Transcript Eukaryotic Cell Structure

Cells
Long, Long Ago….
 Before
microscope, people thought that
diseases were caused by curses and
supernatural spirits
 Microscopes enabled scientists to view
and study cells
 Anton VanLeeuwenhoek – developed
the 1st light microscope
Today’s microscopes
 Today
we have much more advanced
microscopes
light microscope – series of
lenses to magnify objects
 SEM (Scanning Electron Microscope) –
scans the surface of cells
 TEM (Transmission Electron Microscope) –
see structures inside the cell
 Compound
Cell Theory
 All
organisms are composed of cells
 All cells come from other living cells
 Cells are the basic unit of structure and
function
Homeostasis
 All
organisms must maintain a balance
regardless of internal and external
conditions
 This task is controlled by the plasma
membrane
Plasma Membrane
 The
plasma membrane serves as the
boundary between the cell and its
environment
 Allows
specific amount of nutrients to enter
and allow waste to exit
Characteristics of cell
membrane
permeable – allows some
molecules to enter and keeps others out
 Selectively
 Like
a screen door
Plasma Membrane
 Made
up of two
layers of
phospholipids
 Controls what
moves into and out
of the cell
 Selectively
permeable
 AKA: Lipid Bilayer,
Fluid Mosaic, Cell
Membrane
Cell Wall
 Rigid
structure
 Located outside of
plasma membrane
 Found in plant cells,
fungi, some bacteria
and protists
 Provides support and
protection
 Composed of
cellulose
(carbohydrate)
Two Basic Cell Types

Prokaryote

Eukaryote
Nucleus
 Control
center of
the eukaryotic cell
 Contains
directions to
make proteins
 Chromatin –
strands of genetic
material (DNA)
Nucleolus

Structure within the
nucleus
 Produces ribosomes
Ribosomes
 The
site of protein
synthesis
 Found in the
cytoplasm or on
the Endoplasmic
Reticulum
Cytoplasm

Clear, gelatinous
fluid inside the cell
 Helps suspend
organelles
Endoplasmic Reticulum

Site of cellular
chemical reactions
 Series of highly
folded membranes
 Rough Endoplasmic
Reticulum – have
ribosomes attached
 Smooth Endoplasmic
Reticulum – does not
have ribosomes
attached
Golgi Apparatus

AKA: Golgi Body
 Flattened system of
tubular membranes
 Modifies and
packages proteins
 Sort proteins to be
sent to appropriate
destination
Vacuoles

Temporary storage of
materials
 Store food, enzymes,
other materials
needed by the cell,
and waste
 Plant cells usually
have one large
vacuole, animal cells
usually contain many
smaller vacuoles
Lysosomes
 Contain
digestive
enzymes that
digest excess or
worn out
organelles, food
particles, viruses
and bacteria
Chloroplasts

Found in the cells of
green plants
 Organelle that
captures light
energy and
produces food to
store for later use
 Contains chlorophyll
– gives plants their
green color
Mitochondria

Organelles that
transform energy for
the cell
 Double membrane
structure with highly
folded inner
membrane
Cytoskeleton

Support structure for
the cell
 Composed of
microtubules and
microfilaments
 Helps cell to
maintain shape
Cilia and Flagella

Aid in locomotion or
feeding
 May move the entire
cell, or aid in
movement of
substances across
the cell surface
Identify the Following Cellular
Structures
Plant and Animal Cells

Animal Cells
- Don’t have a cell
wall
- Contain centrioles
- Contain many
small vacuoles

Plant Cells
- Generally larger
than animal cells
- Have a cell wall
- Contain
chloroplasts
- Have one large
central vacuole
Critical Thinking : Why are plant and animal cells
similar?
Advantages of highly folded Membranes
 Folded
membranes are an
advantage to a cell because
 Cell
processes can be more efficient
 Membranes provide a larger surface
area for cell process to take place
 Remember
all cell membranes are
made up of phospholipids and by
controlling what goes in and out of
the membrane they help the cell
maintain homeostasis