Cells!
http://koning.ecsu.ctstateu.edu/cell/cell.html
Lesson Overview
Life Is Cellular
Early Microscopes/Cell Discoveries
• Mid 1600’s: scientists use microscopes to observe living things.
• 1665, Englishman Robert Hooke
• Used an early compound microscope
• Nonliving thin slice of cork, a plant material.
• Made of thousands of tiny, empty chambers
• Called them “cells”.
• Holland: Anton van Leeuwenhoek
• examined pond water, saw living things!
• his own mouth
• Discovered what we know today as “bacteria”
Lesson Overview
Life Is Cellular
Early Microscopes/Cell Discoveries
• In 1838, German botanist
Matthias Schleiden
• All plants are made of
cells.
• The next year, 1839
German biologist Theodor
Schwann
• All animals were made
of cells.
• In 1855, German physician
Rudolf Virchow
• New cells could be
produced only from the
division of existing cells,
Cell Theory
• 1)
• 2)
• 3)
Why a theory??
Definition of Cell
A cell is the smallest unit that is
capable of performing life
functions.
Examples of Cells
Amoeba Proteus
Plant Stem
Bacteria
Red Blood Cell
Nerve Cell
Two Types of Cells
•Prokaryotic
•Eukaryotic
Prokaryotic
• Do not have structures
surrounded by membranes
• Few internal structures
• One-celled organisms
– Ex: Bacteria
http://library.thinkquest.org/C004535/prokaryotic_cells.html
ALL LIVING THINGS ARE MADE OF CELLS
Cells __________ a
_____________ OR
ORGANELLES
surrounded
by _______________
Cells __________ a
NUCLEUS AND
ORGANELLES
surrounded
by MEMBRANES
= ________________
= _________________
Bacterial Cell
http://www.earthlife.net/prokaryotes/welcome.html
http://summit.k12.co.us/schools/shs/computer/tkelley/types.html
Eukaryotic
• Contain organelles surrounded by membranes
• Have DNA in nucleus
• Most living organisms
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
Cell Parts
Organelles
-A minute structure within a plant or
animal cell that has a particular job or
function.
-Cells are like factories
Structure and Function
STRUCTURE= How it is built/constructed
FUNCTION= What it DOES and How it WORKS.
How does its Structure dictate it’s Function?
Cytoplasm
•
•
•
•
•
•
Portion of cell outside of nucleus
Holds the organelles
Gel-like mixture
Surrounded by cell membrane
“cyto”=
“plasm” =
NUCLEUS
Largest organelle
in animal cells
Image from: http://www.mccc.edu/~chorba/celldiagram.htm
NUCLEUS
• Surrounded by
NUCLEAR ENVELOPE
(also called NUCLEAR MEMBRANE)
DOUBLE MEMBRANE
Image from: http://www.agen.ufl.edu/~chyn/age2062/lect/lect_06/5_11.GIF
NUCLEUS
NUCLEAR PORES
Openings to allow molecules to
move in and out of nucleus
Image from: http://www.emc.maricopa.edu/faculty/farabee/BIOBK/BioBookCELL2.html
WHAT DOES IT DO?
Contains genetic material (DNA)
DNA is scrunched up
as CHROMOSOMES
in dividing cells
DNA is spread out
as CHROMATIN
in non-dividing cells
WHAT DOES IT DO?
Control center
of cell
Image from:
Genetic code tells the
cell’s parts what to do,
gives instructions.
Image from: http://web.jjay.cuny.edu/~acarpi/NSC/12-dna.htm
NUCLEOLUS
Image from: http://lifesci.rutgers.edu/~babiarz/histo/cell/nuc3L.jpg
Dark spot in
nucleus =
__________
Makes _______________
NUCLEUS
NUCLEOLUS
Surrounded by ______________ MEMBRANE
called the NUCLEAR __________________
___________ CENTER OF CELL
 Nuclear ___________ allow molecules in & out
CONTAINS CELL’S GENETIC MATERIAL (_______)
Dark spot = NUCLEOLUS
makes ___________________ (RNA)
DNA is scrunched up as ______________
in dividing cells.
DNA is spread out as ________________
in non-dividing cells.
