Cell Theory & Cell Organelles Introduction To Cell – Life is Cellular

The Discovery of the Cell LIFE IS CELLULAR!! In 1665, Robert Hooke used an early compound microscope to look at a thin slice of cork, a plant material. Cork looked like thousands of tiny, empty chambers. Hooke called these chambers “cells.” (THINK PRISON CELLS) Cells are the basic units of life. Hooke’s Drawing of Cork Cells Digestive enzyme from a pitcher plant that could be used as an antibacterial agent. Picture: http://www.topnews.in/health/enzymes-carnivorous-plants-could-help-development-new-antibacterial-products-2880

Looked at pond water under a microscope. Found living creatures. Anton van Leeuwenhoek used a microscope to observe tiny organisms (microorganisms) in pond water Looked at pond water under a microscope. Found living creatures.

The Discovery of the Cell The Cell Theory In 1838, Matthias Schleiden concluded that all plants were made of cells. In 1839, Theodor Schwann stated that all animals were made of cells.

The Discovery of the Cell In 1855, Rudolph Virchow concluded that new cells were created only from division of existing cells. These discoveries led to the cell theory!

The Discovery of the Cell The cell theory states: All living things are composed of one or more cells. (you, me, plants, bugs, fish, Spiderman, Colonel Sanders, Jimmy Neutron, Bacteria, Yeast, Jackie Chan) Cells are the basic units of structure and function in living things. (what keeps us upright and helps us live, basically small workers responsible for how we function!) New cells are produced from existing cells. (they can’t just appear out of thin air…cells make new cells by dividing!) Cell Theory

ENDOSYMBIOTIC THEORY In 1970, American biologist, Lynn Margulis, provided evidence that some organelles within cells were at one time free living cells themselves Supporting evidence included organelles with their own DNA Chloroplast and Mitochondria Endosymbiotic Theory - video

Prokaryotes and Eukaryotes What are the characteristics of prokaryotes and eukaryotes? Eukaryotes are cells that contain nuclei. Prokaryotes are cells that do not contain nuclei.

Prokaryote Has no nucleus. Just a mass of DNA No organelles except ribosomes & cytoplasm Always unicellular Example : bacteria

Eukaryote Cells Contain a nucleus. Unicellular or Multicellular- Have organelles, which are surrounded by membranes. Example: plant cells, animal cells

PROKARYOTES AND EUKARYOTES Both Have: Cytoplasm Ribosomes Plasma Membrane With Plants: Cell Wall With (some) Animals: Flagella Prokaryotes do not have a nucleus! Eukaryotes are more complex Eukaryotes are larger

Why are cells named that way? From Greek words… EU means TRUE. (YOU HAVE) PRO means BEFORE. (NO) KARYON means NUCLEUS. Eukaryote = TRUE NUCLEUS; Prokaryote = BEFORE NUCLEUS. All cells have DNA, in eukaryotes it is stored in the nucleus. Prokaryotes don’t have a nucleus, and it floats around in the cytoplasm in an area called the nucleoid. Only eukaryotes have membrane-bound organelles. Video-Comparing Prokaryote and Eukaryote Cells

Test Yourself! Statement Prokaryotic Eukaryotic 1. Have a nucleus 2. Have membrane-bound organelles 3. Contain genetic material (DNA) 4. Can be single or multi-celled 5. Can only be single-celled. 6. Have a plasma membrane and cytoplasm