chemical signals 1
DESCRIPTION
Chemical Signals 1. BIOL 1407. Chemical Signals. Cells use chemicals to communicate with other cells http://www.livevideo.com/video/9DF33CE7B1014B55BEF2322395D72133/neutrophil-chemotaxis.aspx Photo Credit of Neutrophil engulfing anthrax bacteria: Tim Vickers, 2007, Wikimedia Commons. - PowerPoint PPT PresentationTRANSCRIPT
Chemical Signals 1
BIOL 1407
Chemical Signals
• Cells use chemicals to communicate with other cells
• http://www.livevideo.com/video/9DF33CE7B1014B55BEF2322395D72133/neutrophil-chemotaxis.aspx
• Photo Credit of Neutrophil engulfing anthrax bacteria: Tim Vickers, 2007, Wikimedia Commons
Chemical Signaling: Direct Contact
Chemical Signaling: Short-Distance
Chemical Signaling:
Long-Distance
Chemical Signaling Between Individuals
• Pheromones• Video of Orchid Wasp
Mimic: http://www.youtube.com/watch?v=-h8I3cqpgnA
• Photo credit for Spined Soldier Bug eating Mexican Bean Beetle larvae: USDA, 2006, Wikimedia Commons
• Article on Spined Soldier Bug and his pheromones: http://www.nytimes.com/1992/03/01/news/cuttings-the-enemy-s-enemy-is-the-soldier-bug.html?partner=rssnyt&emc=rss&pagewanted=all
Signal Transduction Pathways
Receptors
Target Cells: Have
Receptors for Signal
Target Cells and Specificity
Types of Hormones
Transport and
Receptor Location
Water-Soluble
Hormones
G Proteins
Second Messengers
• cAMP• cGMP
• IP3 and DAG• Calcium• Calmodulin
Lipid-Soluble
Hormones
Steroid Hormones
• Brassinosteroids in plants• Steroid hormones in animals
– Synthesized from Cholesterol– Testosterone, Progesterone, Estrogens– Cortisol and Aldosterone from adrenal cortex
Seed Dormancy and Germination
• ABA – High levels inhibit
germination = promotes dormancy
• Gibberellins– High levels promote
seed germination
Al-your-own skew-Tell-um
Trigger for Desert Seed Germination: Rain
Photo Credit for Storm Over Western Ghats: PlaneMad, 2006, Wikimedia Commons
Desert Seed Germination
• Attenborough Video:– http://www.you
tube.com/watch?v=z1IBnHIOFxs
– Photo Credit for South Africa Desert in Bloom: Winfried Bruenicen, 2001, Wikimedia Commons
Volatile Chemicals
• Jasmonic Acid and Plant Volatiles
• Dodder plant seeks close relationship with tomato plant– http://imagearchive.ps
u.edu/displayimage.php?pos=-19895
• Photo Credit for Dodder in Bloom: Michael Becker, 2005, Wikimedia Commons
Photo Credit for Dodder on Acacia: Khalid Mahmood, 2007, Wikimedia Commons
Photo Credit for Parasitoid Wasp on Plant Bug Nymph: Scott Bauer, USDA, 2003, Wikimedia Commons
The End
Unless otherwise specified, all images in this presentation came from:Campbell, et al. 2008. Biology, 8th ed. Pearson Benjamin Cummings.