Food Science

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Unit

• Food Science

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Problem Area

• Handling and Storing Plant Products

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Lesson

• Testing for Carbohydrates, Fats, and Proteins

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Student Learning Objectives

• 1. Explain why proper nutrition is important for
  all organisms.
• 2. List the six essential nutrients needed by
  organisms and explain their overall importance.
• 3. Explain the importance of water in the body.
• 4. Explain how minerals are important to
  organisms.
• 5. Explain the importance of vitamins to
  organisms.
• 6. Explain the importance of protein for
  organisms.
• 7. Explain why carbohydrates are essential to
  the survival of organisms.
• 8. Explain the importance of lipids.

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Terms

• Adhesion
• Amino acids
• Capillarity
• Carbohydrates
• Catalyst
• Cohesion
• Disaccharides
• DNA
• Enzymes
• Fat soluble vitamins

• Inorganic compounds
• Lipids
• Macrominerals
• Minerals
• Monosaccharides
• Nucleic acids
• Nutrients
• Nutrition
• Organic compounds
• Polar compound

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Terms cont.

• Polysaccharides
• Polyunsaturated fatty acid
• Proteins
• RNA
• Saturated fatty acid
• Steroids

• Trace elements
• Triglycerides
• Vitamins
• Water
• Water soluble vitamins
• Wax

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Why is proper nutrition important for all
organisms?

• A. Three Needs of Humans/Organisms
• 1. FoodFood provides energy.
• 2. WaterWater is necessary for a variety of
  chemical reactions to occur and is the primary
  solvent in our bodies.
• 3. ShelterOur homes and clothing protect from
  the extremes of the environment.

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• B. Nutrition is the process by which animals eat
  food and use it to live, grow and reproduce.
  Proper nutrition allows us and all other
  organisms to function at optimal levels.
  Nutritional stress inhibits our ability to
  function. Early sailors learned to take limes
  with them to prevent scurvy due to a deficiency
  of Vitamin C even though we really have only
  known about Vitamin C for a few short decades.

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• C. Proper Nutrition for animals and plants
  causes
• 1. Increased feed efficiency for livestock as
  well as domesticated and wild animals.
• 2. Increased rate of gain provides bigger
  financial yields for farmers.
• 3. Decreased days to market weight enables
  farmers to increase their overall production and
  profit.
• 4. Increased plant performance and efficiency
  again increases profit.
• 5. Improved nutritional value of foodstuffs.

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• D. Poor nutrition results in lower production and
  returns because of
• 1. Slow plant and animal growth
• 2. Poor reproduction
• 3. Lowered production levels
• 4. Poor health
• 5. Increased death loss

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What are the nutrients that organisms need and
how do they help organisms function?

• Nutrients are substances that are necessary for
  the functioning of an organism.
• A. Six Essential Nutrients
• 1. Water is the primary component of all
  organisms. It is the primary solvent in the body
  which contains all of the dissolved and suspended
  solutes providing the transportation system for
  the body.
• 2. Minerals are an important component of the
  skeleton, soft tissues, and fluids.
• 3. Vitamins act as a catalyst in body processes
  vitamins help chemical reactions to occur in the
  body.
• 4. Proteins are used to build and repair cells.
• 5. Carbohydrates provide energy.
• 6. Lipids provide and store energy.

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• B. These six essential nutrients are all equally
  important to the peak performance of all
  organisms including humans.
• C. Water, minerals, and vitamins are all
  inorganic compounds and protein, carbohydrates,
  and lipids are all organic compounds. Organic
  compounds contain carbon, hydrogen, and oxygen
  and come from living things. Inorganic compounds
  can contain carbon, hydrogen, and oxygen, but
  they come from the earth rather than from
  organisms.

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Why is water important to the body?

• Water is the most important inorganic compound in
  living things.
• A. Water is an excellent solvent and has a high
  heat capacity.
• B. Water makes up about 7080 percent of plants
  and about 75 percent or more of muscles and
  internal organs in animals.

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• C. Water serves many different purposes.
• 1. Our body is made up a variety of solutions. A
  solution consists of solutes and solvents. A
  solute is the substance that is dissolved in the
  solution. The solvent is the substance that
  dissolves the solute. Using a glass of sweet ice
  tea as an examplethe solutes are the tea and the
  sugar and water is the solvent. Water is the
  solvent in which all nutrients (solutes) are
  dissolved and suspended.
• 2. Water reacts with many chemical compounds to
  break down food.
• 3. Water provides rigidity for plants.
• 4. Water regulates body temperature.

