Eukaryotic Cells The Inside Story 2 Types of Cells Prokaryotic Cells • No nucleus • No membranecovered organelles • Circular DNA • Bacteria Eukaryotic Cells DNA Cells • Nucleus • Membrane covered organelles • Linear DNA • All other cells Which is which? Cells come from.. 1 of the 3 parts of the Cell Theory states that All cells come from pre-existing cells So just as large multicellular organisms like humans, dogs, and trees reproduce, your cells do as well So What is Inside a Cell? It turns out that there is a lot more inside a cell than Robert Hooke or Anton von Leeuwenhoek probably would have guessed. Everything, from the structures covering the cells to the structures inside, perform tasks to help keep the cells alive. These structures are called organelles. Holding It All Together All cells have outer coverings that separate what’s inside the cell from what is outside. Cell Membrane Covers all cells, both eukaryotic and prokaryotic Duties include keeping cytoplasm inside Allow nutrients in and waste products out Also interacts with things outside the cell Holding It All Together Cell Wall Only found in plant and bacteria(prokaryotic) cells Cell wall in plants is made of cellulose Provides strength and support to the cell membrane The strength of billions of cell walls in plants enables a tree to stand tall and its limbs to defy gravity The Cell’s Library Nucleus Largest and most visible organelle Covered by a membrane Control center of cell Stores the DNA Nucleolus Dark spot inside the nucleus Stores the materials that will be used later to make ribosomes in the cytoplasm Protein Factories Ribosomes Smallest but most abundant organelles Their job is to hook together amino acids to make proteins Found in both eukaryotic and prokaryotic cells Not covered by a membrane All cells have ribosomes because all cells need protein to live. The Cell’s Delivery System Endoplasmic Reticulum Internal delivery system of a cell Is divided into Smooth and Rough ER based on appearance and function Rough ER Ribosomes are attached making it look pebbled Specializes in protein synthesis Connected to nuclear membrane Proteins synthesized by ribosomes collect in the ER for transport throughout the cell Difference Between Rough and Smooth ER Smooth ER Does not have ribosomes attached Has different functions depending on the cell type Can be responsible for lipid and hormone synthesis Breaks down drugs and certain other chemicals that could damage the cell The Cell’s Power Plants Mitochondria Convert the chemical energy stored in food into ATP which is the molecular fuel that cells use to do work Inner membrane of mitochondria that has many folds is where most of the ATP is made. The reason you breathe air is so that mitochondria have the oxygen they need to make ATP Highly active cells, like those in the liver and heart, may have thousands of mitochondria while other cells may have only a few. The Cell’s Power Plants Chloroplasts Additional kind of energy-converting organelle found in plants and algae Contain flattened, membrane-covered sacs that look like stacks of coins which contain chlorophyll Chlorophyll is what makes plants green and also traps the energy in sunlight which plants use to make sugar The sugar that is produced is used by mitochondria to make ATP The Cell’s Packaging Center Golgi Apparatus Looks like ER but is located closer to the cell membrane Receives and modifies lipids and proteins sent from the ER Final products are then enclosed in a piece of the Golgi’s membrane that pinches off to form small compartment Compartment transports contents to other parts of cell or outside the cell The Cell’s Storage Centers Vacuoles Very large in plant cells, much smaller in animal cells Store water and other liquids If full of water they help support the cell Store the liquids that make roses red and violets blue Contain the juices you associate with oranges and other fruits The Cell’s Storage Centers Vesicles Some form when part of the membrane pinches off the ER or Golgi Others are formed when part of the cell membrane surrounds an object outside the cell Packages of Destruction Lysosomes Special vesicles in animal cells that contain enzymes that digest food particles and wastes Destroy worn-out or damaged organelles Get rid of waste materials and protect cell from foreign invaders If lysosome membrane breaks, the enzymes spill out into the cytoplasm which kills the cell Plant or Animal? Plant or Animal? Homework You are going to create a drawing of a eukaryotic cell. However, instead of making it a realistic cell, your cell should be made of drawings of objects that represent the organelle’s job. For example, the Golgi Apparatus, which transports materials, could be a bus or a car.