Unit C Lesson 3: Essential Substances in the Environment
Completion requirements
Unit C Lesson 3: Essential Substances in the Environment |
Learning Targets |
Big Question: What common substances are essential for life?
Even though there are millions of different combinations of elements in the universe, a certain group of chemicals are necessary for life.
Even though there are millions of different combinations of elements in the universe, a certain group of chemicals are necessary for life.
At the end of this inquiry, you should be able to answer the following questions:
- What are micronutrients and macronutrient?
- Why is having optimum amounts of nutrients in our diet important?
- Why are carbohydrates important?
- Why are lipids important?
- Why are proteins important?
- What is the role of nucleic acids?
- How can indicators be used to test for the presence of various organic molecules?
Pages 196 to 199 as well as 202 and 203 in your textbook will help you answer these questions about essential substances in the environment.
Introduction
Scurvy is a disease that results in bleeding gums, rotting teeth, and ultimately death. It was very common among sailors in the past, especially on long voyages across oceans. Scurvy is now very rare because of the discovery that Vitamin C prevents
and cures scurvy. Eating fresh fruit and vegetables in the key to avoiding and treating the disease.
Rickets is a disease that can appear in young children. Children with rickets will develop bowed legs and frequently suffer from bone fractures. Rickets occurs when vitamin D or calcium levels are low in the growing child.
Vitamin A, most commonly found in carrots and liver, is a substance prevents night blindness (the ability to see in dim light). Complete blindness can occur if you do not have adequate vitamin A in your diet.
In this section, you will learn about these and many other important elements and compounds essential to living things.
Rickets is a disease that can appear in young children. Children with rickets will develop bowed legs and frequently suffer from bone fractures. Rickets occurs when vitamin D or calcium levels are low in the growing child.
Vitamin A, most commonly found in carrots and liver, is a substance prevents night blindness (the ability to see in dim light). Complete blindness can occur if you do not have adequate vitamin A in your diet.
In this section, you will learn about these and many other important elements and compounds essential to living things.
What are Macronutrients and Micronutrients?
Many chemical compounds make up the food that organisms require. Nutrients are elements and compounds that organisms need for living.
Many chemical compounds make up the food that organisms require. Nutrients are elements and compounds that organisms need for living.
Macronutrients are nutrients that organisms require in large amounts. These include fats, carbohydrates , water, and proteins that most creatures need for survival. Macronutrients are responsible for everyday functions of the body, such
as building and repairing tissue, generating energy and heat, regulating hormones, and maintaining normal brain and nerve functions.
Salt, magnesium, calcium, and potassium are also required in large amounts. These are also classified as macronutrients but can be referred to as macrominerals as well. These minerals help ensure healthy teeth, bones, and muscle. They balance the body's fluids. See page 197 in the Science in Action 9 text for a list of the functions of several macronutrients. Notice how plants make use of the six nutrients on the chart compared to how humans use them. Are there similarities?
Micronutrients are compounds that are needed in only minor or trace amounts (less than 100 mg/day). Micronutrients required by humans include 13 vitamins (which are organic) and 12 minerals (which are inorganic) . These include Vitamins
A, B1, B2, B3, B5, B6, B7, B9, B12, C, D, E, and K as well as the minerals potassium, sodium, calcium, phosphorus, chloride, zinc, copper, magnesium, iodine, manganese, molybdenum, and selenium.
Each nutrient (whether it is a micronutrient or macronutrient) must be taken into cells in the correct amounts for life to flourish. Too little or too much of a substance can cause problems with the processes it is involved in. Either way, the organism will be harmed. To make up for missing nutrients in food, humans often take daily supplements of vitamins and minerals.
The optimum amount of each vitamin and mineral provides an organism with the best possible health.
Each nutrient (whether it is a micronutrient or macronutrient) must be taken into cells in the correct amounts for life to flourish. Too little or too much of a substance can cause problems with the processes it is involved in. Either way, the organism will be harmed. To make up for missing nutrients in food, humans often take daily supplements of vitamins and minerals.
The optimum amount of each vitamin and mineral provides an organism with the best possible health.
Watch
Watch the following video carefully, it provides and excellent overview of the nutrients necessary for living things.
What are Organic and Inorganic Substances?
Two types of compounds or elements are found in nature: organic and inorganic.
Two types of compounds or elements are found in nature: organic and inorganic.
Our body needs about 25 various chemicals for normal growth. The complex organization of these chemicals produces organic compounds.
Inorganic compounds comprised of materials that are not biological or carbon-hydrogen based. Examples of inorganic substances are
- ammonia (NH3)
- carbon dioxide (CO2)
- hydrogen peroxide (H2O2)
- oxygen gas (O2)
- salt (NaCl)
- minerals such as magnesium (Mg) and calcium (Ca)
Carbon dioxide, CO2, is considered an inorganic compound although it contains carbon. CO2 was never alive and is not carbon-hydrogen based. When you are determining whether a carbon compound is organic, look to see whether it contains hydrogen in addition to carbon.
