BASIC STRUCTURE OF TYPICAL ANIMAL CELL & TYPES

We know that the cell is the basic and structural building block of life. It is also the most fundamental and smallest biological unit found in living things. Cells can also be categorized as prokaryotic or eukaryotic based on how they are organized. Eukaryotic cells include both plant and animal cells.

1. 1
Basic Structure of a Cell

2. •Cell biology (also cellular biology or cytology)
•the structure, function, and behavior of cells
•basic unit of life 
•Cells are the structural, functional, and
biological units of all living beings.
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3. 3

4. Cells are Us
A person contains about 100 trillion
cells. That’s 100,000,000,000,000
or 1 x 10
14
cells.
There are about 200 different cell
types in mammals (one of us).
Cells are tiny, measuring on
average about 0.002 cm (20 um)
across.
nerve cell

5. 5
First to View CellsFirst to View Cells
•In 1665, Robert
Hooke used a
microscope to
examine a thin
slice of cork
(dead plant cells)
•What he saw
looked like small
boxes
published in Micrographia

6. 6
First to View CellsFirst to View Cells
•Hooke is
responsible for
naming cells
•Hooke called them
“CELLS” because
they looked like
the small rooms
that monks lived in
called Cells

7. 7

Anton van Leeuwenhoek
•In 1673,
Leeuwenhoek (a Dutch
microscope maker),
was first to view
organism (living
things)
•Leeuwenhoek used a
simple, handheld
microscope to view
pond water &
scrapings from his
teeth

8. 8
Beginning of the Cell TheoryBeginning of the Cell Theory
•In 1838, a
German botanist
named Matthias
Schleiden
concluded that
all plants were
made of cells
•Schleiden is a
cofounder of the
cell theory
•In 1839, a
German
zoologist
named
Theodore
Schwann
concluded that
all animals
were made of
cells
•Schwann also
cofounded the
cell theory

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CELL THEORY
•All living things are made
of cells
•Cells are the basic unit
of structure and function
in an organism (basic unit
of life)
•Cells come from the
reproduction of existing
cells (cell division)

10. 10
•In 1855, a German
medical doctor named
Rudolph Virchow
observed, under the
microscope, cells dividing
•Omnis cellula e cellula is a
Latin phrase
•Cells come from the
division of pre-existing
cells

11. Types of Cells
•two types: 
•prokaryotic cells
–lack a nucleus but have a nucleoid region.
–single-celled organisms
–Includes bacteria
–Simplest type of cell
–Single, circular chromosome
•eukaryotic cells
–possess a nucleus
–single-celled or multicellular
–Includes protists, fungi, plants, and animals
–More complex type of cells
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12. 12
Eukaryotic Cell Prokaryotic Cell
Nucleus Present Absent
Number of
chromosomes
More than one One--but not true chromosome:
Plasmids
Cell Type Usually multicellularUsually unicellular (some
cyanobacteria may be multicellular)
True Membrane bound
Nucleus
Present Absent
Example Animals and PlantsBacteria and Archaea
Genetic RecombinationMeiosis and fusion of
gametes
Partial, undirectional transfers DNA
Lysosomes and
peroxisomes
Present Absent
Microtubules Present Absent or rare
Endoplasmic reticulumPresent Absent
Mitochondria Present Absent
Cytoskeleton Present May be absent
DNA wrapping on
proteins.
Eukaryotes wrap
their DNA around
proteins called
histones.
Multiple proteins act together to
fold and condense prokaryotic DNA.
Folded DNA is then organized into a
variety of conformations that are
supercoiled and wound around
tetramers of the HU protein.

13. Eukaryotic Cell Prokaryotic Cell
Ribosomes larger smaller
Vesicles Present Present
Golgi apparatus Present Absent
Chloroplasts
Present (in plants)
Absent; chlorophyll scattered in
the cytoplasm
Flagella Microscopic in size;
membrane bound;
usually arranged as nine
doublets surrounding
two singlets
Submicroscopic in size,
composed of only one fiber
Permeability of
Nuclear Membrane
Selective not present
Plasma membrane with
steroid
Yes Usually no
Cell wall Only in plant cells and
fungi (chemically
simpler)
Usually chemically complex
Vacuoles Present Present
Cell size 10-100um 1-10um
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14. 14
Two Main Types of
Eukaryotic Cells
Plant Cell
Animal Cell

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OrganellesOrganelles
•Very small (Microscopic)
•Perform various functions for a
cell
•Found in the cytoplasm
•May or may not be membrane-
bound

16. 16
Cell or Plasma MembraneCell or Plasma Membrane
Outside
of cell
Inside
of cell
(cytoplasm)
Cell
membrane
Proteins
Protein
channel
Lipid bilayer
Carbohydrate
chains
•Composed of double layer of phospholipids and
proteins
•Surrounds outside of ALL cells
•Controls what enters or leaves the cell
•Living layer

