Topic 4: Digestion and Waste Management Flashcards
What are the three main types of feeders in animals?
Herbivores, Carnivores, Omnivores
Herbivores eat plants and algae, Carnivores eat other animals, and Omnivores consume both.
what does chemical energy come from
cellular respiration (converts glucose into ATP)
What are the essential nutrients that must be obtained through an animal’s diet?
Essential amino acids, Essential fatty acids, Vitamins, Minerals
These nutrients are critical for metabolism and cannot be synthesized in adequate amounts by the body.
how many amino acids can animals make with their enzymes
about half of the 20 amino acids, the rest must be obtained through diet.
How many essential amino acids do adults and infants need?
Adults need 8, infants need 9
Infants require histidine as an additional essential amino acid.
What distinguishes complete proteins from incomplete proteins? and food protein examples
Complete proteins contain all essential amino acids, (like meat, eggs, and cheese) incomplete proteins lack one or more (plant proteins).
What are fat-soluble vitamins and their functions
Fat-soluble vitamins include Vitamin A: for eyes, skin, and immunity, Vitamin D: calcium absorption and bone formation, Vitamin E: for nervous system, and Vitamin K: blood clotting.
However too much can make you sick
what are water soluble vitamins and their functions
B vitamins: usually act as coenzymes like FAD (in ETC). Vitamin C: production of connective tissue.
water soluble can pass through urine
What is malnutrition?
Malnutrition is undernutrition, a shortage of essential nutrients or caloric intake.
It can lead to severe health issues, including deformation, disease, and death.
What are the four main processes of food processing in animals?
Ingestion, Digestion, Absorption, Elimination
These processes are essential for converting food into usable nutrients and waste.
describe ingestion (obtaining food) for: suspension/filter feeders, substrate feeders, fluid feeders, bulk feeders.
suspension: eat small organisms and food particles suspended in the water. substrate: live on or in their food source. fluid: sucl nutrient-rich fluid from a living host
bulk feeders: eat relatively large pieces of food
Describe the 2 main parts in digestion
mechanical: chewing, physical breakdown of substances, Chemical digestion: breaks down complex molecules into simpler and smaller components for absorption.
chemical digestion breaks bonds by adding water (hydrolysis)
What is the difference between intracellular and extracellular digestion?
Intracellular digestion occurs within food vacuoles; (they use lysosomes to digest the molecules to their monomers by hydrolysis), for extracellular digestion food is first broken down outside cells in a digestive cavity.
Sponges use intracellular digestion, while more complex animals use extracellular digestion.
Describe how food is digested in mammals (in a nutshell)
After food is chewed and swallowed it takes 5-10 seconds to get to the stomach, it spends 2-6 hours in the stomach being partially digested by enzymes, food is then passed to the small intestine where it spends 5-6 hours completing digestion and absorption, undigested food then passes through the digestive tract and is eliminated in 12-24 hours via the anus.
What is peristalsis?
Peristalsis is the process that moves food through the alimentary canal.
It involves rhythmic contractions of muscles in the digestive tract.
whats the purpose of sphincters in the alimentary canal of mammals
to prevent backward flow
what are the accessory glands in the mammalian digestive system, and what do they do
salivary glands: produce amylase to digest starch/carbohydrates. pancreas: trypsin, chymotrypsin, proteases, bicarbonates. liver: bile for fat digestion. gall bladder: stores and concentrates bile.
the oral cavity does the mechanical digestion with teeth, what begins the chemical digestion?
still in the mouth
when salivary glands release salivary amylase
What are the components of gastric juice in the stomach, and their functions?
Gastric juice contains hydrochloric acid and proteases.
Hydrochloric acid aids in protein denaturation and activates proteases, which digest proteins. So the stomach mainly digests proteins.
what do parietal cells and chief cells in the stomach release
parietal cells release hydrogen and chloride ions. chief cells: release pepsinogen (inactive pepsin which activates when exposed to the low pH of the stomach)
What is the primary function of the small intestine?
The small intestine completes digestion (mainly fat digestion) and absorbs nutrients.
It is the longest compartment of the digestive system, approximately 6 meters in humans.
what parts of the small intestine does absorption occur? what do these parts contain to help with absorption
in the jejunum, and ileum. they contain highly folded villi which contain microvilli to increase surface area (to 300m squared!)
What is the role of the liver in digestion?
The liver produces bile for fat digestion.
