Biomolecules Part 2

Biomolecules

LC: Recognize the major categories of biomolecules such as
carbohydrates, lipids, proteins, and nucleic acids

References:

Exploring Life Through Science

Breaking Through Science

Science for the 21st Century Learner

YELLOW HIGHLIGHTER: DEFINE PROTEINS,
CARBOHYDRATES, LIPIDS, NUCLEIC ACIDS AND OTHER
TERMS RELATED TO BIOMOLECULES

ORANGE HIGLIGHTER: What is the general
formula for the group?

PINK HIGHLIGHTER: for the primary roles of
these molecules in living organisms

The blue highlighter: monomers and
polymers of the group

•The green highlighter is used for: names of some
specific examples of the group of molecules and
where they would be found.

TERMS

FORMULA

ROLES

MONOMERS/POLYMERS

EXAMPLES

COLOR-CODING STRATEGY

1. I can compare the structures and functions

of carbohydrates, lipids, proteins and

nucleic acid.

2. I can explain how small building blocks can

be used to make a great variety of

molecules that are needed to perform life’s

functions.

3. I can identify common forms of

biomolecules and their functions.

4. I can show appreciations for the

applications of biomolecules to the society

and take actions on how to conserve

world’s resources.

Where are you now in these learning targets?

Hi! You can use this kind of
strategy if you’re doing some
note-taking. This helps you

remember terms.

Families of Biomolecules

• Carbohydrates

•Lipids

•Proteins

•Nucleic Acids

Helpful Mnemonics for you! This represents the
elements mostly found in each biomolecule family.

Food such as milk, meat, fish,

and beans are composed mainly

of proteins.

Proteins are one of the most

important groups of biomolecules
in living cells; they help build and

repair body parts.

The word protein came from the

Greek word proteis, meaning

"first place," which suggests the
importance of these molecules in

living systems.

Proteins are complex biomolecules that contain amino acids linked through the peptide bonds,
They have molecular weight ranging from about 6,000 to over 1 are considered as the most

versatile biomolecules since they serve numerous essential functions in the biological processes.

In fact, they are the primary constituents of living organisms. In addition to carbon, hydrogen,
and oxygen, proteins also contain nitrogen (N). These additional components separate proteins
from carbohydrates. Among the foods rich in protein are animal meat, tuna, cheese, tofu, and

beans.

The

ROLE of
PROTEINS

Open Ended

What are the role of proteins in living organisms?

Proteins play a wide variety of functional roles as represented by the image

below:

Building Blocks of Proteins

Amino Acids

•

Amino acids (monomers) are
linked together to form proteins
(polymers)
–

Each unique sequence of
amino acids forms a different
protein

–

All living things (even viruses)
use the same 20 amino acids

•

20 different Amino Acids
–

Amino end (NH2)

–

Carboxyl end (COOH)

–

Hydrogen

–

R group – variable component

Generally, proteins are made up of monomers called amino acids.

Multiple Choice

What is the monomer of proteins?

• polypeptides

• amino acids

• nucleotides

• monosaccharides

Thousands of amino acids can be synthesized in the laboratory, but only 20
amino acids make up the proteins. Below is the structural formula of amino
acids. Nineteen amino acids have the following general formula, except for

proline.

The four components of an amino
acid:
1.

A central carbon atom with one
nitrogen

2.

One carboxyl group (-COOH)

3.

One amino group (-NH2)

4.

A functional group or side chain ( R )

The side chain, R, consists of
different atoms gives each 20 amino
acids its unique specific properties.

Multiple Choice

What is the name of the bond that joins two amino acids together?

• Peptide bond

• Nucleic bond

• Glycosidic bond

• Ester bond

Amino acids can be classified into essential
and nonessential. The 10 essential amino
acids are not produced by the body, and

include arginine, histidine, isoleucine,

leucine, lysine, methionine, phenylalanine,

threonine, tryptophan, and valine.

We have to eat certain protein-rich foods

to obtain these amino acids. The remaining

10 of the common amino acids are

nonessential and can be produced by the

body.

