PHARMD12 - GENOMICS 1ST SHIFTING

What is pharmacogenomics?

A study of how genes affect drug response, guiding drug selection and dosing.

How does Tamoxifen work in breast cancer treatment?

It binds to estrogen receptors on cancer cells, preventing estrogen binding and DNA synthesis.

What enzyme metabolizes Tamoxifen?

CYP2D6, which converts Tamoxifen into Endoxifen (active form).

What are the four main drug metabolism phenotypes?

Normal, Intermediate, Poor, and Ultrarapid Metabolizer.

What is a genetic polymorphism?

A variation in DNA sequence that occurs in at least 1% of the population.

What is a single nucleotide polymorphism (SNP)?

A change in a single nucleotide in the DNA sequence, affecting gene function and drug response.

What are the three types of SNPs?

Non-coding region SNPs, Non-synonymous SNPs, and Synonymous SNPs.

What are the three key phases of DNA transcription?

Initiation, Elongation, and Termination.

What is the role of RNA polymerase in transcription?

It binds to the promoter region and synthesizes RNA from the DNA template.

What are the three major post-transcriptional modifications of mRNA?

5' capping, Polyadenylation, and Splicing.

What is translation in molecular biology?

A process where ribosomes synthesize proteins based on mRNA sequence.

What are codons and anticodons?

Codons are mRNA sequences specifying amino acids; anticodons are complementary tRNA sequences.

What are the key sites in the ribosome during translation?

A-site (accepts tRNA), P-site (forms peptide bond), E-site (exit site for tRNA).

What is the Shine-Dalgarno sequence?

A bacterial mRNA sequence that helps ribosomes bind for translation initiation.

What are the three types of mutations?

Silent mutation, Missense mutation, Nonsense mutation.

What causes sickle cell disease?

A single nucleotide mutation in the β-globin gene, changing Glutamic Acid (Glu) to Valine (Val).

What is a Punnett square used for?

Predicting possible genotypes and phenotypes based on parental genes.

What is the difference between pharmacokinetics and pharmacodynamics?

Pharmacokinetics is how the body processes a drug (ADME); Pharmacodynamics is how the drug affects the body.

What is the role of the CYP450 enzyme family?

Metabolizes drugs; genetic variations affect drug response.

What is genetic recombination?

A process where genetic material is shuffled during meiosis, increasing genetic diversity.

What is the difference between pharmacogenetics and pharmacogenomics?

Pharmacogenetics studies single genes; pharmacogenomics examines the entire genome's influence on drug response.

What is the difference between homozygous and heterozygous genotypes?

Homozygous has identical alleles; heterozygous has different alleles.

What are introns and exons?

Introns are non-coding regions removed during splicing; exons are coding regions that remain in mature mRNA.

How does an individual’s CYP2D6 phenotype affect Tamoxifen therapy?

Poor metabolizers may need alternative therapy; intermediate metabolizers may require higher doses.

What is the difference between X-linked and Y-linked inheritance?

X-linked traits are inherited from the mother; Y-linked traits are inherited from the father.

What is the role of tRNA in translation?

It carries amino acids to the ribosome and pairs with mRNA codons.

What is the role of ribosomes in protein synthesis?

They facilitate the translation of mRNA into a polypeptide chain.

What is the function of DNA polymerase?

It synthesizes new DNA strands during replication.

What is the function of helicase?

It unwinds the DNA double helix during replication.

What is the difference between semiconservative and conservative DNA replication?

Semiconservative keeps one old and one new strand; conservative keeps the original strands together.

What is a dominant allele?

An allele that expresses its trait even when only one copy is present.

What is a recessive allele?

An allele that only expresses its trait when two copies are present.

What is a haploid cell?

A cell with one set of chromosomes (e.g., sperm, egg).

What is a diploid cell?

A cell with two sets of chromosomes, one from each parent.

What is Mendel’s Law of Segregation?

Each individual has two alleles, and they separate during gamete formation.

What is Mendel’s Law of Independent Assortment?

Genes for different traits assort independently during gamete formation.

What is the function of histones in DNA?

Proteins that help package DNA into chromatin.

What are the four nucleotide bases of DNA?

Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

What are the four nucleotide bases of RNA?

Adenine (A), Uracil (U), Cytosine (C), Guanine (G).

What is the purpose of the promoter region in a gene?

Signals RNA polymerase where to start transcription.

What is an operon?

A group of genes under the control of a single promoter, found in prokaryotes.

What is the role of the Poly-A tail in mRNA processing?

Protects mRNA from degradation and aids in nuclear export.

What is the role of the 5' cap in mRNA processing?

Protects mRNA from degradation and helps ribosome recognition.

What is the function of topoisomerase in DNA replication?

Prevents DNA supercoiling by relieving torsional strain.

What is a silent mutation?

A mutation that changes a codon but does not change the amino acid sequence.

What is a missense mutation?

A mutation that results in a different amino acid in the protein.

What is a nonsense mutation?

A mutation that creates a premature stop codon, leading to a truncated protein.

What is the function of rRNA?

Helps form ribosomes and facilitates translation.

What is the function of snRNA?

Involved in RNA splicing and processing.

What are transcription factors?

Proteins that regulate transcription by binding to DNA sequences.

What are epigenetic modifications?

Chemical changes to DNA or histones that affect gene expression.

What is DNA methylation?

Adding a methyl group to DNA, often silencing gene expression.

What is histone acetylation?

Adding an acetyl group to histones, enhancing transcription.

What is a pharmacogenomic biomarker?

A genetic marker influencing drug response, used in personalized medicine.

What is a haplotype?

A set of genetic variations inherited together on the same chromosome.

What is the central dogma of molecular biology?

DNA → RNA → Protein; the flow of genetic information.

What is a frameshift mutation?

A mutation caused by insertions or deletions shifting the reading frame.

What is an enhancer region in DNA?

A sequence that increases transcription efficiency.

What is the role of ATP in translation?

Provides energy for aminoacyl-tRNA synthesis and peptide bond formation.

What is an inducible operon?

A gene cluster activated by a specific molecule (e.g., lac operon).

What is a repressible operon?

A gene cluster turned off by a specific molecule (e.g., trp operon).

What is a spliceosome?

A complex that removes introns from pre-mRNA and joins exons.

What is a nonsense-mediated decay (NMD) pathway?

A pathway that degrades faulty mRNA to prevent defective protein production.

What is the function of GTP in translation?

Provides energy for initiation, elongation, and termination.

What is a genetic drift?

A random change in allele frequencies within a population over time.

What is a transposon?

A "jumping gene" that moves to different genome locations.