Bile is stored and concentrated in the gall bladder before being released into the small intestine.
where does elimination occur
in the large intestine
fill in the blank: the _ leads to the rectum and anus and its role is to recover water
colon
part of the large intestine
fill in the blank: the _ ferments ingested materials, especially plant materials
cecum
if less water is absorbed than needed in the colon the result is? if more water is absorbed than needed the result is?
less: diarrhea, too much water absorbed: constipation
bc if less is absorbed excess water in feces, if too much absorbed not enough water in feces.
Fill in the blank: The _______ is responsible for storing and eliminating feces.
Rectum
The rectum plays a crucial role in the final stages of digestion.
why do different animals have different dental adaptations
different teeth assortment allow animals to eat different things depending on diet.
like snakes have venamous fangs to capture prey and some animals don’t even have teeth if they don’t need.
What adaptations do herbivores have in their digestive systems? what for?
Longer digestive tracts and mutualistic bacteria (microflora) for cellulose digestion.
they need this because herbivores only eat plants which have cell walls made of cellulose, which is hard to digest because of it’s b-glycosidic linkages
when nucleic acid and proteins break down, enzymes remove nitrogen in the form of ? this is toxic because?
ammonia, toxic bc it interferes with biological processes.
What are the 2 other less toxic forms of nitrogenous waste secreted by animals? how is each form secreted? and what are examples of animals that produce each form
Urea: excreted dissolved in urine (causes water loss), main waste in mammals, amphibians, and some bony fish. Uric Acid: can be excreted as a anhydrous solid waste (no water is lost), main waste in birds, reptiles, insects, land snails.
what are the 4 main steps of excretion in the excretory system
- filtration: body fluid reaches a selectively-permeable barrier where large molecules do not pass through but filtrate does.
- reabsorption: recovers useful molecules and water from filtrate.
- secretion: active transport adds water and non essentual moecules to filtrate
- excretion: removes the filtrate (urine) from the body
How do kidneys function in vertebrates?
Kidneys perform osmoregulation and excretion through a network of tubules and capillaries.
They filter blood and produce urine.
True or False: All animals produce uric acid as their primary nitrogenous waste.
False
While all animals produce uric acid, mammals, amphibians, bony fish primarily excrete urea.
Malpighian tubules excretory system, describe and in what animals?
extend from dead end tips in hemolymph to openings in digestive tracts, no filtration step, in terrestrial arthropods and insects.
They allow for the excretion of waste with minimal water loss. (excrete solid uric acid)
describe the Protonephridia excretory system
in flatworms, network of dea-end tubules connected to dead end openings
metanephridia exretory system
found in most annelids, excretory organs collect fluid directly from coelom
What are the main functions of the kidneys in vertebrates?
Osmoregulation and excretion
What is the general shape and size of the kidneys?
Bean-shaped, ~10cm long
What structures drain urine from the kidneys?
Ureter
What is the sequence of urine flow from the kidneys to the outside of the body?
Kidney → Ureter → Urinary bladder → Urethra
What are the two regions of the kidneys supplied with blood for filtration and reabsorption?
Renal cortex and inner medulla
what are the 3 major filtrate processing regions of the nephron (in the kidney)
proximal tubule, loop of henle (descending then ascending limb), and the distal tubule
What are the two types of nephrons found within the renal cortex and medulla?
- Cortical nephrons (mostly in cortex)
- Juxtamedullary nephrons (mostly in medulla)
How is filtrate formed in the nephron?
From the glomerulus passing fluid to the Bowman’s capsule
how does filtrate exit the nephron, where does it go
exits via the collecting duct going to the renal pelvis
What is the glomerulus composed of?
A ball of capillaries
What are the three major regions of the nephron where processing occurs?
- Proximal tubule
- Loop of Henle
- Distal tubule
Where does filtrate exit the nephron?
Via the collection duct to the renal pelvis
What is the primary function of the proximal tubule?
Reabsorption of water, ions, and nutrients from the filtrate
What process drives passive transport of chloride in the proximal tubule?
Active transport of sodium ions into the interstitial fluid
What follows water movement in the proximal tubule?
Osmosis
What does the descending limb of the loop of Henle reabsorb?
Water via aquaporins
How does the descending limb of the loop of Henle interact with salts?
It has low permeability for salts and other molecules
What occurs in the ascending limb of the loop of Henle?
NaCl is actively transported out into the interstitial fluid
What is the function of the distal tubule?
Regulates K+ and NaCl concentration
What is the role of the collection duct?
Carries filtrate through the medulla to the renal pelvis and forms urine
What regulates reabsorption in the collection duct?
Hormones based on body needs
