Cell Organelles Robert Hooke 1665 discovered cells by
Cell Organelles
Robert Hooke 1665 discovered cells by looking at cork w/ microscope (cork – dead cell walls of plants) (looked like Spartan monk bedrooms with not much going on inside)
Cell Theory All living organisms are composed of one or more cells. The cell is the basic unit of structure and organization in organisms. Cells arise from pre-existing cells.
A cell is like a city = geographical limits, a ruling government, power plants, roads, waste treatment plants, a police force, industry – more like dictatorship than democracy Eukaryotic cells - make up lots of organisms (animals, plants, fungi, and protists) - contain nucleus – which contains DNA and controls the cell - contain lots of organelles of different types, each w/ specific function
in animals - flexible, many different types of cells in plants – rigid due to cell walls, less variety in protozoa – flexible, single-celled, move w/ special organelles
Cilia/Flagella - made out of long protein fibers called microtubules (City limits) cilia - bunch of tiny little arms that wiggle around flagella - one, long whip-like tail. Some cells have neither Ex. sperm cells – flagella Ex. our lungs and throat cells have cilia that push mucus up and out of our lungs.
Cell Membrane past the cilia - a cell membrane of squishy, notrigid (unlike cell wall in plants) in charge of monitoring what comes in and out of the cell selective permeability - meaning that it can choose what molecules come in and out of the cell, for the most part
Cytoplasm/Cytoskeleton/Cent rosomes - landscape of E cell - of wet and squishy cytoplasm - a solution of water and nutrients called cytoplasm – fills cell – provides environment for organelles to function (except nucleus) cytoskeleton - bunch of protein strands that reinforce the cell. Centrosomes - special structural reinforcement/ assemble long microtubules out of proteins hold the cell together.
Endoplasmic Reticulum (ER) (cell's highway system) create a network of membranes that carry stuff around the cell / phospholipid bilayers (same as the cell membrane) two types of ER the smooth ER (factory-warehouse) - smooth in the cell city / help with the creation of important lipids (phospholipids) / detoxifying substances / stores energy in muscle cells The rough ER - bumpy (ribosomes) / synthesizes and packages protein, assembled by…
Ribosomes - float freely throughout cytoplasm or - attached to the outside of nucleus(from which they come) and Rough ER - assemble amino acids into polypeptides To form protein chain -> when complete, the ER sends it to:
Golgi Apparatus - (the post office) made up of flat pancake-like sacs called golgi bodies processes and packages proteins in the form of vesicles made of phospholipids to send elsewhere (inside or outside cell)
Lysosomes (waste treatment plants and recycling center) -> bags full of enzymes that break down cellular waste inside and debris from outside of the cell -> turn it into simple compounds -> transferred into the cytoplasm as new cell-building materials.
Nucleus (controls all aspects – dictator) double-membraned determines which organelles grow and when / what to metabolize / what proteins to synthesize / how and when to divide contains - proteins / DNA (cell information necessary to make proteins) nucleolus - inside the nucleus - gooey splotch of stuff within the nucleus. forms the basic units of ribosomes – carry out the orders of the cell (to assemble x protein)
Mitochondria (its power plants) smooth, oblong organelles / different cells require different amounts (nerve / muscle) where process of respiration takes place converts energy from carbs, fats, and other fuels -> converted into adenosine triphosphate or ATP = which is like the main currency that drives life
long ago animal cells didn't have mitochondria (they existed on their own) one of these things ended up inside of an animal cell, probably because the animal cell was trying to eat it, but instead of eating it, it realized that this thing was good at turning food into energy and it just kept it- to this day they sort of act like their own, separate organisms, like they do their own thing within the cell, they replicate themselves, and they even contain a small amount of DNA (information). This is called ENDOSYMBIOSIS!
Mitochondria are in the egg cell when an egg gets fertilized, and those mitochondria have DNA. But because mitochondria replicate themselves in a separate fashion, it doesn't get mixed with the DNA of the father, it's just the mother's mitochondrial DNA. That means that you and my mitochondrial DNA is exactly the same as the mitochondrial DNA of our mothers. And because of this special DNA is isolated in this way, scientists can actually trace back and back to a single "Mitochondrial Eve" who lived about 200, 000 years ago in Africa.
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