An Introduction to CELLS Jen Cook and E.Coleman 2008

http://porpax.bio.miami.edu/~cmallery/150/unity/cell.text.htm

CELL THEORY: One of the 3 Theories that unify all knowledge in Biology 1. All living things are made of one or more cells. 2. A cell is the smallest thing that can be considered alive. (1839 Schwann & Schleiden ) 3. All cells come from other pre-existing cells by reproduction. (1855 Rudolph Virchow Cells were first discovered in 1663 using one of the first primitive microscopes. They were cells in cork. Robert Hooke [The word cell is from Latin 'cellula' which means small compartment ]

Microscope 1670’s Anton von Leeuwenhoek – first to observe bacteria and protozoa using a more “advanced” microscope. ~ 1833 Robert Brown reported the discovery of the nucleus

TYPES OF CELLS: A. Prokaryotic SIMPLE No nucleus or other complex organelles. b. DNA circular, floating in cytoplasm. 2. TINY : .1 – 10 Mm 3. PRIMITIVE: Similar to first living things. Fossils found up to 3.8 billion years old. 4. KINGDOM: Monera (example: bacteria)

TYPES OF CELLS: B. Eukaryotic 1. COMPLEX Nucleus + many other complex organelles. b. DNA in nucleus; multiple strands (called chromosomes) 2. LARGE: 10-100 Mm (some up to 2 meters long!) 3.ADVANCED: Evolved almost 2 billion years after Prokaryotes. 4. KINGDOMS:all members of Protist, Fungi, Plant, Animal 5. TYPES: a. PLANT b. ANIMAL

Each cell in an organism has a specific job. Depending on its function it may look very different from the “typical” plant or animal cell.

Notes: HOW EUKARYOTIC CELLS EVOLVED The Endosymbiont Theory (“Endo-” = inside; “Symbiosis” = mutually beneficial relationship) 1. Mitochondria and chloroplasts were once free-living prokaryotic organisms. 2. They entered (or were eaten by!) cells of other organisms and began living there.

3. Helped host cells survive: provided ATP (mitochondria) or glucose (chloroplasts). 4. Host cell provided protection for them. 5. And so - they stayed!

All surrounded by double membranes. Evidence Supporting Endosymbiont Theory – Mitochondria and Chloroplasts are very much like bacteria: All surrounded by double membranes. 2. Similar size. a. mitochondria: 0.5 - 4 Mm b. chloroplasts: 4 - 10Mm c. bacteria: 0.5 – 10Mm E Coli (bacteria) Chloroplast Mitochondria

Evidence Supporting Endosymbiont Theory - continued 3. Similar ribosomes. 4. Both have their own DNA (separate from nuclear DNA of the cell) - circular like bacterial DNA. 5. Both reproduce separately from rest of cell - by simple fission, like bacteria.

Basic cell structures/organelles Cell membrane Cell wall (plants only) Nucleus Chromatin Chromosome Chromatids Nucleolus Nuclear envelope/nuclear membrane

Organelles, continued Cytoplasm Cytoskeleton Ribosomes Microtubules Endoplasmic reticulum (rough and smooth) Golgi apparatus Lysosome Vacuole Chloroplast (plants only) Mitochondria Cytoskeleton Microtubules Microfilaments http://www.beaconlearningcenter.com/Weblessons/MixedUpCells/default.htm (good website to learn names and functions of cell organelles)

CELL ANALOGY: A cell is a lot like a town CELL ANALOGY: A cell is a lot like a town. Its organelles do jobs similar to the functions of some entities in a typical town. Which cell organelle is most like each of the following in terms of the work it does for the cell? Master plan; blueprint. Freeway system Cement factory Food producers (farmers) Power plant, electricity generators. 6. Sewage treatment, waste detoxification 7. Water storage tank 8. Border control, INS 9. Mayor’s office 10. Materials packaging & storage Chromatin (DNA) Lysosome Endoplasmic Reticulum Vacuole Ribosome Cell (plasma) membrane Chloroplast Nucleus Mitochondria Golgi body

Review of Animal and Plant Cells Created by T. Bun & J. Cook & E. Coleman

What type of cell is this? PLANT CELL

What type of cell is this? Animal ANIMAL CELL

________ are known as the “power-houses” of the cell because they produce ATP. Nucleus MITOCHONDRIA

The cell membrane is also known as the _______ membrane. What structure controls the movement of materials into and out of the cell? CELL MEMBRANE The cell membrane is also known as the _______ membrane. PLASMA ________ are the sites where proteins are made (“protein synthesis”) in the cell. Plasma RIBOSOMES

thing plant cells store in their vacuoles? What is number 6? A vacuole. What is the main thing plant cells store in their vacuoles? Vacuole WATER

Number 5 is pointing to what? The CELL WALL. Cell Membrane

What structures produce glucose and other carbohydrates (i.e. FOOD!)? CHLOROPLASTS Chloroplast

What organelles store primarily enzymes and waste? LYSOSOMES Vacuoles

What is the structure in the nucleus that makes ribosomes and other kinds of RNA? Nucleolus Nucleolus

What is structure number 13? PC diagram Centrioles CENTRIOLE

What type of cells are these? Cheek Cells HUMAN CHEEK CELLS

What type of cells are these? ELODEA CELLS What are the little green things inside them? CHLOROPLASTS

What kind of cells are these? ONION CELLS Onions are plants. Why are there no chloroplasts in these cells? This part of the plant grows underground. Chloroplasts do photosynthesis – that requires light. There’s no point in having chloroplasts in cells that aren’t exposed to light!

Number 6 is pointing to what structure? Golgi Body GOLGI BODY (aka GOLGI APPARATUS, GOLGI COMPLEX)

CHLOROPLASTS and CELL WALLS The two structures found in plant cells that are never found in animal cells are ____________ & ___________. CHLOROPLASTS and CELL WALLS Cell Wall and Chloroplast

Name structures 1, 2, 5, & 9. NUCLEOLUS MITOCHONDRIA NUCLEUS Nucleolus, Nucleus, ER, Mitochondia ENDOPLASMIC RETICULUM