Cells
Cytologists Welcome
The Micro and the Macro World
Antony van Leeuwenhoek (1632-1723)
Size
variation
Cell
Most
Cells
Size
range
Cell Biology
•1665 - Robert Hooke - cork cells
Hooke was reminded of the
small rooms or “cells” in a
monastery.
Cell Biology
1805 - Lorenz Ohen - cell theory
– All living things originate from, and are made of cells
– Spontaneous Generation debunked
1835 - Matthias Schleiden – Botanist
– & Theodor Schwann – Zoologist
- Schleiden - all plants are made of cells and the cell is
the basic unit of tissue function
- Schwann - all animals are composed of cells
1859-Rudolf Virchow - “Ommia cellula e cellula”
– “All cells come from cells”
Cell Theory
All living things are composed of cells
New cells are produced from preexisting
cells.
Cells are the basic units of structure
and function in living things
What happens on the Macro Level
happens on the Micro Level
Cells
Prokaryotes
Cells that have genetic
material that is not
contained in the nucleus,
No membrane bound
organelles
All bacteria
Archaean
Eukaryotes
Contain a nucleus in which
their genetic material is
separated from the rest of
the cell,
Membrane bound organelles
Most life forms
Mixture of prokaryotic &
eukaryotic characteristics,
with some unique
properties
Kingdom Archaea

The archaea very much resemble
bacteria, so much so that they were
once thought to be a weird group of
bacteria. However, by studying
archaeal cells on a molecular level,
scientists have now come to think that
these "weird bacteria" actually are a
separate category of life altogether. In
fact, in some ways, archaea are more
like you than they are like bacteria!
Archeaens Distinctives -Extremophiles
Many archaeans thrive in conditions that would kill
other creatures: boiling water, super-salty pools,
sulfur-spewing volcanic vents, acidic water and deep
in Antarctic ice. These types of archaea are often
labeled "extremophiles," meaning creatures that love
extreme conditions.
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Nucleus
Eukaryotic Cell
Organelles
General Archaean Structure
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell
Organelle – specialized organs, “little organs”
Nucleolus
Nucleus
Ribosome
(attached)
Nuclear
envelope
Ribosome
(free)
Cell
Membrane
Mitochondrion
Smooth
endoplasmic
reticulum
Rough
endoplasmic
reticulum
Centrioles
Golgi apparatus
Animal Cell
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
Animal Cells
Centrioles
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Organelles in Plant & Animal Cells
Nucleus – contains nearly
all the cells DNA with coded
instructions for making
proteins and other important
molecules.
Nuclear envelope –
surround nucleus, composed
of two membranes, allow
materials to move in and out
of the nucleus
Organelles in Plants & Animal Cells
Chromatin – DNA bound to
protein, material you can see
in the nucleus
Chromosomes –
condensed chromatin,
contains genetic information
that is passed from one
generation to the next
Nucleolus – where
assembly of ribosomes
begins
Organelles in Plants & Animal Cells
Ribosomes – make proteins
Endoplasmic reticulum –
assemble lipids of the cell
membrane, along with proteins
and other materials that are
exported from the cell
Rough ER – contains
ribosomes on the outside of the
ER
Smooth ER – ribosomes are
not found of the surface of the
ER
Organelles in Plants & Animal Cells
Golgi apparatus –
modify, sort and
package proteins and
other materials from
the ER for storage in
the cell or secretion
outside the cell, the
“UPS guys” of the cell
Organelles in Plants & Animal Cells
Lysosome – digestion or
breakdown of lipids
carbohydrates and proteins into
small molecules that can be
used by the rest of the cell.
Vacuoles – store materials
such as water, salts, proteins,
and carbohydrates.
