DNA replication

• What is the central dogma of genetics?

  It describes the flow of genetic information from DNA to mRNA to protein.

  
• What is a gene?

  A gene is a length of DNA.
• What is a genome?

  A genome is the full complement of DNA for an organism.

  
• How many genes do humans have approximately?

  Humans have approximately 25,000 genes.
• What are the building blocks of DNA and RNA?

  The building blocks are nucleotides.

  
• What distinguishes DNA from RNA in terms of sugar?

  DNA contains deoxyribose, while RNA contains ribose.

  
• How are the carbon atoms in sugars numbered?

  The carbon atoms are numbered from 1' to 5'.
• What happens to the hydroxyl group in deoxyribose?

  The hydroxyl group at the 2' carbon is replaced by a hydrogen atom.

  
• What are the two types of nitrogenous bases?

  Purine bases and pyrimidine bases.

  
• How are purine bases structured?

  Purine bases have two interlocked rings.
• How are pyrimidine bases structured?

  Pyrimidine bases have a single ring structure.
• What is a nucleotide triphosphate composed of?

  A nucleotide triphosphate consists of a base, a sugar, and three phosphates.
• What type of bond joins nucleotides together?

  Nucleotides are joined by 3' to 5' phosphodiester bonds.

  
• What is the directionality of a DNA strand?

  A DNA strand has a 5' end and a 3' end.
• What is the structure of DNA?

  DNA has a double helix with anti-parallel orientation.

  
• What forms the backbone of the DNA structure?

  The sugar-phosphate backbone forms the exterior of the DNA structure.

  
• What is complementary base pairing in DNA?

  Complementary base pairing involves A-T and G-C pairs.
• How many hydrogen bonds are formed between A and T?

  Two hydrogen bonds are formed between A and T.
• How many hydrogen bonds are formed between G and C?

  Three hydrogen bonds are formed between G and C.
• What does the sequence of bases in DNA represent?

  The sequence of bases is the storage form of genetic information.
• What is the significance of complementarity in DNA?

  Complementarity ensures that the quantity of A equals T and G equals C.
• What is the structure of a nucleosome?

  A nucleosome consists of 8 histone proteins forming an octamer core particle.

  
• What is the role of histone tails in chromatin structure?

  Histone tails are important for chromatin structure but are not involved in nucleosome structure.

  
• How does acetylation affect chromatin structure?

  Acetylation promotes a looser DNA structure and aids transcription.

  
• What is the role of histone acetyl transferase (HAT)?

  HATs activate transcription by unwinding DNA.

  
• What is the role of histone deacetylase (HDAC)?

  HDACs repress transcription by condensing DNA.

  
• What is the clinical relevance of HDAC inhibitors like Vorinostat?


  HDAC inhibitors are FDA approved for treating cutaneous T-cell lymphoma and solid malignancies.

  
• What is the function of telomeres?

  Telomeres cap the ends of chromosomes and maintain structural integrity.
• What is the difference between heterochromatin and euchromatin?

  Heterochromatin is highly condensed and gene-poor, while euchromatin is extended and gene-rich.
• What percentage of the human genome is composed of protein-coding regions?

  Only about 1.5% of the human genome is composed of protein-coding regions.
• What is the ENCODE project?

  The ENCODE project aims to identify biochemical functions of components of the human genome.
• What is mitochondrial DNA?

  Mitochondrial DNA is a circular, double-stranded DNA containing 37 genes.
• What are the components of a human gene?

  A human gene consists of promoter elements, UTRs, exons, and introns.

  
• What is the role of the promoter in a gene?

  The promoter recruits proteins necessary for transcription.
• What is the function of exons in a gene?

  Exons code for amino acid sequences in proteins.
• What is the function of introns in a gene?

  Introns are poorly understood but are involved in splicing.
• What is the significance of the 3' UTR in a gene?

  The 3' UTR is important for mRNA stability.
• What is the process of DNA replication?

  DNA replication is a complicated process involving many proteins.

  
• What is semiconservative replication?

  Semiconservative replication involves one parental and one newly synthesized strand.

  
• What are the requirements for DNA replication?

  Requirements include a single-stranded template, dNTPs, a replisome, and a primer with a free 3' end.