Biological Macromolecules
At the end of the
lesson, you should be
able to:
1. Distinguish between
carbohydrates,
proteins, lipids, and
nucleic acids.
2. Summarize the
general characteristics
of each biomolecule
List of important terms:
• a. Carbohydrate • i. Glycerol
• b. Saccharides • j. Fatty acid
• c. Glycosidic bond • k. Phospholipids
• d. Proteins • l. Steroids
• e. Amino acid
• m. Nucleic acid
• f. Peptide bond
• n. Nucleotides
• g. Lipids
• h. Triglyceride • o. Alcohol
• p. Amine
Carbohydrates
• What elements do you see in the structure/
formula?
• What do you notice with the chemical formula
of glucose?
• The molecular formula for glucose is C6H12O6 or
H-(C=O)-(CHOH)5-H.
• Its empirical or simplest formula is CH2O, which
indicates there are two hydrogen atoms for each
carbon and oxygen atom in the molecule.
Carbohydrates
• The word carbohydrate may
be broken down to carbon and
hydrate.
• Has the ratio of C:H:O is 1:2:1.
• Another term for carbohydrate
is saccharide. This term is
derived from the Latin word
saccharum referring to sugar--
a common carbohydrate.
• the primary energy source of
the human body.
Classifications of Carbohydrates:
1. Monosaccharide
(one saccharide)
• Glucose Used in
dextrose, blood sugar;
the form utilized by the
human body
1. Monosaccharide
(one saccharide)
•Galactose Found in milk
and milk products
1. Monosaccharide
(one saccharide)
•Fructose
Found in
fruits and
honey
2. Disaccharide
(two saccharides)
• Maltose
• Glucose + Glucose
• Found in malt
2. Disaccharide
(two saccharides)
• Sucrose
• Glucose + Fructose
• Found in regular
table sugar,
sugarcane, and
sugar beet
2. Disaccharide
(two saccharides)
• Lactose
• Glucose + Galactose
• Found in milk and
milk products
Classifications of Carbohydrates:
3. Polysaccharide (many saccharides)
• Starch / Amylose - Storage form of glucose in plants.
• Amylopectin - Storage form of glucose in plants.
• Glycogen - Storage form of glucose in animals, stored
in the liver and muscles.
• Cellulose - Structural material in plants-cell wall in
wood, wood fiber Cannot be digested by humans.
Protein
• came from the Greek term proteios
meaning first.
• composed of four elements,
namely, carbon, hydrogen, oxygen
and nitrogen.
• Sulfur and other metals are
sometimes also found in proteins.
• are also called polypeptides.
Examples of proteins and their structure and
functions are:
1. Keratin
• is a structural protein found
in hair, skin, and nails. It is a
highly cross-linked protein
containing α-helix and β-
pleated sheets. Sheep’s
wool is made largely of
keratin.
Examples of proteins and their
structure and functions are:
2. Fibroin / Silk protein
• Fibroin is found in silk. Silk
has a smooth and soft
texture.
• It is one of the strongest
natural fibers that have high
resistance to deformation. It
is also a good insulation.
Examples of proteins and their structure and
functions are:
3. Collagen
• Collagen is a major insoluble fibrous protein found in
connective tissues such as tendons, ligaments, skin,
cartilage and the cornea of the eye. It comprises as much
as 30% of proteins in animals.
Examples of proteins and their structure and
functions are:
3. Myoglobin
• Myoglobin is a
polypeptide that
stores oxygen in
muscles.
Examples of proteins and their structure and
functions are:
4. Hemoglobin
• Hemoglobin is a globular protein that carries oxygen from
the lungs to the bloodstream.
Enzymes
• Function to catalyze
chemical reactions.
• Examples of
enzymes:
1. Lipase
- help in digestion
of fats
Examples of enzymes
are:
2. Pepsin
- help in breaking
down proteins
into peptides
(smaller units).
Examples of
enzymes are:
3. Sucrase
- also called
invertase, help in
the digestion of
sugars and
starches.
Lipids
• provide more energy per
gram than carbohydrates and
proteins,
• serve other functions such as
material for cell membrane,
• insulation to maintain body
temperature,
• aid in digestion, and as signal
molecules.
1. Triglyceride
Classifications 2. Phospholipid
of lipids: 3. Wax, and
4. Steroid
Lipids
• structure of a triglyceride:
• it has three chains
connected to a backbone
• it has long chains mainly
composed of C and H
• it is composed of C, H, O
Fatty acids
• are long-chain carboxylic acids that are insoluble in water.
• Fatty acids can be saturated or unsaturated.
• Common examples are fat and oil.
