How do prokaryotic (bacteria) cells reproduce? simulation (sim u ‘la shen) (noun) - a controlled model of a situation used to study it Meteorologists run simulations of the atmosphere in order to predict the weather
Binary Fission or Asexual Reproduction
Cell Organelles!
Cell Membrane Also called plasma membrane Protects and supports the cell Controls what enters and leaves the cell Lipid Bilayer (what does this mean??) Found in all cells – prokaryotes and eukaryotes!
Cell Wall Found in eukaryotic plant and protist cells; also in prokaryotes Adds protection, rigidity, and support Outside of cell membrane Made of cellulose (a polysaccharide!) Allows water and dissolved substances to pass through.
The Nucleus Controls most activities in the cell Contains DNA – the coded instructions for making proteins & other molecules for the cell The nuclear envelope has nuclear pores, where things can enter or leave See?
Nucleolus Small, dense region in the middle of the nucleus This is where ribosomes are formed.
Cytoplasm Clear fluid within cell that contains all organelles Moves materials throughout the cell It’s the light blue/gray stuff in this picture
Ribosomes Makes proteins in the cell May be free in cytoplasm or attached to ER Proteins are vital to life- all cells must produce them!!! In prokaryotes and eukaryotes
Golgi Apparatus Stacks of membranes used for storing, modifying, or packaging chemicals Packaged chemicals can be stored inside the cell or secreted outside the cell Cells that make saliva or mucus have many Golgi bodies
Endoplasmic Reticulum Series of folded membranes that form sacs or tubes Rough ER has ribosomes attached
Smooth vs. Rough ER Smooth ER Smooth - no ribosomes! Synthesizes (makes) lipids Detoxifies drugs Rough ER Ribosomes make it look rough or bumpy Ribosomes synthesize (make) proteins, so the Rough ER is where this happens!
Lysosomes Found near Golgi Contain digestive enzymes to digest unwanted particles Help white blood cells to destroy bacteria Clean-up crew!
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Vacuoles Store food, water, or waste materials Plant cells have large vacuoles Vacuoles and lysosomes working together! Amazing! Astounding!
Chloroplasts Found in eukaryotic plant cells & some protist cells Chloroplasts capture light energy and convert it into chemical energy during photosynthesis
Mitochondria Energy producers – the “powerhouse” of the cell! Convert chemical energy into useable energy Many mitochondria in muscle cells – why?? Found in all eukaryotes, including animal & plant cells Contain DNA from ovum – so all your mitochondria are from your mom!
Endosymbiotic Theory Mitochondria are the result of endocytosis of aerobic bacteria Chloroplasts are the result of endocytosis of photosynthetic bacteria Endocytosis: A substance gains entry into a cell without passing through the membrane
Evolution of Mitochondria
Evolution of Chloroplast
Does the timing make sense? Prokaryotes were present before eukaryotes
Evidence for Endosymbiotic Theory Mitochondria and chloroplasts have many characteristics of free living bacteria: 1- contain DNA similar to bacterial DNA 2- have ribosomes of similar size and structure to those of bacteria 3- reproduce by binary fission like bacteria
Cytoskeleton Overlapping network of filaments and fibers that support the cell and help it maintain its shape Can also help cells move Microfilaments and microtubules
Centrioles Centrioles help to organize the cell during cell division They migrate to either side of the cell and help to pull it apart Only found in animal cells! Centrioles are made of microtubules
Types of Eukaryotes: Animal vs. Plant Cells No cell walls (only cell/plasma membrane) No chloroplasts Many small vacuoles for storage Cell wall (gives rectangular shape) and cell/plasma membrane Chloroplasts for photosynthesis One large central vacuole Animal cellsPlant cells
Plant Cell
Animal Cell
The End ICells!