Animal Nutrition Flashcards
1
Q
What are the three categories of animal diet?
A
Herbivore - feed on plants or algae
Carnivores - eat other animals
Omnivores - eat other animals as well as plants or algae
2
Q
How does the book define nutrition?
A
food being taken in, taken apart, and taken up.
3
Q
What are the three things that an animals diet should supply?
A
Chemical energy - to be used in cellular processes like ATP productionor gene expression
Organic carbon (sugars) and nitrogen (proteins) to build macromolecules (proteins, fats, sugars, nucleic acids)
Essential nutrients - materials that animal cells require but cant be synthesized by the animal
4
Q
What are some roles of essential nutrients?
A
Enzyme substrates (linoleic acid)
Coenzyme
Cofactors (minerals)
Essential amino acids
5
Q
How many different amino acids do animals use? How many of these are essential, and what does that mean?
A
Animals use 20 different amino acids
8 of these are essential meaning that they must be obtained in a prefabricated form
6
Q
What is the difference between plant and animal proteins?
A
plant proteins are incomplete which means they dont provide all of the essential amino acids that animals need.
animal proteins are complete (meat and eggs) which means they provide all essential amino acids animals need
7
Q
What is a primary use of fatty acids? Does a deficiency in this often occur?
`
A
to make the cell membrane
Deficiency does not often occur
8
Q
How many vitamins are there total? What are they divided into? How can you remember them?
A
13
Water soluble - B vitamins and C
Fat soluble - A, D, E, K
9
Q
What is the condition called when deficient in vitamin C? B9 and B12? D?
A
C - scurvy
B9 & B12 - anemia
D - Rickets (bone deformities in children, soft bone in adults)
10
Q
What is the typical function of vitamins? Are they generally needed in large amounts?
A
Usually coenzymes, needed for an enzyme to carry out its function
Needed in typically small amounts
11
Q
Are minerals organic or inorganic? What are they used for?
A
Inorganic
Needed for enzymes and nerves to function
12
Q
What are some examples of minerals we need?
A
Less than 200mg/day - Fe. Fluorine, Iodine
More than 200mg/day - Mg, Ca, Na, Cl, K, P, S
13
Q
What is iodine used for?
A
Thyroid hormone
14
Q
Deficiency in calcium and phosphorus?
A
Bone loss
15
Q
Deficiency in iodine causes?
A
goiter, weakness
16
Q
Too much sodium may cause?
A
HTN
17
Q
What does malnutrition mean? How does it differ from undernutrition?
A
Malnutrition - failure to obtain adequate nutrition
Undernutrition - not enough food to provide adequate chemical energy for body.
18
Q
What is golden rice?
A
an engineered rice strain that contains beta-carotene that is converted to vitamin A by the body.
19
Q
Can deficiencies in essential nutrients cause deformities, disease, or death?
A
YES
20
Q
What are some things that will happen to an undernourished individual?
A
- use up stored fat and carbohydrates
- break down its own proteins
- lose muscle mass
- suffer protein deficiency in the brain
- die or suffer irreversible damage
21
Q
How might cattle, deer, and other herbivores prevent deficiencies in phosphorus?
A
Consuming concentrated sources of salts and other minerals.
22
Q
What are the four main stages of food processing in animals and their basic description?
A
- Ingestion - act of eating or feeding
- Digestion:
- Mechanical - act of chewing to break down food to smaller pieces to create more surface area for enzymes to act.
- Chemical via enzymatic hydrolysis to break down to monomeric units - Absorption - molecules absorbed by bodies cells
- Elimination - undigested foods passed out of body
23
Q
What are the four ways animals feed and some examples of each?
A
Filter or suspension feeding - sifting small food particles from the water. Mostly aqautic animals that do this, like humpback whale.
Substrate feeding - animals that live in on on their food source. Maggots or leaf miner caterpillar.
Fluid feeding - suck nutrient-rich fluid from living host. Like mosquitos, bees, hummingbirds.
Bulk feeding - eat relatively large pieces of food. Such as humans, pythons.
24
Q
What are the two types of digestion covered in class and descriptions of each?
A
Intracellular digestion - occurs inside the cell in food vacuoles that contain hydrolytic enzymes (contained in lysosomes that attach to vacuole). ALL ANIMALS PERFORM THIS. SEE PIC.
Extracellular digestion - occurs outside the cell in body compartments.
25
What are the two types of compartments where extracellular digestion occurs that an animal may have? Advantages or disadvantages?
