digestion & waste Flashcards
(101 cards)
1
Q
Essential Nutrient
A
- we make most fatty acids and amino acids
- those we can’t make “essential”, therefore must obtain from the diet
- plants make many essential nutrients
- cultures around the world developed complete diets
ex: beans and rice to obtain all essential amino acids
2
Q
Vitamins
A
organic molecule needed for metabolism
- 2 types of vitamins
- water-soluble vitamins
- the B vitamins (B1, B2, B3, B5, B6, B7, B9, B12)
- vitamin C
- fat-soluble vitamins (eggs, carrots, nuts, broccoli)
- A, D, E, and K
- water-soluble vitamins
3
Q
Minerals
A
- inorganic molecules
- we need many minerals in trace amounts (ex: Na+, K+, etc)
- these are found in many food (like: vegetables, eggs, milk etc.)
4
Q
Filter feeding
A
such as the humpback whale; move water through a filtering structure to obtain food
5
Q
Substrate feeding
A
are animals that live in or on their food source
6
Q
Fluid feeding
A
suck nutrient-rich fluid from a living host
7
Q
Ingestion
A
bringing food into your body, act of eating or feeding
8
Q
Digestion
A
the breaking down of food into smaller pieces
9
Q
Absorption
A
the animal’s cells take up (absorb) small molecules such as amino acids and simple sugars
10
Q
Elimination
A
completes the process as undigested material passes out of the digestive tract
11
Q
Gastrovascular cavity
A
a central cavity with a single opening in the body of certain animals; that functions in digestion and the distribution of nutrients throughout the body
- some animals have only one gastrovascular cavity:
- cnidarians & flatworms
12
Q
Alimentary cavity
A
a complete digestive tract with 2 openings (consisting of a tube running between a mouth and an anus)
13
Q
Incisor
A
“are the front teeth present in most mammals.”
14
Q
Canine
A
“a pointed tooth between the incisors and premolars of a mammal, often greatly enlarged in carnivores.
15
Q
Premolar
A
” are transitional teeth located between the canine and molar teeth.
- have a flat biting surface. “
16
Q
Molar
A
“are large, flat teeth at the back of the mouth.”
17
Q
Cellulose
A
“Humans cannot digest cellulose, but it is important in the diet as fibre.”
18
Q
Cellulase
A
“an enzyme that convert cellulose into glucose or a disaccharide.”
19
Q
Ammonia
A
- is a byproduct of protein metabolism
- animals must remove it from their bodies
- 3 primary ways:
- as AMMONIA (MOST AQUATIC VERTEBRATES)
- as urea (ex: humans)
- as uric acid (most non-mammalian land animals)
20
Q
Urea
A
a form of ammonia
ex: humans
21
Q
Uric acid
A
a form of ammonia
most non-mammalian land animals
22
Q
Filtration
A
(1st step of excretory system)
blood pressure PUSHES water and solutes across filter membrane
23
Q
Reabsorption
A
(2nd step of excretory system)
water and important solutes (salts, sugars, amino acids, bicarbonate, etc.) are returned to the blood (either actively or passively)
24
Q
Secretion
A
(3rd step of excretory system)
toxins (ex: drugs) are actively secreted out of blood into the excretory tube
25
Excretion
(4th step of excretory system)
| filtrate is excreted as urine
26
the Protonephridium (an excretory system example)
ex: in flatworms
- remember: NO circulatory system! (so no blood pressure/blood)
1. cellular waste dumped out through cell membranes within body INTO INTERSTITIAL FLUID
2. cilia PULL interstitial fluid into tubules, where it is filtered
3. filtrate travels through tubules and EXITS body wall via small pores
27
the Metanephridium (an excretory system example)
ex: in earthworms (similar to ours)
- remember: CLOSED circulatory system! (have blood pressure - in order to push things across the membranes)
1. cilia PULL IN fluid from coelom (body cavity)
2. In that liquid that they PUSH all the filtrate through membranes into tubules
3. Things are reabsorbed back into the blood as necessary
4. Left over ACCUMATES into bladder as urine
5. Eliminated out
28
the Malpighian tubule (an excretory system example)
ex: in insects
- NO circulatory system!
