Download Eukaryotic Cell Organelles

Eukaryotic Cell Organelles
Lesson Objectives
• Identify the structure and function of the
parts of a typical eukaryotic cell.
• Compare and contrast structures of plant
and animal cells.
Main Idea
• Eukaryotic cells contain organelles that
allow the specialization and the separation
of functions within the cell.
Boundaries
• Plasma Membrane
– Selectively permeable
– Around outside of cell and eukaryotic cell
organelles
– Composed of phospholipid bilayer
– Flexible
Boundaries
• Cell Wall
– Found in prokaryotes, plant cells, fungi,
bacteria, and some protists
– Very porous; not selective on what comes
through
– Rigid
– Located outside the plasma membrane
– Provides support and protection
– Made of cellulose, a carbohydrate (sugar)
polysaccharide
Boundaries
Cytoskeleton and Cytoplasm
• Cytoskeleton
– Supporting network of
long, thin protein fibers
– Forms a framework for
the cell
– Provides an anchor for
the organelles
– Made of microtubules
and microfilaments
• rapidly assemble and
disassemble for
movement purposes.
• Cytoplasm
– Internal environment
of the cell
– Semifluid
– Like jell-o
– Prokaryotes perform
all chemical functions
in the cytoplasm.
The Control Center
• Nucleus
– Manager of the eukaryotic cell
– Contains the DNA, which has all the
directions for making proteins for growth,
function, and reproduction
• Controls the activity of other organelles because
of this!
– Master set of directions for protein synthesis
is contained in chromatin, which are strands
of DNA attached to proteins.
The Control Center
• Nucleolus
– Site of ribosome production
• Nuclear Envelope
– Double membrane surrounding the nucleus
– Similar to plasma membrane
– Nuclear pores allow larger-sized substances
to move in and out of the nucleus
The Nucleus
Ribosomes
– Site where cells assemble enzymes and other
proteins according to the DNA sequence
– Made of RNA and proteins
– NOT bound by a membrane
– Found in both eukaryotic and prokaryotic cells
– Found freely floating in the cytoplasm and
attached to parts of the endoplasmic reticulum
Assembly and Transport
• Endoplasmic Reticulum (ER)
–
–
–
–
Membrane system of folded sacs and interconnected channels
Provides a big workspace within the cell
Looks like an accordion or fan folded into the cell
Rough ER has ribosomes attached and serves as the site for
protein and lipid synthesis The site where ribosomes attach to
the ER is where protein synthesis takes place.
– Proteins made on ER have specific functions and can go
anywhere
– Smooth ER has no ribosomes is the site of carbohydrate and
lipid synthesis
– Compared to a road or highway
The Endoplasmic Reticulum
Assembly and Transport
• Golgi Apparatus
– After proteins are produced, they are
transferred to here
– System of flattened, tubular membranes
– Modifies, sorts, and packages proteins for
their appropriate destination
– Like the post office
Golgi Apparatus
Vacuoles and Storage
• Vacuoles
– Membrane bound spaces
– Temporary storage of materials
– Stores food, enzymes, other materials
needed, and waste products
– Plant cells usually have one large vacuole
– Animal cells have many small vacuoles
Vacuoles
Lysosomes and Recycling
• Lysosomes
– Contain digestive enzymes
– Ex. clean-up crew
– Found in animal cells and rarely plant cells
– Digests excess or worn out organelles, food,
and engulfed viruses or bacteria
– Membrane prevents the digestive enzymes
from destroying the cell
Lysosomes and Recycling
• Lysosomes can fuse with a vacuole and
dispense their enzymes into it.
• This procedure digests the contents of the
vacuole.
• Sometimes, lysosomes eat the cell that
contains it.
• Ex. Tadpole’s tail
A Lysosome
Centrioles
• Organelles made of microtubules that
function during cell division
• Located in the cytoplasm of ANIMAL cells
and most protists
• Found near the nucleus
Mitochondria
• Membrane bound organelles found in both plant
and animal cells that transform energy, usually
from sugars, for the cell.
– Ex. Generators or powerhouses
• Has an outer membrane and highly folded inner
membrane.
• Inner folds provide a large surface area where
energy-storing molecules are produced by
breaking the bonds in sugars.
• Layers of the inner folds are called cristae.
• Can vary in number depending on the type of
cell in which it resides.
The Powerhouse
Chloroplasts
• Cell organelles that capture solar light energy
and produce food to store for a later time.
• Found in plant cells and responsible for
photosynthesis
• Has a double membrane, with an outer
membrane and a folded inner membrane system
of thylakoids, that resembles a stack of coins.
• Stroma is the fluid that surrounds the inner
membranes.
Chloroplasts
• Contain the green
pigment chlorophyll.
• Chlorophyll is
responsible for
trapping the light
energy and giving
leaves and stems
their green color.
Support and Locomotion
• Cilia and flagella help in locomotion and
feeding.
• They are composed of microtubules (thin,
hollow protein cylinders) with one central
pair surrounded by nine additional pairs.
• The entire structure is surrounded by a
plasma membrane.
Support and Locomotion
• Cilia - short, numerous, hair like
projections that move in a wave like
motion
– Also found on stationary cells to help move
substances across the cell
• Flagella - longer projections that move
with a whip like motion
• For unicellular organisms, cilia and flagella
are the major means of locomotion.
Plant Cell
Animal Cell