Topic 16
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http://ed.ted.com/lessons/the-wacky-historyof-cell-theory
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Cells are the basic
units of structure and function in all
organisms
 Smallest unit that can carry out
all of the functions of life
The discovery of the cell, its structure and
its function is the result of the hard work
of many scientists using developing
technology.

A CELL is the basic
structure of all living
things
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Everything living is
made up of at least
one cell
Can you think of some
different types of cells?

All new cells arise
from already preexisting cells
through a process
called cell division
 Some cells divide
sexually
 Some divide
asexually (binary
fission)
Yeah, Yeah, Yeah- How do you know
if they’re too small to see??
We CAN! Through MICROSCOPES!
Consider the items in the following list. Place the items in the appropriate
column in the table below.
chicken egg
water in tree bark
tree bark
amoeba
Bacteria
chlorophyll
human egg
human hair
virus
chloroplast
sperm
sweat
Single Cell
Many Cells
Not a Cell
Single Cell
Many Cells
Not a Cell
Bacteria
Tree Bark
Sweat
Human Egg
Human Hair
Chlorophyll
Sperm
Water in tree bark
Amoeba
Virus
Chicken Egg
Chloroplast

In 1665, Robert Hooke used
an early compound
microscope to look at a thin
slice of cork
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The cork appeared to be made of
tiny, empty chambers
Hooke called them “cells” because
they reminded him of rooms in a
monastery
Hooke did not see living cells,
he only saw parts of the cell
walls of dead cells
 Anton van Leeuwenhoek used
a single-lens microscope to
observe pond water and other
things
 In 1675, Anton van
Leeuwenhoek became the
first person to observe living
cells
 He discovered that the water
was filled with tiny, singlecelled organisms
 In 1838, Matthias Schleiden concludes that all plants
are made up of cells
 In 1839, Theodor Schwann concludes that all animals
are made up of cells
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For hundreds of years, people had
thought that organisms could come
from nonliving matter, an idea known
as spontaneous generation

In 1855 the German biologist Rudolf
Virchow says
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that all cells come from the division of
preexisting cells
In 1864, Louis Pasteur,


working with yeast cells,
demonstrated microorganisms can not
arise from completely nonliving matter
 In 1966 Lynn Margulis
 Proposes that certain
organelles, tiny structures
within some cells, were once
free-living bacteria
 Known as the endosymbiotic
theory
 now generally accepted theory to
explain how certain organelles were
formed

The cell theory is a fundamental
concept of biology and it states
that:
1) All living things are
composed of one or more
cells
2) Cells are the basic units of
structure and function in
living things
3) New cells are produced
from existing cells
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What are the
two major
types of cells?
What
structure is
present in one
type, but
absent in the
other?
What are
some
examples of
eukaryotic
cells?
Cells fall into two broad
categories, depending on
whether they contain a
nucleus.
 Eukaryotes are cells that
contain nuclei.
 Prokaryotes are cells
that do not contain nuclei.
 The nucleus is a large membrane-enclosed structure that
contains the cell’s genetic material in the form of DNA.

EUKARYOTES
PROKARYOTES
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Nucleus is absent
No membrane-bound
organelles
Most 1-10 um in size
Evolved 3.5 billion years
ago
Only unicellular
bacteria and
archaebacteria
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Nucleus is present
Many membrane-bound
organelles
Many 2-1000um in size
Evolved 1.5 billion years
ago
All other cells (animal,
plant, fungi, and protist)

Both eukaryotes and
prokaryotes have
 a cell membrane
 genetic material
(DNA)
 ribosomes
 cytoplasm
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Animal Cell
Have Mitochondria
Small Vacuole
NO cell wall
Flexible shape
Plant Cell
Have mitochondria
AND Chloroplasts
 Large central vacuole
 Has a Cell wall
 More defined shape
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Both have:
 A nucleus
 Mitochondria
 Cell membrane
 Peroxisomes and



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lysosomes
Endoplasmic Recticulum
(ER)
Golgi Apparatus
Ribosomes
Cytoplasm
Centrioles an cytoskelaton
http://www.cellsalive.com/cells/3dcell
.htm
Fill in your chart as we describe the parts of the cell

The “filling” of the cell

Holds all organelles in
place
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Contains nutrients

Network of protein
filaments
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Functions:
 Aids in cell SHAPE and
internal organization
 Also aids in
TRANSPORT
▪ Like conveyor belts of the
cell
• Contains the genetic
material
• DNA
• Main control center of
the cell’s activities
• Initiation site of cell
division
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In PLANT cells

Not the same as a membrane
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Function:
 structural support
 Shape

Made of cellulose in plant cells

In PLANT cells

Act like tiny solar
panels
 Capture sun’s energy
and convert it to
chemical energy (FOOD)
 Site of Photosynthesis

Gives plants their
green color

Power house of the cell
 Supplies the cell with ENERGY

Site of cellular respiration
 2-membrane enclosure
▪ Outer membrane
▪ Inner membrane (cristae)

Matrix- fluid inside the
mitochondria
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Function:
 Assembles lipid and protein
components to be exported
out of the cell

Rough ER
 Lined with ribosomes
 Protein synthesis

Smooth ER
 No ribosomes
 Membrane lipid synthesis

Located on exterior of
nucleus

Not considered
organelles

Protein-making
structures
 Factories that make
proteins
 On rough ER and freefloating in cytoplasm

UPS of the cell

Modifies, sorts and
packages proteins from
ER and cellular materials
for storage or release

Budding vesicles pinch
off golgi
 Shipping cellular materials
to final destination point
Golgi
Apparatus
Animal Cell
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Function:
 Storage of cell nutrients
▪
▪
▪
▪
Water
Salts
Proteins
Carbs
 Central Vacuole (in plants)
▪ Largest organelle
▪ Aids in cell shape
Plant Cell
Waste and toxic chemical
management
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Lysosomes:
 Break down & recycle
macromolecules
Peroxisome

Peroxisomes
 Breaks down toxic
materials in cell

Aka- Plasma membrane

Surrounds the entire cell
 Like your skin does for your body

Made up of
 Proteins
 Lipids (fats)
 Carbohydrates

Function: Regulates what
materials come in and out of the
cell
 Often referred to as a “semi-
permeable” membrane- only lets
certain materials in or out

http://www.purposegames.com/game/animal-cellorganelles-labeling-interactive-game

http://www.sheppardsoftware.com/health/anatomy
/cell/index.htm