- NO liquid is pushed through a filtration membrane
1. Waste materials are ACTIVELY transported into tubules from hemolymph
(liquid "insect blood" that bathes everything surrounds the malpighian tubules and materials are transported into malpighian tubules and water follows just following the concentration gradient)
2. Waste is combined with dietary waste/digestive tract
3. Water & important solutes (ions, valuable organic molecules) recovered in rectum
4. Everything else REMOVED through ANUS
29
Nephron
the tubular excretory unit of the vertebrate kidney
30
List the requirements for cellular respiration within animal tissues.
- the activities of cells, tissues, organs, & whole animals depend on sources of chemical energy in the diet
- this energy is used to produce ATP, which powers processes ranging from DNA replication & cell division to vision & flight
- to meet the continuous requirement for ATP, animals ingest & digest nutrients, including:
1. carbohydrates
2. proteins, and
3. lipids
...for use in cellular respiration & energy storage**
31
Outline the basic nutritional requirements animals obtain from their diets.
each animal has a suite of essential nutrients - molecules that the animal cannot produce & therefore must obtain from the diet
1. essential amino acids
2. essential fatty acids
3. vitamins
4. minerals
32
Define essential nutrient.
- we make most fatty acids and amino acids
- those we can't make are "essential" (have to eat something that will provide them for us, can't build them ourselves)
- plants make many essential nutrients
EX: beans and rice to obtain all essential amino acids
33
Explain the four stages of food processing by animals.
ingestion: bringing food into your body, act of eating or feeding
digestion: the breaking down of food into smaller pieces
absorption: the animal's cells take up (absorb) small molecules such as amino acids and simple sugars
elimination: completes the process as undigested material passes out of the digestive tract
34
Identify examples of the four animal feeding mechanisms.
suspension feeders: EX: CLAMS & OYSTERS feed on tiny morsels of food in the water that passes over their gills; cilia sweep the food particles to the animal's mouth in a film of mucus
- many aquatic animals; which eat small organisms or food particles suspended in the water
filter feeders: EX: the HUMPBACK WHALE; move water through a filtering structure to obtain food
substrate feeders: EX: LEAF MINER CATERPILLAR, the larva of a moth, is eating through the soft tissue of an oak leaf, leaving a dark trail of feces in its wake OR MAGGOTS (fly larvae), which burrow into animal carcasses
- are animals that live in or on their food source
fluid feeders: EX: MOSQUITO has pierced the skin of its human host with hollow, needle-like mouth parts and is consuming a blood meal OR APHIDS tap the phloem sap of plants OR in contrast to such parasites, some actually benefit their host AKA hummingbirds and birds move pollen b/t flowers as they fluid-feed on necter
- suck nutrient-rich fluid from a living host
bulk feeders: most animals, including HUMANS, which eat relatively large pieces of food
35
Describe the benefits of eating a prey item in pieces rather than whole.
need to get it across the membranes, if you swallow a piece of pie you won't be able to shove pie through intestinal lining into the blood stream and you're body cells won't be able to do anything with a piece of pie, so you need to break it down to be able to do anything with it *
36
Summarize the function of each of the four mammalian tooth types.
incisor: "to cut"
canine: "for tearing apart food" *sharpest teeth
premolar: "tearing and crushing food"
molar: "grind food during chewing"
37
Predict a mammal's diet based on its dental formula.
carnivore: EX: dog or cat families
- generally have large, pointed INCISORS & CANINES that can be used to kill prey & rip or cut away pieces of flesh
- the jagged premolars & molars crush & shred food
herbivore: EX: horses & deer
- usually have PREMOLARS & MOLARS with broad ridged surfaces that grind tough plant material
- the incisors & canine are generally modified for biting off pieces of vegetation
- sometimes, canines are absent
omnivore: EX: humans
- are adapted to eating both plants & meat
- adults have 32 teeth
- from front to back along either side of the mouth are 4 bladelike INCISORS of biting, a pair of pointed CANINES for tearing, 4 PREMOLARS for grinding, & 6 MOLARS for crushing
38
Compare internal and external digestion.
intracellular digestion: EX: sponges
- the hydrolysis of food INSIDE food vacuoles (cellular organelles in which hydrolytic enzymes break down food - simplest digestive compartments), begins after a cell engulfs solid food by phagocytosis or liquid food by pinocytosis
extracellular digestion: EX: in most animal species
- hydrolysis of food begins with extracellular digestion, the breakdown of food in compartments that are continuous OUTSIDE of the animal's body
39
Identify which animals employ intracellular digestion, extracellular digestion, or both.
intracellular digestion:
- sponges!
