1.2 Ultrastructure of cells Flashcards
What are prokaryotes?
Prokaryotes are unicellular organisms with a simple cell structure without compartmentalization, including bacteria and archaea.
How do prokaryotic cells differ from eukaryotic cells in terms of internal structure?
Prokaryotic cells lack a nucleus and membrane-bound organelles, with all metabolic processes occurring within the cytoplasm.
What is the significance of the plasma membrane in prokaryotic cells?
The plasma membrane surrounds the cell, controlling the movement of substances in and out of the cell.
How do prokaryotes reproduce?
Prokaryotes reproduce by binary fission, a process that produces two genetically identical cells.
What role do plasmids play in prokaryotic cells?
Plasmids are small circles of DNA that carry a few genes, often providing antibiotic resistance and used in genetic modification.
Define eukaryotes.
Eukaryotes are organisms with complex cells, where the genetic material is isolated from the cytoplasm by a membrane-bound nucleus.
What is compartmentalisation in eukaryotic cells?
Compartmentalisation refers to the formation of compartments within the cell by membrane-bound organelles, allowing for specialized functions.
How does the nucleus function in eukaryotic cells?
The nucleus controls all activities of the cell, including the reproduction of unicellular organisms.
What is the function of mitochondria in eukaryotic cells?
Mitochondria are the sites of cellular respiration, generating ATP for the cell.
Describe the role of the Golgi apparatus in eukaryotic cells.
The Golgi apparatus processes and packages proteins, which are then released in Golgi vesicles.
What is the advantage of electron microscopes over light microscopes?
Electron microscopes have a much higher resolution, allowing for the detailed observation of small cellular structures and disease-causing particles.
How has electron microscopy contributed to our understanding of cellular structures?
It has enabled the detailed study of organelles, such as the thylakoid membranes of chloroplasts and the actin and myosin filaments of muscle, enhancing our understanding of cellular functions.
What are the key applications of electron microscopes in biological research?
Electron microscopes are used to study the ultrastructure of cells, observe small cellular structures like viruses and protein complexes, and aid in the detailed examination of organelles within cells to understand their functions and interactions.
What is the primary function of exocrine gland cells in the pancreas?
Exocrine gland cells in the pancreas secrete digestive enzymes into the pancreatic duct, which then enters the small intestine to aid in food digestion.
How are digestive enzymes produced and secreted by the exocrine gland cells of the pancreas?
Digestive enzymes are synthesized on the rough endoplasmic reticulum, processed and packaged in the Golgi apparatus, and then transported in vesicles that fuse with the plasma membrane to release the enzymes.