1. Gastrovascular cavity - Have a single opening (mouth/anus) to a digestive pouch that also distrubutes nutrients throughout the body (vascular). Cnidarians (jellyfish, polyps, corals) sponges, and flatworms.
2. Alimentary canal - Complete digestive tract (mouth and anus). earthworms, insects, birds, and humans.
The advantage of an alimentary canal is that one compartment can be used for ingestion while another can digest.
P.902 for pictures of each of these.
26
What are the different organs vs. the different accessory glands in the mammalian digestive tract? What is a sphincter?
Organs - esophagus, stomach, small and large intestine, rectum
Accessory glands - salivary glands, pancreas, liver, gallbladder
A sphincter is a bottleneck between major compartments.
27
Why do we need a sphincter between esophagus and stomach? Stomach and small intestine?
Stomach and esophagus - prevents reflux of acid, limits amount of food we can eat.
Stomach and small intestine - allows for stomach to begin digestive processes before food moves into smal intestine.
28
What is the function of the pancreas, liver, and gallblader in the digestive system? Does the stomach absorb anyhting? Basic function of small intestine and large intestine
Pancrease - releases digestive enzymes into the small intestine.
Liver - produces bile to emulsify fats in small intestine.
Gallbladder - stores bile produced by liver.
Stomach aids in digestion ONLY
Small intestine - further digestion AND absorption
Large intestine - resorption of water and form feces
29
Describe the purpose of thses components: oral cavity, salivary glands (4 parts of saliva), teeth, tongue, pharynx, and esophagus.
1. Oral cavity - Ingestion
- teeth - grind food (mechanical digestion)
- tongue - shapes food into bolus or ball
2. Salivary glands - secrete saliva that is composed of:
- Mucous - protect mouth, lubricate food
- amylase - hydrolyzes starch and glycogen to small polysaccharides (chemical digestion)
- Lysozyme - kills bacteria
- buffers - neutralize acidity and prevent tooth decay
3. Pharynx (throat) - branches into trachea and esophagus
- epiglottis - covers trachea when swallowing
4. Esophagus - has muscles that push bolus down the stomach via:
- Peristalsis - alternating waves of smooth muscle contraction and relaxation
30
When trachea is open (epiglottis up and not down), even while chewing, the esophageal sphincter is?
closed (contracted) to allow for breathing even while chewing.
LOOK AT PICTURE
31
Why does the stomach have many folds and elastic walls?
So it can expand
32
Where is gastric juice secreted and what does it consist of?
HCl (hydrochloric acid) and pepsin (protease - enzyme that breaks down proteins)
33
What is the pH of the stomach approximately?
2
34
What is the purpose of the acidic pH of the stomach?
Denature proteins to better expose their peptide bonds for digestion via pepsin
Kills bacteria
35
What is the purpose of the mucous that is secreted in the stomach? How often is the lining of the stomach replaced?
To protect the stomach lining from the acidic environment.
Replaced every 3 days
36
What is the mixture of the undigested food and gastric juice called?
chyme
37
What does churning mean?
coordinated contractions and relaxations that mixes stomach contents, occurs every 20 seconds, facilitates chemical digestion
38
How long after a meal does chyme typically leave the stomach?
2-6 hours after a meal
39
What are the three secretory cells of the stomach and what do each secrete?
Mucous cells - mucous
Chief cells - pepsinogen (inactive form of pepsin)
Parietal cells - components of HCl (activates pepsinogen and disrupts ECM that binds together food material being digested)
40
What happens during heartburn?
OTherwise known as acid reflux
Backflow of chyme through esophageal sphincter to lower esophagus
41
Describe the process of peptic ulcer formation? What causes this generally?
Caused by acid tolerant H. pylori generally
Damaged areas of stomach lining caused by disruption of mucous layer of stomach by helicobater pylori colonization that allows for acidic stomach contants to damage epithelial cells
42
Why is the small intestine considered small? Approximately how long is it?
Its small in diameter
\> 20ft long in humans
43
What occurs in the duodenum? Approximately how long is it?
10 inches long
This is the place in the small intestine where chyme mixes with digestive juices from the pancreas, liver, gallbladder, and intestinal gland cells.
44
What are the 3 divisions of the small intestine in order?
1. Duodenum
2. Jejunum
3. Ileum
45
Describe the function of the pancreas in regards to digestion.
Secretes alkaline solution that neutralizes acidic chyme (bicarbonate).
