Transcript Cell Structures and Their Functions

Cell Structures and Their Functions
Things Common To All Cells
Cell Membrane –
Cytoplasm –
Genetic Material –
Ribosomes –
Cell Types
Prokaryotic –
Eukaryotic –
Structures Found in All Eukaryotic Cells
Nucleus –
Mitochondria –
Endoplasmic Reticulum –
Golgi Complex –
Vesicles and Vacuoles –
Lysosomes –
Cytoskeleton –
Structures Found in Plant Cells
Cell Wall –
Chloroplasts –
Structures Found in Animal Cells
Centrioles –
Transport Through Cell Membranes
Membrane Structure –
Passive Transport –
Active Transport –
Unit III – Cells
Learning Goal 2
Cell Structures and Their Functions
Things Common to All Cells
• Cell Membrane
• Regulates materials
entering and leaving
the cell.
• Cytoplasm
• Fluid substance in
which all cell
structures are
suspended.
• Genetic Material
• The nucleic acid DNA
which holds
instructions for all cell
functions.
• Ribosomes
• Structures on which
proteins are built.
Cell Types
Prokaryotic Cells
• Lack a nucleus and other membrane-bound
organelles.
• All bacteria are prokaryotic.
Eukaryotic Cells
• Contain genetic material enclosed in a nucleus
• All cells of protists, fungi, plants, and animals
Structures Found in Eukaryotic
Cells
Nucleus –
Controls all cell functions
using DNA instructions.
Mitochondria –
Site of cellular
respiration.
Produces energy for cells
in the form of ATP.
Structures Cont.
Endoplasmic Reticulum
Manufactures and
transports some cell
molecules. Rough ER
contains ribosomes.
Golgi Apparatus –
Prepares molecules for use
in the cell or in other cells.
Structures cont.
• Vesicles and
vacuoles
• Function in storage of
substances.
• Lysosomes
• Contain digestive
enzymes that break
down nutrients and
old cell parts.
Cytoskeleton –
Network of fibers that
help the cell maintain
its shape and allow
movement.
Plant Cell Structures
Cell Wall –
Surrounds cell membrane
in plant, fungi, and
bacterial cells. Helps
support and protect the
cell.
Chloroplasts –
Found in plant cells. Site
of photosynthesis where
carbohydrates are
produced.
Animal Cell Structures
Centrioles –
Found only in animal
cells. Play a role in
cell division.
Membrane Structure
Details
• The basic structure of cell
membranes is a double
layer of phospholipid
molecules.
• Various types of proteins
are embedded in the
membrane as well.
Passive Transport
Movement of molecules through the membrane
using no energy
• Diffusion
Movement of
molecules from an
area of high
concentration to an
area of low
concentration until
equilibrium is
reached.
Facilitated Diffusion
• Diffusion through cell
membranes with the
help of channel
proteins.
• Necessary for
molecules that are too
large (like glucose) or
too strongly charged
to diffuse through the
bilayer.
Osmosis
• Diffusion of water molecules
through cell membranes.
• Results in changes in osmotic
pressure (water pressure).
• Hypotonic: More water outside
of cell so water moves in.
• Isotonic: Same amount of
water outside and in.
• Hypertonic: Less water outside
of cell so water moves out.
Active Transport
• Movement of molecules
through cell membranes
that requires energy.
Molecular Transport
• Small molecules and ions
(charged atoms) are
carried across
membranes by proteins in
the membrane that act
like energy-requiring
pumps.
• Needed to move
molecules from areas
outside of the cell where
they are less
concentrated than inside.
Endocytosis
• Endocytosis is the
process of taking
material into the cell
by means of
infoldings, or pockets
of the cell membrane.
• Needed for extremely
large molecules or
large quantities of
molecules.
Exocytosis
• The membrane of a
vesicle, containing
material that needs to
exit the cell, fuses
with the cell
membrane, forcing
the contents out of
the cell.