Intro to Cells & Prokaryotic cells Unit 3 – The Cell

Review What is a cell? A cell is the smallest unit that is capable of performing life functions. One of the characteristics of life is being made up of units called cells. Organisms may be: Unicellular: made of 1 cell Multicellular: made of many specialized cells

Who saw them first? Robert Hooke in 1665, was the first person to use the word "cell" to identify microscopic structures when he was describing cork.

Background Anton Van Leeuwenhoek : Father of Microbiology, created the first microscope. Matthias Schleiden ( 1830’s) All plants are composed of cells. Theodor Schwann (1831) All animals are made of cells. Rudolf Virchow (1858) Found that every cell comes from a pre-existing cell.

Cell Theory 1. All organism are made up of cells 2. A cell is the structural and functional unit of organs and ultimately, organisms. 3. Cells are capable of self – reproduction and cells come only from pre-existing cells

Cell Types Prokaryotic Eukaryotic No Nucleus Nucleus

Eukaryotic vs. Prokaryotic similarities Vesicles DNA present Ribosomes Vacuole Cell wall Cytoplasm Plasma membrane Vesicles DNA present Ribosomes Vacuole Cell wall (some) Cytoplasm Plasma membrane

Eukaryotic vs. Prokaryotic differences NO nucleus No membrane bound organelles (mitochondria, lysosomes, ER, gogi body etc.) No chromosomes (plasmids) No chloroplast (chlorophyll scattered in cell) Unicellular ~1-10 um Nucleus Membrane bound organelles (mitochondria, lysosomes, ER, gogi body etc.) Chromosomes Chloroplast (some) Mostly multicellular ~10-100 um

Prokaryotic Cell Parts Flagellum – move the bacterium in a fluid medium Cytoplasm – a semifluid medium that make up the majority of the cell Ribosomes – responsible for making proteins Nucleiod – where the DNA is located Capsule – gelationous sheath called a slime layer that surrounds the cell wall Cell Well – gives the cell its shape Plasma Membrane – regulates the movement of molecules into and out of the cytoplasm. Plasmid – external single DNA molecule Pili – hairlike structure used in bacterial conjugation (sharing of genetic material.

Prokaryotic Cell Parts