Exam 2 Flashcards
Excretion
Waste that have been metabolized by cells
Defecation
Wastes that have passed through digestive system, mouth->anus
Frass
Defecation of insects– products are passed through alimentary canal and malpighian tubules
Digestable food for insects
Proteins (into amino acids), lipids, carbohydrates, and ions (Na, K, Cl)
Gains during metabolisim
Metabolic, food, drinking
Loss during during metabolism
Cuticular, fecal, spiracular
A major consideration when discussing excretion systems is..
Water balance
Control of water metabolism is achieved by…
Diet and habitat
Habitat determines… (water conversation)
type of structure for renal system and nitrogenous waste
Darkling beetles water conservation
Extremely dry– has waxes on epicuticle and body positions to condense water from humid air
Mealworms water conservation
Extremely dry– Cryptonephric systems (allows for reabsorption of water and absorption of atmospheric water)
Stonefly water conservation
Extremely wet– always in water
Hindgut overview (renal system)
Maintains homeostatis, two main interacting parts: malphian tublues and hindgut rectal pads
Hindgut renal parts
Ileum, malpighian tubules, pyloric valve, colon, rectum
Renal system insects
Maintains homeostasis in the hemolymph (“blood”) by controlling levels of water and salt
Malpighian tublues function
Purify the hemolymph of waste and toxins, maintaining homeostasis– primary excretion organ
Malpighian tubules was originally described by…
Marcello Malpighi
Malpighain tubules are… (structure)
blind tubes that outgrowths the alimentary canal– positon marks junction of midgut and hindgut, not lined with intime, considered apart of hindgut
Intima
Cuticular layer that lines the foregut and hindgut of the alimentary canal
In some insects the Malpighian tubules have…
muscles
Alimentary canal
A long tube of organs that food travels through from the mouth to the anus
Malpighian tublues create (movement)…
a withering movement which improves fluid contact, aid of matieral movement, and mixing hemocoel content
Heomcoel
Main body cavity of an insect
Which insects have Malpighian tubules?
Majority insects– additionally myriapods, arachnids, and tardigrades
Insects without Malpighian tublues
Aphids– lost secondarily
Malpighian tubules produce…
filtrate/urine
MT process
Unselective removal of substance from hemolymph through active transport-> final product is primary urine
Active transport in MT (Ions)
Ions (K+ and Na) and cross cell membrane which creates osmotic gradient (water sugars and amino acids follow)
Active transport MT (non-metabolizable)
Occurs in some amino acids and toxic compounds
MT removes
Excess dietary components (specific undigestible ions/extra nutrients), Nitrogenous wastes from metabolism, toxin products from plant defenses, pesticides, etc.
Insect nitrogenous wastes
Amino acids, nephrocytes
Carbohydrates and lipids waste
Energy captures as ATP (lots of CO2 and H2O left over)– excess is stored
Protein waste
Converted into gulcose, glycogen, or fat– leaves behind nitrogenous waste (toxic)
Protiens
Long chains of amino acids/polypeptides– structural proteins or enzymes that catalyze biochemical processes
Converation of nitrogenous waste
Nitrogenous waste to molecules that minimize toxicity (some animals can do the same)
Types of Nitrogenous wastes
Uric acid (terrestrial insects), urea (mammals), ammonia (aquatic organisms/calliphoridae)
Calliphoridae
Family of dipulra
Insect waste product excreted by… (terrestrial)
White dry powder– since they need to conserve water
Insects waste product excreted by… (aquatic)
Clear fluid (excess water) due to needing to converse ions due to osmosis
Conversion process required a lot of…
energy
Ammonia is ____ toxic
extremely
Urea is ____ toxic
moderately
Uric acid is ____ toxic
non-
Amino acid structure
Amine group, central carbon, r group, carboxyl group–> forms polypeptide chain
Demination
Break down of amino acids to amine group (waste product) and carboxyl group
Ammonia with aquatic insects
Highly toxic but insects in aqueous environments can easily get rid of ammonia/live with ammonia
Ammonia is ___ in water
soluble (can cross cell membranes easily)
Terrestrial organisms unable to carry enough ____ to dilute ammonia
water
Toxicity of Ammonia can be reduced by converting to ___
Urea
Uric acid qualities
Low toxicity, insoluble in water, required more energy– can be removed with minimal water or retained in the body
Hind gut recycling
Water and ion absorption from urine and feces, cyptonephridial system for water conservation
Cryptonephridial system
Absorb water from atmospheric hind gut **?
Hindgut three compartments
Ileum, colon, and rectum
