Structure and
Function of
Cells
State Objective 3.b.
What are Cells?
 The
cell theory states the following:
All living things are composed of cells.
 Cells are the basic units of structure and function
in living things.
 All cells are produced from other cells.

Two Types of Cells
 Prokaryotic
cells lack membranebound internal structures.
 Ex.
Bacteria
 Eukaryotic
cells contain membranebound structures
 Ex.
Blood cells (plant and animal cells)
Tour of Eukaryotic Cells
Cell Wall
 Rigid
layer that surrounds the cells of plants
and some other organisms(bacteria)
 It
helps protect and support.
 Made of strong material called cellulose.
Cell Membrane
 The
cell membrane protects the contents of the cell and
helps control the materials that enter and leave.

Allows food and oxygen into the cell and waste products
out of the cell.
Moving Material into & out of
Cells
 Cell
membranes are
selectively permeable.
 Two types:
 Passive
Transport allows
materials to pass through
the cell membrane
without using energy
 Active Transport requires
the cell to use energy by
using transport proteins to
move materials across the
cell membrane
Cytoplasm
A
thick, clear, gel-like fluid that fills the regions between
the cell membrane and the organelles of Eukaryotic
cells.

Organelles are tiny cell structures that carry out specific
functions with-in the cell.
Nucleus
 The
nucleus is the cell’s control center, directing all of
the cell’s activities.


Contains DNA
Nucleolus makes ribosomes which are small grain-shaped
organelles that make proteins
Energy
 Known
H2O
Mitochondrion
as the “powerhouses” of the cell because they
convert energy in food molecules to energy the cell
can use to carry out its functions
Endoplasmic Reticulum
 The
ER transports proteins and other materials
throughout the cell


spots on this organelle are ribosomes, which produce
proteins
similar to the system of hallways in a building.
Golgi Apparatus
 Receive
proteins and other newly formed materials
from the ER, packages them, and distributes them to
other parts of the cell.
Lysosomes
 Break
down large food particles into smaller ones
 Break down old cell parts so they can be reused (like
the recycling center)
Chloroplast
 Green
structures typically found in plant cell to make
food by photosynthesis.

Captures energy from sun-light and changes it to energy
the cell needs to make food.
O
₂
Glucose
Vacuole
 Type
of sac that stores water, food, and other materials
needed by the cell.

Vacuoles in plants cell are larger than those in animal cells.
Vacuole
Comparing Plant and Animal Cells
 Plant
cells have a larger vacuole for more
storage.
 Plants have chloroplasts for carrying out
photosynthesis.
 Plants have cell walls for shape & support.
Name
That
Part
Chloroplast
Cytoplasm
Mitochondria
Nucleus
Cell Membrane
Lysosome
Golgi Apparatus
Cell Wall
Ribosomes
Endoplasmi
c Reticulum
Vacuole
Click on organelle to activate name (cursor will change for “live” organelles).
Compare
a cell to a school.
For each organelle, describe
something in the school that
would perform that same
function. Include nucleus,
mitochondria, chloroplast,
endoplasmic reticulum,
lysosomes, vacuole, cytoplasm,
cell membrane, cell wall
Types of Cells
Types of Cells
 Not
all cells are the same.
 Cells with different structures perform
different functions.
 Both plants and animals have specialized
cells that perform specific functions.
Organization of Life
 Cells-
smallest basic unit of life
 Tissues- a group of cells that perform a
function
 Organs- a group of tissues
 Organ systems- a group of organs
 Organism
Types of Tissues
 Epithelial
 Connective
 Muscle
 Nervous
Epithelial Tissue
 Tissue
that covers internal or external
surfaces of an animal’s body
 They may consist of single or many layers.
 Cells are packed tightly together with little
space between.
 Classified by shape and function.
 Examples: skin, linings of internal organs,
blood vessels
Squamous Epithelium
Cuboidal Epithelium
Connective Tissue
 Connects
and supports other tissues.
 Cells are often spaced farther apart.
 Examples include blood, bone, cartilage,
ligaments, tendons, adipose
Blood
 Tissue
that carries oxygen, nutrients,
removes wastes, and fights infection.
 Made of red blood cells, white blood
cells, and platelets.
 Red blood cells contain a protein called
hemoglobin that attaches to oxygen
molecules.
Red Blood Cells
• Shaped like
flattened
disks.
• Do not
contain
nuclei.
• Most
numerous cell
in the body.
Blood
 White
blood cells can move in and out of
blood vessels to fight infection.
 Larger but fewer in number than red
blood cells.
 Body can increase production when an
infection occurs.
White Blood Cells
Blood
 Platelets
are tiny, oval-shaped cells that
help blood form clots.
 Stick together when blood vessels break.
 Are constantly being replaced.
Platelets
Bone
A
rigid connective tissue made mostly of
calcium.
 Provides shape and support, protection,
and allow the body to move.
 Compact bone- hard, strong outer
covering.
 Spongy bone- mesh-like center of bones
that contains marrow.
Bone
Which is compact? Which is
spongy?
Adipose Tissue
A
loose connective tissue also called fat.
 Stores energy, cushions and insulates the
body.
 Found beneath the skin and around
internal organs.
Adipose Tissue
Other Connective Tissues
 Cartilage
is a tough, flexible tissue that
covers the ends of bones.
 Ligaments are fibrous, slightly stretching
tissues that connect bones at a joint.
 Tendons connect muscles to bones and
allow movement.
Ligaments, Tendons, and
Cartilage
Muscle Tissue
 Tissues
that contract and relax to allow
the body to move.
 Three types: skeletal, smooth, cardiac
 Skeletal attaches to bones. Smooth is
found in internal organs. Cardiac is found
in the heart.
 Skeletal muscle is voluntary and striated
(striped).
Muscles
Nervous Tissue
 Neurons
(nerve cells) are the basic unit of
the nervous system.
 Form the brain, spinal cord, and other
nerves.
 Controls the body and responds to stimuli.
Parts of a Neuron
Cell
body- contains
nucleus
Axon- carries messages
from the cell
Dendrite- receives
messages from other cells.
Neurons
How Tissues Work Together
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.