Figure 1 – Methanol, CH3OH, is an organic molecule, while carbon dioxide (CO2) is inorganic. Salt (NaCl) is an inorganic substance. Sugar (C6H12O6) is an organic substance.
Organic Molecules
There are four main types of organic molecules that are essential to life:
There are four main types of organic molecules that are essential to life:
- carbohydrates
- lipids
- proteins
- nucleic acids
Determining the composition of foods
How do we test for various components in foods? See the chart on page 200 in Science in Action 9 for a quick snapshot identifying how this can be done. This section describes and demonstrates each of the tests.
How do we test for various components in foods? See the chart on page 200 in Science in Action 9 for a quick snapshot identifying how this can be done. This section describes and demonstrates each of the tests.
Carbohydrates
Carbohydrates are organic molecules made of carbon, hydrogen, and oxygen. Your body uses carbohydrates, also called carbs, to make glucose, which is the fuel that gives you energy. Your body can use glucose immediately or store it in your liver and muscles for later use.
Carbohydrates are two main types:
Carbohydrates are organic molecules made of carbon, hydrogen, and oxygen. Your body uses carbohydrates, also called carbs, to make glucose, which is the fuel that gives you energy. Your body can use glucose immediately or store it in your liver and muscles for later use.
Carbohydrates are two main types:
- Simple carbohydrates such as fructose and glucose. Glucose is the simple sugar made by green plants when they undergo photosynthesis.
- Complex carbohydrates are composed of many glucose molecules joined together. Examples of some complex carbohydrates are cellulose, starch, and glycogen. Complex carbohydrates take the body longer to digest because they must be broken
down in the intestines to produce glucose.
Fruits and
Vegetables
Vegetables
Bread, cereals, and other
grains
grains
Milk and Milk Products
Foods containing added sugars (cakes, cookies, and beverages)
Determining the composition of foods: Carbohydrates
Testing for Starch (a type of carbohydrate)
Positive result for starch:
When iodine (which is reddish-brown) is added to a solution that contains starch, the solution changes to a blue-black colour.
Negative result for starch:
If no starch is present, the solution turns reddish-brown, indicating that iodine is in the solution and no reaction has occurred.
When iodine (which is reddish-brown) is added to a solution that contains starch, the solution changes to a blue-black colour.
Negative result for starch:
If no starch is present, the solution turns reddish-brown, indicating that iodine is in the solution and no reaction has occurred.
Watch
To see the test that determines if certain foods (apples and potatoes), contain starch, watch the "Starch Test".
Testing for
Glucose
or Sugar (a type of carbohydrate)
Positive result for sugar
If Benedict’s solution (which is blue) is added to a solution that contains glucose and then heated, a colour change occurs. (Note: Because heat is required, it is an endothermic reaction.) If the resulting solution is yellow-orange or red, sugar is present. (Note: The closer the colour is to red, the more sugar is present.)
Negative result for sugar
If there is no sugar present, the solution may turn mauve or blue, indicating that Benedict’s solution is present but no reaction has occurred.
If Benedict’s solution (which is blue) is added to a solution that contains glucose and then heated, a colour change occurs. (Note: Because heat is required, it is an endothermic reaction.) If the resulting solution is yellow-orange or red, sugar is present. (Note: The closer the colour is to red, the more sugar is present.)
Negative result for sugar
If there is no sugar present, the solution may turn mauve or blue, indicating that Benedict’s solution is present but no reaction has occurred.
Watch
To see the test that determines if certain foods (bread, nuts, and grape juice), contains sugar, watch the "Benedict's Test for Reducing Sugars".
Interactive
Carbohydrates
- The BrainPOP video, "Carbohydrates", describes and reinforces the differences between simple and complex carbohydrates.
Click here
to watch the video.
You will need a username and password to access the video.
- Username: 0099
- Password: students
- Click here to complete the BrainPOP quiz on Carbohydrates. Remember to check your answers at the end!
Lipids
Fats, oils, and waxes belong to the group of naturally occurring organic materials called lipids. Lipids are organic molecules that are made of long chains of hydrogen, oxygen, and carbon atoms. Because lipid molecules are composed primarily of carbon and hydrogen, they are unable to dissolve in water.
Lipids are produced in both plants and animals. Lipids are used for energy storage and are required to make the cell membrane for every cell in the body. They are used to cushion and protect the heart, kidneys, and liver. Lipids are necessary to maintain healthy hair and skin, the proper functioning of the nervous system, and the absorption of vitamins A, D, E, and K.
Figure 2 – Oleic acid is the main fatty acid component of both olive oil and human body fat.
Determining the composition of foods: Lipids
Lipids: Testing for Lipids (Fats)
As we all know from experience, lipids leave translucent spots (grease spots) on clothing as well as paper.
As we all know from experience, lipids leave translucent spots (grease spots) on clothing as well as paper.
Positive test for lipids
A couple of drops of solution are placed on a piece of paper. Fifteen minutes later, after the paper has a chance to dry, hold the paper to a light. If you see a translucent spot, the solution contained lipids.
