EXPECTATIONS
In this self-learning module, you will be able to;
1. describe carbohydrates and its classification (monosaccharides,
disaccharides and polysaccharides);
2. identify foods that contains carbohydrates;
3. appreciate the importance of carbohydrates as one of the bases of the
molecules of life.
LESSON
Carbohydrates are the major source of energy in our body. These are
simple sugar, starch sugar and cellulose. All carbohydrates contain carbon
hydrogen and oxygen.
Carbohydrates are classified as monosaccharide, disaccharide, and
polysaccharide according to the number of monosaccharides linked
together to form a molecule.
Monosaccharide, “mono” means one and saccharides also known as
carbohydrates. They often called simple sugar that cannot be hydrolyzed to
simple sugar. It is white solid at room temperature and very soluble in water.
Glucose (C6H12O6) is the most important of the monosaccharides It is
found in the free state in the plant and animal tissue. It is the major
carbohydrates of the body and it is carried by the bloodstream to all parts of
the body. It is sometimes known as blood sugar because it is most
abundant carbohydrates in the blood found in urine of those who have
diabetes mellitus (sugar diabetes). Some examples include, honey, dried
fruits such as apples, dates and sultanas. Canned fruits such as pineapple,
strawberry and plum, fresh fruits including grapes, apples, pear, kiwi &
banana.
Disaccharides are carbohydrates that yield two monosaccharide
molecules upon hydrolysis. The three disaccharides that are separately
important from the biological point of view are sucrose, lactose, and
maltose. This provides quick source of energy, because they’re only made
up of two sugar molecules, they’re easily broken down by enzymes in your
digestive system into their monosaccharides and then absorbed into their
bloodstream Some examples include, sugar cane and sugar beet, table
sugar, manufactured foods, such as cakes, cookies, and dark chocolate,
sweet root vegetables such as beetroot and carrots.
Sucrose (C12H12O11), glucose + fructose -commonly known as table
sugar in the free state throughout the plant kingdom. Good sources of
sucrose are sugar cane, sugar beets, maple syrup and sorghum.
Lactose (C12H12O11), glucose + galactose-or milk sugar is found in
nature mainly in the milk of mammals. Human milk contains about 6.7%
lactose and cow’s milk contains about 4.5% of the same.
Maltose, glucose + glucose-is found much less commonly in nature
than either sucrose or lactose. It is found in sprouting grains.
Polysaccharides are also called complex carbohydrates and can be
hydrolyzed into many monosaccharide units’, examples, vegetables, fruit,
nuts, cereal bran. Three of the most important polysaccharides are starch,
cellulose and glycogen.
Starch is a polymer of glucose. It is found mainly in the seeds, roots
and tubes of plants. The chief sources of starch are corn, potatoes, rice, and
cassava whose uses are for foods.
Cellulose, like starch, is also a polymer of glucose. It differs from starch
in a way the cyclic glucose unit are linked together to form chains. It is the
chief structural components of plants and woods. Cotton fibers are almost
pure cellulose. After removal of moisture, these fibers consist of about 50%
cellulose. It is also used for making rayon fibers, photographic fil and
cellophane. It is an important source of bulk in the diet.
Glycogen is the reserve carbohydrates of the animal kingdom and it is
often called animal starch. It is formed in the body by polymerization of
glucose and stored, especially, in the liver and muscle tissue. When the
body needs it, glycogen is converted back to glucose, which is ultimately
oxidized to carbon dioxide and water with the release of energy. The energy
is used by the body for maintenance, growth, and other normal functions.
Watch the video in your video lesson 7. Observe the testing of sugar
content among some samples using the Benedict Solutions. What can you
infer? https://www.youtube.com/watch?v=J7glsbXAmdU
Some health-conscious individual is very particular of what we call a
high and low carb (carbohydrate) intake. Do we really need to consider this
low and high carb intake in our health habit? Studies typically describe
carbohydrate intake as a percentage of energy, instead of an amount in
grams. There is no agreed definition of what constitutes low or high-carb
intake – but above 45% of total energy intake is generally considered high,
and below 26% is low (The Conversion Academic Rigor, Journalistic Flair,
September 13, 2018). The low-carb group sometimes gets better results
due to higher protein intake, examples lean meat, vegetable, nuts and
seeds and some fruits. The logical conclusion from these studies is that we
should think more about overall diet rather than single macronutrients, on
the other hand, either diet can outperform the other if you eat less—
groundbreaking, we know
ACTIVITY 1: HOW SWEET ARE YOU?
Sugars are an important source of energy with glucose being the most important for the body.
The brain requires around 130 grams of sugar (glucose) per day to keep functioning. How sweet are
the sugars? Refer to the table below of the relative sweetness of sugars and sugar substitutes based on
fructose =100.
Match column A with its corresponding percentage relative sweetness in Column B.
COLUMN A COLUMN B
1. Fructose a. 58
2. Sucrose b. 100
3. Glucose c. 19
4. Maltose d. 43
5. Lactose e. 9.2
ACTIVITY 2: WHICH DOESN’T BELONG TO THE GROUP?
Direction: Encircle the word that does not belong to the group. Reason out.
Reason
carbohydrates lipids proteins vitamins
glucose maltose galactose fructose
sucrose starch lactose maltose
glycogen starch lactose cellulose
monosaccharides disaccharides polysaccharides carbohydrates
\
ACTIVITY 3: MOLECULES OF LIFE
Fill in the graphic organizer. Choose your answers from the box below.
(Draw the graphic organizer in separate of Paper)
POST TEST
Let us measures how much you have learned from this module. Write the letter and words of the
correct answer in your answer sheet.
1. What carbohydrates are best to include in your eating habit?
A. Candy and white rice B. Sweetened yogurt
C. Fruits and vegetables D. White pasta and sugary breakfast cereals
2.Disaccharides are double sugars. Which one is not a disaccharide?
A. cakes C. dark chocolate
B. cookies D. honey
3. Carbohydrates are found in a wide array of both healthy and unhealthy foods. Which of the
following foods contain greater amount of carbohydrates?
A. apple B. bread C. fruits D. vegetables
4. The simplest building units of a relatively large carbohydrates molecule is,
A. Cellulose B. Disaccharides C. Monosaccharides D. Starch
5. Which does not belong to the group?
A. Cellulose B. Protein C. Starch D. Sugar water
6. What are the components of carbohydrate?
A. carbon
B. carbon and hydrogen
C. carbon and oxygen
D. carbon hydrogen and oxygen
7. Disaccharides are double sugars. Which one is not a disaccharide?
A. galactose B. lactose C. maltose D. sucrose
8. Which of the following serves as animal starch?
A. cellulose B. fructose C. glucose D. glycogen
9. What do you call a process that break down humans’ carbohydrates?
A. hydrolysis B. metabolism C. photosynthesis D. protein synthesis
10. What polysaccharides cannot be digested by human beings?
A. cellulose B. glucose C. starch D. sucrose