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•Lies immediately
against the cell
wall in plant cells
•Pushes out
against the cell
wall to maintain
cell shape
Cell Membrane in PlantsCell Membrane in Plants
Cell membrane

18. 18
•Found outside of the cell
membrane
•Nonliving layer
•Supports and protects
cell
•Found in plants, fungi, &
bacteria
Cell wallCell WallCell Wall

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•Jelly-like substance
enclosed by cell
membrane
•Provides a medium for
chemical reactions to
take place
•Contains organelles to
carry out specific jobs
Cytoplasm of a Cell Cytoplasm of a Cell
cytoplasm

20. 20
MitochondrionMitochondrion
(plural = mitochondria)(plural = mitochondria)
•“Powerhouse” of the cell
•Generate cellular energy
(ATP)
•More active cells like
muscle cells have MORE
mitochondria
•Both plants & animal cells
have mitochondria
•Site of CELLULAR
RESPIRATION (burning
glucose)

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Interesting Fact ---Interesting Fact ---
•Mitochondria
Come from
cytoplasm in the
EGG cell during
fertilization
Therefore …
•You inherit your
mitochondria from
your mother!

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Endoplasmic Reticulum - EREndoplasmic Reticulum - ER
Two kinds of ER ---ROUGH & SMOOTH
•Network of hollow membrane tubules
•Connects to nuclear envelope & cell
membrane
•Functions in Synthesis of cell products &
Transport

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Rough Endoplasmic Reticulum (Rough Rough Endoplasmic Reticulum (Rough
ER)ER)
•Has ribosomes on its
surface
•Makes membrane
proteins and proteins
for export out of cell

24. 24
Functions of the Smooth ERFunctions of the Smooth ER
•Makes membrane
lipids (steroids)
•Regulates calcium
(muscle cells)
•Destroys toxic
substances (Liver)

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RibosomesRibosomes
•Made of PROTEINS and rRNA
•“Protein factories” for cell
•Join amino acids to make proteins through
protein synthesis


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RibosomesRibosomes
Can be attached to
Rough ER
OR
Be free
(unattached)
in the
cytoplasm

27. 27
Golgi BodiesGolgi Bodies
•Stacks of Stacks of flattened flattened
sacssacs
•Have a shipping side Have a shipping side
((cis facecis face) & a ) & a
receiving side (receiving side (trans trans
faceface))
•Receive Receive proteinsproteins made made
by ERby ER
•Transport vesiclesTransport vesicles
with modified proteins with modified proteins
pinch off the endspinch off the ends Transport
vesicle
CIS
TRANS

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Golgi BodiesGolgi Bodies
Look like a stack of pancakes
Modify, sort, & package
molecules from ER
for storage OR
transport out of cell

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LysosomesLysosomes
•Contain Contain digestive enzymesdigestive enzymes
•Break down Break down food, food,
bacteria,bacteria, and and worn out worn out
cell partscell parts for cells for cells
•Programmed forProgrammed for cell cell
death (APOPTOSIS)death (APOPTOSIS)
•Lyse & Lyse & release enzymesrelease enzymes
to break down & recycle to break down & recycle
cell parts)cell parts)

30. 30
Lysosome DigestionLysosome Digestion
• Cells take in
food by
phagocytosis
• Lysosomes
digest the food
& get rid of
wastes

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•Controls the normal

activities
of the cell
•Contains the DNA in
chromosomes
•Bounded by a


nuclear envelope
(membrane) with
pores
•Usually the largest
organelle
Nucleus-The Control Organelle Nucleus-The Control Organelle

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•Each cell has fixed


number of
chromosomes that
carry genes
•Genes control cell
characteristics
Nucleus
NucleusNucleus

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Inside the Nucleus -
The genetic material (DNA) is found
DNA is spread out
And appears as
CHROMATIN
in non-dividing cells
DNA is condensed &
wrapped around proteins
forming
as CHROMOSOMES
in dividing cells

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What Does DNA do?What Does DNA do?
DNA is the hereditary
material of the cell
Genes that make up the DNA
molecule code for different
proteins

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Nucleolus
•Inside nucleusInside nucleus
•DisappearsDisappears when when
cell dividescell divides
•Makes ribosomesMakes ribosomes
that make that make
proteinsproteins

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CytoskeletonCytoskeleton
•Helps cell maintain cell
shape
•Also help move organelles
around
•Made of proteins
•Microfilaments are
threadlike & made of
ACTIN
•Microtubules are tubelike
& made of TUBULIN

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CentriolesCentrioles
•Found only in animal
cells
•Paired structures near
nucleus
•Made of bundle of
microtubules
•Appear during cell
division forming mitotic
spindle
•Help to pull chromosome
pairs apart to opposite
ends of the cell