cell Flashcards
description of a live cell was first given by?
antom von leeuwenhoeak
discovery of nucleus
robert brown
the hypothesis that the bodies of plants and animals are made up of cells and products of cells is given by
theodore schwann, a british zoologist
main arena of cellular activities in all types of cells
cytoplasm
non- membrane bound organelles
ribosomes (found in all cells, prokaryo and eukaryo)
centriole
presence of ribosomes
; in all types of cells
; organelle within organelle (chloroplast and mitochondria)
; on rough ER
; in cytoplasm as well
length of mycoplasma and bacteria
0.3 micrometre
3-5 micrometre
diametre of human RBC
7 micrometer
genetic material of prokaryotics
basically naked
not enveloped by a nuclear envelope
single chromosome / circular DNA
double stranded
plasmids
small circular DNA outside genomic DNA
; confers certain PHENOTYPIC characters to bacteria (ex- resistance to antibiotics)
what kind of DNA is used to monitor bacterial transformation in foreign DNA
plasmid
special charachteristic of prokaryotic orgaisms
- inclusion
; mesosome- essentially infoldings of cell membranes - specialzied differentiated forms of cell membrane
functions of mesosome
cell wall formation
DNA replication & distribution to daughter cells
respiration
secretion
increase in SA of plasma membrane & enzymatic content
membranous extension in cyanobacteria
chromatophores (contains pigments)
bacterial flaggelum is made up of three parts-
filament, hook and basal body
filament is the longest structure and extends from the cell surface to the outside
inclusion bodies
unique feature of prokaryotes
reserve material is stored in the cytoplasm in the form of inclusion bodies
not bound by any membrane
ex- phosphate granules
cyanophycean granules
glycogen granules
gas vacuoles are found in blue green and purple green photosynthetic bacteria
plastids are found in
a) animal cells
b) plant cells
c) both
plant cells only
peroxisome is found in
plant cell
peroxiome is found in
animal cell
the lipid component of cell membrane mainly consist of
phosphoglycerides
in human beings the membrane of the RBC have _ % protein and _ % lipids
52% protein
40% lipids
composition of cell membrane
composed of lipids arranged in a bilayer
also contain protein and carbs
fluid mosaic model
given by singer and nicolson
;; acc to this model, the quasi fluid nature of LIPID enables lateral movement of proteins within the overall bilayer
thefluidityofthemembraneisbecauseoflipids
the fluid nature of cell membrane helps to enhance what functions
cell growth
formation of intercellular junction
secretion
endocytosis
cell division