Mutations and Genetic Engineering

A set of flashcards summarizing key concepts from the lecture on mutations and genetic engineering.

What are mutations?

Mutations are changes in DNA sequence.

What is the impact of mutations?

Mutations can lead to differences in amino acid sequences, which can be detrimental or beneficial.

How do mutations occur?

Mutations can occur due to errors in DNA replication, environmental factors, or spontaneously.

What is sickle cell disease?

A genetic disorder caused by a mutation in the beta-globin gene, resulting in abnormally shaped red blood cells.

What is the normal shape of red blood cells?

Normal red blood cells are round and flow well through blood vessels.

What is the impact of sickle cell mutation on red blood cells?

It causes red blood cells to be misshapen, leading to poor blood flow.

What is gene therapy?

A technique that involves influencing genes to reduce or eliminate the effects of a genetic disorder.

Can gene therapy potentially cure sickle cell disease?

Yes, because sickle cell disease is genetically inherited.

What are point mutations?

Point mutations are alterations where one nucleotide is replaced by another.

What is a silent mutation?

A mutation that changes one nucleotide but does not alter the amino acid sequence.

What does a missense mutation do?

It changes one nucleotide leading to a different amino acid sequence.

What is a nonsense mutation?

A point mutation that introduces an early stop codon, making the protein nonfunctional.

What is a frameshift mutation?

A mutation that alters the reading frame of the gene, often due to insertion or deletion.

What happens in an insertion mutation?

One or more nucleotides are added, shifting the reading frame of all subsequent codons.

What occurs during a deletion mutation?

One or more nucleotides are removed, shifting the reading frame of all subsequent codons.

What is an inversion mutation?

A mutation where a group of DNA nucleotides is flipped to read in reverse order.

What is a translocation mutation?

It involves moving segments of DNA from one chromosome to another, potentially combining portions of different genes.

How do germ cell mutations affect future generations?

Mutations in germ cells can be passed on to the next generation.

What are mutagens?

Chemical or physical agents that can damage DNA and cause mutations.

What approach does viral vector gene therapy use?

An altered virus inserts healthy versions of the gene into the patient's genome.

What is the first step in the viral vector gene therapy for sickle cell disease?

Remove stem cells from the patient.

What happens to the stem cells in viral vector therapy?

The virus inserts the normal gene into the stem cells.

What is the final step in viral vector gene therapy?

Introduce the modified cells back into the patient.

What is the gene switch approach in gene therapy?

It focuses on changing gene expression, particularly increasing gamma-globin production.

What is hydroxyurea?

A drug that increases the expression of gamma-globin.

How does CRISPR work?

It cuts DNA at a target sequence and can replace or inactivate genes.

What is the significance of the beta-globin gene in sickle cell disease?

The mutation in this gene directly causes the symptoms of sickle cell disease.

What are the types of mutations?

Point mutations, frameshift mutations, and rearranged DNA mutations.

What distinguishes a missense mutation from a silent mutation?

A missense mutation results in a different amino acid sequence; a silent mutation does not.

How do mutations affect protein function?

They can change the protein shape and function or make it nonfunctional.

What can cause mutation during DNA replication?

Errors that escape correction by DNA repair enzymes.

What role do environment play in mutations?

Many environmental components can act as mutagens.

What happens to modified cells in viral vector therapy?

They produce the normal version of beta-globin.

How can gene therapy alleviate sickle cell disease symptoms?

By providing a functional beta-globin gene.

What is the difference between insertion and deletion mutations?

Insertion adds nucleotides; deletion removes nucleotides, both shifting the reading frame.

What can happen as a result of rearranged DNA mutations?

They can cause significant changes in protein shape and function.

What is a consequence of frameshift mutations?

They can lead to severely modified protein sequences.

In what cells do beneficial mutations primarily occur?

Germ cells, as they can be inherited.

How long has CRISPR been under development?

It is relatively new and still undergoing research.

What can a nonsense mutation result in?

A protein that is too short and nonfunctional.

Why is gene therapy potentially used for treating mutations?

It targets the underlying genetic causes of diseases.

What happens to normal hemoglobin production in sickle cell patients?

They produce abnormal hemoglobin due to beta-globin mutations.

What role do enzymes have in DNA repair?

They correct mistakes made during DNA replication.

What are the driving questions of this chapter?

What are mutations, their impact, and how can genetic engineering be used to treat genetic diseases?

Are all mutations harmful?

No, some mutations can be beneficial or neutral.

What is the legacy of beta-globin mutations?

It leads to the genetic condition known as sickle cell disease.

What is one possible outcome of gene therapy?

Restoration of normal red blood cell shape and function.