Foundations-Cells-5
From CellBiology
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 - chemical processes within and relating to living organisms.
- chromosome territory - 3 dimensional region of the nucleus occupied by a specific chromosome.
- compartment - a separate section region or part of a structure.
- cytoskeleton - formed together by the 3 separate filaments systems (microfilaments, microtubules, and intermediate filaments) within cells. Note the nucleus only contains intermediate filaments.
- DNA - Deoxyribonucleic acid the basic structure of our genes located in the nucleus and within mitochondria.
- metabolic process - chemical processes/transformations required for survival of cells.
- mitochondria -
- nucleus -
- nucleolus - functional compartment within the nucleus formed by a number of chromosomes and contains genes for the ribosome.
- nuclear envelope - double membrane surrounding the nucleus.
- nuclear pore - protein channel in the nuclear envelope that regulates transportation between the nucleus and the cytoplasm.
- organelle - membrane enclosed compartment within a cell that has a specific function.
- symbiotic - interaction between two different organisms living in close physical association. Note this is an theoretical evolutionary term for mitochondria, as they cannot today exist as a separate organism.
- vesicles - general term for small membrane enclosed spaces within the cytoplasm.
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....
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
Proposed model for nucleus organelle membrane evolution |
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
- 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 |