Review: Nucleus
•
•
•
•
Directs cell activities
Separated from cytoplasm by nuclear membrane
Contains genetic material – DNA
Double membrane
•
•
•
•
Nickname: “The Control Center”
Function: holds the DNA
Parts:
Nucleolus (noo KLEE uh lus)
– Dark spot in middle of nucleus that helps make ribosomes
Organelles That Store, Clean
Up, and Support
• Vacuoles
• Lysosomes
• Cystoskeleton
Vacuoles:
• The cells
‘storage units’,
• Store:
VACUOLES
Image from: http://www.biologycorner.com/resources/plant_cell.gif
Large in plant cells
http://library.thinkquest.org/3564/Cells/cell93.gif
VACUOLES
• Storage space for
WATER, salts,
proteins (enzymes),
carbohydrates, and
waste
• Small in ANIMAL
CELLS
• NO VACUOLES in
bacteria
Vacuoles in plants
• In many plant cells,
there is a single, large
central vacuole filled
with liquid.
– Increases their ability
to support heavy
structures such as
leaves and flowers.
-It’s what makes lettuce crisp
– When no water, it wilts
Lesson Overview
Life Is Cellular
Vacuoles and Vesicles
Nearly all eukaryotic cells contain smaller membraneenclosed structures called _____________.
Vesicles are used to store and move materials between
cell organelles, as well as to and from the cell surface.
VACUOLES
VESICLES
Storage space for: _______________
Huge in __________cells ,
small in _____________ cells,
Not in _________________
_____________________ are
used to store and move
materials between organelles
Lysosomes:
• the ‘cleanup crews’ of
the cell
• Small organelles filled with
_________________.
• Breaks down “food:” lipids,
proteins, and carbohydrates,
into small molecules to be
used by rest of cell.
• Also breaks down “old”
organelles.
LYSOSOMES
•Can remove
junk too
Image modified from: http://www.people.virginia.edu/~rjh9u/lysosome.html
LYSOSOMES
Found in Animal cells and sometimes in Plant cells, although rare
Sac containing _________________________
FUNCTION:
Breaks down __________, _________________, ____________
The Cytoskeleton:
• Complex network of protein filaments
The Cytoskeleton:
• Support, maintains cell shape
• Transports materials within the cell, like a conveyor belt
• Helps cells move
• Made of proteins
• Microfilaments and microtubules are two of the principal protein
filaments that make up the cytoskeleton.
Microfilaments
–
–
–
–
Threadlike structures made up of a protein called actin.
Extensive networks
Produce a tough, flexible framework that supports the cell.
Help cells move.
• Microfilament assembly and disassembly is responsible for the
cytoplasmic movements that allow cells, such as amoebas, to crawl
along surfaces
Microtubules
– Hollow structures made up of proteins known
as tubulins.
– Play critical roles in maintaining cell shape.
Microtubules
• Important in cell
division
• In animal cells, structures
known as centrioles are
also formed from tubulins.
• Centrioles are located
near the nucleus and help
to organize cell division.
• Centrioles are not found in
plant cells.
• Microtubules also
help to build
projections from the
cell surface
– cilia and flagella
– enable cells to swim
rapidly through liquids.
Green---Nuclei
Purple----Microfilaments
Yellow----Microtubules
CENTRIOLESorganize cell division in animals cells
Help separate/sort
chromosomes
Lesson Overview
Life Is Cellular
Organelles That Store, Clean Up, and
Support
What are the functions of vacuoles, lysosomes, and the cytoskeleton?
Vacuoles store materials like water, salts, proteins, and carbohydrates.
Lysosomes break down lipids, carbohydrates, and proteins into small
molecules that can be used by the rest of the cell. They are also involved
in breaking down organelles that have outlived their usefulness.
The cytoskeleton helps the cell maintain its shape and is also involved in
movement.
Organelles That Build Proteins
• Ribosomes
• Endoplasmic Reticulum (ER)
• Golgi Apparatus
Lesson Overview
Life Is Cellular
Organelles That Build Proteins
• Protein Purpose/Function:
• Control rate of reactions
• Regulate cell processes (Enzymes in lysosomes)
• Form cellular structures (Cytoskeleton)
• Transport materials in and out of cell (Cell Membrane proteins)
• Help fight disease
• Made of H O N C
• Cells need to build new molecules all the time, especially proteins
• Big part of the cell is devoted to their ______________________ and
____________________________.
• Because proteins carry out so many of the essential functions of
living things
Lesson Overview
Life Is Cellular
Ribosomes
• Made of small particles of ________________ and ______________
• found throughout the cytoplasm in all cells and on Rough ER
• Produce/Assemble proteins by following coded instructions from DNA.
• Proteins targeted for export to the cell membrane or to specilazed
locations within the cell, complete their assembly on ribosomes BOUND
to the RoughEndoplasmic Reticulum
RIBOSOMES
• Protein factory for cell
• Join amino acids to make polypeptide chains
which make up proteins.

