Cellular Structure and Function 7.1 Cell Discovery and Theory 7.2 The Plasma Membrane

The Discovery of the Cell Cell: The basic structural and functional unit of all living organisms Cell: The basic structural and functional unit of all living organisms Robert Hook Robert Hook Looked at cork Looked at cork Used the word “cell” to describe what he saw Used the word “cell” to describe what he saw Anton van Leeuwenhoek Anton van Leeuwenhoek Designed his own microscope after reading a book written by Hook! Designed his own microscope after reading a book written by Hook! First to study living cells under microscope First to study living cells under microscope

The Cell Theory 3 parts: 1. All living things are made of cells 2. The cell is the basic unit of structure and organization in all living organisms 3. All cells can only come from other living cells, cells pass on genetic information to their daughter cells Video Clip Video Clip

Microscopes Development of this technology allowed scientists to actually see cells for the first time Development of this technology allowed scientists to actually see cells for the first time Compound Light Microscopes Compound Light Microscopes How do you calculate total magnification? How do you calculate total magnification? Needed to look at cells Needed to look at cells Electron Microscopes Electron Microscopes Developed during WWII Developed during WWII Needed to see the smaller things inside of cells Needed to see the smaller things inside of cells

Cell Membranes Cell Membrane and plasma membrane mean the same thing Cell Membrane and plasma membrane mean the same thing The Cell Membrane is made of lipids and transport proteins The Cell Membrane is made of lipids and transport proteins There are two layers of lipids, so it is sometimes called a Lipid bi-layer There are two layers of lipids, so it is sometimes called a Lipid bi-layer The proteins float around in the lipids The proteins float around in the lipids Why is it called a Fluid Mosaic Model? Why is it called a Fluid Mosaic Model? The membrane never actually stops moving The membrane never actually stops moving Selectively Permeable: The cell membrane can actually choose what moves into and out of the cell! Selectively Permeable: The cell membrane can actually choose what moves into and out of the cell!

Two Basic Cell Types Virus Eukaryotic cells Prokaryotic cells

Major Parts of Viruses Protein shell Protein shell Nucleic acid (DNA or RNA) Nucleic acid (DNA or RNA)

Viruses Major Structures: Major Structures: Not a cell! Not a cell! DNA or RNA core in some kind of coat organization: DNA/RNA just floats around DNA or RNA core in some kind of coat organization: DNA/RNA just floats around Complexity and Organization Complexity and Organization No complexity No complexity No organization No organization How do we get more viruses? How do we get more viruses? Can not reproduce without a host cell Can not reproduce without a host cell Is it a cell? Is it a cell? Not a cell Not a cell EX: Ebola, West Nile

Major Parts of Prokaryotic Cells DNA DNA Cytoplasm Cytoplasm Cell membrane Cell membrane

Prokaryotic Cells Major Structures: Major Structures: Free floating DNA within cytoplasm Free floating DNA within cytoplasm Cell Membrane Cell Membrane Usually chromosome (DNA) is in a loop Usually chromosome (DNA) is in a loop Complexity and Organization Complexity and Organization Some organization Some organization Little complexity Little complexity How do we get more prokaryotic cells? How do we get more prokaryotic cells? Cell reproduces Cell reproduces Is it a cell? Is it a cell? Always s Single-Celled organism Always s Single-Celled organism Ex: Bacteria, Cholera, E.coli

Major Parts of Eukaryotic Cells Nucleus Nucleus DNA (chromatin vs. chromatid) DNA (chromatin vs. chromatid) Cytoplasm Cytoplasm Cell membrane Cell membrane Membrane Bound Organelles Membrane Bound Organelles

Eukaryotic Cells Major Structures: Major Structures: Chromosomes (DNA) is found within a nucleus Chromosomes (DNA) is found within a nucleus Contains membrane bound organelles Contains membrane bound organelles Complexity and Organization Complexity and Organization Highly organized Highly organized Very complex Very complex How do we get more eukaryotic cells? How do we get more eukaryotic cells? Cell reproduces Cell reproduces Is it a cell? Is it a cell? Single-cell Single-cell Multi-celled organisms Multi-celled organisms Ex: Plants, Animals, You, Protozoa, Fungi

Organelles in Eukaryotic Cells 7.3 Structures and Organelles

Cell Wall (#4) -only in plant cells -provides physical protection and support -made of a starch ____ 11

Cell (Plasma) Membrane (below #1, red line) acts as a boundary layer to contain the cytoplasm (fluid in cell) selectively permeable: able to select chemicals that pass in and out of cells

Endoplasmic Reticulum (#2 and #6) -Transports chemicals between cells and within cells -Rough ER (#6) has ribosomes while Smooth ER does not (#2) ____ 11

Ribosomes (#6 small red dots) -Site where proteins are made

Nucleus (#10) -contains DNA -selectively permeable to control movement in or out, like the cell membrane ____ 11 10____________

Vacuole (#9) - produces turgor pressure against cell wall for support - stores water and various chemicals - much smaller in animal cells ____ 11 9_____

Cytoplasm (#7) -"molecular soup" -holds together all of the cell's organelles, and divides the organelles within the cell. ___7

Mitochondria (#8) - the major energy production center in eukaryotes _____8

Golgi (#11) -consists of stacks of sacs -packages materials for export from the cell ____ 11

Chloroplast (no number, green organelle) Function in photosynthesis to make sugar from sunlight Found only in plants

Plant and Animal Cells