Cell unit 3 Flashcards
what are other names for ribosomes
Palade’s particles
*Universal cell organelle
*Smallest cell organelle
*Organelle within organelle
*Protein factory of cell
give the components of
i) 50s
ii)30s
iii)60
iv)40s
i) 5s+23s
(ii) 16s
iii) 5s+5.8s+28s
iv)18s
what joins the 2 subunits of ribosomes
Magnesium ion is essential for the
binding the ribosome sub units. Mg+2
form ionic bond with phosphate groups
of r- RNA of two subunits.
They join only during protein synthesis, but other times they are free in the cytoplasm
differentitate microfilaments and microtubules and intermediate filaments
Microfilaments
*Consists of Actin protein
*Solid, linear rod like
structure
*Mechanical support
*Maintenance of cell shape
*Cell motility (as in
pseudopodia)
*Muscle contraction
Microtubules
*Consists of Tubulin protein
*Hollow, cylindrical tube like
structure
*Mechanical support
*Maintenance of cell shape
*Cell motility as in cilia or flagella
*Chromosomal movement
Intermediate filament
*Solid, linear rod like
structure
*Mechanical support
*Maintenance of cell shape
*Formation of nuclear
lamina
differentiate cilia and flagellum
cilia
->small
-> more numeroud
->oar like movement( to and fro)
-> help in movement, attachment feeding and sensation
flagella
-> large
-> lesser in number
-> whip like movement, undulating
-> only locomoiton
centrioles are self duplicating strcutures
what are peroxisomes/uricosomes
These are found in both plant and animal cells. Peroxisomes contain catalase enzyme
which is concerned with peroxide (H2O2) metabolism. Catalase degrade the H2O2 into
water and oxygen.
In plants, peroxisomes are found in cells of green tissues and concerned with
photorespiration (glycolate pathway).
Peroxisomes are also involved in beta-oxidation of fatty acids.
what are glyoxysomes
Glyoxysomes occurs only in plants especially in fatty seeds (castor seed, ground nut seed etc.).
Glyoxysomes are considered as a highly specialised peroxisomes. Glyoxylate cycle takes
place in glyoxysomes. This cycle convert fats into carbohydrats.
found in endosperm of germinating cells
what were the basic dyes used to dye nuclei
acetocarmine
give examples of:
(i) multinucleate
(ii) dinucleate
(iii)enucleate
(i) phycomycets fungus
(ii) paramoecium
(iii) mature rbc, sieve tube cells
other names of nucleoplasm
Nucleoplasm / Nuclear matrix / Karyolymph/Karyoplasm.
what is nuclear lamina
The inner side of inner nuclear membrane is lined by nuclear lamina. This structure is
formed by filaments of lamin protein.
what are types of chromatin
Euchromatin :- This is lightly stained and diffused part of chromatin. Which is
transcriptionally or genetically more active.
Heterochromatin :- This is dark stained, thick and condensed part of
chromatin. Heterochromatin is genetically less active or inactive chromatin.
where is nucleolus connected to chromatin
Nucleolus usually attached to chromatin or chromosomes at specific site called
Nucleolar organiser region/NOR.
Nucleolus is called Ribosome factory of cell.
what is a genome
‘A complete set n o
chromosomes inherited as a unit from one parent is known as genome.
