SCIENCE
QUARTER 4 – MODULE 2
(Week 3-4)
Four Categories
of Biomolecules
1
What I Need to Know
Food is one of the basic needs of living organisms. Different types of food give us
different nutrients. For instance, grains provide carbohydrates for energy; egg
gives proteins for growth and repair and so on. These compounds belong to the
four main categories of biomolecules; carbohydrates, proteins, lipids and nucleic
acids.
This module will provide you with information and simple activities that
will help you understand the four main categories of biomolecules.
After going through this module, you are expected to:
1. identify the major categories of biomolecules such as carbohydrates,
lipids, proteins and nucleic acids (S10MT-IVc-d-22)
2. differentiate the biomolecules from each other in terms of their structure
and function;
3. recognize the importance of the four categories of molecules in our body
What I Know
Directions: Read each item carefully. Write only the letter of the correct answer
for each question. Use a separate sheet for your answers.
1. Which is NOT a major source of protein?
2.
3.
4.
5.
6.
7.
A. egg
C. milk
B. fish
D. vegetable
The most abundant monosaccharide in nature is
.
A. glucose
C. maltose
B. lactose
D. sucrose
Cholesterol is a/an
.
A. essential oil
C. steroid
B. saturated fat
D. unsaturated fat
Which has the most lipids?
A. banana
C. cheese
B. champorado
D. olive oil
Which is a polysaccharide?
A. glycogen
C. fructose
B. glucose
D. lactose
DNA is unique among molecules because it can
.
A. replicate itself
B. come apart and reform
C. form multiple polymer complex
D. withstand very high temperatures
These are the major constituent of the plasma membrane.
A. Fats
C. Phospholipids
B. Oils
D. Steroids
2
8. These are produced by the living cells that serve as catalyst in biochemical reactions.
9.
10.
11.
12.
13.
14.
15.
A. amino acids
C. hormones
B. enzymes
D. polypeptide
The monomers that make up proteins are
.
A. amino acids
C. glucose
B. fatty acids
D. nucleotides
These are chemical signaling molecules secreted by the endocrine glands.
A. amino acid
C. hormones
B. enzymes
D. nucleic acid
These are macromolecules that are the key in the continuity of life.
A. Carbohydrates
C. Nucleic acids
B. Lipids
D. Proteins
These are the monomers of nucleic acids.
A. DNA
C. Polynucleotide
B. Nucleotide
D. RNA
Cellulose and starch are examples of
.
A. Disaccharide
C. Oligosaccharide
B. Monosaccharide
D. Polysaccharide
How many amino acids are there?
A. 20
B. 21
C. 22
D. 23
Which polysaccharide is stored in the liver and the muscles?
A. Chitin
B. Cellulose
C. Glycogen
D. Starches
3
Lesson
1
Four Categories of
Biomolecules
What’s In
Directions: Find all the hidden BIOMOLECULE words in the word search puzzle
below. Words can be spelled forward, backward, downward and upward. The
keywords are listed in the pool of words written after the puzzle.
Amino Acid
Carbohydrates
Cellulose
Cholesterol
Deoxyribonucleic acid
Enzyme
Glucose
Hormones
Lipids
Monosaccharide
Nucleic acids
Nucleotides
Phospholipids
Proteins
Steroid
What’s New
Carbohydrates, lipids, proteins and nucleic acids are the four main
categories of biomolecules. These macromolecules are composed of smaller
components called monomers.
4
Activity 1: Biomolecule Building Blocks
Below is a graphic organizer. Write on each column the different building
blocks or monomers of each biomolecules. Choose from the pool of words below.
Amino acids
Fatty acids
CARBOHYDRATES
Glucose
PROTEINS
LIPIDS
Nucleotides
NUCLEIC ACIDS
What is It
Biomolecules are the most essential organic molecules, which are involved in the
maintenance and metabolic processes of living organisms. These non-living molecules are
the actual foot-soldiers of the battle of sustenance of life. They range from small molecules
such as primary and secondary metabolites and hormones to large macromolecules like
proteins, nucleic acids, carbohydrates and lipids.
