Difference between revisions of "Foundations-Cells-5"

From CellBiology
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==Terms==
 
==Terms==
 +
* '''biochemical process''' -
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* '''compartment''' -
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* '''DNA''' -
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* '''metabolic process''' -
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* '''mitochondria''' -
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* '''nucleus''' -
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* '''nuclear envelope''' -
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* '''nuclear pore''' -
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* '''organelle''' -
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* '''symbiotic''' -
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* '''vesicles''' -
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 +
  
 
== Compartments ==
 
== Compartments ==

Revision as of 14:42, 5 February 2018

Compartments


This lecture is also an introduction to cell compartments and describes the structure of membranes forming these compartments.


Draft - this online lecture is currently in 2020 draft status. This notice removed when completed.
Cells and Membranes: 1 Cells and sizes | 2 Prokaryotes | 3 Viruses and prions | 4 Plasma membrane | 5 Compartments | 6 Membrane structure | 7 Membrane specialisations | Foundations - Moodle

Terms

  • biochemical process -
  • compartment -
  • DNA -
  • metabolic process -
  • mitochondria -
  • nucleus -
  • nuclear envelope -
  • nuclear pore -
  • organelle -
  • symbiotic -
  • vesicles -


Compartments

  • Physical Compartments - membrane bound
    • Nucleus, Cytoplasm, Organelles
    • cell nomenclature based upon presence or absence of these compartments (eukaryotic, prokaryotic).
  • Functional Compartments - not membrane bound
    • spatial localization for targeting, activation and inactivation, signaling.

Major Cellular Compartments

  • Nucleus (nuclear) - contains a single organelle compartment
  • Cytoplasm (cytoplasmic) - contains many organelle compartments

Organelle Number/Volume

  • How many organelles?
  • How much space within the cell do they occupy?
  • Are all the cells the same?

Take a typical mammalian liver cell....

Liver Structure


Table 12-1. Relative Volumes Occupied by the Major Intracellular Compartments in a Liver Cell (Hepatocyte)

Table 12-2. Relative Amounts of Membrane Types in Two Kinds of Eucaryotic Cells


Compartments are Dynamic - Movies showing flexibility of membranes and their changing shape and size.

Nuclear Compartment

Membrane evolution.jpg

Proposed model for nucleus organelle membrane evolution

Nucleus cartoon3.jpg

Nucleus cartoon

  • Nuclear envelope - a double membrane with pores passing through both membranes.
  • Nuclear matrix - consisting of Intermediate filaments (lamins)
  • Nucleoli (functional compartment - localised transcription DNA of RNA genes)
  • Chromosomes (DNA and associated proteins)

Note

  • there are no additional membrane compartments within the nucleus itself.
  • you will not see chromosomes in interphase cell nuclei (only during mitosis/meiosis).

Cytoplasmic Compartment

Mitochondria
  • Cytoplasmic Organelles - Membrane bound structures (Endoplasmic reticulum, golgi apparatus, mitochondria, lysosomes, peroxisomes, vesicles)
  • Cytoskeleton - 3 filament systems
  • Cytoplasmic “structures” - Ribosomes (translation)
  • Proteins - Receptors, signaling, metabolism, structural
  • Viruses, bacteria, prions


Functional compartments (you cannot see a membrane)

  • occur in nucleus, cytoplasm, in organelles and outside organelles
  • signaling, metabolic reactions, processing genetic information, cytoskeleton dynamics, vesicle dynamics



Draft - this online lecture is currently in 2020 draft status. This notice removed when completed.
Cells and Membranes: 1 Cells and sizes | 2 Prokaryotes | 3 Viruses and prions | 4 Plasma membrane | 5 Compartments | 6 Membrane structure | 7 Membrane specialisations | Foundations - Moodle