• Saturated fatty acids contain single bonds in its hydro-carbon
chain whereas unsaturated fatty acids contain double bonds.
Fatty acids
saturated fatty acids
• with hydrogen
• All the carbon
molecules have two
hydrogen atoms
attached to it.
Fatty acids
Unsaturated fatty
acids
- Carbons with a
double bond only
have one hydrogen
atom attached to it.
Triglyceride
• Fat and oil are the most
common examples of
lipids. They are under
triglycerides because they
are composed of glycerol
and three fatty acids.
Triglyceride
Fat
- refers to solid triglyceride usually from
animal sources such as meat, milk,
butter, margarine, eggs, and cheese.
Oil
- refers to liquid triglycerides from plant
sources.
- Examples are olive oil, corn oil,
sunflower oil, and soybean oil.
- Animal fat contains high percentages of
saturated fatty acids while plant oil are
mostly unsaturated fatty acids.
Phospholipids
• contains glycerol, two fatty acids, and a
phosphate group. Unlike other lipids,
phospholipids have a polar and non-polar end.
• This property allows it to transport molecules
in the bloodstream. It is also a major component
in the cell membrane.
• The two parts of a phospholipid can be termed
as the hydrophilic head (phosphate group) and
hydrophobic tail (fatty acid group).
• This dual property allows phospholipids to
form a phospholipid bilayer.
Activity: 1
A. Nucleic Acid
Guide questions:
1. Why are nucleic acids named so?
2. What comprises nucleic acids?
3. What is another term for nucleic acids?
4. What are the three parts of a nucleotide?
5. What are common examples of nucleic acids?
6. What is the primary role of DNA?
7. How does RNA help in protein synthesis?
8. What are the bases of DNA? of RNA?
9. How are DNA and RNA similar?
10. How are DNA and RNA different?
Short reading for Nucleic Acid
• Nucleic acids play an essential role in the storage, transfer, and expression of
genetic information. Nucleic acid was discovered by a twenty-four year-old Swiss
physician named Friedrich Miescher in 1868. He was puzzled that an unknown
substance in white blood cells did not resemble carbohydrates, proteins, or lipids.
He was able to isolate the substance from the nucleus and initially called it
nuclein. He eventually was able to break down nuclein into protein and nucleic
acids. He found out that nucleic acids contain carbon, hydrogen, oxygen,
nitrogen, and phosphorus.
• The most common examples of nucleic acids are DNA (deoxyribonucleic acid) and
RNA(ribonucleic acid). DNA is a nucleic acid that carries the genetic code of
organisms. It is fondly termed as the blueprint of life. RNA, on another hand,
carries the information from the DNA to the cellular factories for the synthesis of
proteins. If carbohydrates are composed of saccharide units, proteins of amino
acids, and lipids of fatty acids, nucleic acids are composed of nucleotides. Nucleic
acids are also known as polynucleotides. A nucleotide has three parts:
• a. Nitrogenous base
• b. Five-carbon carbohydrate or sugar
• c. Phosphate group
B. Summarize their
understanding about
Biological
Macromolecules by filling
up the table below:
Activity 2
• Create a mind map of the things you remember about Carbohydrates,
Proteins, Lipids and Nucleic Acid.
Answers for Nucleic Acid
1. Why are nucleic acids named so?
- Around 1868, Friedrich Miescher isolated an unknown weakly acidic
substance from the nucleus of white blood cells, hence the term
nucleic acid.
2. What comprises nucleic acids?
- Nucleic acids are composed of nucleotides.
3. What is another term for nucleic acids?
- Nucleic acids are also known as polynucleotides.
4. What are the three parts of a nucleotide?
- A nucleotide has a five-carbon sugar, a phosphate group and a
nitrogenous base
5. What are common examples of nucleic acids?
- DNA and RNA
Answers for Nucleic Acid
6. What is the primary role of DNA?
- It is the blueprint of life. Our genetic code is found in the DNA.
7. How does RNA help in protein synthesis?
- RNA helps in protein synthesis by carrying out the instructions encoded in the
DNA.
8. What are the bases of DNA? of RNA?
- DNA: Adenine, Guanine, Tyrosine, Cytosine RNA: Adenine, Guanine, Uracil,
Cytosine
9. How are DNA and RNA similar?
- They have the same three bases: A, G, C.
- They both have nucleotides containing one phosphate group, a five-carbon sugar, and a
nitrogenous base.
- Both are used in the manufacture of proteins
10. How are DNA and RNA different?
• - DNA is double stranded while RNA is single strand
• - DNA has deoxyribose for its sugar while RNA has ribose
• - DNA has thymine while RNA has uracil
