Structure and function of a nucleus

• Nucleus


  Contains genetic information and is the site of protein synthesis
• Proteins


  • Enzymes required for chemical reactions
  • Structural role in cells
  • Transport molecules
• Protein synthesis


  1. Genetic information in nucleus transcribed to mRNA

  2. mRNA leaves nucleus

  3. Ribosome reads mRNA and synthesizes protein
• Transcription


  Process of converting genetic information in nucleus to mRNA
• Translation


  Process of ribosome reading mRNA and synthesizing protein
• Nucleoplasm


  Material inside nucleus containing molecules needed for DNA and RNA synthesis
• Nuclear envelope


  • Double phospholipid bilayer membrane surrounding nucleus
  • Contains nuclear pores to allow molecules to enter and leave
• Nuclear pores


  Allow molecules to enter and leave the nucleus
• Chromatin


  DNA coiled around histone proteins, forms chromosomes
• Nucleolus


  Site of ribosomal RNA synthesis and ribosome subunit assembly
• Chromosomes are not visible inside the nucleus unless the cell is undergoing mitosis or meiosis