Carbohydrates
Carbohydrates are an essential part of our diet; grains, fruits, and vegetables
are all natural sources of carbohydrates. Carbohydrates provide energy to the body,
particularly through glucose, a simple sugar. Carbohydrates also have other
important functions in humans, animals, and plants. Carbohydrates can be
represented by the formula (CH2O)n, where n is the number of carbon atoms in the
molecule. In other words, the ratio of carbon to hydrogen to oxygen is 1:2:1 in
carbohydrate molecules. Carbohydrates are classified into three subtypes:
monosaccharides, disaccharides, and polysaccharides.
Monosaccharides are simple sugars,
examples are glucose, which is the most
abundant, galactose (part of lactose, a milk
sugar) and fructose (found in fruit).
Disaccharides form when two
monosaccharides undergo a dehydration
reaction (a reaction in which the removal of
a water molecule occurs). Common
disaccharides include lactose (found in
milk, composed of galactose and glucose),
maltose (malt sugar), and sucrose (table
sugar, composed of glucose and fructose). A
long chain of monosaccharides linked by
5
Figure 1: Glucose, galactose, and fructose have the
same chemical formula but slightly different
structures.
covalent bonds is known as a polysaccharide. Starch, glycogen, cellulose, and chitin
are examples of polysaccharides.
Lipids
Lipids are insoluble biomolecules, defined by an overall lack of polarity
necessary for solubility in water-based solutions. In popular culture, fats are
synonymous with lipids, giving lipids a negative role in diet and health. However, lipids
play vital roles in many cellular processes including energy storage, structural
support, protection, and communication. Common lipid groups include waxes,
steroids, fats and oils, and phospholipids.
Fats and oils are the most abundant lipids and are also called triglycerides.
Triglycerides are lipids that store energy. It is composed of two main components –
glycerol and fatty acids. Fatty acids can be saturated or unsaturated.
Saturated
fats have
Figure 2: Structure of Saturated and
straight carbon chains because they only
Unsaturated Fatty Acid
contain
single
carbon-carbon bonds.
Saturated fats pack together closely and are
solid at room temperature. Saturated fats are
typically found in animal products. Butter is
a good example.
Unsaturated fats have a kink in their
chain caused by a double bond or even a
triple bond between carbons. Because of
these kinks, unsaturated fats can't pack
together very closely, making them liquid at
room temperature. They are typically found
in plant products. Vegetable oil is a good
example. The hydrocarbon chains of both
Source:
saturated and unsaturated fats are attached
https://dlc.dcccd.edu/biolo
gy1-3/lipids
to a carboxylic acid functional group. This is
what makes them fatty acids.
Phospholipids are the major constituent of the plasma membrane. It protects
the cell by providing a selective barrier that regulates movement of molecules between
the inside and outside of the cell
A phospholipid has both hydrophobic and hydrophilic regions. The fatty acid
chains are hydrophobic and exclude themselves from water, whereas the phosphate
is hydrophilic and interacts with water.
Cells are surrounded by a membrane, which has a bilayer of phospholipids. The
fatty acids of phospholipids face inside, away from water, whereas the phosphate
group can face either the outside environment or the inside of the cell, which are both
aqueous.
Unlike the phospholipids and fats discussed earlier, steroids have a ring
structure. Although they do not resemble other lipids, they are grouped with them
because they are also hydrophobic. All steroids have four, linked carbon rings and
several of them, like cholesterol, have a short tail.
Cholesterol is a steroid. Cholesterol is mainly synthesized in the liver and is
the precursor of many steroid hormones, such as testosterone and estradiol. It is also
the precursor of vitamins E and K. Cholesterol is the precursor of bile salts, which
help in the breakdown of fats and their subsequent absorption by cells. Although
cholesterol is often spoken of in negative terms, it is necessary for the proper
6
functioning of the body. It is a key component of the plasma membranes of animal
cells.
Waxes are made up of a hydrocarbon chain with an alcohol (–OH) group and a
fatty acid. Examples of animal waxes include beeswax and lanolin. Plants also have
waxes, such as the coating on their leaves, that helps prevent them from drying out.
