Chapter
6
Quizzes:
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Chapter
Cum.
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Appendix
Summary
Art
Art
Unit 2: The Cell
A Tour of the Cell
Review
Notes
Med
Choi
Fill
All
organisms
are made of
cells
, which are either
prokaryotic
or
eukaryotic
.
Cells are generally
microscopic,
which enables them to have a high
surface
to
volume
ratio,
to facilitate the exchange of materials into and out of the cell.
All
cells
are bounded by a
plasma
membrane, and contain
chromosomes
,
ribosomes
, and a
semifluid
substance called the
cytosol
.
Eukaryotic
cells have membrane-bound
organelles
and can be grouped into 2 main types:
animal
cells and
plant
cells.
The
nucleus
contains most of the
genetic
material in the cell, and is bounded by a nuclear
envelope
with many
nuclear
pores
.
Ribosomes
carry
out
protein
synthesis.
The
endoplasmic
reticulum
(ER) is continuous with the nuclear
envelope
.
Rough
ER, which contains
ribosomes
, produces
proteins
and
membranes
.
Smooth
ER lacks ribosomes and are involved in
lipid
synthesis.
The
Golgi
apparatus
is the cell's "Shipping and Receiving Center".
The
lysosome
contains enzymes to carry out intracellular digestion by
phagocytosis
(cell
eating
), and breaks down damaged organelles by
autophagy
(self
eating
).
The membrane-bound
organelles
involved in cellular transport form the
endomembrane
system.
Plant cells contain a large
central
vacuole
, which stores organic compounds and water.
Mitochondria
are
the cell's "power plant" and perform
cellular
respiration
.
Chloroplasts
perform
photosynthesis
in
leaves and other green organs of
plants
and in
algae
.
The
cytoskeleton
is a network of
fibers
which provides
support
for the cell, and enables
motility
.
Microtubules
help maintain cell
shape
, and guide the
movement
of cell components.
Cilia
and
flagella
use
microtubules
for motion in some
cells.
Microfilaments
called
actin
and
myosin
are protein filaments that function in cellular motility, such as the contraction in
muscle
fibers.
Contraction of actin and myosin
filaments
, together with sol-gel
reversals,
also result in
amoeboid
crawling
of a cell through the
movements
of
pseudopodia
.
Cytoplasmic
streaming
in
plant
cells also involve microfilaments to
circulate
nutrients among organelles.
Review:
Animal Cell Structure and Function.
Cell types.
Review:
Plant Cell Structure and Function.
Differences.