Cell Structure &
Function
Famigletti
TEKS 7.12
D) Differentiate between structure and function in
plant an animal cell organelles including cell
membrane, cell wall, nucleus, cytoplasm,
mitochondrion, chloroplast & vacuole
E) Compare the functions of a cell to the functions of
organisms such as waste removal
F) Recognize that according to cell theory all organism
are composed of cells and cell carry on similar
functions such as extracting energy from food to
sustain life
• The Cell Theory grew out of the
work of many scientists and
improvements in the microscope.
Scientists that contributed to the Cell Theory:





Hooke:
Leeuwenhoek:
Schleiden:
Schwann:
Virchow:
• Early studies led to the development of
the cell theory.
The Cell theory has three principles.
1. All organisms are made up of cells
2. All existing cells are produced by other living cells
3. The cell is the most basic unit of life
Two Types of Cells
•Prokaryotic
•Eukaryotic
Cells are the basic unit of life
all living things share the following characteristics:
•
•
•
•
•
•
Growth
Response to environment
Reproduce
Get & use energy
Get rid of waste
Adapt to changes
Prokaryotic
Pro- NO
• NO nucleus
• NO-membrane
bound organelles
• Few internal
structures
• One-celled
organisms, Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
Eukaryotic
Eu- YOU
• Contain organelles surrounded by membranes,
including nucleus!
• Most living organisms including plants & animals
Plant
http://library.thinkquest.org/C004535/eukaryotic_cells.html
Animal
“Typical” Animal Cell
http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif
“Typical” Plant Cell
http://waynesword.palomar.edu/images/plant3.gif
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Bacteria!
Nerve Cell
Which is the prokaryote?
Red Blood Cell
Internal Structures
& their functions
Cell Membrane
• Outer membrane of cell
that controls movement in
and out of the cell
• Cell membrane protects
and separates the rest of
the cell from external
environment.
• Double layer that only
allows specific things
through
http://library.thinkquest.org/12413/structures.html
The cell membrane is a barrier that
separates a cell from the external
environment.
Cytoplasm
•
Jelly-like substance
•
Is everywhere inside the
cell membrane and outside
the nuclear membrane
•
Cytoplasm important for cell
structure
•
Water allows chemical
reactions to occur
•
Provides medium for
chemical reactions and
movement between
organelles
Cytoskeleton
•
Cytoskeleton has
many functions
1. Microtubules give
cells shape; move
DNA
2. Intermediate
filaments, give cells
strength
3. Microfilaments allow
cells to move and
divide
Centrosome and Centrioles
• Specialized parts of the
cytoskeleton
• Centrioles are tubes found
in the centrosomes
• Centrioles help divide
DNA during mitosis.
• Centrosomes make
microtubles which make
spindle fibers
Nucleus
Stores genetic information
•
•
•
Nuclear envelope – double
membrane that encloses
DNA
Nuclear Pores –
Nucleolus – contains tiny
organelles for making
proteins
Endoplasmic Reticulum
 Series of folded membranes
“Intracellular Highway”
 Many processes occur on surface and lumen
(interior of membranes)
ex: Production of proteins
and lipids
Endoplasmic Reticulum
• There are two types:
– Rough Endoplasmic
Reticulum (R.E.R.): contain
ribosomes
– Smooth Endoplasmic
Reticulum (S.E.R.): no
ribosomes
Lumen
Ribosome
 Ribosome's link amino
acids to form proteins
 Made of protein and
RNA
 Made in nucleolus;
leave through nuclear
pores
Golgi Apparatus
• Closely stacked membranes
• Package, Sort, and Processes
Proteins from the E.R.
Vacuoles
• Fluid-filled sacs used for storage
• Central vacuole unique to plant cells
– plants shrivel when central vacuoles don’t have enough
water
– Can contain toxins that help the plant survive
Lysosomes
• Contain enzymes inside to digest
material; defend cell from invading
bacteria and viruses
• Surrounded by a membrane; protects
cell from being broken down
Plant cells
Have TWO features Animal Cells Do Not
Cell wall: gives
protection, support,
and shape to cell
Chloroplasts:
organelles that
perform
photosynthesis
Cell Structure & function
• Animal cells have various structures so that they
may perform their individual functions to the best
of their ability
Neuron
• The unique structure of the neuron is
dedicated to the efficient and rapid
transmission of neural signals.
Red blood cells
• Red blood cells lack a nucleus which helps
them to squeeze through tight capillary
spaces
Cell Movement
• Some cells have structures to hel them to
move.
• These structures are cytoskeleton
extensions, called cilia or flagella.