Mitochondria – powerhouse of
the cell, contain own DNA,
endosymbiotic theory, possible
descendent of ancient
prokaryotes
Organelles in Plants & Animal Cells
Cell membrane
ER
microtubule
microfilament
ribosomes
mitochondria
Cytoskeleton – support the
cell, involved in maintaining
shape and involved in
movement
Microfilament – threadlike
structures made of protein
called actin, framework of cell,
help with movement
Microtubules – hollow
structures made up of protein,
maintain cell shape, important
in cell division help build
projections from the cell surface
such as cilia, flagella
Organelle in Plants Only
Chloroplasts –
captures the suns
energy from sunlight
and convert it to
chemical energy in a
process called
photosynthesis
Organelle in Animals Only
Centrioles –
microtubules that aid in
cell division
Structure of the Cell Membrane
Outside
of cell
Proteins
Carbohydrate
chains
Cell
membrane
Inside
of cell
(cytoplasm)
Protein
channel
Lipid bilayer
Cell membrane – regulates what enters and
leaves the cell, lipid bilayer, mosaic of different
molecules
Cell Wall
Cell Wall - in plants
only, provides protection
and support for the cell
Plants v. Animal Cells
PLANTS
Chloroplasts
Large vacuoles
Cell wall
No centriole
Does not usually have
lysosomes
ANIMALS
No chloroplasts
Smaller vacuoles
No cell wall
Centriole
Lysosomes
Diffusion Through Cell Boundaries
Glucose
molecules
Diffusion –
particles tend to
move from an area
where they are
more concentrated
to an area where
they are less
concentrated until
they reach
equilibrium, no
energy required
Protein
channel
High
Concentration
Cell
Membrane
Low
Concentration
Osmosis
Osmosis – diffusion of water through a
selectively permeable membrane
Facilitated Diffusion
Facilitated Diffusion
movement of specific
molecules across cell
membranes through
protein channels, does
not require energy, only
if there is a higher
concentration of a
particular molecule on
one side than the other
side
Active Transport
Molecule to
be carried
Active transport - requires
energy, low concentration to
high concentration
•Endocytosis
Energy
•Phagocytosis
•Pinocytosis
•Exocytosis
Molecule
being carried
Phagocytosis
Cell Specialization
Cell Specialization – cells
throughout an organism
can develop in different
ways to perform different
tasks.
Unspecialized Cells – cells
must perform all of the
tasks needed for survival
Levels of Organization
Muscle cell
Smooth muscle tissue
Stomach
Atom – Molecule - Organelle – Cell –
Tissue – Organ – Organ System Organism
Digestive system
Examples
Nervous, digestive
Brain, stomach
nerves, muscle
neuron, smooth muscle cell
Organelles, nucleus
Water, sugar, fat
Oxygen, carbon
Proton, electron
Section 10-1
Ratio of Surface Area to
Volume in Cells
Cell Size
Surface Area
(length x width x 6)
Volume
(length x width x height)
Ratio of Surface Area
to Volume
Limits to Cell Growth – cannot move nutrients and
waste through the cell, “DNA overload”
Enzymes
• a protein that does a special job
• lock and key theory, specific fit
• effected by temp. pH concentration…
•Can build or break down molecules
•Catalyze reactions
Catalyst – speeds up the rate of a chemical
reaction
Chapter 9
The Cell Cycle and Cellular
Reproduction
Concept Map
Cell Cycle
includes
G1 phase
Interphase
M phase
(Mitosis)
is divided into
is divided into
S phase
G2 phase
Prophase
Metaphase
Anaphase
Telophase
During Interphase (S
phase), each
chromosome is
replicated, consisting of
two identical “sisters” or
sister chromatids.
Centromere attaches
the sister chromatids.
The Cell Cycle
G1 phase
M phase
S phase
G2 phase
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Interphase – cell grows and replicates its DNA and
centrioles
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Prophase – chromatin condenses in to the
chromosomes, centrioles separate, spindle forms,
nuclear envelope disappears
plant
animal
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Metaphase – chromosomes line up in the center of
the cell, each chromosome is connected at the
centromere to the spindle fiber.
plant
Spindle fibers
Asters
animal
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Anaphase – sister chromatids separate into
individual chromosomes and are moved apart
plant
animal
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Telophase – chromosomes gather at opposite ends
of the cell, two nuclear envelopes will form.
plant
animal
Mitosis and Cytokinesis
Spindle
forming
Centrioles
Nuclear
envelope
Chromatin
Interphase
Centromere
Chromosomes
(paired chromatids)
Prophase
Cytokinesis
Spindle
Centriole
Telophase
Nuclear
envelope
reforming
Centriole
Individual
chromosomes
Metaphase
Anaphase
Cytokinesis – the cytoplasm pinches in half, each
daughter cell has duplicate chromosomes.
Control of Cell Division
Cells have contact inhibition, they will continue
growing until in contact with other cells.
Effect of Cycling
The sample is injected
into a second cell in G2
of interphase.
A sample of
cytoplasm
is removed
from a cell
in mitosis.
RESULT: Caused nondividing cells to divide
As a result, the second
cell enters mitosis.
Cyclins – regulate the timing of the cell cycle in
eularyotic cells along with internal and external
regulators
Cancer
Definition / Causes
–
–
–
Cancer is the uncontrolled growth of cells
Changes in a cells’ DNA can lead to unrestrained
cell reproduction
Cells are produce a growth factor and never stops
dividing
OR
–
Cells do not produce a suppressor protein and it
never stops dividing
Cancer
Normal vs. Cancerous)
Shape of cell
Normal
Cell
Cancer
Cell
Anchorage
dependent
Contact
inhibition
Flattened,
monolayer
yes
yes
Rounded,
globular
no
no
Cancer
Tumors - 2 types
1. Benign - slow growing, noninvasive, no
metastasis
2. Malignant - rapid growth, invasive, metastatic
Cancer Research ?’s
What is the common & proper name for this cancer?