Proteins
Proteins are one of the most abundant organic molecules in living systems and
have the most diverse range of functions of all macromolecules. Proteins may be
structural, regulatory, contractile, or protective; they may serve in transport, storage,
or membranes; or they may be toxins or enzymes.
The functions of proteins are very diverse because there are 20 different
chemically distinct amino acids that form long chains, and the amino acids can be in
any order. For example, proteins can function as enzymes or hormones. Enzymes,
which are produced by living cells, are catalysts in biochemical reactions (like
digestion) and are usually proteins. Enzymes can function to break molecular bonds,
to rearrange bonds, or to form new bonds. An example of an enzyme is salivary
amylase, which breaks down amylose, a component of starch.
Hormones are chemical signaling molecules,
usually proteins or steroids, secreted by an
endocrine gland or group of endocrine cells that act
to control or regulate specific physiological
processes,
including
growth,
development,
metabolism, and reproduction. For example, insulin
is a protein hormone that maintains blood glucose
levels.
Proteins have different shapes and molecular
weights; some proteins are globular in shape
whereas others are fibrous in nature. For example,
hemoglobin is a globular protein, but collagen,
found in our skin, is a fibrous protein. Protein shape
is critical to its function. Changes in temperature,
pH, and exposure to chemicals may lead to
permanent changes in the shape of the protein,
leading to a loss of function or denaturation. All
proteins are made up of different arrangements of
the same 20 kinds of amino acids.
Amino acids are the monomers that make
up proteins. Each amino acid has the same
Figure 3: Amino acids are
fundamental structure, which consists of a central
carbon atom bonded to an amino group (–NH2), a
made up of a central carbon
carboxyl group (–COOH), and a hydrogen atom.
bonded to an amino group (–
Every amino acid also has another variable atom or
NH2), a carboxyl group (–
group of atoms bonded to the central carbon atom
COOH), and a hydrogen atom.
known as the R group. The R group is the only
The central carbon’s fourth
difference in structure between the 20 amino acids;
bond
varies
among
the
otherwise, the amino acids are identical.
different amino acids.
The sequence and number of amino acids
ultimately
determine a protein’s shape, size, and
Source:
function.
Each
amino acid is attached to another
https://opentextbc.ca/biology
amino acid by a covalent bond, known as a peptide
/chapter/2-3-biologicalbond. The products formed by such a linkage are
molecules/
called polypeptides.
7
Nucleic Acids
Nucleic acids are key macromolecules in the continuity of life. They carry the
genetic blueprint of a cell and carry instructions for the functioning of the cell.The two
main types of nucleic acids are deoxyribonucleic acid (DNA) and ribonucleic acid
(RNA). DNA is the genetic material found in all living organisms, ranging from singlecelled bacteria to multicellular mammals.
The other type of nucleic acid, RNA, is mostly involved in protein synthesis. The
DNA molecules never leave the nucleus, but instead use an RNA intermediary to
communicate with the rest of the cell. Other types of RNA are also involved in protein
synthesis and its regulation.
DNA and RNA are made up of monomers known as nucleotides. Each
nucleotide is made up of three components: a nitrogenous base, a pentose (fivecarbon) sugar, and a phosphate group. Each nitrogenous base in a nucleotide is
attached to a sugar molecule, which is attached to a phosphate group.
DNA has a double-helix structure. It contains
the sugar deoxyribose. It is composed of
nitrogenous bases adenine (A), thymine (T),
cytosine (C) and guanine (G). These
nitrogenous bases pair together and follows a
rule: cytosine pairs with guanine while
adenine pairs with thymine. These base pairs
are held together by hydrogen bonds.
https://www.thesciencehive.co.uk/nucleotidesand-nucleic-acids
RNA, on the other hand has a single-helix
structure. The sugar that forms its backbone
is called ribose. The nitrogenous bases for
RNA are adenine, guanine, cytosine and
uracil. As for the base pairing, cytosine (C)
pairs with guanine (G) and adenine (A) pairs
with uracil (U)
What’s More
Activity 1. CARBS
Identification. For each molecule below, determine if it is a monosaccharide,
a disaccharide, or a polysaccharide. Write your answer on the space provided
for every item.
