The Cell:History and Theory
Chapter 7 Powerpoint #2 Honors Biology
http://ed.ted.com/lessons/the-wacky-history-of-cell-theory#reviewhttp://www.youtube.com/watch?v=2hnWzRxX2z8
Cell Theory and the Scientists Who Helped
Shape It
Scientists and the Cell Theory
Anton van Leeuwenhoek• Born: October 24, 1632• Died: August 30, 1723
• He is known as the “Father of Microscopy.”
http://en.wikipedia.org/wiki/Anton_van_Leeuwenhoek
Anton van Leeuwenhoek• Discoveries:
- 1673: He looked at pond scum under the microscope and discovered small organisms he called animalcules or little animals (Protists)- 1676: discovered
bacteria using his teeth gunk
http://www.kent.k12.wa.us/staff/TimLynch/sci_class/chap09/lesson_protista/Protista_Lesson.html#Algae
Robert Hooke• Born: July 18, 1635• Died: March 3, 1703
• Wrote and published “Micrographia”
• Known as the “English Father of Microscopy”
http://www-groups.dcs.st-and.ac.uk/~history/PictDisplay/Hooke.html
Robert HookeContributions:
- He observed pieces of cork from the bark of a cork tree under the microscope.
- His observations led him to coin the word “cell.”- “Cell”- means little rooms in Latin- He compared the small boxes to the small rooms that monks lived in.
http://www.learner.org/channel/courses/essential/life/session1/closer1.html
Matthias Schleiden• Born: April 5, 1804• Died: June 23, 1881
• German botanist
• Discovered that all plants were made of cells
• Contributed to the creation of the cell theory
http://www.britannica.com/eb/article-9066147/Mathias-Jacob-Schleiden
Theodor Schwann• Born: December 7, 1810• Died: January 11, 1882
• German zoologist
• Concluded that all animals are made of cells.
• Contributed to the creation of the cell theory http://www.nndb.com/people/357/000096069/
Rudolph Virchow• Born: October 13, 1821• Died: September 5, 1902
• German pathologist
• He is known as the “Father of Pathology.”
• Discovered that all living cells come only from other living cells.
http://en.wikipedia.org/wiki/Image:Rudolf_Virchow.jpg
The Cell Theory1. All living things are made of cells.
(Not made of cells=not living)2. Cells are the basic units of
structure and function in living things (anything smaller than cell=not living)
3. Living cells come only from other living cells (reproduction)
Two Main Types of CellsProkaryote(Pro=before, karyo=nucleus)• generally smaller and simpler• DO NOT have a nucleus –
DNA free-floating• No membrane bound organelles• All prokaryotic organisms are unicellular• Have cell walls• example: all bacteria
Two Main Types of CellsEukaryote (Eu=true, karyo=nucleus)• Big, complex• Contains a nucleus,• Contains dozens of specialized cell parts
(organelles)• Some unicellular organisms, many multicellular• example: all plants, animals, and fungi
Cell Types (Review)Eukaryotic1. Contains a nucleus and other membrane bound organelles.
2. Rod shaped chromosomes
3. Found in all kingdoms except the Eubacteria and Archaebacteria
Prokaryotic1. Does not contain a nucleus or other membrane bound organelles.
2. Circular chromosome
3. Found only in the Eubacteria and Archaebacteria Kingdoms
Viruses• Have genetic material• NOT LIVING!!!!• Can only survive in host
cell
Two Main Types of CellsProkaryote vs. Eukaryote
Both:• Have a cell membrane• Contain DNA• Have cytoplasm with ribosomes
Parts and Functions of Eukaryotic Cells
Organelles
• “mini-organs”• Each part of a cell with a specific job
is called an organelle
Cell-City Analogy• Just as a city is made up of many different components,
each with respective functions that they perform for the city to thrive, a cell is also made of structures (organelles), each with specific roles and duties.
Nucleus• Contains the genetic
material (DNA) & controls the cell’s activities
• Provides protection for nuclear material
• Made of 3 parts: – (1) nuclear envelope– (2) nucleolus– (3) chromatin
Nuclear Envelope• Double –membrane layer that
surrounds the nucleus of a cell
Nucleolus• Small, dense region within most
nuclei that produces rRNA
Chromatin• combination of DNA and proteins
Ribosome• Site of protein synthesis• May be either free-floating or
attached to E.R.
Endoplasmic Reticulum • Network of transport
Channels• 2 Kinds
– Smooth ER(SER): Synthesis of lipids and steroids
– Rough ER (RER): Synthesis and processing of proteins (ribosomes make it “rough”)
Golgi Apparatus • Packages proteins from the RER for secretion.• Packages lipids & steroids from the SER in to
vesicles to send to other organelles, or out of the cell.
Lysosome• Membrane-enclosed sac of enzymes needed to
break down cellular debris • recycling the cell's organic material• Made by the Golgi apparatus
Mitochondrion • Releases energy from glucose (cellular
respiration)• Makes ATP, the main energy source for almost
all cell processes.
Cytoplasm• Contents of a cell inside the cell
membrane but outside of the nucleus.• The gel-like substance in the
cytoplasm is called cytosol
Cell Membrane• Thin, Flexible barrier around a cell that regulates
what enters and leaves the cell.• More about this later…
Microtubule
• Long, thin filament that functions in the movement and support of the cell
• Hollow tube of protein that maintains cell shape and functions as a “track” along which organelles move through the cell
Cell membrane
Endoplasmicreticulum
Microtubule
Microfilament
Ribosomes Mitochondrion
CytoskeletonMicrofilament
Animal Cells ONLY !!!
Centriole• One of two small cylindrical structures
near the nuclear envelope of animal cells.• It helps organize microtubules during cell
division• Helps build cilia & flagella
Plant Cells ONLY !!!
Cell Wall• Provides structure and
protection to the cell. Found outside cell membrane in plants, algae, and some bacteria
• Made of:– Cellulose – Plants– Chitin – Fungi– Peptidoglycan - Bacteria
Chloroplast• Converts energy
from the sun into chemical energy, in the form of glucose
Vacuole • Membrane-bound sac, largest structure in
plant cell• Helps maintain water pressure in the cell• Site in the cell where water, salts, proteins,
and carbohydrates are stored
Animal Cells Plant Cells
Centrioles
Cell membraneRibosomes
NucleusEndoplasmic reticulum
Golgi apparatusLysosomesVacuoles
MitochondriaCytoskeleton
Cell WallChloroplasts
Compare Cell Sizes
http://learn.genetics.utah.edu/content/begin/cells/