Genes and Proteins

Genes and Proteins

Middle School

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Learning Objectives

• Define the terms gene, DNA, chromosome, and protein.

• Describe the relationship between DNA, genes, and proteins.

• Explain the process of protein synthesis, including transcription and translation.

• Explain what gene mutations are and how they can affect an organism.

Key Vocabulary

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Gene

A hereditary unit on a chromosome that determines traits and controls protein production.

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Chromosome

A single, highly organized piece of DNA which contains very many genes.

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DNA

Deoxyribonucleic acid is a molecule that carries the genetic code for cell growth.

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Protein

A molecule that provides structure and support for cells and regulates the body's tissues.

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Replication

The cellular process of making an identical copy of a DNA molecule before division.

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Transcription

The process in which a cell makes a copy of RNA from a DNA template.

Key Vocabulary

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Translation

The important process where a protein is finally made from an RNA molecule's instructions.

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Gene Regulation

The biological ability of cells in an organism to turn genes on and off.

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Mutation

A permanent change in the DNA sequence of a gene or chromosome.

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Mutagen

A physical or a chemical agent that has the ability to cause a change in DNA.

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Genetic Disorders

Medical conditions which are caused by mutations that have occurred in an organism's genes.

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The Blueprint of Life: DNA, Genes, and Chromosomes

• The nucleus is the cell's control center, containing the blueprints for life.

• These blueprints are on chromosomes, which are long molecules made of DNA.

• Chromosomes are divided into short segments of DNA called genes.

• Genes provide coded instructions for passing traits to the offspring.

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Multiple Choice

What is the primary function of a gene?

• To provide coded instructions for passing on traits

• To hold the nucleus together in the cell

• To release energy for the cell to use

• To help the cell move around

Multiple Choice

What is the structural relationship between DNA, genes, and chromosomes?

• Chromosomes are long molecules of DNA that are divided into genes.

• Genes are long molecules of DNA that are divided into chromosomes.

• DNA is made from a combination of genes and chromosomes.

• Chromosomes and genes are separate molecules from DNA.

Multiple Choice

A scientist observes that an organism has an incorrect trait. Based on the flow of information from the blueprint to the trait, where would the scientist most likely find the source of this error?

• In the coded instructions of a gene

• In the membrane surrounding the nucleus

• In the cell's energy production process

• In the main body of the chromosome itself

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Proteins: The Building Blocks of Life

• Genes contain the instructions your body needs to create essential proteins.

• Proteins build your skin and hair and control all cellular processes.

• A protein's unique shape determines its specific job or function.

• A DNA mutation can change a protein’s shape, stopping its proper function.

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Multiple Choice

What is the primary role of proteins in the body?

• To build structures and control cellular processes.

• To store the body's genetic instructions.

• To provide the body with a source of energy.

• To change the shape of an organism's DNA.

Multiple Choice

What is the most important factor that determines the specific job of a protein?

• Its unique shape.

• The type of cell it is in.

• The gene that provides its instructions.

• The amount of hair and skin a person has.

Multiple Choice

Based on the information provided, what is the most likely outcome if a DNA mutation causes a protein to have a different shape?

• The protein will likely be unable to perform its function.

• The protein will start to perform a new, more useful function.

• The body's genes will immediately correct the protein's shape.

• The cell will use the misfolded protein for energy instead.

How Proteins Are Made

• First, DNA is copied into a messenger RNA (mRNA) molecule during transcription.

• Then, the mRNA carries the instructions to a ribosome in the cytoplasm.

• The ribosome reads the mRNA to build a new protein from amino acids.

Multiple Choice

What is the first step in the process of making a protein?

• DNA is copied into an mRNA molecule.

• A ribosome builds a new protein.

• Amino acids are carried to the cytoplasm.

• mRNA carries instructions to the DNA.

Multiple Choice

What is the primary role of the messenger RNA (mRNA) molecule?

• It carries the instructions for building a protein to the ribosome.

• It reads the DNA to build a new protein from amino acids.

• It copies the ribosome to create new instructions.

• It provides the amino acids needed to build the protein.

Multiple Choice

Based on the steps of protein synthesis, what would happen if a ribosome was unable to read the instructions carried by the mRNA?

• The ribosome would not be able to build a new protein.

• The DNA would not be able to make a copy of itself in transcription.

• The amino acids would be used to make mRNA instead.

• The mRNA would go back to the DNA with the instructions.

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How Do Cells With the Same Genes Differ?

• All your cells have the same genes, but they perform different functions.

• Gene regulation is the ability of cells to turn genes on and off.

• Gene expression is using a gene’s information to make a specific protein.

• This process allows different cells to have specialized jobs in your body.

Multiple Choice

What is gene regulation?

• The ability of a cell to turn genes on or off.

• The process of making a protein from a gene.

• The way a cell divides to create new cells.

• The method cells use to create new genes.

Multiple Choice

What is the primary purpose of cells using gene regulation and expression?

• It makes all cells in the body identical.

• It changes the genes within a cell's nucleus.

• It allows cells to become specialized for different functions.

• It stops cells from making any proteins.

Multiple Choice

A nerve cell and a skin cell from the same person have the same genes, but they look and act differently. What is the best explanation for this?

• The skin cell has a different set of genes than the nerve cell.

• Different genes are expressed in each cell, leading to different proteins and functions.

• The nerve cell has no genes, while the skin cell has a full set.

• Only the skin cell can turn its genes on and off.

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What Are Gene Mutations?

• A mutation is a permanent change in the DNA sequence of a gene.

• ​Mutagens, like chemicals or X-rays, can cause these changes in DNA.

• Mutations can be harmful, beneficial, or have no effect at all.

• Harmful mutations may cause genetic disorders like sickle cell anemia.

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Multiple Choice

What is a gene mutation?

• A permanent change in the DNA sequence of a gene.

• A temporary change in a cell's structure.

• The process of a cell growing and dividing.

• A beneficial adaptation passed from parent to offspring.

Multiple Choice

What is the relationship between mutagens, like X-rays, and genes?

• They can cause permanent changes in the DNA of genes.

• They are created by genes to help the body.

• They are always beneficial to an organism's survival.

• They are a normal part of a gene's life cycle.

Multiple Choice

What can be concluded about the mutation that causes sickle cell anemia?

• It is an example of a harmful change in a DNA sequence.

• It is a beneficial change that helps the body fight disease.

• It is a temporary change with no significant effect.

• It is a mutation that has no effect on the body.

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Common Misconceptions

Misconception	Correction
All gene mutations are harmful.	Mutations can be harmful, beneficial, or have no effect at all.
All genes in a person's body are active and being used all the time.	Gene regulation ensures that only the necessary genes are 'turned on' in a cell.
DNA, genes, and chromosomes are three completely separate things.	Genes are specific sections of the DNA molecule, which is structured into a chromosome.

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Summary

• Genes are DNA segments on chromosomes that provide instructions to build proteins.

• Protein synthesis creates proteins from DNA using transcription and translation.

• Gene regulation controls which genes are active, allowing cells to specialize.

• Mutations are permanent DNA changes that can be harmful, neutral, or helpful.

Poll

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