1.
2.
3.
4.
5.
Fructose
Cellulose
Glucose
Sucrose
Glycogen
_________________
_________________
_________________
_________________
_________________
6.
7.
8.
9.
10.
8
Starch
Maltose
Lactose
Chitin
Ribose
___________________
___________________
___________________
___________________
___________________
Assessment 1
Directions: Read each item carefully. Write only the letter of the correct answer
for each question. Use a separate sheet for your answers.
1. Carbohydrates are organic compounds made up of
2.
3.
4.
5.
A. Carbon and hydrogen
B. Carbon, hydrogen and oxygen
C. Carbon, hydrogen, oxygen and sulfur
D. Carbon, hydrogen, oxygen and nitrogen
The most common monomer of carbohydrate is __________.
A. amino acid
B. glucose
C. lactose
D. nucleotide
All of the following are polysaccharides EXCEPT
A. cellulose
B. glucose
C. glycogen
D. starch
Which is the simplest form of carbohydrates?
A. Disaccharide
C. Oligosaccharide
B. Monosaccharide
D. Polysaccharide
Which is a correct pair?
A. disaccharide: fructose
C. polysaccharide: cellulose
B. monosaccharide: sucrose
D. polysaccharide: glucose
Activity 2. FACT OR BLUFF ON LIPIDS
Directions: Write FACT if the statement is correct and BLUFF if the
statement is wrong on the space/column provided for every item.
No.
1
2
Statements
Fact or Bluff
Lipids are insoluble molecules.
3
Lipids are important in providing
energy aside from carbohydrates.
Butter is an example of unsaturated fats.
4
Fats and oils are the most abundant lipids.
5
Waxes are the major component of the
plasma membrane.
All saturated hydrocarbons contain single
bonds and they are produce only by
animals.
Unsaturated hydrocarbons contain one or
more double bonds.
Vegetable oil, corn oil, and olive oil are
produced by plants.
Cholesterol is a precursor of vitamins A
and K.
Unsaturated fats are solid at room
temperature.
6
7
8
9
10
9
Assessment 2
1. Fats and oils are also known as _______?
A. Peptides
B. Polymers
C. Polypeptides
D. Triglycerides
2. Which of these are not lipids?
A. Fats
B. Oils
C. Proteins
D. Waxes
3. Lipids are insoluble in water because lipid molecules are ____________.
A. hydrophilic
B. hydrophobic
C. neutral
D. polar
4. What is the molecular formula for cholesterol?
A. C37H45OH
B. C27H45OH
C. C25H47OH
D. C25H45OH
5. What is the reason why trans fats are harmful to our health? Trans
fats___________.
A. make the blood viscous.
B. contain harmful artificial preservatives.
C. have been altered chemically which make it dangerous.
D. have a long shelf life and stay in the bloodstream longer than other
lipids
Activity 3. WORD PUZZLE ON PROTEIN
Word Scramble. Unscramble the letters to find the PROTEIN words from the
list below.
1. MEENZY - a protein that acts as a biological catalyst
2. OMAIN DICAS – building blocks of protein
3. DIONTATURAEN – the alteration of a protein
4. LEPTIPODEYP – long chains of amino acids
5. ALAMYSE – an enzyme that breaks down starch
6. GEG – food rich in protein
7. SOROMNEH – chemical signaling molecules
8. NEGOLLCA – a fibrous protein
9. NUSILIN – a hormone that maintains blood glucose levels
10. TIPDEEP DONB – a bond that holds the amino acids together.
Assessment 3
Modified True or False. Write T if the statement is true. If the statement is
false, change the underlined word or phrase to make the statement true.
Write the correct word on the blank.
____________1. Proteins are made up of carbon, hydrogen, oxygen, nitrogen
and sulfur.
____________2. There are 22 amino acids found in human protein.
____________3. Amino acid is the building block of protein.
____________4. Amino acids are joined together by a hydrogen bond.
____________5. Collagen is a globular protein.
10
Activity 4. DNA and RNA
Analogy. Complete the following.