- also, Platyhelminthes (flatworms), Ctenophora (comb jellies), and Cnidaria (coral, jelly fish, and sea anemones)
extracellular digestion:
- this more advanced type of digestion occurs in chordates, annelids, and crustaceans.
40
Discuss the advantages of an alimentary canal over a gastrovascular cavity.
alimentary canal aka COMPLETE digestive tract is better because food moves along the alimentary canal in a single direction, the tube can be organized into specialized compartments that carry out digestion & nutrient absorption in a stepwise fashion
- an animal with an alimentary canal can ingest food while earlier meals are still being digested, a feat that is likely to be difficult or inefficient for animals with gastrovascular cavities
41
Discuss, with examples, the effects of increasing intestinal surface area on efficiency.
circular folds contain villi & microvilli
- because it massively increase surface area
- if it was just a simple tube, there would be a very small amount of SA and not a lot would give through, it would just pass through & get out the body
- tons of lining where nutrients can pass in & out
42
Categorize an animal's diet based on the structure of its digestive tract.
```
gastrovascular cavity (digestive compartment with 1 opening):
- cnidarians & flatworms
```
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food vaculoes (cellular organelles in which hydrolytic enzymes break down food; are the simplest digestive compartments):
- sponges
```
```
alimentary canal (a complete, digestive tract with 2 openings)
- molluscs, annelids, nematodes, arthropods, echinoderms, chordates
```
43
Summarize mechanisms that herbivores use to breakdown cellulose.
- mutualistic symbiosis is particularly important in herbivores
- much of the chemical energy in herbivore diets comes from the cellulose of plant cell walls, but animals don't produce enzymes that hydrolyze cellulose
- INSTEAD, many vertebrates (& termites) host large populations of mutualistic bacteria & protists in fermentation chambers in their alimentary canals
- these microorganisms have enzymes that can digest cellulose to simple sugars & other compounds that the animal can absorb
44
Summarize the origins and forms of nitrogenous waste.
ammonia is a byproduct of protein metabolism
- animals must remove it from their bodies
- corrosive & toxic; accumulates if you don't get red of it
- 3 primary forms:
1. as ammonia
2. as urea
3. as uric acid
45
Identify what animals use each form of nitrogenous waste.
- as ammonia (most aquatic vertebrates)
- as urea (ex: humans)
- as uric area (most non-mammalian land animals)
46
Explain the four stages of urine production.
1. filtration: blood pressure PUSHES water & solutes across filter membrane
2. reabsorption: water & important solutes (salts, sugars, amino acids, bicarbonate, etc.) are returned to the blood (either actively or passively)
3. toxins (ex: drugs) are actively secreted out of blood into the excretory tube
4. filtrate is excreted as urine
47
Locate where these stages occur in the four types of excretory organs.
1. filtration - in the GLOMERULUS
- filtrate is formed when blood pressure forces fluid from the blood in the glomerulus into the lumen of Bowman's capsule
2. reabsorption - in the PROXIMAL TUBULE
- is critical for the recapture of ions, water, & valuable nutrients from the huge volume of initial filtrate
3. secretion - in the PROXIMAL/DISTAL TUBULE
4. excretion - in the COLLECTING DUCT
- receives processed filtrate from many neurons & transports it to the renal pelvis
image page 1037 ish **
48
Describe the linkages between the digestive, respiratory, renal, and circulatory systems.
"The respiratory system brings oxygen into the lungs when you breathe. The digestive system breaks food down into nutrients such as glucose. Now the circulatory system enters the picture. It transports glucose and other nutrients from the digestive system to the cells."
49
Why do we eat?
- to obtain energy
- to obtain carbon (to build macromolecules)
- to obtain lots of other nutrients, especially "essential nutrients"
- essential fatty acids
- essential amino acids
- minerals
50
What are the 4 types of macromolecules?
