Topic 4: Digestion and Waste Management

Question 1

What are the three main types of feeders in animals?

Answer 1

Herbivores, Carnivores, Omnivores

Herbivores eat plants and algae, Carnivores eat other animals, and Omnivores consume both.

Question 2

what does chemical energy come from

Answer 2

cellular respiration (converts glucose into ATP)

Question 3

What are the essential nutrients that must be obtained through an animal’s diet?

Answer 3

Essential amino acids, Essential fatty acids, Vitamins, Minerals

These nutrients are critical for metabolism and cannot be synthesized in adequate amounts by the body.

Question 4

how many amino acids can animals make with their enzymes

Answer 4

about half of the 20 amino acids, the rest must be obtained through diet.

Question 5

How many essential amino acids do adults and infants need?

Answer 5

Adults need 8, infants need 9

Infants require histidine as an additional essential amino acid.

Question 6

What distinguishes complete proteins from incomplete proteins? and food protein examples

Answer 6

Complete proteins contain all essential amino acids, (like meat, eggs, and cheese) incomplete proteins lack one or more (plant proteins).

Question 7

What are fat-soluble vitamins and their functions

Answer 7

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

Question 8

what are water soluble vitamins and their functions

Answer 8

B vitamins: usually act as coenzymes like FAD (in ETC). Vitamin C: production of connective tissue.

water soluble can pass through urine

Question 9

What is malnutrition?

Answer 9

Malnutrition is undernutrition, a shortage of essential nutrients or caloric intake.

It can lead to severe health issues, including deformation, disease, and death.

Question 10

What are the four main processes of food processing in animals?

Answer 10

Ingestion, Digestion, Absorption, Elimination

These processes are essential for converting food into usable nutrients and waste.

Question 11

describe ingestion (obtaining food) for: suspension/filter feeders, substrate feeders, fluid feeders, bulk feeders.

Answer 11

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

Question 12

Describe the 2 main parts in digestion

Answer 12

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)

Question 13

What is the difference between intracellular and extracellular digestion?

Answer 13

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.

Question 14

Describe how food is digested in mammals (in a nutshell)

Answer 14

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.

Question 15

What is peristalsis?

Answer 15

Peristalsis is the process that moves food through the alimentary canal.

It involves rhythmic contractions of muscles in the digestive tract.

Question 16

whats the purpose of sphincters in the alimentary canal of mammals

Answer 16

to prevent backward flow

Question 17

what are the accessory glands in the mammalian digestive system, and what do they do

Answer 17

salivary glands: produce amylase to digest starch/carbohydrates. pancreas: trypsin, chymotrypsin, proteases, bicarbonates. liver: bile for fat digestion. gall bladder: stores and concentrates bile.

Question 18

the oral cavity does the mechanical digestion with teeth, what begins the chemical digestion?

still in the mouth

Answer 18

when salivary glands release salivary amylase

Question 19

What are the components of gastric juice in the stomach, and their functions?

Answer 19

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.

Question 20

what do parietal cells and chief cells in the stomach release

Answer 20

parietal cells release hydrogen and chloride ions. chief cells: release pepsinogen (inactive pepsin which activates when exposed to the low pH of the stomach)

Question 21

What is the primary function of the small intestine?

Answer 21

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.

Question 22

what parts of the small intestine does absorption occur? what do these parts contain to help with absorption

Answer 22

in the jejunum, and ileum. they contain highly folded villi which contain microvilli to increase surface area (to 300m squared!)

Question 23

What is the role of the liver in digestion?

Answer 23

The liver produces bile for fat digestion.

Bile is stored and concentrated in the gall bladder before being released into the small intestine.

Question 24

where does elimination occur

Answer 24

in the large intestine

Question 25

fill in the blank: the _ leads to the rectum and anus and its role is to recover water

Answer 25

colon

Question 26

# part of the large intestine fill in the blank: the _ ferments ingested materials, especially plant materials

Answer 26

cecum

Question 27

if less water is absorbed than needed in the colon the result is? if more water is absorbed than needed the result is?

Answer 27

less: diarrhea, too much water absorbed: constipation ## Footnote bc if less is absorbed excess water in feces, if too much absorbed not enough water in feces.

Question 28

Fill in the blank: The _______ is responsible for storing and eliminating feces.

Answer 28

Rectum ## Footnote The rectum plays a crucial role in the final stages of digestion.

