BIOCHEM

• What is the structure of DNA?

  DNA is a double helix

  
• What does it mean for the two strands of DNA to be antiparallel?

  It means the strands run in opposite directions
• How are the two strands of DNA described as complementary?

  Each strand pairs with specific bases on the opposite strand
• What are the components of a nucleotide?

  • Nitrogenous base
  • Pentose sugar
  • Phosphate group

  
• Which nitrogenous bases are found in both RNA and DNA?

  Adenine, guanine, and cytosine

  
• Which nitrogenous base is found only in DNA?

  Thymine

  
• Which nitrogenous base is found only in RNA?

  Uracil

  
• What is the UV absorption range of nucleobases?

  Nucleobases absorb light in the range of 250–270 nm
• What are the characteristics of the nucleotide and nucleoside backbone?

  • Negatively charged backbone
  • DNA sequence stores genetic information
  • Directionality with distinct 5’ and 3’ ends

  
• In what direction is the DNA sequence read?

  The sequence is read from 5’ to 3’
• What is the significance of the phosphodiester linkage in nucleotides?

  It connects the nucleotides in the DNA backbone

  
• How does the DNA sequence affect its stability?

  The sequence determines the melting point of the DNA
• What is the melting point of DNA?

  It is the temperature at which half the DNA is denatured

  
• How does the content of G≡C base pairs affect the melting point of DNA?

  The higher the G≡C content, the higher the melting point

  
• What is the structure of RNA?

  RNA is typically single-stranded
• What is the primary function of proteins in relation to nucleic acids?

  Proteins are synthesized based on the information encoded in nucleic acids
• What are the specific functions of adenine, guanine, cytosine, thymine, and uracil?

  Adenine and guanine are purines; cytosine, thymine, and uracil are pyrimidines

  
• What are the differences between DNA and RNA?

  • DNA: double-stranded, contains thymine, stores genetic information
  • RNA: single-stranded, contains uracil, involved in protein synthesis

  
• Transcription occurs in the nucleus, while translation takes place on ribosomes.
• Protein synthesis involves transcription (DNA to mRNA) and translation (mRNA to protein).
• The three-dimensional structure of proteins is determined by the primary, secondary, tertiary, and quaternary structures.
• In transcription, mRNA is produced from DNA by adding complementary bases (adenine with thymine or uracil).
• Translation involves decoding the sequence of codons into amino acid sequences using tRNAs as adaptors.
• mRNA carries the code for making a polypeptide chain.
• The process of gene expression begins with transcription, where DNA serves as a template for the formation of an mRNA molecule.
• tRNA brings specific amino acids to the growing peptide chain during translation.
• Amino acids are joined together through peptide bonds to form polypeptides.
• Translation involves decoding the sequence of amino acids based on the codons present in the mRNA molecule.
• In eukaryotic cells, transcription occurs in the nucleus and translation occurs on ribosomes attached to the endoplasmic reticulum.
• Translation is the second step in gene expression, where the mRNA molecule directs the assembly of amino acids into a polypeptide chain according to the genetic code.
• Protein synthesis is regulated by various factors such as hormones, growth factors, and environmental conditions.
• Translation uses ribosomes to read the genetic code on mRNA and bring together the correct amino acids to form a protein.
• Protein synthesis is the process by which cells make proteins from amino acids.
• Proteins have various functions such as enzymes, structural components, hormones, antibodies, transport proteins, and storage proteins.
• Quelles sont les caractéristiques générales de la réplication de l'ADN?

  La réplication de l'ADN est semi-conservative, bidirectionnelle et semi-discontinue.
• Pourquoi la réplication de l'ADN est-elle considérée comme semi-conservative?

  Parce qu'une nouvelle molécule d'ADN double brin contient une brin original et un brin nouvellement synthétisé.
• Que se passe-t-il lors de la réplication bidirectionnelle de l'ADN?

  Les brins parentaux sont déroulés et répliqués simultanément dans deux directions.
• Quel est le point d'origine de la réplication de l'ADN appelé?

  OriC.
• Pourquoi la réplication de l'ADN est-elle décrite comme semi-discontinue?

  Parce que la synthèse est continue pour le brin directeur et discontinue pour le brin tardif.
• Dans quelle direction se produit toujours la synthèse de l'ADN?

  Dans la direction 5' -> 3'.