Cell Structure Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
All organisms are composed of one or more cells. Cell Theory All organisms are composed of one or more cells. Cells are the basic units of organization for all organisms. Cells arise only by division of a previously existing cell. Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Why are Cells Small? As a cell’s size increases, its surface area: volume ratio decreases Advantage of small cell size is explained by surface area-to-volume ratio. As a cell’s size increases, its volume increases much more rapidly than surface area. Cell membrane plays a key role in controlling cell function (the door) Small cells have more surface area per unit volume (larger door) Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Prokaryotic Cells Bacterial cells are small, consisting of cytoplasm surrounded by a plasma membrane enclosed within a rigid cell wall. Many propelled by flagellum (flagella). Simple organization Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Can be compared to a factory Eukaryotic Cells Contain numerous membrane-bound structures (organelles) where biochemical reactions take place Can be compared to a factory Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Organelle Function Factory part Nucleus Directs the cell Main office Cell membrane Lets some things in/out Door Mitochondria Burns sugar to release energy Generator Rough Endoplasmic Reticulum (ER) & Smooth ER Produces proteins Produces lipids Conveyor belt Golgi Apparatus Packages proteins Packing dept. Ribosomes Put together proteins Workers Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Organelle Function Factory part Chloroplast Plant cells only Stores sunlight energy in sugar for later use Solar panels Lysosomes Animal cells only Recycles used cell parts Recycling center Vacuole Storage of food & water Very large in plant cells Storage room Cell wall Structural support Fence; external support beams Vesicles Moves particles around cell or to cell membrane for export Cart Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Raven - Johnson - Biology: 6th Ed Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Raven - Johnson - Biology: 6th Ed Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Raven - Johnson - Biology: 6th Ed Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Raven - Johnson - Biology: 6th Ed Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Chloroplast Structure Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Viruses are microscopic infectious agents (1/10 the size of bacteria) What is a virus? Viruses are microscopic infectious agents (1/10 the size of bacteria) Consist of DNA or RNA with a protein coat. Not considered living Cannot reproduce outside host Cannot be killed Not made of cells Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies
Copyright © McGraw-Hill Companies Permission required for reproduction or display Raven - Johnson - Biology: 6th Ed. - All Rights Reserved - McGraw Hill Companies