Also secretes trypsin and chymotrypsin to digest proteins
46
Describe the function of the liver in regards to digestion.
secretes bile to emulsify fats which aids in their digestion and absorption
47
Describe the function of the gallbladder in regards to digestion.
stores and concentrates bile
48
How is chyme and digestive juices pushed along the small intestine?
Peristalsis
49
Become familiar with this picture.
50
What chemical digestion occurs in the oral cavity, pharynx, and esophagus and what chemical is responsible?
AMYLASE
Enzyme that digests large polysaccharides like glycogen and starch into disaccharide maltose and other smaller polysaccharides.
Disaccharides like maltose, sucrose and lactose are not further broken down by amylase.
51
What chemical digestion occurs in the stomach and what chemical is responsible?
Pepsin
Protease that breaks down proteins into smaller polypeptides.
52
What chemical digestion occurs in the small intestine VIA PANCREAS and what chemicals are responsible?
Pancreatic amylases - break down polysaccharaides that didn't get fully digested in the oral cavity.
Pancreatic trypsin and chymotrypsin - protease enzyme that breaks down proteins into smaller polypeptides.
Carboxypeptidase - further breaks down polypeptides into smaller polypeptides
Pancreatic nucleases - enzyme that breaks down DNA and RNA into nucleotides
Pancreatic lipase - enzyme that breaks down emulsified fats (via bile) into glycerol, fatty acids, and monoglycerides
53
What chemical digestion occurs in the small intestine VIA INTESTINAL EPITHELIUM and what chemicals are responsible?
Disaccaridases - break down disaccarides to monosaccarides.
Dipeptidases, carboxypeptidase, and aminopeptidase - convert polypeptides and dipeptides to amino acids
Nucleotidases - breaks nuceotides down to nucleosides
Nucleosidases and phosphatases - breaks down nucleosides to nitrogenous bases, sugars, and phosphates
54
What are some monosaccharide examples?
Glucose and galactose
55
What is the difference between a nucleotide and nucleoside?
Nucleotide - sugar, nitrogenous base, phosphate group
Nucleoside - sugar & nitrogenous base
56
Where does absorption begin?
SMALL INTESTINE
jejunum
57
In the jejunum and ileum, these regions are highly folded into what are called? Each epithelial cell of these regions have many microprojections called what?
What is the purpose of these two structures?
Folds are called villi
Each epithelial cell have microprojections called microvilli
The purpose of these villi and microvilli is to increase the surface area for nutrient absorption
58
Describe the basic process of absorption of amino acids and sugars in the small intestine. Where do the nutrients absorbed from the small intestine go to? Why does it go there first?
Amino acids and sugars pass through the epithelium of the small intestine and enter into surrounding capillaries.
These capillaries converge to veins and eventually form the hepatic portal vein that leads directly to liver
This portal circulation exists to regulate the distribution of nutrients to the rest of the body as well as remove toxic substances before they reach the rest of the body.
59
Describe triglyceride absorption in 5 steps.
1. Large fat globules in small intstine are broken into fat droplets via bile salts.
2. Lipase breaks down triglycerides in fat droplets into fatty acids and monoglycerides
3. fatty acids and monoglycerides diffuse into epithelial cell and reform into triglycerides (some glycerols and fatty acids pass directly into capillaries)
4. triglycerides are incorporated into chylomicrons which make them water-soluble
5. These chylomicrons leave epithelial cell via exocytosis and enter lacteals (part of lymphatic system) where the lymph takes them to large veins and eventually to heart.
60
What is the large in large intestine in reference to? How long is it in humans?
Large is in reference to diameter
5ft long in humans
61
What are the three divisions of the colon spoken about in class?
Colon, cecum, rectum
62
What are the functions of the colon?
Colon - reabsorbs 90% of water from digestive juices (goes into hepatic portal circulation), also contains bacteria that produce vitamin K and several B vitamins
63
What is the function of the cecum? Where does the appendix come into play?
Connected to ileum via ileocecal valve
Ferment plant material (via anaerobic bacteria and protists)
Appendix - extension of cecum that plays a very minor role in immunity
64
What is the function of the rectum? What is feces?
Store feces until it is eliminated through the anus
Feces - wastes of the digestive tract that becomes more solid as it moves down the colon.
65
How many sphincters are in control of bowel movements? Voluntary of involuntary?
Two
Inner - involuntary
Outer - voluntary
66
What are the 3 evolutionary adaptations of vertebrate digestive systems that correlate with their diet we covered in class?