Image by: RIedell
Image from: http://www.ust.hk/roundtable/hi-tech.series/1_b1.jpg
RIBOSOMES
Can be __________________ or __________ to Rough ER
MADE OF ______________ & ________
FUNCTION: _____________________
Found in _____________ types of cells
Lesson Overview
Life Is Cellular
Endoplasmic Reticulum
• Internal membrane system
• In Eukaryotic cells
• Assemble:
• Assemble some ___________________and other materials that are
exported from the cell.
Lesson Overview
Life Is Cellular
Rough Endoplasmic Reticulum , ER
• Involved in the synthesis of proteins
• Given this name because of the ribosomes found on its surface
• Newly made proteins leave these ribosomes and are inserted into the rough
ER, where they may be chemically modified.
Lesson Overview
Life Is Cellular
Smooth Endoplasmic Reticulum, ER
• The other portion of the ER
• Ribosomes are not found on its surface…so Smooth
• Contains collections of enzymes that perform specialized tasks
• S
• D
Lesson Overview
Life Is Cellular
Golgi Apparatus
• Proteins produced in the rough ER move next into the Golgi
apparatus, which appears as a stack of flattened membranes
-like a “flattened stack of pancakes”
• Proteins are bundled into tiny vesicles that bud from the ER and
carry them to the Golgi apparatus.
Lesson Overview
Life Is Cellular
Golgi Apparatus
• _______________, _____________, and _________________
proteins and other materials from the ER for storage in the cell or
release outside the cell.
• Like a customization shop, where the finishing touches are put on
proteins before they are ready to leave the “factory.”
Lesson Overview
Life Is Cellular
Golgi Apparatus
Then…..Proteins are “shipped” to their final
destination inside or outside the cell, via
vesicles.
Lesson Overview
Life Is Cellular
Review: Organelles That Build Proteins
What organelles help make and transport proteins?
Proteins are assembled on ribosomes.
Proteins made on the rough endoplasmic reticulum include those that will
be released, or secreted, from the cell as well as many membrane
proteins and proteins destined for lysosomes and other specialized
locations within the cell.
The Golgi apparatus modifies, sorts, and packages proteins and other
materials from the endoplasmic reticulum for storage in the cell or release
outside the cell.
Lesson Overview
Life Is Cellular
Organelles That Capture and Release
Energy
• Mitochondria (myt oh KAHN dree uh)
(plural)
• Mitochondrion (singular)
• Chloroplasts (KLAWR uh plasts)
Lesson Overview
Life Is Cellular
Organelles That Capture and Release
Energy
• All living things require a source of energy.
• powered by food molecules that are built using energy from the sun.
Organelles involved ------Chloroplasts and mitochondria
Lesson Overview
Life Is Cellular
Chloroplasts
• In plants and some other organisms
(protists, algae)
• The biological equivalents of solar
power plants.
• Capture the energy from sunlight
and convert it into food that contains
chemical energy
=
(More on this in Chapter 8)
Contain _________________
= Green Pigment
CHLOROPLASTS
http://media.pearsoncmg.com/bc/bc_campbell_essentials_2/cipl/04/HTML/source/04-17-chloroplast-nl.htm
Surrounded by double
membrane
Has its own DNA molecules
You will learn all these minute structures in Chapter 8
CHLOROPLAST
Surrounded by ____________ membrane
Contain_____________________,a green pigment
FOUND ONLY IN _____________ CELLS and some other
photosynthetic organisms.
___________________________ is the name of the
process that plants do, converting sun energy to food!
MITOCHONDRION
(plural=MITOCHONDRIA)
Look like
“little sausages”
Image from: http://instructional1.calstatela.edu/dfrankl/CURR/kin150/Images/mitochondria.jpg
Lesson Overview
Life Is Cellular
Mitochondria
• Found in nearly all eukaryotic cells, including plants
• Mitochondria are the power plants of the cell.
Convert the chemical energy stored in food into
compounds that are more convenient for the cell
to use.
MITOCHONDRIA
• Surrounded by a
DOUBLE membrane
•Has its own DNA
•Folded inner membrane
increases surface area
for more chemical
reactions
Image from: http://www.biologyclass.net/mitochondria.jpe
MITOCHONDRIA
Come from
cytoplasm in EGG
You inherit your
mitochondria from
your mother!
http://www.wappingersschools.org/RCK/staff/teacherhp/johnson/visualvocab/p14%5b1%5d.jpg
MITOCHONDRION (pl. MITOCHONDRIA)
Surrounded by _____________ membrane
Contains its own ___________
_____________ of cell
Lesson Overview
Life Is Cellular
Mitochondria and Chloroplasts
• Chloroplasts and mitochondria contain
their own genetic information in the form of
small DNA molecules.
