Cell and Its Organelles Flashcards
collective term for different substances that make up the cell
Protoplasm
5 substances that comprise the protoplasm
water- 70-85%
proteins- 10-20%
lipids- 2%
carbohydrates- 1%
type of protein present in cells mainly in the form of long, thin filaments
structural proteins
use of structural proteins
provide contractile mechanism of all muscles
provide the “cytoskeleton” of cilia, nerve axons, and mitotic spindles
type of protein composed of protein molecules in globular form
globular proteins
example of globular proteins
enzymes
2 most important lipids in cells;
are the main components of the cell membrane and intracellular membranous barriers
phospholipids and cholesterol
provide the cytoskeleton of organelles;
tangled mass of filamentous tubules that holds the parts of cytoplasm and nucleoplasm
microtubules
“neutral fat”
triglycerides
provide inorganic chemicals for cellular reaction;
used for operation of some cellular control mechanisms
ions
insoluble polymer of glucose
glycogen
penetrated protein molecules that provide specialized pathways in the cell membrane
pores
3 main components of the lipid bilayer
phospholipids
sphingolipids
cholesterol
substances impermeable to the lipid bilayer
water-soluble substances:
ions
glucose
urea
substances permeable to the lipid bilayer:
fat-soluble substances:
oxygen
carbon dioxide
alcohol
amino alcohol where sphingolipids were derived
sphingosine
determines the degree of perm/impermeability of the bilayer
cholesterol and its fluidity
surrounds the nucleus
nuclear envelope
separates the 2 parallel membranes of the nucleus
perinuclear cisterna
avenues of communication between the nucleoplasm and the cytoplasm
nuclear pore
parts of the nuclear pore complex (4)
co-axial rings
scaffold
transporter
thick filaments
co-axial ring facing the cytoplasm
outer ring or cytoplasmic ring
co-axial ring facing the nucleoplasm
inner ring or nucleoplasmic ring
forms the major mass of the pore complex;
surrounds and entwines the periphery of pore
scaffold
maintains fusion of nuclear membrane;
supports the transporter;
provides diffusion of channels
scaffold
proteinaceous ring occupying the center of the pore;
transport materials in and out of the nucleus
transporter
radiate out into the cytoplasm;
act as staging area for protein binding to the transporter
thick filaments
continuous mesh of filaments imposed between the inner nuclear membrane and the peripheral heterochromatin
nuclear lamina
function of nuclear lamina
helps to organize and provide support to the lipid bilayer and perinuclear chromatin
thread-like structure composed of regularly spaced discoid subunit made up of octomers of (proteins) 2 molecules of each of four histones
chromatin
four histones in chromatins
H4
H3
H2A
H2B
condensed, inactive form of chromatin
heterochromatin
location of heterochromatin
periphery of the nucleus
unwound/extended, active form of chromatin
euchromatin
location of euchromatin
scattered throughout the nucleus
large and pale nucleus with extended chromatin
vesicular nucleus
small and dark nucleus with condensed chromatin
pyknoitic nucleus
tightly coiled clump of chromatin;
inactive counterpart of 2X chromosomes
sex-chromatin
two chromatids joined to one another
chromosome
constricted segment that links the chromatids
centromere
trilaminar disc at the centriole that connects the chromosome to the spindle
kinetochore
portion of the protoplasm that is surrounded by the nuclear envelope
nucleoplasm
composition of a nucleoplasm (4)
interchromatin
perichromatin granules
ribonucleoprotein
nuclear matrix
structure that includes the nuclear pore, nuclear lamina complex, residual RNP network and fibrillar elements
nuclear matrix