Download - Chemical messengers
Chemical Messenger :is any compound that serves to transmit a messages
• Long range chemical messengerHormone
• a chemical factor that triggers a social response in members of the same speciesPheromone
• a protein sequence which acts as a hormone or neurotransmitterNeuropeptide
• communicates to adjacent cellsNeurotransmitter
Neurotransmitter chemicals that transmit signals across
a synapse from one neuron to another 'target' neuron (braincell)
Tubocurarine chloride
Tubocurarine (also known as d-tubocurarine or DTC) is a toxic alkaloid and skeletal muscle relaxant in the category of non-depolarizing neuromuscular-blocking drugs, used adjunctively in anesthesia to provide skeletal muscle relaxation during surgery
Deadly Effects Nurotransmitter • Muscarinic receptors
– Bind acetylcholine (Ach) in the autonomic nervous system (ANS)
– Also binds muscarine (a mushroom toxin) that• Mimics Ach (agonistic action) and can cause a
severe parasympathomimetic to the point of death
Deadly Effects Nurotransmitter
• Nicotinic receptors– Bind Ach at neuromuscular junctions– Also binds curare (poison arrow frog toxin) and
blocks the receptor (antagonistic action)• Causes paralysis and very potentially death
Hormones
• What are they?– Chemical messengers secreted by
specialized cells• from isolated endocrine cells which makes up the
diffuse endocrine system• from neurons• from immune system cells producing cytokines
– Where do they go?• Into blood (most)• Into environment (ectohormones or pheromones)
How do hormones get from point A to B?
secret by specific cell
Travel in blood stream
water insoluble require (protein)
transport mechanism
It act by binding to receptor on target cells
Act by
• Altering rates of enzyme mediated reactions
• Control the movement of molecules across the plasma membrane
• Regulating the rate of gene expression (& therefore protein production)
Hormones classified by structure
– Peptide/protein hormones
– Steroid hormones
– Amino acid based hormones
Amino acid hormones
– Derived from tyrptophan– Produces Melatonin & Serotonin
*serotonin is classified as a neurohormone as it is synthesized and secreted by neurons of the GI tract for regulation of motility and CNS
Steroid Hormones
– Lipophilic hormone • No storage• Production is on an “as needed” • Can have the precursors in cytoplasm ready to go• Require protein transports in blood• Based on cholesterol• Produced using SER in the
Adrenal cortex
Gonads
Placenta• Secretion is by simple diffusion
chemical structure of some novel phytoestrogens. a. arylbenzofurans, b. acteoside, c. martynoside, d. ellagic acid, e.deoxybenzoines, f. ethoxymethylphenol, g. catechin, h. epicatechin, i. glyecollins, j. lindleyin, k. gRhi, l. glabrene, m. glabridin, n.isoliquitireginin chalone, o. soyasapogenol A, p. soyasapogenol B.
Fig. 45-3
Water-soluble Lipid-soluble
Steroid:Cortisol
Polypeptide:Insulin
Amine:Epinephrine
Amine:Thyroxine
0.8 nm
- Types of insect communication - Visual communication. - Chemical communication. - Tactile communication. - Acoustic communication..
Phermons: Chemical signals that carry information from one individual to another member of the same species. These includes sex attractants, alarm substance and many other intraspecific messages.
In alfalfa butterflies, males have U.V. reflective scales and missing scales is a sign for male ageing.
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1- Queen bee emit phermones that affects the development of workers bee.
2- Ants use phermones to recruit nest mates to a food source.
3- When laying their eggs, some flies moths and beetles use certain phermones to repel insects of the same and competing species, thereby protecting their progeny.
5- Many insect females use phermones to attract male for mating.
6- Some male moths use phermones to entice female to mate with them. Scorpionflies male attack
female by mating pheromone
• For many insects, love is truly blind. Using sex phermones in a tube made really try to mate with that tube.