- nucleic acids
- proteins
- polysaccharides
- fat
51
What are organic compounds?
complex molecules with a carbon structure
52
What are polymers?
chains of individual organic molecules (monomers)
53
What are the monomers that make up nucleic acids?
nucleotides
54
What are the monomers that make up proteins?
amino acids
55
What are the monomers that make up polysaccharides?
monosaccharides
56
What are enzymes?
are proteins that break down other molecules
| - they're names after the thing they break down plus "-ase"
57
What is a vitamin?
organic molecule needed for metabolism
58
2 types of vitamins?
1. water-soluble vitamins (get urined out - PLANTS, milk, wheat, vegetables, tomatoes, fruit etc.)
- the B vitamins (B1, B2, B3, B5, B6, B7, B9, B12)
- vitamin C
2. fat-soluble vitamins (eggs, carrots, nuts, broccoli and plants too)
- A, D, E, and K
59
Who is Linus Pauling?
pushed vitamin C consumption (helps keep scurvy away but you just need enough)
60
What is a mineral?
inorganic molecules (ex: Na+, K+, etc.)
- we need many minerals in trace amounts
- they are found in many of the same foods above (like plants, vegetables, etc.)
61
Are minerals "essential"?
yes, b/c we can't make elements
| - can't make ourselves, have to obtain from something else
62
What's an easy way of ensuring a balanced diet?
eat all colours of the rainbow!
63
What are the recommended dietary allowances?
Canadian RDAs & US RDAs both developed from the National Academy of Sciences
- % Daily Values on food labels based in part on RDAs
- Canadian and US food labels aligned
- 1/2 fruits & veggies
- 1/4 proteins
- 1/4 whole grains
64
What is the metabolic rate?
rate of energy consumed by your body
65
What is the basal metabolic rate?
rate of energy consumed when not doing anything: approx. 1500 kcal/day, depending on body size, etc.
66
How much kcal's do you burn on a marathon?
approx. 3000 kcal
67
What type of tissue lines the intestines?
simple columnar epithelium
| - good at moving things back & forth, can pull digestive materials into the cells & put them in the bloodstream
68
Which animals only have a gastrovascular cavity?
cnidarians & flatworms
| - some also use food vacuoles
69
Which animals don't even have a gastrovascular cavity?
sponges
| - the only animals that use ONLY food vacuoles
70
What is the crop?
before stomach
- mostly food storage chamber
- little if any digestion
- worms, insects, birds
71
What is the stomach (midgut)?
- some digestion, some food storage, very little absorption
- insects (midgut), birds, mammals
- alcohol is ingested really easily from the stomach in humans
- goes right through stomach lining quickly (that's why it hits you fast)
72
What is the gizzard?
not all have
- some food storage
- some digestion (often with rocks!)
- worms, birds
73
What is the small intestine?
majority of digestion & absorption occurs here
| - some digestion, most absorption
74
What is the large intestine?
hindgut in insects
| - waste compaction & water recovery
75
What is involved in the mammalian digestive system?
digestion begins in the mouth
- mechanical digestion: teeth & (to some extent the tongue) begin breaking up food
- chemical digestion: salivary amylase begins hydrolyzing starch (plant glucose polymers) & glycogen (animal "balls of glucose)
76
What is mechanical digestion?
teeth & (to some extent the tongue) begin breaking up food
77
What is chemical digestion?
salivary amylase begins hydrolyzing starch (plant glucose polymers & glycogen (animal "balls of glucose)
78
What are parietal cells?
- secrete H+ & Cl-
- HCl unfolds proteins (exposes peptide bonds b/t them)
- breaks things down
79
What are chief cells?
- secrete pepsinogen
- HCl converts pepsinogen
- -> pepsin (breaks molecular bonds)
- pepsin also converts pepsinogen --> pepsin
- pepsin breaks peptide bonds
80
What are mucous cells?
- secrete mucous
| - protects stomach, without it the stomach would be severely damaged, ulcers
81
What is the function of the pancreas?
- makes pancreatic juice (enzymes + base)
| - neutralizes HCl
82
What is the function of the liver?
- PRODUCES bile (like detergent; mix of bile salts to break up fat)
- FILTERS blood (via hepatic portal vein)
- MAKES fat & glycogen
- is involved in both forming fat molecules & (indirectly) breaking down fat molecules!
83
What is the function of the gallbladder?