1. DNA: deoxyribose; RNA: _______________
2. Adenine: thymine; _______________: guanine
3. DNA: _______________; RNA: cytoplasm
4. RNA: single stranded; DNA: _______________
5. Thymine: DNA; _______________: RNA
6. _______________: nucleic acid; amino acid: protein
7. DNA: _______________; RNA: ribonucleic acid
8. nitrogenous bases: _______________; amino acids: peptide bond
9. _______________: hereditary traits; carbohydrates: energy
10. DNA; adenine, thymine, cytosine and guanine; _______________: adenine,
uracil, cytosine and guanine
What I Have Learned
Great job! You are almost done with this module. Let’s summarize what you have
learned from the lesson and activities by filling in the blanks. Use a separate sheet
of paper and write only your answer.
Biomolecules are substances that are produced by cells and living organisms.
It consists of four major types: carbohydrates, lipids, proteins and nucleic acids.
Carbohydrates provide energy to the body and is classified into three
subtypes 1)
,2)
and 3)
.
Lipids are hydrophobic or non-soluble in water because they are non-polar
molecules. They are the building blocks of many hormones and are important
constituent of the plasma membrane. Lipids include 4)
, 5)
, 6)
and 7)
. Proteins are one of the most
abundant organic molecules in living systems and have the most diverse range of
functions of all macromolecules. 8)
are monomers that make up protein.
The functions of proteins are very diverse because there are 20 different chemically
distinct amino acids that form long chains, and the amino acids can be in any order.
For example, proteins can function as 9)
or 10)
. Nucleic acids
are key macromolecules in the continuity of life. They carry the genetic blueprint
of a cell and carry instructions for the functioning of the cell. The two main types of
nucleic acids are 11)
and 12)
.
11
What I Can Do
At this point, you are going to complete the table below by filling in the
necessary information.
Biomolecule
Monomer
Function
Elements
Structure
Carbohydrates
Lipids
Proteins
Nucleic Acids
Assessment
Directions: Read each item carefully. Use a separate sheet for your answers. Write
only the letter of the correct answer for each question.
1. Fats and oils are known as
.
A. Peptides
C. Polypeptides
B. Polymers
D. Triglyceride
2. What kind of polysaccharide is that which cannot be digested by human beings?
A. Cellulose
C. Starch
B. Glycogen
D. Sucrose
3. What is the function of carbohydrates?
A. energy storage
C. information storage
B. digestion of foods
D. building muscles and cells
4. These are made up of a hydrocarbon chain with an alcohol (–OH) group and a
fatty acid.
A. Fats and oils
C. Steroids
B. Phospholipids
D. Waxes
12
5. The following statements about Cholesterol are true EXCEPT.
A. It is a phospholipid
B. It is the precursor of vitamins E and K.
C. It is mainly synthesized in the liver and is the precursor of many hormones
D. All of the above
6. These are macromolecules that are the key in the continuity of life.
A. Carbohydrates
C. Nucleic acids
B. Lipids
D. Proteins
7. These are the monomers of nucleic acids.
A. DNA
C. Polynucleotide
B. Nucleotide
D. RNA
8. Cellulose and starch are examples of
.
A. Disaccharide
C. Oligosaccharide
B. Monosaccharide
D. Polysaccharide
9. How many amino acids are there?
A. 20
B. 21
C. 22
D. 23
10. Which polysaccharide is stored in the liver and the muscles?
A. Cellulose
C. Glycogen
B. Chitin
D. Starches
11. Which is NOT a major source of protein?
A. egg
C. milk
B. fish
D. vegetable
12. The most abundant monosaccharide in nature is
.
A. glucose
C. maltose
B. lactose
D. sucrose
13. Cholesterol is a/an
.
A. essential oil
C. steroid
B. saturated fat
D. unsaturated fat
14. Which has the most lipids?
A. banana
C. cheese
B. champorado
D. olive oil
15. Which is a polysaccharide?
A. glucose
C. fructose
B. glycogen
D. lactose
13
Additional Activities
Additional Activity 1: Concept Map on Biomolecules
Directions: Complete the concept map below.
