The Cell: History and Theory Chapter 7 Powerpoint #2 Honors Biology

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 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 Hooke Contributions: - 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 Theory All living things are made of cells. Cells are the basic units of structure and function in living things. Living cells come only from other living cells.

Two Main Types of Cells Prokaryote generally smaller and simpler DO NOT have a nucleus – DNA is not contained All prokaryotic organisms are unicellular example: all bacteria

Two Main Types of Cells Eukaryote = “true nucleus” Contains a nucleus Contains dozens of specialized cell parts (organelles) Some unicellular organisms, many multicellular example: all plants, animals, and fungi

Cell Types (Review) Eukaryotic 1. Contains a nucleus and other membrane bound organelles. 2. Rod shaped chromosomes 3. Found in all kingdoms except the Eubacteria and Archaebacteria Prokaryotic 1. Does not contain a nucleus or other membrane bound organelles. 2. Circular chromosome 3. Found only in the Eubacteria and Archaebacteria Kingdoms

Prokaryote vs. Eukaryote Two Main Types of Cells Prokaryote vs. Eukaryote Both: Have a cell membrane Contain DNA Have cytoplasm with ribosomes

Endoplasmic reticulum Prokaryotes Eukaryotes Cell membrane Contain DNA Ribosomes Cytoplasm Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton

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

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…

Cytoskeleton Microfilament Microtubule Cell membrane Endoplasmic reticulum Microtubule Microfilament Ribosomes Mitochondrion Microfilament 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 Microtubule

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

Endoplasmic reticulum Animal Cells Plant Cells Centrioles Cell membrane Ribosomes Nucleus Endoplasmic reticulum Golgi apparatus Lysosomes Vacuoles Mitochondria Cytoskeleton Cell Wall Chloroplasts