Macromolecules Practice

Macromolecules Practice

High School

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Learning Objectives

• Define macromolecules, monomers, and polymers, and how they are formed and broken down.

• Identify the four major classes of biological macromolecules.

• Describe the structure, monomers, and functions for each macromolecule class.

• Provide examples and common food sources for each macromolecule type.

Key Vocabulary

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Macromolecule

A large molecule, often a polymer, made of repeating monomer subunits essential for life's processes.

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Monomer

The single basic building block unit that joins with others to form a larger polymer molecule.

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Dehydration Synthesis

A chemical reaction where monomers are joined by removing a water molecule to form a polymer.

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Hydrolysis

The chemical breakdown of a compound by reacting with water, splitting a polymer into monomer subunits.

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Amino Acid

The monomer building block of proteins, containing an amino group, a carboxyl group, and a unique R group.

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Building Blocks of Life

Dehydration Synthesis

• This process joins monomers together to build larger molecules called polymers.

• It is an anabolic, or building, reaction that forms a chemical bond.

• During this process, a water molecule is released as a product.

Hydrolysis

• This process breaks down large polymers into their individual monomer units.

• It is a catabolic, or breakdown, reaction that breaks a chemical bond.

• To break the bond, a water molecule is added or consumed.

Multiple Choice

Which process is responsible for breaking down a large polymer into its smaller monomer subunits by adding water?

• Hydrolysis

• Polymerization

• Dehydration Synthesis

• Anabolism

Carbohydrates: Quick Energy

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Monosaccharides

• ​Monosaccharides are the basic building blocks of all carbohydrates.

• ​​They are simple sugars, consisting of just one sugar molecule.

• ​Glucose is a common and very important monosaccharide for energy.

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Disaccharides

• ​Disaccharides are formed when two simple sugars are joined together.

• ​​This joining is a chemical reaction linking two monosaccharide molecules.

• ​Table sugar, also known as sucrose, is a common disaccharide.

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Polysaccharides

• ​Polysaccharides are large molecules made of many linked monosaccharides.

• ​​Plants store their energy as a polysaccharide known as starch.

• ​Cellulose is a polysaccharide that provides structure to plant cells.

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Solved Example 1
A carbohydrate molecule has 6 carbon atoms. Based on the typical 1:2:1 ratio of elements in carbohydrates, how many hydrogen and oxygen atoms does this molecule contain?

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Step 1: Analyze and Sketch the Problem

• Goal: Determine the number of hydrogen and oxygen atoms in a carbohydrate with 6 carbon atoms.

• Knowns: Number of Carbon (C) atoms = 6. The ratio of Carbon:Hydrogen:Oxygen is 1:2:1.

• Unknown: Number of Hydrogen (H) atoms = ?; Number of Oxygen (O) atoms = ?

• Formula: Use the ratio C:H:O = 1:2:1.

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Solved Example 1
A carbohydrate molecule has 6 carbon atoms. Based on the typical 1:2:1 ratio of elements in carbohydrates, how many hydrogen and oxygen atoms does this molecule contain?

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Step 2: Solve for the Unknown

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Solved Example 1
A carbohydrate molecule has 6 carbon atoms. Based on the typical 1:2:1 ratio of elements in carbohydrates, how many hydrogen and oxygen atoms does this molecule contain?

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Step 3: Evaluate the Answer

• Check the ratios: C:H is 6:12, which simplifies to 1:2. C:O is 6:6, which simplifies to 1:1.

• The calculated number of atoms (12 for H, 6 for O) correctly fits the 1:2:1 ratio for a carbohydrate with 6 carbon atoms.

Multiple Choice

A carbohydrate is made of multiple monosaccharide units. What is its primary function in living organisms?

• Providing long-term energy storage

• Serving as a source of quick energy

• Storing genetic information

• Acting as a structural component of cell membranes

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What are Lipids?

• Lipids are made of C, H, and O and do not mix with water.

• They provide long-term energy storage, insulation, and form some hormones.

• Lipids are a major structural component of all cell membranes.

• Their building blocks are molecules called glycerol and fatty acids.

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Multiple Choice

Based on the information provided, what is a primary role of lipids in the body?

• Catalyzing chemical reactions as enzymes.

• Long-term energy storage and forming cell membranes.

• Providing a source of quick energy.

• Storing and transmitting genetic information.