1. Dentition
2. Stomach and intestinal
3. Mutualistic adaptations
67
Describe the evolutions of dentition in regards to herbivores, carnivores, and omnivores.
Carnivore (dogs and cats) - long pointed incisiors and canines. jagged premolars and molars.
Herbivore (horses and deer) - premolars and molars with broad, ridged surfaces. Incisors and canines modified for biting off pieces of vegetation, may not have any canines in some cases.
Omnivores (humans) - adapted to both plants and meat consumption. pointed canines, blade-like incisors, premolars for grinding and molars for crushing.
68
Describe the stomach and intestinal adaptations between carnivors, omnivores and herbivores discussed in class.
Carnivors - large expandable stomachs to allow for long time between meals and allows for bulk eating once prey has been caught (like in python or a lion)
Herbivores and Omnivores - Have longer alimentary canals (as well as cecums) in relation to their body size than carnivores. this allows the longer required time for plant digestion to occur (cell walls make them tough). For example between the similarly sized koala and coyote the koalas intestines are much longer.
69
What are the mutualistic evolutionary adaptations talking about in regards to the digestive system?
The microbiome - the bacteria present in and on our bodies.
Different in infants, toddlers, adults, and elderly
70
What 2 systems play a crucial role in controlling digestion?
Nervous (enteric division) and endocine systems
71
What hormone is released when food arrives in stomach and stretched stomach walls? What does this hormone stimulate?
Gastrin - stimulates production of gastric juices in the stomach.
72
Once chyme enters the duodenum what two hormones are released?
CCK (choleocystokinin) - Stimulates release of bile from gallbladder and pancreatic enzymes
Secretin - stimulates bicarb to be released from pancreas
73
If the chyme is rich in fats, there will be high levels of secretin and CCK to aid in digestion of them. What is the inhibitory property that these high levels produce?
These high levels will decrease the secretion of gastric juices and inhibit peristalsis, slowing digestion so fats can be properly broken down.
74
As you go through when each digestive hormone is released, what is shown?
Each step is activated when food reaches a new compartment in the alimentary canal.
75
Understand blood glucose control via negative feedback loops.
BG rises - pancreas beta cells release insulin - insulin stimulates glycogen storage in liver and glucose shift into cells (especially skeletal muscle) - blood glucose levels drop back down
BG falls - pancreas alpha cells release glucagon - liver releases glucose into blood via glycogen stores - glucose level rises
76
What is an important maintenance factor for maintaining energy storage and metabolic balance via glucose homeostasis?
Glycogen synthesis and breakdown.
77
What are the two roles the pancreas plays?
Endorcrine - via blood glucose control
Exocrine - via digestive enzyme release to small intestine and bicarbonate release
78
What is DM?
Describe the difference between DMI and DMII.
Abnormally high blood glucose levels that leads to problems with the heart, blood vessels, kidneys, and eyes.
DMI - Insulin-dependent or juvenile diabetes - autoimmune disorder in which immune cells destroy beta cells (INSULIN DEFICIENCY), requires daily insulin injections or insulin pump.
DMII - non-insulin-dependent - insulin is produced, but the target cells fail to uptake glucose from the blood (DECREASED TISSUE RESPONSE TO INSULIN)... Risk factors: heredity, obesity, sedentary lifestyle... accounts for 90% of diabetes and is 7th most common cause of death in the US.
79
What do the words diabetes and mellitus mean?
Diabetes - pass through
mellitus - honey
REFERS TO SWEET TASTE IN URINE DUE TO GLUCOSE PRESENT
80
What are the 3 Ps in regards to diabetes?
Polyuria - urinating a lot, lot of glucose present.
Polydipsia - increased thirst
Polyphagie - increased hunger
81
Describe the functions of ghrelin, insulin, leptin, and PYY in regards to appetite and consumption. Which is the only hormone listed that increases appetite? Where do these hormones act to produce their effects?
ghrelin (think stomach growling) - secreted from stomach wall and triggers feelings of hunger
insulin - secreted from pancrease and suppresses appetite
leptin - secreted from fat tissue and suppresses appetite
PYY - secreted from small intestine and counters ghrelin, suppresses appetite.
GHRELIN IS ONLY HORMONE THAT INCREASES APPETITE
These hormones act on the satiety center of the brain
82
What is a leptin knockout mouse? What are they used for?
These are mice that have had both their maternal and paternal leptin genes removed in order to study obesity, high cholesterol, and athersclerosis
Lack of leptin gives them the inability of feeling full, contributes to obesity.
