioxide, water, and a few minerals.     Out of this little factory comes food for plants and practically every other living thing on earth - including us.     Good on yer, Chloroplast! More on the Industrious Chloroplast   Granum     The little round flat pillow or pancake shaped things are called thylakoids. A stack of them is called a granum. Two or more stacks are called grana (granums would have been too easy).     There can be from 2 to around 100 thylakoids in one granum. The little tube like strands connecting thylakoids from granum to granum are called stroma lamellae (see the chloroplast drawing below). Thylakoid     Now we have finally journeyed to the place where it all starts. The chlorphylls and other pigments that start the process are here, on the outer layer of the thylakoids. Photons from sunlight hit the pigments, electrons are "knocked" loose, and off they go to energize the complicated process of photosynthesis.     Sometimes the thylakoid is also called the photosynthetic membrane. That is easier for some of us to remember. The membrane and the space inside it (shown in yellow), is where the light or light-dependent reaction takes place. The so-called dark, or light independent reactions, take place in the stroma (shown in gray here).

• Only a small percentage of corn grown in the United States is actually consumed by humans. The highest percentage is fed to livestock to produce meat, milk and eggs for consumption here and abroad.

• Ethanol fuel production only uses the starch in the corn kernel. The protein, fat and other nutrients are used for other food and feed products. For example, ethanol plants also produce distillers grains, a high-value feed that is replacing corn in traditional beef, pork, poultry and dairy rations.

• Bottom line:We are getting more out of a kernel of corn by creating not only more fuel, but more food for animals and people around the world.

National Corn Growers Association

• These two ears of corn demonstrate vividly the difference between adequate and inadequate soil management and crop production.

http://www.cropsci.uiuc.edu/research/rdc/urbana/morrow.cfm

Genetic Engineering

http://www.pbs.org/wgbh/harvest/engineer/transgen.html

Working for Better Corn Production

• Sampling soil from the Morrow Plots around 1904: At left is James H. Pettit, an assistant in soil analysis at the Agricultural Experience Station; at right, Cyril G. Hopkins, head of the Department of Agronomy from 1900 to 1919.

http://www.cropsci.uiuc.edu/research/rdc/urbana/morrow.cfm

European corn borer (left) and cotton bollworm (right) are two pests controlled by Bt corn and cotton, respectively.

Source: USDA.

http://cls.casa.colostate.edu/TransgenicCrops/current.html#Bt

Diagram of the BT refuge strategy, in which at least 20% of a farm's corn acreage must be planted to non-BT corn. R = resistant European corn borer

adult; S = susceptible adult.

http://cls.casa.colostate.edu/TransgenicCrops/current.html#Bt

rn hybrid with a Bt gene (left) and a hybrid susceptible to European corn borer (right). Source: Monsanto

Transposons

The reddish streaks on these corn grains are caused by transposons.

• The following illustration shows how grain color in Indian corn may be affected by transposons. The different cards represent a linear sequence of genes on a chromosome. The ace of spades represents a transposon that moves to different positions on the chromosome. The jack of diamonds represents the gene for purple pigmentation in the corn grain. When the transposon (ace of spades) moves to a position adjacent to the gene for pigmentation (jack of diamonds), the pigmentation gene is blocked and no purple is synthesized (white area):

When the transposon (ace of spades) moves away from the gene for pigment production (jack of diamonds), the production of purple pigment is resumed (continuous purple area). In this example the

gene for pigment production (jack of diamonds) is not adjacent to a transposon (ace of spades):

When a transposon moves to different positions within cells of the corn kernel, the coloration gene is "turned on" or "turned off" depending on whether it lands in a position

adjacent to the pigmentation gene. Transposons may also have a profound effect on embryonic development and tumor formation in animal cells. Oncogenes

(genes that cause tumors) may be activated by the random reshuffling of transposons to a position adjacent to the oncogene. Transposons may also be useful in genetic engineering with eukaryotic

cells, by splicing in transposons to activate certain genes. The implications from Barbara McClintock's discovery

of transposons may be far-reaching and as significant as Watson and Crick's discovery of the structure of DNA.

Federoff, N.V. 1984. "Transposable Genetic Elements in Maize."     Scientific American Volume 250 (Number 6): 84-98.

Corn Study, detail (Figure 0038), 2004. Photography Austin Young

Alcohol Fermentationhttp://

www.emc.maricopa.edu/faculty/farabee/BIOBK/alcferm.gif