Cells Flashcards
what is the cell theory?
states that organisms consist of cells and the products of cells and that all cells come from pre existing cells
how can cells be studied?
microscopy
light microscope
TEM
seperating cotent via centrifuge and then using biochemical tech to study the fractionated components
genetics and transcriptomics
why are cells so small?
surface/ volume considerations
surface to volume ratio of a cell decreases with increasing size
why are cells spherical?
surface to volume ratio decreases with increasing sphericity
for small spherical cells compared to larger ones of volume is seved by a larger area of surface
transport of things in and out of the cell is more rapid with smaller ccells
tme of diffusion of a molecule is proportional to what?
distance ^2
some cells are very large what is different about them?
they are metabolically inactive or they are non-spherical or they have many nuclei
what are prokaryotic cells?
include bacteria and archaea
smaller non-compartmentalized, have no nucleus or cytoskelton, small genome
what are eukaryotic cells?
larger incluse protists, plants, animals, fungi
have membrane-bounded compartmentalization of functions have nucleus and cytoskeleton and larger genome
the plasma membrane is what?
selective barrier that surrounds all cells
allows some things to pass through but not all
the membrane that surrounds the organelles in eukaryotic cells are what?
selective barries they myriad functions in the cell are therefore compartmentalized
the Nucleus is what?
the protected area bound by two membranes where chromosomes are located and where genes are transcribed
what are the contents of the nucleus?
chromatin (organized into chromosomes)
nucleolus
enzyme that work on dna
nuclear lamina
what do ribosomes do?
where protein synthesis takes place
what do ribosomes consist of ?
two subunits, a larger one and a smaller one, each composed of ribosomal RNA and many proteins
free risosomes are located where?
cytosol