- stores & concentrates bile
| - can live without it
84
Why does the small intestine have circular folds, villi and microvilli?
massively increase surface area
- if it was just a simple tube, there would be a very small amount of SA and not a lot would give through, it would just pass through & get out the body
- tons of lining where nutrients can pass in & out
85
How are different materials absorbed in the small intestine? (FOR SUGARS)
- some sugars (ex: fructose) PASSIVELY follow concentration gradients into epithelial cells
- other sugars (ex: glucose), amino acids/small peptides, & vitamins are transported ACTIVELY into epithelial cells
- have ATP channels on small intestine that GRAB these things & pull them in
- pass from epithelial cells into hepatic portal vein for filtering in liver
86
How are different materials absorbed in the large intestine?
- Na+ is pumped out of the intestinal lumen into epithelial cells
- using ATP
- water follows by osmosis
87
What are the pros & cons of the ammonia form?
- extremely toxic
+ easily diffuses into water
+ no additional cost in its removal
88
What are the pros & cons of the urea form?
- toxic (but not as bad)
+ can be safely stored in larger quantities
- energy cost in converting ammonia to urea (water based)
- water lost in urine
89
What are the pros & cons of the uric acid form?
+ not as toxic
+ can be safely stored almost indefinitely
+ stored/eliminated as solid
--> no water loss
- even higher energy cost in converting ammonia to uric acid
90
What are the kidney basics?
- blood: from renal artery (all blood is delivered to the liver from this artery)
- -> afferent arteriole
- -> glomerulus (within Bowman's capsule)
- -> efferent arteriole (think: Exit Egress)
- -> peritubular capillaries vasa recta
- -> renal vein
- pressurized filtration occurs in glomerulus
- closed circulatory system, so pressure
91
Osmolarity increases with...
increasing depth!
92
Transport is passive when...
following gradient!
93
Transport is active (uses ATP) when...
against gradient!
94
What is one of the most energetically expensive organs in the body?
the kidney!
95
What is the general rule according to energy in & out of your body?
you need to consume as much energy as your going to expand
| - if you consume more than you expand you will gain weight, if you consume less than your weight you will lose weight
96
What is part of the Alimentary Canal?
- oral cavity (mouth)
- tongue
- pharynx
- esophagus
- small intestine
- large intestine
- rectum
- anus
ALL part of digestive tract
97
What is part of the Accessory Organs?
- salivary glands
- liver
- gallbladder
- pancreas
NOT apart of digestive tract, but important for digestion
98
How does each region contribute to the stepwise processing of filtrate into urine?
1. PROXIMAL TUBULE: reabsorption in the proximal tubule is critical for the RECAPTURE of ions, water, & valuable nutrients from the huge volume of initial filtrate
2. DESCENDING LIMB OF THE LOOP OF HENLE: reabsorption of water continues as the filtrate moves into the descending limb of the loop of henle
- here numerous water channels formed by AQUAPORIN proteins make the transport epithelium freely permeable to water
3. ASCENDING LIMB OF THE LOOP OF HENLE: the filtrate reaches the tip of the loop & then travels within the ascending limb as it returns to the cortex
4. DISTAL TUBULE: plays a key role in regulating the K+ & NaCl concentration of body fluids
- this regulation involves variation in the amount of K+ secreted into the filtrate as well as the amount of NaCl reabsorbed from the filtrate
- contributes to pH regulation by the controlled secretion of H+ & reabsorption of HCO3-
5. COLLECTING DUCT: carries the filtrate through the medulla to the renal pelvis
- the transport epithelium of the nephron & collecting duct processes the filtrate, forming the urine
99
Unlike the descending limb, what does the ascending limb do different?
it has a transport epithelium studded with ion channels, but not water channels
- indeed, this membrane is impermeable to water
- which is critical to this function
100
What do the proximal tubule & the distal tubule have in common?
helps maintain a relatively constant pH in body fluids
101
How are different materials absorbed in the small intestine? (FOR FAT)
- fat gobules are broken into triglycerides
- triglycerides are broken into fatty acids & monoglycerides
- they diffuse passively into epithelial cells
- they are repackaged into triglycerides (back together again)
- triglycerides are coated with phospholipids, cholesterol, and proteins, forming water-soluble "chylomicrons"
- pass from epithelial cells via exocytosis into lacteals & transported by lympth to the heart for distribution