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• D. Chemical properties of water are unique and
  aid to its universal importance.
• 1. Cohesion is the bonding of water molecules to
  each other. This can be evidenced in a puddle of
  water on a table. Water is a polar compound.
  Water has a net charge of zero (one hydrogen and
  two oxygen atoms bond resulting no charge).
  However, because of the molecular structure (how
  the atoms bond together), a water molecule has an
  imbalance in its charge resulting in a slightly
  negative pole and a slightly positive pole.
  Because of this, water molecules bond to other
  water molecules very easily.
• Waters high heat capacity is due to its
  polarity it takes a great deal of heat or energy
  to break the bonds between water molecules. This
  is why it takes a pot of water a seemingly long
  time to boil the heat must work to break the
  bonds before the water will boil. This
  characteristic is good for organisms because we
  would die if a small amount of heat were needed
  such as from the sun to cause us to boil.

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• 2. Adhesion is the bonding of water molecules to
  other substances. Again water bonds to other
  substances easily because of polarity, especially
  other polar compounds. A small drop of water will
  adhere to the side of your car or to the wall.
• 3. Capillarity is the ability of a liquid to move
  upward against the force of gravity by molecular
  attraction to a surrounding surface. Water is
  able to move from the roots of a plant to the
  leaves because of cohesion and adhesion. Looking
  at a clear graduated cylinder will help to
  visualize how capillarity works in plants. The
  water bonds to the inside of the graduated
  cylinder due to adhesion. Water molecules bond to
  themselves due to cohesion. As the water moves up
  the sides of the cylinder due to adhesion,
  cohesion pulls more water molecules upward. The
  narrower the tube, the faster the liquid will
  move upward against the force of gravity.

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Why are minerals important to organisms?

• Minerals are found in rocks, soil, and water and
  are essential to the body for optimal
  performance.
• A. The primary purpose of minerals is that they
  become part of the body making up bones, fluids,
  and tissues.
• B. Macrominerals are needed in large quantities.
  Macrominerals include sodium, calcium phosphorus,
  potassium, and magnesium.
• C. Trace elements are needed in smaller
  quantities, but are just as important to your
  health. Copper, tin, iodine, and iron are
  examples of trace elements.

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• D. Many ailments can be attributed to a low
  mineral intake. Thus, many doctors recommend that
  humans take vitamin and mineral supplements.
• 1. Anemia or a feeling of tiredness can be
  attributed to low iron levels.
• 2. Fatigue, rapid pulse, and increased appetite
  can result form low levels of iodine.
• 3. Muscle tremors or shaking can result from
  insufficient levels of magnesium.
• 4. Low calcium levels can result in poorly formed
  teeth and bones resulting in Osteoporosis or
  brittle bone disease. Calcium is needed for a
  variety of chemical reactions and muscle
  contractions to occur. Osteoporosis can result
  from the bodys compensation of a lack of calcium
  by removing it from the bones.

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Why are vitamins important to organisms?

• Vitamins serve as a catalyst in the body meaning
  that they cause chemical reactions to occur. They
  do not provide energy or build the body.
• A. Vitamins serve many purposes including
• 1. clotting of blood
• 2. formation of bones
• 3. aiding reproduction at both the cellular and
  multicellular levels
• 4. keeping membranes healthy
• 5. producing milk
• 6. prevention of certain nervous system disorders

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• B. Vitamins can be classified as either fat
  soluble or water soluble.
• 1. Water soluble vitamins include vitamins C and
  B. This means that the vitamins must be consumed
  every day because your body uses C and B vitamins
  as they are needed. Excess amounts of these are
  excreted from the body.
• 2. Fat soluble vitamins include vitamins A, D, E,
  and K. These vitamins are stored in the body and
  used as needed.

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• C. Vitamins are essential to the proper
  functioning of the body, but they are needed in
  very small amounts. The recommended daily
  allowance of Vitamin C is only 60 mg, but one
  ounce of Vitamin C contains 28,000 mg. Large
  doses of vitamins can have negative effects on
  the body as well.
• D. Animals receive most of the vitamins that they
  need through their feed, but supplements can be
  purchased to add to their ration.
• E. Vitamins are usually made up of carbon,
  hydrogen, oxygen, and nitrogen.

