Cells The Building Blocks of Life

A cell A cell

Why Know This? Cells  tissues  organs  organ systems  organism Cells  tissues  organs  organ systems  organism If something goes wrong at the cellular level then it can effect the entire body. Cyanide shuts down mitochondria = no energy = death

Composition Biomolecules (proteins, lipids, carbohydrates, nucleic acids) make up and are produced by cells. Biomolecules (proteins, lipids, carbohydrates, nucleic acids) make up and are produced by cells. - example, phospholipids, cholesterol, proteins and carbohydrates make the cell membrane - example, phospholipids, cholesterol, proteins and carbohydrates make the cell membrane Organelles (little organ) compartments made of membrane each with specific functions allowing for division of labor. Organelles (little organ) compartments made of membrane each with specific functions allowing for division of labor. -example: mitochondria are -example: mitochondria are the site of cellular respiration the site of cellular respiration

History of the Cell Robert Hooke (1665)-looked at dead cells and coined the term cells Robert Hooke (1665)-looked at dead cells and coined the term cells

History of the Cell Anton Van Leeuwenhoek first to view live cells- “Wee Beasties” Anton Van Leeuwenhoek first to view live cells- “Wee Beasties”

History of the Cell Cell Theory Developed by Schledin, Schwann, and Virchow Developed by Schledin, Schwann, and Virchow - 3 Parts Cells are the basic unit of structure and function in living things. Cells are the basic unit of structure and function in living things. All living things are composed of cells. All living things are composed of cells. All cells come from preexisting cells. All cells come from preexisting cells.

Microscopes and Cells Light Microscopes – can magnify up to 1000x Light Microscopes – can magnify up to 1000x - Simple microscope - one lens - Compound microscope – 2 lenses working together working together Electron microscope – use a beam of electrons to create images – can magnify up to 500,000x Electron microscope – use a beam of electrons to create images – can magnify up to 500,000x - Transmission – shows interior - Transmission – shows interior features features - Scanning – shows exterior features - Scanning – shows exterior features

Light Microscope Light Microscope Transmission Electron Microscope (TEM) Transmission Electron Microscope (TEM) Scanning Electron Microscope (SEM )

A. B. C.

The First Cell Prokaryotes were the first organisms Prokaryotes were the first organisms Pro=before karyote=kernel Bacteria are prokaryotes. Bacteria are prokaryotes.

Prokaryote Characteristics All prokaryotes have the following: All prokaryotes have the following: cell membrane – surrounds and controls what enters and leaves cell controls what enters and leaves cell cytoplasm cytoplasm ribosomes - makes protein cell wall DNA – circular loop found in a region called the nucleoid

Prokaryote Characteristics What bacteria don’t have What bacteria don’t have - nucleus - nucleus - membrane bound organelles - membrane bound organelles

Eukaryotes - True Kernal Eu = true Karyote = kernal – refers to the nucleus Eu = true Karyote = kernal – refers to the nucleus Eukaryotes evolved after prokaryotes Eukaryotes evolved after prokaryotes prokaryotes appeared 3.8 billion years ago prokaryotes appeared 3.8 billion years ago eukaryotes appeared 1.5 billion years ago eukaryotes appeared 1.5 billion years ago Types of Eukaryotes – Plants, Animal, Fungi, Protists Types of Eukaryotes – Plants, Animal, Fungi, Protists

Eukaryotes Similarities, all eukaryotes have: Similarities, all eukaryotes have: Cell membrane – surrounds Cell membrane – surrounds cell controls what enters and cell controls what enters and leaves cell leaves cell Cytoplasm Cytoplasm Nucleus membrane bound structure that houses Nucleus membrane bound structure that houses and protects the DNA and protects the DNA Linear DNA Linear DNA Ribosomes make protein Ribosomes make protein Organelles structure within the cell which perform specialized functions for the cell Organelles structure within the cell which perform specialized functions for the cell example: mitochondria break down example: mitochondria break down biomolecules to produce biomolecules to produce energy (ATP) for the cell energy (ATP) for the cell

Prokaryotic vs Eukaryotic Prokaryotic vs Eukaryotic Size 0.3 – 5.0 microns Size 0.3 – 5.0 microns Size 10 – 50 microns Size 10 – 50 microns

Endosymbiont Theory

Explains the origins of mitochondria and chloroplasts Explains the origins of mitochondria and chloroplasts - chloroplasts were once free living photosynthetic bacteria (prokaryotes) - chloroplasts were once free living photosynthetic bacteria (prokaryotes) - they were engulfed by a larger cell - they were engulfed by a larger cell - the photosynthetic bacteria produced food for the larger cell which protected it - the photosynthetic bacteria produced food for the larger cell which protected it

Mitochondria were once free living bacteria which were capable of aerobic cellular respiration Mitochondria were once free living bacteria which were capable of aerobic cellular respiration - a larger cell engulfed them - a larger cell engulfed them -the engulfed cells produced energy -the engulfed cells produced energy from food supplied by the large cell from food supplied by the large cell which protected them which protected them

Some Evidence for the Endosymbiont Theory both chloroplasts and mitochondria have circular DNA– like bacterial DNA both chloroplasts and mitochondria have circular DNA– like bacterial DNA both are surrounded by 2 membranes 1 from the bacteria and 1 from the host – inner membrane is similar to that in prokaryotes both are surrounded by 2 membranes 1 from the bacteria and 1 from the host – inner membrane is similar to that in prokaryotes both are similar in size to bacteria both are similar in size to bacteria structure of chloroplasts similar to photosynthetic bacteria structure of chloroplasts similar to photosynthetic bacteria Both contain ribosomes like those in prokaryotes Both contain ribosomes like those in prokaryotes Both reproduce by binary fission like prokaryotes Both reproduce by binary fission like prokaryotes

Photosynthetic Chloroplast Photosynthetic Chloroplast Bacteria Bacteria