What is the cause of this cancer?
What are the effects of this cancer?
– Micro – What is happening at the cellular level?
– Macro – What symptoms does the patient experience?
What treatments are available?
What is the typical outcome / prognosis?
Stem Cell Research
Stem Cell Research
What Are Stem Cells?
• Stem Cells are unspecialized, which means
that they do not have a specific function.
• They are cells that are capable of dividing
and renewing themselves for long periods.
• Stem Cells can give rise to specialized cells.
In other words, these cells can be given a
specific function.
Embryonic Stem Cells
• Embryonic stem cells are derived from embryos.
In other words, they come from embryos that
develop eggs that have been fertilized.
• These stem cells have the ability to transform
themselves into any other type of cell in the body.
• Five days after fertilization, the human embryo
becomes a blastocyst, a hollow sphere of about
100 cells. The cells in the inner sphere go on to
form the tissues in the body, which are the
embryonic stem cells.
Embryonic Stem Cells
Adult Stem Cells
• Adult stem cells is one type of stem cell. They are
unspecialized cells found among functional cells in a
tissue or organ like the brain, skin and liver.
• The primary role of adult stem cells are to maintain and
repair the tissue, which they are found.
• The origin of adult stem cells are unknown in mature
tissues.
• In adults, however, there are a very small amount of
stem cells in each tissue.
Unspecialized Adult Stem Cells
Differences Between Adult and
Embryonic Stem Cells
• Embryonic stem cells had two important qualities: they can
become almost anything in the body and can be grown in culture in
an unlimited quantity.
• Even though the embryonic stem cell can transform to more cells,
they are rejected more. Also, they are more likely to become
cancerous.
• Adult stem cells has limitations to what they can transform to and
they don’t transform as quickly as embryonic stem cells. They are
difficult to grow in quantity and worries about genetic
abnormalities due to radiation exposure.
• The biggest advantage of adult stem cells is that they are rarely
rejected by patients and they aren’t as controversial as embryonic
stem cells.
Why Are They Important?
• Potential is enormous
because they can help us
to understand more about
the development of the
human body.
• They have the ability to
restore any type of cell
and could help cure
Parkinson’s and Diabetes.
• They hold the promise of
the complete regeneration
of the human body.
Embryonic Stem Cell
Importance Of Stem Cells
• Human stem cells could be
used to test new drugs
because they can specialize
them and try drugs on
different types of cells.
• They can regenerate cells
and issues by being directed
to differentiate the cells into
specific types.
• They can revolutionize the
way we cure diseases.
Stem Cell Potentials
• Totipotent cells are cells that
have the ability to become any
kind of specialized cell.
• Pluripotent stem cells are cells
that have the potential to become
other kinds of specialized cells,
but mostly becomes the cell it
derives from.
• Committed stem cells are cells
that can’t become a different kind
of specialized cell. Does what it
is first made out to be.
• This measures the potential of a
stem cell.
Controversy?
•
•
•
•
•
Pro
Stem cell research has the
potential to help cure diseases
that were never thought
possible.
Most embryonic stem cells are
from embryos that were obtain
from fertilization clinics.
Have consent from donors to
use embryos and it is legal to
proceed with stem cell
research.
Adult stem cells can be
extracted without harm.
People will not have to wait for
organ donors
Con
• Stem cell research can lead to
cloning because embryos are
needed. An event in
Northeast U.S. sparked the
idea of cloning.
• Can cause an increase in
abortions and isn’t moral
standards.
• Extracting stem cells from
embryos kills the cell/ doesn’t
develop.
• Considered murder when
embryos are destroyed.
• May cause genetic
abnormalities or cause
cancer in patients that are in
need of help.
Specialized Cells
• When unspecialized stem cells give rise to specialized cells, the
process is called differentiation. This is triggered by signals
inside and outside stem cells. Internal signals are controlled by
the cell’s genes and external signals are controlled by chemicals
secreted by other cells or other molecules in the environment.
• Adult stem cells tend to generate the types of tissues they reside
in, but there have been rare cases in adult stem cells where a cell
from one tissue can form different cells for different tissues. This
phenomenon is called plasticity.
• If stem cells are grown in certain conditions, they can remain
unspecialized cells, however, if the cells are allowed to clump
together, they can specialize spontaneously. To generate specific
types of specialized cells, scientists try to control the
differentiation of stem cells (mostly embryonic). Scientists have
established “recipes” to create specific cell types. Main problem
is that they can’t reliably direct differentiation of embryonic
stem cells.