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Why do organisms need protein?

• Living things are made up of many different
  chemical molecules. After carbohydrates, protein
  is the second most abundant nutrient found in
  plants. Proteins make up the bulk of all solid
  material within your body and the bodies of other
  animals. Your muscle, skin, hair, and inside
  organs are largely protein. Proteins are
  essential for body growth and repair.
• They also make up some hormones which function in
  chemical control in the body and are found in
  enzymes and antibodies. There are many kinds of
  proteins found in plants and they are classified
  by their origin. Protein deposited in seeds is
  the major source for human consumption. Protein
  is essential for many of lifes biological
  processes.

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• A. The main purpose of protein is to build and
  repair cells. Three to five percent of the bodys
  cells are rebuilt every day. Protein is also the
  major component of the bodys genetic code.
  Proteins are an organic compound that is composed
  of one or more chains of polypeptides.
  Polypeptides are in turn made from amino acids.
• B. Amino acids are monomers (single chemical
  units) that form proteins.

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• 1. Each amino acid contains a central carbon atom
  and four other atoms or groups that bond
  covalently to the carbon atom. Different amino
  acids have different R groups.

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• 2. There are only 20 known amino acids, but there
  are thousands of different proteins. The human
  body can manufacture only 11 of the 20 amino
  acids. The other nine are called essential amino
  acids and must be consumed through the food that
  is eaten.
• C. A dipeptide is two amino acids bonded
  together. A polypeptide is a long chain of amino
  acids. Proteins are composed of 2 or more
  polypeptides.
• D. Enzymes are proteins that act as catalysts in
  intermediary metabolism which is a series of
  chemical reactions in which energy is released in
  slow controlled amounts so that cells will not be
  damaged. Enzymes lower the activation energy that
  is needed thus decreasing the amount of
  activation energy that is needed for a chemical
  reaction to occur.

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• E. Nucleic Acids are complex organic molecules
  that store important hereditary information in
  the cells nucleus.
• 1. DNA or deoxyribonucleic acid is hereditary
  information in the form of a large molecule. DNA
  stores all of the essential information that is
  needed for directing all of the cells
  activities.
• 2. RNA or ribonucleic acid stores and transfers
  information that is essential for the
  manufacturing of proteins. RNA is found in the
  nucleus and in the cytoplasm of the cell.
• F. Foods high in protein include beans, meat,
  nuts, cheese, and eggs. Feedstuffs high in
  protein include soybeans, peanuts, cottonseed,
  linseed, and urea (nonprotein nitrogen). Protein
  from animal sources is usually of a higher
  quality than plant protein. Nutritionists
  recommend that about 15 of the human diet
  should be made up of protein.

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Why are carbohydrates important for organisms?

• Carbohydrates are organic compounds that are the
  main source of energy for organisms. If low
  levels are carbohydrates are consumed, the body
  will use fat and protein for energy. This can
  result in insufficient levels of fat and protein
  to perform other vital functions.
• A. Carbohydrates are composed of carbon, hydrogen
  and oxygen. The number of carbon atoms will vary,
  but the hydrogen and oxygen atoms will be found
  in a ratio of 21. Water is also found to have a
  21 ratio.

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• B. There are three types of carbohydrates.
• 1. Monosaccharides are simple sugars or single
  molecule sugars. They contain 1 carbon 2
  hydrogen 1 oxygen. The most common
  monosaccharides are glucose, fructose, and
  galactose all have a chemical formula of C6 H12
  O6 . Molecules that have the same molecular
  composition, but have different structures are
  called isomers.
• a. Glucose is the main source of energy for
  plants and animals is created during
  photosynthesis (H2 OCO2 light à O2 C6 H12 O6
  ).
• b. Fructose is found in fruits and is the
  sweetest of all the monosaccharides.
• c. Galactose is found in milk.

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• 2. Disaccharides are double sugars.
• a. Lactose is found in milk and is formed from
  glucose and galactose.
• b. Sucrose is created from fructose and glucose
  and is found in sugar cane and sugar beets.
• c. Maltose is formed from two glucose molecules.
• 3. Polysaccharides are complex molecules
  containing three or more monosaccharides.
• a. Glycogen is how animals store glucose.
• b. Starch is how plants store glucose. Starch is
  found in potatoes, bread, vegetables, and rice.
  Plants are the primary producers of
  carbohydrates.
• c. Cellulose is found in plants and is
  indigestible by humans. Ruminants are able to
  digest cellulose because of the presence of
  microorganisms in their stomach.