Negative test for lipids
A couple of drops of solution are placed on a piece of paper. Fifteen minutes later, after the paper has a chance to dry, hold the paper to a light. If there is no translucent spot, the solution does not contain lipids.
A couple of drops of solution are placed on a piece of paper. Fifteen minutes later, after the paper has a chance to dry, hold the paper to a light. If you see a translucent spot, the solution contained lipids.
Negative test for lipids
A couple of drops of solution are placed on a piece of paper. Fifteen minutes later, after the paper has a chance to dry, hold the paper to a light. If there is no translucent spot, the solution does not contain lipids.
Watch
To see the test that determines if certain foods (bread, nuts and grape juice, contains lipids, watch the "Test for Fats".
Interactive
Fats
- Watch the BrainPOP video to learn more about the importance of fats.
Click here
to watch "Fats".
You will need a username and password to access the video.
- Username: 0099
- Password: students
-
Click here
to complete the BrainPOP quiz on Fats. Remember to check your answers at the end!
Proteins and Amino Acids
A protein is an organic molecule made from combinations of different types of amino acids.
There are 20 different essential amino acids. Protein molecules consist of about 50 to more than 3 000 amino acid molecules linked together. When proteins are digested, they are broken down into individual amino acids. Plants produce all 20 types of amino acids. Animals cannot manufacture all the amino acids they require and must obtain the remainder from their food. Animals must eat protein to obtain the amino acids that they need to stay healthy.
Alanine is a type of amino acid molecule. Alanine helps the body to convert glucose into energy.
Figure 3 – Proteins are made up of CHON (carbon, hydrogen oxygen, and nitrogen).
Proteins do everything from building your body’s structure to controlling chemical reactions. They form the core of the endocrine and immune systems. Hormones in the endocrine system control many of the body’s functions such as maintaining
a constant temperature. They transport molecules and small ions throughout the body.
Building muscles is often associated with proteins ; however, proteins are also required to build bones, cartilage, nails, hair, and skin.
An enzyme is a type of protein that speeds up chemical reactions in the body. An enzyme is a type of catalyst. The last three letters in any enzyme name are “ase”. For example, lactase is the enzyme that breaks down lactose (a type of carbohydrate) in the digestive system. Proteins are also the building blocks in living matter, but they can be broken down for energy when needed.
Building muscles is often associated with proteins ; however, proteins are also required to build bones, cartilage, nails, hair, and skin.
An enzyme is a type of protein that speeds up chemical reactions in the body. An enzyme is a type of catalyst. The last three letters in any enzyme name are “ase”. For example, lactase is the enzyme that breaks down lactose (a type of carbohydrate) in the digestive system. Proteins are also the building blocks in living matter, but they can be broken down for energy when needed.
Determining the composition of foods: Proteins
Testing for Proteins
Positive result for protein
When a Biuret solution [a blue solution made from sodium hydroxide, NaOH, and copper(II) sulfate, CuSO4] is added to a solution that contains protein, the solution changes to a mauve colour.
Negative result for starch
If there is no protein present, the colour of the solution may only change slightly and the mauve colour will not form.
When a Biuret solution [a blue solution made from sodium hydroxide, NaOH, and copper(II) sulfate, CuSO4] is added to a solution that contains protein, the solution changes to a mauve colour.
Negative result for starch
If there is no protein present, the colour of the solution may only change slightly and the mauve colour will not form.
Watch
To see the test that determines if certain foods (bread, nuts, and grape juice), contains protein watch the "Biuret Test for Proteins".
Which substance contained the most protein? How do you know?
The nuts contained the most protein because the mauve colour was most intense in the test tube containing the nuts.
Nucleic acids
Nucleic acids are the blueprint for your body. They are the largest and most complicated molecules in organisms. Nucleic acids use chemical codes to store all the instructions for your body’s function and growth.
Each living organism has its own unique set of DNA and RNA. DNA and RNA are types of nucleic acids. DNA has two strands of genetic information whereas RNA has one strand of genetic information. To make a protein, a cell has to follow a set of instructions from the DNA. The RNA is used to deliver and interpret the DNA codes for the cell.
If you would like to review DNA covered in Biological Diversity (Unit A, Lesson 12), click here
Nucleic acids are the blueprint for your body. They are the largest and most complicated molecules in organisms. Nucleic acids use chemical codes to store all the instructions for your body’s function and growth.
Each living organism has its own unique set of DNA and RNA. DNA and RNA are types of nucleic acids. DNA has two strands of genetic information whereas RNA has one strand of genetic information. To make a protein, a cell has to follow a set of instructions from the DNA. The RNA is used to deliver and interpret the DNA codes for the cell.
If you would like to review DNA covered in Biological Diversity (Unit A, Lesson 12), click here
Interactive
RNA
- Watch the BrainPOP video to learn more about the importance of nucleic acids.
Click here
to watch "RNA".
You will need a username and password to access the video.
- Username: 0099
- Password: students
- Explore some of the other interactive activities on the page when you have finished watching the video.