True or False: A virus is a kind of bacteria. 1.True 2.False
Viruses A virus is usually not considered living. A virus consists only of a protein coat (sometimes with a lipid outer layer) and a piece of genetic material (DNA or RNA).
Bacteria vs. Virus FeaturesBacteriaVirus Reproduces independently? Has genetic material? Has cell membrane? Has metabolism? Living?
Eukaryotic Features Cells contain ________________ ________________. _________ holds multiple strands of _____, which condense into _______________ during cell division. May be single-celled or multi-cellular organisms.
Plant Cell - same organelles as an animal cell, plus a few more ribosomesfree ribosome nuclear pore nuclear envelope chromatin (DNA) nucleolus ______ smooth endoplasmic reticulum vesicle rough endoplasmic reticulum Golgi apparatus __________________ _____________________plastid _____________ plasmodesma _________________ central vacuole cytosol
Things we will see in cells First let’s focus on things we can see using a light microscope and ordinary stains: Cell nucleus Cell membrane Cell wall Plastids (Chloroplast, amyloplast, chromoplast) Plant cell vacuole
Amyloplasts and other plastids starch globules 0.5 micrometer plastid
Protein-making Machinery Information for making proteins is in _____, stored in the ___________. An ______ copy is made in the nucleus and sent out to the rough Endoplasmic Reticulum (ER). Proteins leave the ER and are finished and packaged in the _____ ___________.
Organelles in Cell Energy Chloroplasts capture energy from the sun and use that energy to manufacture sugars (chemical energy storage). Mitochondria break the bonds in sugars and release the energy that was stored there.
Single-Celled Organisms Single-celled organisms carry out the same functions that our multicellular bodies do, but all within a single cell. How do they do it?
One-celled Eukaryotic organisms have unique challenges. A Paramecium must: ingest food excrete waste sense and respond to the environment
(a) Cilium (b) Flagellum propulsion of fluid return strokepower stroke plasma membrane direction of locomotionpropulsion of fluid continuous propulsion
cilium Paramecium 0.1 micrometer protein "arms" central pair of microtubules section of cilium (transmission EM) basal body plasma membrane
contractile vacuole full reservoir contracted reservoir
pore collecting ducts central reservoir Reservoir contracts, expelling water through pore. Water enters collecting ducts, fills central reservoir.
Recap Prokaryotic cells have no membrane- bound organelles. Eukaryotic cells have membrane-bound organelles, which compartmentalize processes for better efficiency. ALL cells have a cell membrane and DNA.