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• C. Nutritionists recommend that about 55 of the
  human diet be composed of carbohydrates. Humans
  should consume plenty of fruits, vegetables, and
  whole grain breads.
• D. Unused carbohydrates are converted to fat and
  are stored in the body for future use.
• E. The storage form of carbohydrates found in
  tuber, bulbs and roots is starch. Two forms of
  starch are known amylose and amylopectin.
  Carbohydrates in the form of starch are not used
  by the plant because starch is insoluble in
  water. However, plants manufacture the enzyme
  amylase which breaks starch down into soluble
  sugars for use by the plant. Amylase is an enzyme
  important in germination because it breaks down
  the starch present in seed to provide energy for
  the growing seedling. Starch is easily digested
  by animals and an important source of energy.

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Why do organisms need lipids to survive?

• Lipids are important chemical molecules that are
  present in living organisms. Lipids are a fatty
  compound made up of carbon, hydrogen, and oxygen.
  They do not dissolve in water and thus are
  referred to as hydrophobic.
• A. Lipids are used for storage of energy, to add
  flavor to food, for a healthy skin and hair, for
  the nervous system, and for a variety of chemical
  processes. Lipids can be added to animal feeds
  helping to improve flavor, palatability, texture,
  and energy levels. Lipids are also needed to
  carry and store fat soluble vitamins. Fat soluble
  vitamins include vitamins A, D, E, and K.

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• B. The three primary types of lipids include
  triglyceride, wax, and steroid.
• 1. Triglyercides are made up of three fatty acid
  molecules and one glycerol molecule. Examples of
  triglycerides include oils and fats.
• a. Oils are triglycerides that are liquid at room
  temperature and are typically found in the seeds
  of plants.
• b. Fats are solid at room temperature and are
  found in animals.
• 2. Wax is a lipid consisting of a long fatty acid
  joined to a long alcohol chain. Because waxes are
  highly waterproof, they are found in the waxy
  coating of leaves and in ears.
• 3. Steroids include cholesterol and cortisone and
  are found in hormones, nerve tissue, and plant
  poisons.

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• C. Lipids are created when a molecule of glycerol
  is joined to any number of fatty acids. Examples
  of fatty acids include lauric acid, butyric acid,
  and caproic acid.
• 1. Some fatty acids are made by the body.
  Essential fatty acids are not made in the body
  and must be consumed. Therefore, a no fat diet is
  not acceptable.
• 2. Depending upon how much hydrogen is found in a
  fatty acid determines whether it is saturated or
  polyunsaturated. When the molecule is completely
  full of hydrogen, it is called a saturated fatty
  acid. Saturated fats are solid at room
  temperature and are primarily found in meat and
  coconut.
• 3. Fats that are liquid at room temperature are
  called polyunsaturated fatty acids. They are
  found in fish and in plants.
• 4. Hydrogenation is a process where
  polyunsaturated fats can be made solid at room
  temperature. Whipped topping and margarine are
  examples of foods created through this process.

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• D. Most fats found in plants are deposited in the
  seed. For example, coconut contains 65 crude
  fat, soybeans 1520 crude fat and corn contains
  approximately 59 crude fat. Fats are the most
  concentrated food energy source.
• E. In the United States, fat contributes nearly
  50 of the calories in the average diet. Recent
  studies linking high fat diets with
  cardiovascular disease and elevated cholesterol
  levels in the blood have caused people to cut
  back on their daily consumption of fat. Usually
  this has meant that persons eat less red meat and
  eggs, but it is also necessary to monitor intake
  of saturated fats from plant products as well.

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• F. Most doctors agree that an average person
  should consume about 30 of their daily caloric
  intake as fat and should have their body fat
  percentage be around 20 depending on various
  factors. Fats are an important part of the diet.
• G. Foods containing lipids include margarine,
  butter, chips, plant oils, nuts, meat, eggs,
  cheese, milk, and ice cream.

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Review/Summary

• Why is proper nutrition important for all
  organisms?
• What are the nutrients that organisms need and
  how do they help organisms function?
• Why is water important to the body?
• Why are minerals important to organisms?
• Why are vitamins important to organisms?
• Why do organisms need protein?
• Why are carbohydrates important for organisms?
• Why do organisms need lipids to survive?