Cellular organelles

• How are prokaryotes and eukaryotes classified?

  By morphology and presence of nucleus
• What does the term "prokaryote" mean?

  Pre-nucleus
• What are the two main types of prokaryotes?

  Bacteria and Archaea
• What does the term "eukaryote" mean?

  True nucleus
• What are the characteristics of prokaryotic cells?

  They are small, simple, and lack a nucleus and organelles

  
• What is the typical diameter range of prokaryotic cells?

  0.2-2 µm
• What is the structure of prokaryotic ribosomes?

  They are small and simple

  
• How many genes does a prokaryotic genome typically have?

  At least 500 genes
• How do eukaryotic cells differ from prokaryotic cells in size?

  Eukaryotic cells are about 10 times larger than prokaryotic cells
• What is a key feature of eukaryotic cells regarding their nucleus?

  They have a true nucleus with a membrane
• What are some specialized organelles found in eukaryotic cells?

  Membrane-bound organelles like mitochondria and Golgi apparatus

  
• What is the function of the cytoskeleton in eukaryotic cells?

  Provides structure and motility
• How many genes do humans have?

  25,000 to 30,000 genes
• What is the difference between cytoplasm and cytosol?

  Cytoplasm includes all cell contents except the nucleus, while cytosol is the aqueous gel around organelles
• When are chromosomes visible in a cell?

  When a cell is about to divide
• What are the main organelles in eukaryotic cells?

  • Nucleus
  • Nucleolus
  • Rough Endoplasmic Reticulum
  • Smooth Endoplasmic Reticulum
  • Golgi Apparatus
  • Lysosomes
  • Mitochondria

  
• What is the function of the nucleolus?

  It is the site of ribosome production
• What is the structure of the nuclear envelope?

  It is a double lipid bilayer with pores

  
• What is the role of nuclear pores?

  They permit RNA, proteins, and other molecules to move in and out of the nucleus
• What is the function of the endoplasmic reticulum?

  It is involved in the biosynthesis and modification of lipids and proteins

  
• What is the difference between smooth and rough endoplasmic reticulum?

  Smooth ER lacks ribosomes, while rough ER has ribosomes on its surface
• What is the function of the Golgi apparatus?

  It processes, packs, and exports proteins and lipids

  
• What are the three regions of the Golgi apparatus?

  Cis, medial, and trans Golgi

  
• What happens to lipids and proteins in the Golgi apparatus?

  They enter, progress through stages, undergo modifications, and are packed in vesicles for export

  
• What are lysosomes and their function?

  They are acidic organelles involved in degradation of unwanted organelles and phagocytosed materials
• What enzymes do lysosomes contain?

  Acid hydrolases that work at low pH
• How do lysosomes maintain their acidic environment?

  Through a proton pump and chloride channel
• What does the cytoplasm contain within the cell membrane?

  Cell contents except the nucleus
• What is the primary function of the cytosol?

  It is the site of chemical reactions and metabolic pathways
• What is the nucleus responsible for?

  DNA and RNA synthesis
• What does the nucleolus produce?

  Ribosomes
• When are chromosomes visible?

  When they condense as the cell is about to divide
• What is apoptosis?

  It is the process by which a cell destroys itself
• What is the nuclear envelope composed of?

  A double lipid layer with pores
• What is the function of the pores in the nuclear envelope?

  They allow RNA and proteins to move appropriately
• What does the inner membrane of the nuclear envelope contain?

  Proteins that act as binding sites for chromosomes
• What is the nuclear lamina?

  A network of fibrous filaments that provide support to the nuclear envelope
• What is the rough endoplasmic reticulum involved in?

  Protein synthesis, secretion, and modification
• What is the primary function of the smooth endoplasmic reticulum?

  Involved in lipid metabolism and storage of Ca$^{2+}$
• Where are smooth endoplasmic reticulum abundant?

  In hepatocytes