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Saturated vs. Unsaturated Fats

Saturated Fats

• Contain only single bonds between their carbon atoms in the fatty acid chain.

• Each carbon atom is fully 'saturated' with as many hydrogen atoms as possible.

• These fats, like butter, are typically solid at room temperature.

Unsaturated Fats

• Feature at least one double bond between carbon atoms in the fatty acid chain.

• The double bond creates a kink or bend in the molecule's overall structure.

• These fats, such as olive oil, are typically liquid at room temperature.

Multiple Choice

What key structural difference causes unsaturated fats like oils to be liquid at room temperature, while saturated fats like butter are solid?

• Having a higher number of oxygen atoms.

• The presence of at least one double bond in their fatty acid chains.

• Being 'saturated' with more hydrogen atoms.

• The absence of glycerol in their structure.

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Proteins: The Workhorses

• Proteins are molecules of C, H, O, and N, built from amino acids.

• Of 20 types, 8 essential amino acids must come from your diet.

• Each amino acid has a unique side chain called an 'R' group.

• They function as enzymes, provide structure, aid movement, and form antibodies.

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Multiple Choice

What are the fundamental building blocks of proteins, and what element is found in proteins but not typically in carbohydrates or lipids?

• Monosaccharides; Nitrogen

• Nucleotides; Phosphorus

• Fatty acids; Phosphorus

• Amino acids; Nitrogen

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What Are Nucleic Acids?

• Nucleic acids are macromolecules that store and transmit genetic information.

• ​They are composed of Carbon, Hydrogen, Oxygen, Nitrogen, and Phosphorus.

• Their monomer is a nucleotide with a sugar, phosphate, and base.

• DNA, a major type, forms a double helix with this structure.

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Multiple Choice

Which of the following correctly lists the three components of a nucleotide, the monomer of nucleic acids?

• Amino acid, R group, and carboxyl group

• Simple sugar, carbon ring, and oxygen atom

• Sugar, phosphate group, and nitrogenous base

• Glycerol, fatty acid, and phosphate group

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Common Misconceptions about Macromolecules

Misconception	Correction
All fats are unhealthy.	Unsaturated fats are healthy; lipids are vital for long-term energy and insulation.
Carbohydrates are the only source of energy.	Carbohydrates provide quick energy, while lipids offer long-term energy storage.
The body can make all necessary amino acids.	There are 8 essential amino acids that must be obtained from food.

Multiple Choice

A newly discovered molecule is found to be a major component of a cell's membrane, is insoluble in water, and provides long-term energy. How would this molecule be classified, and why?

• As a nucleic acid, because all cell components are made of them.

• As a protein, because it is part of a cell's structure.

• As a lipid, because it is insoluble in water and stores energy long-term.

• As a carbohydrate, because it provides energy.

Multiple Choice

Explain the structural difference between starch (a polysaccharide) and a protein, referencing their respective monomers.

• Starch is a chain of amino acids, while a protein is a chain of monosaccharides.

• Starch is made of glycerol and fatty acids, while proteins are made of nucleotides.

• Both are chains of nucleotides, but they are folded in different ways.

• Starch is a chain of monosaccharides, while a protein is a chain of amino acids with complex folding.

Multiple Choice

A genetic mutation occurs in an organism that alters the sequence of nucleotides in a DNA molecule. Predict the most likely downstream effect of this change.

• The process of hydrolysis would be permanently halted throughout the organism.

• The structure and function of a corresponding protein could be altered, as protein sequence is determined by DNA.

• The cell membrane would lose its insolubility, affecting its function as a barrier.

• The body's ability to store quick energy as a carbohydrate would be compromised.

Multiple Choice

How do dehydration synthesis and hydrolysis work together to manage the body's macromolecules?

• Both processes build larger molecules, one using water and one releasing it.

• Dehydration synthesis breaks down molecules for energy, and hydrolysis builds them for storage.

• Dehydration synthesis builds polymers for storage or function, and hydrolysis breaks them down to release monomers for use elsewhere.

• Both processes break down large molecules to release energy and water.

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Summary

• The four main types of macromolecules are carbohydrates, lipids, proteins, and nucleic acids.

• Monomers form polymers through dehydration synthesis, and hydrolysis breaks them apart.

• Carbohydrates provide quick energy, and lipids provide long-term energy storage.

• Proteins have diverse roles, while nucleic acids store and transmit genetic information.

Poll

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

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