Macromolecules Biomolecules

Macromolecules Biomolecules

High School

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Learning Objectives

• Define the four main types of biomolecules: carbohydrates, lipids, proteins, and nucleic acids.

• Identify the monomers and polymers for each major class of biomolecule.

• Describe the primary functions of each type of biomolecule in living organisms.

• Compare the elemental composition and structures of carbohydrates, lipids, proteins, and nucleic acids.

Key Vocabulary

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Monomer

A small molecule that can be bonded to other identical molecules to form a polymer.

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Polymer

A large molecule composed of smaller repeating molecules known as monomers.

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Macromolecule

A large organic molecule, such as a carbohydrate, lipid, protein, or nucleic acid.

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Carbon

The essential elemental building block of large organic molecules found in all living things.

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What Are Biomolecules?

• Biomolecules are large organic molecules that are essential for life.

• ​The term ‘organic’ means they contain the element carbon.

• They are polymers built from smaller repeating units called monomers.

• This process of joining monomers is called polymerization.

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Multiple Choice

What is the general process of joining small molecular units called monomers to form the large macromolecules found in living things?

• Decomposition

• Hydrolysis

• Polymerization

• Photosynthesis

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What Are Carbohydrates?

• Carbohydrates are composed of Carbon (C), Hydrogen (H), and Oxygen (O) atoms.

• The monomer is a monosaccharide, such as glucose, a simple sugar.

• Glycosidic bonds link monosaccharides to form polymers called polysaccharides like starch.

• They provide short-term energy, and structure to plant cell walls.

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Multiple Choice

Which of the following correctly pairs the monomer of carbohydrates with its primary function?

• Fatty Acid; Long-term energy storage

• Nucleotide; Storing genetic information

• Amino Acid; Catalyzing reactions

• Monosaccharide; Providing short-term energy

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What Are Lipids?

• Lipids consist of Carbon (C), Hydrogen (H), and some Oxygen (O) atoms.

• ​Their building blocks are fatty acids and glycerol, forming larger triglycerides.

• Lipids provide long-term energy storage, insulation, and form cell membranes.

• Cell membranes are made of phospholipids with a hydrophilic head and hydrophobic tails.

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Multiple Choice

What is the primary function of lipids, such as triglycerides, in the body?

• Long-term energy storage and insulation

• Providing quick, accessible energy

• Storing and carrying genetic information

• Catalyzing most biological reactions

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What Are Proteins?

• Proteins contain carbon (C), hydrogen (H), oxygen (O), and nitrogen (N).

• ​They are polymers made of smaller monomer units called amino acids.

• Amino acids are linked together by special connections called peptide bonds.

• Their functions include structure (keratin), transport (hemoglobin), and speeding up reactions (enzymes).

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Multiple Choice

Which of the following best describes the monomer of a protein and the bond that links these monomers together?

• Fatty Acid, Ester bond

• Monosaccharide, Glycosidic bond

• Amino Acid, Peptide bond

• Nucleotide, Phosphodiester bond

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Nucleic Acids

• Nucleic acids contain carbon, hydrogen, oxygen, nitrogen, and phosphorus atoms.

• ​The monomer is a nucleotide, with a sugar, phosphate, and nitrogenous base.

• Nucleotides are linked by phosphodiester bonds to form polymers like DNA and RNA.

• They store and transmit genetic information needed to build proteins.

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Multiple Choice

According to the slide, what are the three distinct components that make up a nucleotide?

• A monosaccharide, a peptide bond, and a 5-carbon sugar

• An amino acid, a phosphate group, and a nitrogenous base

• A glycerol, a fatty acid, and a phosphate group

• A 5-carbon sugar, a phosphate group, and a nitrogenous base

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Common Misconceptions About Macromolecules

Misconception	Correction
All fats are unhealthy.	Some fats are essential, like phospholipids and unsaturated fats.
Carbohydrates are only for energy.	Some carbohydrates provide structural support to plant cells.
Proteins are just for building muscle.	Proteins also act as enzymes, transport oxygen, and form hair.
You need supplements for nucleic acids.	Nucleic acids are in all foods from plants or animals.

Multiple Choice

Why are lipids a more effective molecule for long-term energy storage compared to carbohydrates?

• Lipids contain more C-H bonds, storing more energy per gram.

• Carbohydrates cannot be broken down by the body.

• Lipids are water-soluble, making them easy to transport.

• Carbohydrates provide structural support, not energy.

Multiple Choice

How does the difference in glycosidic bonds in starch (alpha) and cellulose (beta) relate to their different functions in plants?

• Alpha bonds are for structure, and beta bonds are for energy storage.

• The bonds have no effect on function.

• Beta bonds create straight, strong chains for structure, while alpha bonds create branched chains for easy energy access.

• Alpha and beta bonds are identical in structure and function.

Multiple Choice

An unknown globular biomolecule is found to be water-soluble and contains a non-protein iron group that binds oxygen. How would you classify this molecule and its function?

• A transport protein like hemoglobin, functioning to carry oxygen.

• A carbohydrate, functioning as short-term energy.

• A nucleic acid, functioning to store genetic code.

• A lipid, functioning as a cell membrane component.

Multiple Choice

If a genetic mutation prevented a cell from performing polymerization, what would be the most critical and immediate consequence?

• The cell could not break down molecules to release energy.

• The cell would fill with excess water due to faulty membranes.

• The cell would be unable to synthesize proteins, store long-term energy, or build polysaccharides.

• The cell's monomers would spontaneously break apart.

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Summary

• All biomolecules are large polymers with a carbon backbone.

• Carbohydrates provide quick energy and structure for plants.

• Lipids store long-term energy and make up cell membranes.

• Proteins have diverse roles, including transport and acting as enzymes.

• Nucleic acids store and transmit genetic instructions for life.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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• 4