DNA Transcription to Translation

• What is the primary function of the nuclear envelope?

  Protection and compartmentalization
• What is the role of the nucleolus?

  It produces ribosomal RNA and proteins
• What is chromatin composed of?

  DNA and proteins
• What is the function of histones in the nucleus?

  They help DNA to coil and package
• How large is the nucleus in a eukaryotic cell?

  Around 5µm in diameter
• What is the structure of the nuclear envelope?

  It is a lipid bilayer with pores

  
• What does the H and E stain visualize in cells?

  Nucleic acids and proteins
• What are the constituents of ribosomes?

  Small and large subunits with rRNA

  
• What is the complete ribosome size in eukaryotic cells?

  80S
• What is the function of the A site in ribosomes?

  It binds incoming tRNA with amino acids

  
• What is the role of the Golgi apparatus?

  Processes and sorts proteins for transport
• What are the main components of the Golgi apparatus?

  Flattened, membrane-bound sacs called cisternae

  
• How does the Golgi apparatus receive proteins?

  Proteins enter via the cis face

  
• What is the function of mRNA?

  It carries genetic code from nucleus

  
• What are the three main types of RNA?

  tRNA, rRNA, and mRNA
• What are purines in DNA?

  Adenine and guanine
• How do adenine and thymine pair in DNA?

  They pair via two hydrogen bonds
• What is the significance of triplet codons in DNA?

  They can specify 64 different amino acids

  
• Why is the genetic code considered degenerate?

  Most amino acids have multiple codons
• What is the start codon for translation?

  AUG

  
• What happens during transcription initiation?

  RNA polymerase binds to the promoter

  
• What is the role of RNA polymerase during transcription elongation?

  It adds complementary RNA nucleotides

  
• What is the purpose of RNA processing in eukaryotic cells?

  To remove introns and modify mRNA

  
• What is the function of the poly-A tail in mRNA?

  It protects mRNA from degradation

  
• What signals the termination of translation?

  A stop codon is reached

  
• What is the chemical formula for alanine?

  C$3$H$7$NO$2$
• What is the property of arginine?

  It is basic
• What is the single-letter code for asparagine?

  N
• What is the significance of reading frames in genetic code?

  They determine correct codon grouping
• What are the stages of transcription?

  1. Initiation
  2. Elongation
  3. Termination

  
• What are the steps of RNA processing in eukaryotic cells?

  • Removal of introns via splicing
  • Addition of a 5' cap
  • Addition of a poly-A tail

  
• What are the functions of the three types of RNA?

  • tRNA: Carries amino acids to ribosomes
  • rRNA: Forms ribosomes for translation
  • mRNA: Carries genetic code from nucleus

  
• What are the differences between the small and large ribosomal subunits?

  • Small subunit (40S): Contains 18S rRNA and 33 proteins
  • Large subunit (60S): Contains 5S, 5.8S, 28S rRNA and 49 proteins

  
• What is the role of the Golgi apparatus in protein processing?

  • Receives proteins from the ER
  • Processes and sorts proteins for transport
• What is the significance of codon redundancy in the genetic code?

  • Most amino acids have multiple codons
  • The genetic code is nearly universal
• What is the process of translation initiation?

  • Begins with start codon AUG
  • Small ribosomal subunit aligns with mRNA
  • Initiator tRNA binds to P site

  
• What happens during translation elongation?

  • tRNA binds to A site
  • Peptide bond forms between amino acids
  • Unbound tRNA moves to E site

  
• What is the process of translation termination?

  • Signaled by stop codon
  • No tRNA binds to stop codon
  • Completed polypeptide is released

  
• What is the role of RNA polymerase in transcription?

  • Binds to promoter
  • Unwinds DNA
  • Synthesizes RNA from DNA template

  
• What is the importance of the 5' cap and poly-A tail in mRNA processing?

  • Protects mRNA from degradation
  • Facilitates export from the nucleus