Question 29

why do different animals have different dental adaptations

Answer 29

different teeth assortment allow animals to eat different things depending on diet. ## Footnote like snakes have venamous fangs to capture prey and some animals don't even have teeth if they don't need.

Question 30

What adaptations do herbivores have in their digestive systems? what for?

Answer 30

Longer digestive tracts and mutualistic bacteria (microflora) for cellulose digestion. ## Footnote 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

Question 31

when nucleic acid and proteins break down, enzymes remove nitrogen in the form of ? this is **toxic** because?

Answer 31

ammonia, toxic bc it interferes with biological processes.

Question 32

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

Answer 32

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.

Question 33

what are the 4 main steps of excretion in the excretory system

Answer 33

1. filtration: body fluid reaches a selectively-permeable barrier where large molecules do not pass through but filtrate does. 2. reabsorption: recovers useful molecules and water from filtrate. 3. secretion: active transport adds water and non essentual moecules to filtrate 4. excretion: removes the filtrate (urine) from the body

Question 34

How do kidneys function in vertebrates?

Answer 34

Kidneys perform osmoregulation and excretion through a network of tubules and capillaries. ## Footnote They filter blood and produce urine.

Question 35

True or False: All animals produce uric acid as their primary nitrogenous waste.

Answer 35

False ## Footnote While all animals produce uric acid, mammals, amphibians, bony fish primarily excrete urea.

Question 36

Malpighian tubules excretory system, describe and in what animals?

Answer 36

extend from dead end tips in hemolymph to openings in digestive tracts, no filtration step, in terrestrial arthropods and insects. ## Footnote They allow for the excretion of waste with minimal water loss. (excrete solid uric acid)

Question 37

describe the Protonephridia excretory system

Answer 37

in flatworms, network of dea-end tubules connected to dead end openings

Question 38

metanephridia exretory system

Answer 38

found in most annelids, excretory organs collect fluid directly from coelom

Question 39

What are the main functions of the kidneys in vertebrates?

Answer 39

Osmoregulation and excretion

Question 40

What is the general shape and size of the kidneys?

Answer 40

Bean-shaped, ~10cm long

Question 41

What structures drain urine from the kidneys?

Answer 41

Ureter

Question 42

What is the sequence of urine flow from the kidneys to the outside of the body?

Answer 42

Kidney → Ureter → Urinary bladder → Urethra

Question 43

What are the two regions of the kidneys supplied with blood for filtration and reabsorption?

Answer 43

Renal cortex and inner medulla

Question 44

what are the 3 major filtrate processing regions of the nephron (in the kidney)

Answer 44

proximal tubule, loop of henle (descending then ascending limb), and the distal tubule

Question 45

What are the two types of nephrons found within the renal cortex and medulla?

Answer 45

* Cortical nephrons (mostly in cortex) * Juxtamedullary nephrons (mostly in medulla)

Question 46

How is filtrate formed in the nephron?

Answer 46

From the glomerulus passing fluid to the Bowman's capsule

Question 47

how does filtrate exit the nephron, where does it go

Answer 47

exits via the collecting duct going to the renal pelvis

Question 48

What is the glomerulus composed of?

Answer 48

A ball of capillaries

Question 49

What are the three major regions of the nephron where processing occurs?

Answer 49

* Proximal tubule * Loop of Henle * Distal tubule

Question 50

Where does filtrate exit the nephron?

Answer 50

Via the collection duct to the renal pelvis

Question 51

What is the primary function of the proximal tubule?

Answer 51

Reabsorption of water, ions, and nutrients from the filtrate

Question 52

What process drives passive transport of chloride in the proximal tubule?

Answer 52

Active transport of sodium ions into the interstitial fluid

Question 53

What follows water movement in the proximal tubule?

Answer 53

Osmosis

Question 54

What does the descending limb of the loop of Henle reabsorb?

Answer 54

Water via aquaporins

Question 55

How does the descending limb of the loop of Henle interact with salts?

Answer 55

It has low permeability for salts and other molecules

Question 56

What occurs in the ascending limb of the loop of Henle?

Answer 56

NaCl is actively transported out into the interstitial fluid

Question 57

What is the function of the distal tubule?

Answer 57

Regulates K+ and NaCl concentration

Question 58

What is the role of the collection duct?

Answer 58

Carries filtrate through the medulla to the renal pelvis and forms urine

Question 59

What regulates reabsorption in the collection duct?

Answer 59

Hormones based on body needs