• The endosymbiotic theory suggests that
chloroplasts and mitochondria may have
descended from independent
microorganisms.
Lesson Overview
Life Is Cellular
Organelles That Capture and Release
Energy
What are the functions of chloroplasts and mitochondria?
Chloroplasts capture the energy from sunlight and convert it into food that
contains chemical energy in a process called photosynthesis.
Mitochondria convert the chemical energy stored in food into compounds
that are more convenient for the cells to use.
Lesson Overview
Life Is Cellular
Cellular Boundaries
• Cell Membrane
• Cell wall
Lesson Overview
Life Is Cellular
Cellular Boundaries
• Cells are surrounded by a barrier known as the cell
membrane.
• Many cells, also produce a strong supporting layer
around the membrane known as a cell wall.
Lesson Overview
Life Is Cellular
function: provide support and protection for the cell.
Who has a cell wall?
Prokaryotes
plants
Algae
fungi
and many prokaryotes
Cell Walls
Animal cells do not have cell walls.
• Lie outside the cell membrane
• Most are porous enough to allow water, oxygen, carbon dioxide, and
certain other substances to pass through easily.
Lesson Overview
Life Is Cellular
Cell Membranes
FUNCTION:
•R
•S
• Found in ALL cells, prokaryotes and eukaryotes
Lesson Overview
Life Is Cellular
Cell Membranes
• double-layered sheet called a __________ ___________
• gives cell membranes a flexible yet strong structure
• forms a barrier between the cell and its surroundings.
Lesson Overview
Life Is Cellular
Cell Membranes:
The Properties of Lipids
• oily fatty acid chains interact strongly with water.
• The fatty acid portions of a lipid are _______________, or “water-hating,”
• the glycerol end of the molecule is ________________, or “water-loving.”
LIPID TAILS ARE
HYDROPHOBIC
HYDROPHILIC 
“water loving”
HYDROPHOBIC 
“water-hating”
Image by Riedell
Lesson Overview
Life Is Cellular
Cell Membranes:
The Properties of Lipids
When such lipids are mixed with water, their hydrophobic fatty
acid “tails” cluster together while their hydrophilic “heads” are
attracted to water.
A lipid bilayer is the result.
Lesson Overview
Life Is Cellular
The Properties of Lipids
• Head groups of lipids in a bilayer are exposed to water
• Fatty acid tails form an oily layer inside the membrane
from which water is excluded.
• Oil and water do not mix
Cell Membrane:
The Fluid Mosaic Model
• Protein molecules
are embedded in
the lipid bilayer.
• Form channels and
pump
• moves materials
across cell
membrane
• carbohydrate
molecules attached
to proteins
•
act like chemical
identification
cards
Lesson Overview
Life Is Cellular
The Fluid Mosaic Model
proteins can move around and “float”
different kinds of molecules make up the cell membrane,
so…..scientists describe the cell membrane as a “fluid
mosaic.”
Fluid= can move
 “mosaic” has different parts
Cell membranes MOVE!
Animation from: http://www.sp.uconn.edu/~terry/images/anim/fluidmem.gif
Molecules in cell membranes are
constantly moving and changing
= “Fluid Mosaic Model”
Lesson Overview
Life Is Cellular
The Fluid Mosaic Model
• Many substances can cross biological membranes,
• Some are too large or too strongly charged to cross the lipid bilayer.
• If a substance can cross a membrane = permeable membrane
• If a substance cannot pass through = impermeable membrane
• Most biological membranes are selectively permeable,
• some substances can pass across them and others cannot.
• Selectively permeable membranes = semipermeable
membranes.
Lesson Overview
Life Is Cellular
Cellular Boundaries
What is the function of the cell membrane?
The cell membrane regulates what enters and
leaves the cell and also protects and supports
the cell.
Only in Plant Cells:
Compare
Only in Plant Cells
Only in Animal Cells
Compare/Contrast
Prokaryotes
• DNA not in a nucleus
• No membrane bound
organelles
• No mitochondria
Eukaryotes
• Has a nucleus
• Membrane bound
organelles
• Mitochondria/Chloroplast
• Cell wall
• Cell membrane
• Ribosomes
• Some cell walls
• Cell membrane
• Ribosomes