Transcript THE CELL
THE CELL
“The smallest unit that can carry
out all the processes of life.”
Discovery of the Cell
ROBERT HOOKE
First to observe cells.
He examined cork
cells.
“These little boxes
reminded him of the
small rooms in which
monks lived, so he
called them cells.”
Discovery of the Cell
Anton van Leeuwenhoek – First person
to examine living cells & father of
microscopy
Matthias Schleiden – “All plants are
composed of cells.”
Theodore Schwann – “All animals are
composed of cells.”
Rudolf Virchow – “All cells come from
existing cells.”
The Cell Theory
Schleiden, Schwann, & Virchow
All living things are composed of one or
more cells.
Cells are organisms’ basic units of
structure & function.
Cells come from existing cells.
CELL DIVERSITY
Cells range in size
from .2 um to 2 m.
Average plant &
animal cells are 10 to
50 um in diameter.
Cuboidal & spherical.
TYPES OF CELLS
Eukaryotes –
Contains a nucleus
and membrane-bound
organelles.
Prokaryotes – Lacks
a nucleus. (bacteria)
Organelle – A cell
component that
performs specific
functions in the cell.
ORGANELLES
Nucleus
Cell Membrane
Cytoplasm
Ribosomes
Rough Endoplasmic
Reticulum
Smooth Endoplasmic
Reticulum
Golgi Apparatus
Mitochondria
Lysosomes
Cytoskeleton Microtubules &
Microfilaments
Cilia
Flagella
The Nucleus
Directs activities of
the cell.
Contains DNA.
Nucleolus – synthesis
of ribosomes.
Nuclear pores
Nuclear envelope
Nucleoplasm
CYTOPLASM
Contains various
organs in the cell
Gelatin-like fluid
called cytosol which
has dissolved salts,
minerals, and organic
molecules
DNA
Deoxyribonucleic acid
Encodes information
important for the
synthesis of proteins.
CELL MEMBRANE
Made of lipids &
proteins.
Provides shape &
flexibility.
Selectively
Permeable - a
complex barrier that
keeps out some
molecules & allows
others through.
RIBOSOMES
Carry out protein
synthesis.
Attached ribosomes attached to Rough
ER; produce proteins
to be exported by the
cell.
Free ribosomes produce proteins for
the cell.
ENDOPLASMIC RETICULUM
Rough Endoplasmic
Reticulum - (ER) - A
membrane system
covered with
ribosomes; aids in
protein synthesis.
Smooth ER - Few or
no ribosomes;
intracellular pathway
for proteins.
GOLGI APPARATUS
System of
membranes.
Processing,
packaging, &
secreting organelle
of the cell.
MITOCHONDRIA
“Powerhouse of the
cell.”
Carries out cellular
respiration.
LYSOSOMES
Contains digestive
enzymes.
Digests food &
disease-causing
bacteria.
CYTOSKELETON
Provides a structural
framework for the cell.
Microtubules - long,
slender protein tubes
Microfilaments - fine
protein threads.
CILIA & FLAGELLA
Function in movement.
Composed of proteins.
Cilia - small & hair-like; covers entire
surface of the cell.
Flagella - long & slender; found singly or in
pairs.
VACUOLES
Store substances
inside the cell.
Plant cells have large
central vacuoles.
PLASTIDS
Convert solar energy
into chemical energy.
Chloroplast - contain
green pigments
Chromoplast synthesize & store
other pigments.
Leucoplast - store
food, such as
starches.
Plant cells only!!
CENTRIOLES
Structure that
appears during
animal cell division
CHLOROPLASTS
Found in plant cells
only
Where the energy of
sunlight is converted
into chemical energy
during photosynthesis
Contain green
pigment called
chlorophyll
CELL WALL
Only in plant cells
Lies outside the cell
membrane
Supports and protects
the plant
DIFFERENCES BETWEEN PLANT &
ANIMAL CELLS
ANIMAL CELLS
Centrioles
Small vacuoles
PLANT CELLS
Plastids
Large central vacuole
Cell Wall