Prelim-Physio star

• Nucleus - Double membrane-bound large structure containing chromatin.
• Nucleus


  Chromosomes (DNA) contain the genetic blueprint for every protein in the body
• Nuclear envelope/membrane - Double lipid bilayer with nuclear pore complexes
• Function of nuclear envelope 


  Separates and mediates transport between nucleus and cytoplasm
• Nucleolus - Dense non-membrane-bound structure in nucleus that synthesizes ribosomal RNA
• Ribosomes - Small structures free in cytoplasm or bound to endoplasmic reticulum. Consist of two subunits of ribosomal RNA.
• Endoplasmic reticulum - Extensive membrane system within the cell; may be rough (rER) with associated ribosomes, or smooth (sER)
• what is the function of Endoplasmic reticulum

  proteins synthesised on ribosomes (rER), synthesis of some lipids (sER)
• Golgi apparatus/stack - Stacks of flattened membrane-bound cisternae
• What is the function of Golgi apparatus

  Final assembly and glycosylation of proteins and dispatch to their ultimate destination
• Mitochondria - Double membrane-bound organelles with folded inner membrane
• what is the function of mitochondria

  Energy production, mainly in the form of ATP
• Plasma membrane - Lipid bilayer containing intrinsic proteins and with an external coat of carbohydrate
• what is the function of plasma membrane

  Divides cell from external environment and mediates interactions with external environment
• Cytoskeleton - Microfilaments, intermediate filaments

  and microtubules
• Function of cytoskeleton

  Maintain cell shape and orientation, cell movement, movement of organelles around
• Secretory vesicles - Membrane-bound vesicles often with a protein coat, e.g. COP I, clathrin
• Function of secretory vesicles

  Transport materials between different cell compartments and to plasma membrane for export
• Phagosomes/endosomes-including sorting and recycling endosomes -Membrane-bound vesicles containing material imported into cell
• function of phagosomes

  Phagocytosis and transport of cargo to intracellular destination
• Lysosomes - Membrane-bound vesicles containing hydrolytic enzymes
• Function of lysosomes

  Killing of pathogenic organisms (in phagocytic cells) and degradation of waste products
• Peroxisomes - Membrane-bound vesicle containing oxidases and catalase
• Function of peroxisomes

  Production of hydrogen peroxide
• Lipid droplets - Non-membrane-bound spherical aggregates of lipid of variable size
• Glycogen granules - Non-membrane-bound granules and aggregates of granules (rosettes)
• Lipofuscin - Brown pigment in cytoplasm
• Melanin - Brown pigment in cytoplasm
• Eukaryotes:

  • Organisms that possess a true nucleus and membrane-bound organelles
  • Have a defined nucleus with a nuclear envelope
  • Genome is tightly packed and organized into a complex of chromosomes
  • Ribosomes are larger and 80S
  • Organelles are membrane-bound
  • Have a longer generation time
  • Taxonomic diversity is low compared to prokaryotes
  • Can undergo both sexual and asexual reproduction
  • Have a larger cell size
• Prokaryote:

  • Organisms that lack membrane-bound organelles and a nucleus
  • Lack a defined nucleus, but have a nucleoid without an envelope
  • Genome is an irregular complex of DNA with only one loop of stable chromosomes
  • Generally multicellular, but there are unicellular prokaryotes as well
  • Ribosomes are smaller and 70S
  • Membrane-bound organelles are absent
  • Have a shorter generation time
  • Have very high taxonomic diversity
  • Reproduction takes place only via asexual binary fission and budding
  • Have a smaller cell size
• What type of cellular transport is not dependent on the Na gradient?

  simple diffusion, facilitated diffusion, primary active transport
• Is simple and facilitated diffusion, active or passive.

  Active; downhill
• Which of the transports is not carrier-mediated?

  Simple diffusion
• which of the transports does not use metabolic energy

  simple diffusion and facilitated diffusion
• Which of the transports uses metabolic energy but not indirect

  cotransport and countertransport
• What is the 2/3 fluid in the body?

  Intracellular fluid
• What is the 1/3 fluid in the body?

  Extracellular fluid
• Early weeks of embryonic life: primitive nucleated RBC produced in the

  yolk sac
• middle trimester of gestation: mainly produces RBC

  liver
• last month of gestation and after birth

  bone marrow