Answer Key
1. D
2. A
3. C
4. D
5. A
6. A
7. C
8. B
9. A
10. C
11. C
12. B
13. D
14. A
15. C
What I Know
What’s In
References
Printed Materials:
Acosta, H., L. Alvarez, D. Angeles, R. Arre, MP. Carmona, A. Garcia, A. Gatpo, et al. Science - Grade
10 Learner's Material. Pasig City, Philippines: Rex Bookstore, Inc. and Department of
Education, 2015.
Acosta, H., L. Alvarez, D. Angeles, R. Arre, MP. Carmona, A. Garcia, A. Gatpo, et al. Science - Grade
10 Science Teacher's Guide. Pasig City, Philippines: Rex Bookstore, Inc. and Department of
Education, 2015.
Electronic Sources:
https://opentextbc.ca/biology/chapter/2-3-biological-molecules/
https://dlc.dcccd.edu/biology13/proteins#:~:text=Proteins%20are%20the%20most%20diverse,protect%20and%20maintain%20cell
%20shape.
https://chem.libretexts.org/Bookshelves/Organic_Chemistry/Map%3A_Organic_Chemistry_(McMurr
y)/27%3A_Biomolecules_-_Lipids
https://courses.lumenlearning.com/microbiology/chapter/carbohydrates/#:~:text=Carbohydrates%2
C%20the%20most%20abundant%20biomolecules,chemically%20linked%20by%20glycosidic%20bond
s.
SCIENCE 10 LEARNING ACTIVITY SHEET
MODULE 2: FOUR CATEGORIES OF BIOMOLECULES
Name:
Grade & Section:
Date:
Score:
Most Essential Learning Competency: Recognize the major categories of
biomolecules such as carbohydrates, lipids, proteins, and nucleic acids.
Part 1. Analogy. Answer the following correctly.
1. Vegetable oil: lipid; table sugar: __________________
2. Glucose: monosaccharide; starch: __________________
3. __________________: fructose; dextrose: glucose
4. Grapes: __________________; malungay: polysaccharide
5. Galactose and glucose: __________________; glucose and fructose: Sucrose
6. Apple: __________________: milk: lactose
7. Monosaccharide: simple sugar: polysaccharide: __________________
8. Table sugar: sucrose: __________________: fructose
9. __________________: high glucose; glucagon: low glucose
10. Glycogen: liver and muscles; __________________: adipose tissues
Part 2. Fill in the Blanks. Complete the statements below. Choose your answers
from the box below.
1. Lipids are _____________ in water.
2. Fats and oils are also known as _____________.
3. The presence of double bonds in the fatty acids lowers its _____________.
4. Fatty acids are insoluble in water but soluble in _____________ solvents.
5. Cholesterol is a kind of _____________.
6. _____________ is made from vegetable oils that are liquid at room temperature.
7. Garlic in dietary preparations lowers _____________.
8. _____________ is essential for cholesterol absorption.
9. Physical exercise_________ the serum cholesterol level.
10. Saturated fatty acids tend to have _____________ melting points than
unsaturated fatty acids.
Choices:
nonpolar
margarine
steroid
Cholesterol
melting point
bile
Insoluble
higher
triglyceride
Lowers
Part 3. Matching Type: Match column A with column B. Write the letter only on
the space provided.
A
B
____1. Good source of protein
A. arginine
____2. They are synthesized by the body
B. amino acid
____3. The biological catalysts
C. beans
____4. Breaks down lactose into
D. enzymes
glucose and galactose
E. lactase
____5. Building blocks of protein
F. lysine
____6. Conditional amino acid
G. nonessential amino acids
____7. Essential amino acid
H. pentose
____8. Sequence of a chain of amino acid
I. polymers
____9. Act as emulsifying agent
J. primary protein structure
____10. Consist of monomers
K. protein
Part 4. Fill in the comparison table.
Basis of Comparison
DNA
1. Number of strands
2. Location in the cell
3. Type of sugar
4. Nitrogenous bases
5. Pairing of bases
RNA