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Cells Cell Structure & Function Cells & Energy Cell Growth & Division. Chapter 3, 4, and 5. http://www.youtube.com/watch?v=Ow0jH2Eg8v4. Living things come in different sizes. How does the size of a cell in a tadpole compare to the size of a blue whale? .
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CellsCell Structure & FunctionCells & EnergyCell Growth & Division Chapter 3, 4, and 5 http://www.youtube.com/watch?v=Ow0jH2Eg8v4
How does the size of a cell in a tadpole compare to the size of a blue whale? • Most cells in a whale are identical to the cells in a tadpole.
What makes a whale so much larger? • A whale has more cells than a tadpole or the frog that the tadpole grows into.
Prefixes • Cyto= cell • Iso= Equal • Kary= Kernel • Hyper= Above • Endo= Within • Hypo= Below • Exo= Out of
Robert Hooke • First to identify cells by observing cork from the bark of an oak tree. • 1665
Anton van leewenhoek • Described living things and observed them in greater detail. • Called them “animalcules” • 1674
Matthias Schleiden • Found that plants are made of cells • 1838
Theodore Schwann • All living things are made of cells • 1839
Rudolf Virchow • Proposed that cells come from pre-existing cells • 1855
Three Major principles of the cell theory • 1. All organisms are made of cells • 2.All existing cells come from pre-existing cells • 3. Cells are the basic unit of life.
What is the relationship between structure and function of your cells? • The way they are shaped directly relates to their job or function. http://www.youtube.com/watch?v=u54bRpbSOgs
Examples • 1. Long, thin nerve cells transmit sensory info from your brain to the rest of your body. • 2. Short, blocky skin cells that cover and protect the body.
http://www.youtube.com/watch?v=HNP1EAYLhOs&feature=fvwrel • http://www.youtube.com/watch?v=Rpj0emEGShQ&feature=related
Cells are separated into two categories • 1. Prokaryotic • 2. Eukaryotic
Cell Comparison • Prokaryotic • No nucleus or membrane bound organelles • DNA is suspended in the cytoplasm and circular • Single celled • Cell Walls • Evolved 3.5 bya • Ex- Bacteria, • cyano-bacteria • Eukaryotic • Has a nucleus with membrane bound organelles • Nucleus store the genetic material and is linear • Multicellular or unicellular • Larger, more complex • Plants and animals • Evolved 1.5 mya Both: * Microscopic in size * Composed of similar building blocks * Cell Membrane * Cytoplasm * Have DNA * Loaded with ribosome's
Levels of organization • Ranges from smallest to largest
Cell Differentiation • Defined- Process where a generic cell develops into a specific type of cell. • Example-> zygote -> embryo • Allows germ cells, stem cells, and somatic cells to develop and mature.
Why is it crucial? • Crucial for embryonic development, plays a role in the functioning of many organisms throughout their lives.
The Beginning • 3.8 billion years ago the oceans were full of organic molecules (carbon based) and single celled organisms called microbes (anaerobic- no oxygen) deposited many minerals onto the Earth’s surface-> changing the topography and giving off oxygen as a by-product of photosynthesis. • Marine cyanobacteria (made up of a single prokaryotic cell) is the oldest known photosynthetic life form. • Some CB live in colonies called stromatolites (domed, rocky structures) and some have been found and aged to be 3.5 billion years old. May have helped pave the way for aerobic life forms (oxygen breathing).
Endosymbiotic Theory • Defined as: ecological theory in which one organism lives within the body of another and they both benefit from each other. • Suggests that early mitochondria and chloroplasts were once simple prokaryotic cells that were taken up by smaller prokaryotic cells (1.5 bya). Instead of being digested the small ones survived inside the larger ones.
Small prokaryotes took on the role of the mitochondria in the larger cell, which got its energy in the form of ATP. If it took in the prokaryote that acted like a chloroplast – the larger cell could use photosynthesis to make sugars (cyanobacteria). • Based her theory on: • Mitochondria and Chloroplasts have their own DNA and ribosome's • They copy themselves within the cell they are found which means they were once distinct organisms, most likely ancestors of prokaryotes • Same size as prokaryotes • DNA forms a circle • Gene structures are similar to prokaryotes http://bugs.bio.usyd.edu.au/learning/resources/CAL/Microconcepts/moviePages/incorporation.html
How do we put this all together???? • Mitochondria and Chloroplasts are found in both plant and animal cells which are eukaryotic cells. Eukaryotic cells did not exist until 1.5 bya, therefore they evolved from prokaryotic cells (bacteria) • The leap from free floating molecules to the first true cells is still unknown.
Cell Organelles http://www.youtube.com/watch?v=rABKB5aS2Zg&feature=related
Cell Membrane • Boundary between the cell and the outside and controls the passage into and out of the cell. • Semi-permeable= some things come in and some things go out.
Cytoplasm • Jellylike substance that contains proteins, nucleic acids, minerals, and ions. • Contains many organelles (little organs)
Cytoskeleton • Network of proteins that is constantly changing to meet the needs of a cell. Protects.
Three Main Fibers: • 1. Microtubules= long hollow tubes. Give cells its shape and acts as “tracks” for organelle movement. • 2. Intermediate filaments- give a cell its strength • Microfilaments- tiny threads that allow the cell to move and divide. Help the muscle contract and relax.
Cell Wall • Plants only, made up of cellulose • Protects, supports, and shapes the cell.
Vacuole • Fluid filled sacs • Full of water, nutrients, and waste that is on its way out.
Central Vacuole • Fluid filled sac used for storage of materials needed by the cell such as water, food, enzymes, and inorganic molecules.
Chloroplast • Plants only • Carry out photosynthesis by capturing and converting solar energy. • Have chlorophyll = green
Vesicle • Small sacs that divide some materials from the cytoplasm and transport these materials from place to place in a cell.
Nucleus • Storehouse of the DNA • Protein synthesis occurs here • Control center of the cell
Nucleolus • Dense region in the middle of the nucleus • Ribosome's are made here
Nuclear Membrane/ Envelope • Double membrane around the nucleus • Protects the nucleus • Has pores around it for molecules to pass in and out
Nuclear Pore • Allows things to move in and out of the nucleus.
Smooth Endoplasmic Reticulum • No ribosomes • Lots of folds, inner membrane= lumen • Makes proteins and lipids • Controls calcium levels in muscles • Breaks down drugs and alcohol
Rough Endoplasmic Reticulum • Covered in ribosomes • Attached to the nucleus • Produces, transports enzymes and proteins throughout the cell.
Ribosomes • Makes Proteins and RNA • Tiny balls that link amino acids together to form proteins • Site of protein synthesis
Centrosome • Small region of cytoplasm that produces microtubules, contains centrioles. • Microtubules are made here. • During mitosis this divides and the two parts move to opposite sides of the cell.
Golgi Apparatus • Processes, sorts, packages, and delivers proteins and carbohydrates into vesicles for export out of the cell. • Membrane contains enzymes
Mitochondria • Supply energy to the cell • Converts food into energy (glucose into ATP) • Have their own ribosome's and DNA