Because of the biological functions of
amino acids, they are important. in

nutrition and are commonly used in food

supplements and in food technology.

Glycine is the simplest amino acid. Its side chain consists only of a hydrogen atom.

Alanine the next simple amino acid, has a methyl group for its side chain.

The function of a protein is greatly affected by its

shape and how the amino acids were put together.

Proteins have four levels of structures, with each more

complex than the last.

What dictates their structure is simply the sequence of the

amino acids. According to complexity, protein structure can be
primary, secondary, tertiary, and quaternary. Figure

Image on the left shows the four different protein

structures. How does one differ from the other?

As you noticed, primary structure is the linear sequence of

amino acids that form a protein. Meanwhile, the secondary
structure is the spatial arrangement of the polypeptide chain
of a protein. It has two types: the alpha helix and the beta
pleated sheet. As you can see in the figure, in a helix, the
chain is coiled like a spring. The helix is held together by
hydrogen bonds between the loops of a coil. On the other
hand, in the pleated sheet, chains are held together by
hydrogen bonds between adjacent chains.

These structures of the protein secondary structures were

suggested by Linus Pauling and his colleagues in 1951.

Looking at the tertiary structure, it refers to the final

three-dimensional shape of a single polypeptide molecule
where the alpha helix and the pleated sheet are folded
forming a globular protein. It is termed globular since proteins
are approximately spherical

Multiple Choice

Which protein structure describes a protein's three-dimensional shape?

• Primary

• Secondary

• Quaternary

• Tertiary

Multiple Choice

Which protein structure is only found in proteins with more than one polypeptide chain?

• Primary

• Secondary

• Tertiary

• Quaternary

Multiple Choice

Proteins have four significant levels of structure.

• TRUE

• FALSE

Multiple Choice

Many proteins function as enzymes. An enzyme is a molecule that catalyzes

or speeds up chemical reactions in the body.

• TRUE

• FALSE

Multiple Choice

Proteins are biomolecules composed of amino acid units.

• TRUE

• FALSE

Nucleic Acid

The building blocks of living

organisms are the nucleic acids.

Just like proteins, nucleic acids are
the most important biomolecules.

They serve as the blueprint of life.

They are responsible in encoding,

transmitting, and expressing genetic

information.

Friedrich Miescher in 1869

•Isolated what he called
nuclein from the nuclei of
pus cells

•Nuclein was shown to have
acidic properties, hence it
became called nucleic acid

•Thus, he was the first to
identify DNA.

© 2016 Paul Billiet ODWS

There are two types of nucleic acids. These are the deoxyribonucleic acid (DNA) and the
ribonucleic acid (RNA). How does one differ from the other? Look at their comparison in

the image below. Both will be discussed in details as the lesson progresses.

Can you differentiate the two types of nucleic acids?

The distribution of nucleic acids in the eukaryotic

cell

• DNA is found in the nucleus

with small amounts in
mitochondria and chloroplasts

• RNA is found throughout the

cell

© 2016 Paul Billiet ODWS

NUCLEIC ACID STRUCTURE

•Nucleic acids are
polynucleotides

•Their building blocks
are nucleotides

© 2016 Paul Billiet ODWS

Multiple Choice

What's the monomer of a nucleic acid?

• DNA

• nucleotide

• RNA

• amino acid

Multiple Choice

What is the function of nucleic acids?

• store genetic information

• build skin, hair, nails, muscles

• store energy (long-term)

• store energy (short-term)

Multiple Choice

From the nucleotide on the right, which part is labeled 2?

• Sugar

• Phosphate

• Nitrogenous Base

• Phosphorous

NUCLEOTIDE STRUCTURE

PHOSPHATE

SUGAR

Ribose or

Deoxyribose

NUCLEOTIDE

BASE

PURINES

PYRIMIDINES

Adenine (A)
Guanine(G)

Cytocine (C)
Thymine (T)
Uracil (U)

© 2016 Paul Billiet ODWS

Ribose is a pentose.

C1

C5

C4

C3

C2

O

© 2016 Paul Billiet ODWS

RIBOSE

DEOXYRIBOSE

CH2OH

H

OH

C

C

OH

OH

C

O

H
H

H

C

CH2OH

H

OH

C

C

OH

H

C

O

H
H

H

C

Spot the difference

© 2016 Paul Billiet ODWS

Open Ended

THE SUGAR-PHOSPHATE
BACKBONE

•The nucleotides are all
orientated in the same
direction

•The phosphate group joins
the 3rd Carbon of one
sugar to the 5th Carbon of
the next in line.

P

P

P

P

P

P

© 2016 Paul Billiet ODWS

ADDING IN THE BASES

•The bases are attached to the 1st
Carbon

•Their order is important
It determines the genetic information
of the molecule

P

P

P

P

P

P

G

C

C

A

T

T

© 2016 Paul Billiet ODWS

DNA IS MADE OF
TWO STRANDS OF
POLYNUCLEOTIDE

P

P

P

P

P

P

C

G

G

T

A

A

P

P

P

P

P

P

G

C

C

A

T

T

Hydrogen bonds

© 2016 Paul Billiet ODWS

DNA IS MADE OF TWO STRANDS OF
POLYNUCLEOTIDE

•The sister strands of the DNA molecule run in opposite
directions (antiparallel)

•They are joined by the bases

•Each base is paired with a specific partner:
A is always paired with T
G is always paired with C
Purine with Pyrimidine

•Thus the sister strands are complementary but not
identical

•The bases are joined by hydrogen bonds, individually
weak but collectively strong.

© 2016 Paul Billiet ODWS

The Double Helix (1953)

www.chem.ucsb.edu/.../images/WatsonCrick.jpg

© 2016 Paul Billiet ODWS

James Watson, Francis Crick, and

Maurice Wilkins won the 1962 Nobel

Prize in Medicine for their discovery of

the molecular structure of DNA.

Published in April 1 953, their

discovery showed that a DNA molecule

has two strands coiled around each

other in a double helix.

Through this model, scientists were
able to understand DNA replication

and the transmission of genetic

information. Other developments in

the field of molecular biology followed

as well, such as the Human Genome

Project which Watson directed. The

project sequenced the 3 billion bases

of the human DNA and led to better

understanding of genetic diseases and

disorders.

So, can you now differentiate the two nucleic acids?

Please feel free to

message your Science
Teacher for clarification!

PROCESS QUESTIONS:

WHY

BIOMOLECULES

IMPORTANT?

Open Ended

WHY BIOMOLECULES ARE IMPORTANT?

As a

Lasallian,
how can

you translate
what you had
learned into
something

useful?

1. I can compare the structures and functions

of carbohydrates, lipids, proteins and

nucleic acid.

2. I can explain how small building blocks can

be used to make a great variety of

molecules that are needed to perform life’s

functions.

3. I can identify common forms of

biomolecules and their functions.

4. I can show appreciations for the

applications of biomolecules to the society

and take actions on how to conserve

world’s resources.

What did you accomplish from the list of the

learning targets?

Note: Use these learning targets to self-evaluate. When
you read and do activities, always go back to these goals
to check if you have achieved it.

(Picture of the food label here.)

What is the food you ate made up of?

Why do you think we eat those food?

Worksheet #2

Select one food label from the food that you consumed for the day. Inspect the food label. What is the
food that you ate made up of? Write this down. Why do you think we eat those food? Use the table
below for your answer.

Worksheet #1

How are nucleic acids

linked to heredity?

(In answering worksheets, make sure
to write the question first, then give
the answers.

For Learning Target # 1, below is the summary of lessons discussed:

I can compare the structures and functions of carbohydrates, lipids, proteins

and nucleic acid.

I can explain how small building blocks can be used to make a great variety of molecules that are needed to

perform life’s functions.

I can identify common forms of biomolecules and their

functions.

I can show appreciations for the applications of biomolecules to the society

and take actions on how to conserve world’s resources

The activities below and the lessons gave you opportunities to reflect on how biomolecules are used in the

society. You were asked as well to translate your learnings into something useful.

The End