AN SCI 311 Nutrition Exam 1

Water absorption is primarily passive and follows absorption of electrolytes, thus water absorption occurs mainly in:

stomach and small intestine

small intestine only

small intestine and colon

stomach and colon

small intestine and colon

Na-K ATP-ase is an enzyme that

maintains an un-equal distribution of Na and K in cellular compartments

maintains an equal distribution of Na and K in cellular compartments

functions only if dietary intake of Na or K is deficient to regulate homeostasis

functions only if dietary intake of Na or K is excessive to regulate homeostasis

maintains an un-equal distribution of Na and K in cellular compartments

In healthy animals at maturity, body water is in a steady balance:

except for small stores in adipose vacuoles that are not saturated with fat

except for small stores in inter-abdominal spaces

unless food/feed ingredients contain greater than 20% moisture

because water is not stored

because water is not stored

Chemical properties of Na, K & Cl provide unique functions in cells because they:

repel water molecules and create a boundary at the membrane surface

bind tightly to water and membranes to promote transport

readily dissociate to form ionic bonds

provide covalent links between proteins and nucleic acids

readily dissociate to form ionic bonds

Which organ has the most direct involvement in homeostasis of Na, K, and Cl?

liver

small intestine

stomach

kidney

kidney

The immediate substrate that supplies ammonium ions in renal compensation to chronic dietary acid loads is:

alanine

glutamine/glutamate

asparagine/aspartic acid

urea

glutamine/glutamate

Water allows thermoregulation because it ____.

does not react with electrolytes

effectively insulates organs from external temperature changes

requires relatively small amount of heat to reflect a change in temperature

readily loses heat upon evaporation

readily loses heat upon evaporation

Which chemical property of water allows animals to retain heat generated by metabolism:

low specific heat of water relative to other solvents

high specific heat of water relative to other solvents

ability to maintain high concentrations of electrolytes

high dielectric constant

high specific heat of water relative to other solvents

Sodium is the major extracellular cation, which anion provides the major counter-ion to balance sodium extracellular fluids?

bicarbonate

chloride

phosphate

magnesium

chloride

The ions involved in the net elimination of H ions from the body under conditions of renal compensation to chronic dietary acid loads are:

urea and Ca

Ca and phosphate

NH4 and phosphate

NH4 and NH3

NH4 and phosphate

The concentrations of all compounds and ions (regardless of valence) in solution describes:

electrochemical neutrality

electrochemical negativity

acid-base balance

osmotic balance

osmotic balance

Which statement best describes the relationships in substrates relative to metabolic water produced upon oxidation:

Fat, CHO, and protein provide equal amounts of water

Protein releases water upon metabolism, but no water is released by fats and CHO

Fat provides ~ 2x as much water as an equal weight of CHO and protein

Fat provides ~ 2x as much water as an equal molecule of CHO and protein

Fat provides ~ 2x as much water as an equal weight of CHO and protein

Distinguish between metabolic water and drinking water.

Metabolic water and drinking water are different sources of water. Metabolic water comes from nutrient metabolism inside your body and through oxidation of substances such as proteins, fats and carbohydrates in the food you consume.

Drinking water is taken in on the outside of the body through fluid intake such as food and and beverages.

Define a nutrient and explain the key implications of the definition in terms of the ingredients consumed by animals.

A nutrient is an element or compound that is provided through the diet. Examples of nutrients are water, vitamins, some fatty acids, minerals, and some amino acids.

Key implications of the definition in terms of the ingredients consumed by animals include balancing the essential nutrients for the physiological roles of growth, reproduction, or maintenance required by at least one species. Water is the most essential nutrient; humans can only go 3-4 days without water in their diet. Water is used for the body's metabolism and thermoregulation, therefore it is very crucial in the diet and an ingredient consumed by humans.

Which ingredients are likely to contribute a greater proportion of the osmotic load of the solution?

potassium chloride, salt, magnesium oxide, and calcium lactate.

These contain electrolytes, and their roles are important to change osmolarity and maintain a balance.

As a beneficial nutrient supplement for "normal, healthy animals" which ingredient(s) are likely the most beneficial?

water, salt, potassium chloride, calcium lactate, magnesium oxide, and sugar. Water is the most essential nutrient, which is why it is listed first because it is the most used ingredient in the electrolyte drink. Water helps with hydration

As a beneficial nutrient supplement for "an animal struggling with dehydration associated with diarrheal disease" which ingredient(s) are likely the most beneficial?

The ingredients that are likely most beneficial for an animal struggling with dehydration associated with diarrheal disease are water, sodium chloride, and potassium chloride.

Eight glasses (8 ounces each) of water per day for healthy humans.

is a minimum requirement regardless of water consumed with other foods

must be consumed to prevent dehydration in a thermoneutral environment

is a maximum requirement

Is a common recommendation with limited scientific basis

Is a common recommendation with limited scientific basis

Potassium is the major intracellular cation, which inorganic anion provides the major counter-ion to balance potassium in intracellular fluids?

Phosphate

Magnesium

Chloride

Bicarbonate

Phosphate

Explain osmolarity and why Na, K and Cl (electrolytes), rather than other compounds, contribute the major role for the body's maintenance of osmotic balance.

Osmolarity is the concentration of solutes in a solution. Higher dissolved solutes, higher osmolarity because they have a larger mmol value and more readily dissolved in water than a compound.

Explain why phosphate is an effective buffer for physiological systems

Phosphate has an ideal pka value - around 7. This is similar to the physiological value, Phosphate can accept and donate H at physiological pH.

Parietal cells are located in which region of the gastrointestinal tract and secrete what substance?

fundic region and produce HCl

ileum region and produce mucins

fundic region and produce mucins

ileum region and produce HCl

fundic region and produce HCl

Pancreatic proteolytic enzymes ______.

Are released as zymogens that must be activated via an endopeptidase

All answers are correct

Require water to perform hydrolysis of peptide bonds

Result in production of small (di, tri) peptides and amino acids

All answers are correct

BIle made by the liver is typically stored in the gallbladder of most animals species with the exception of:

Chickens, since avians are insectivores and the gallbladder is absent

Horses, since equines are hindgut fermenters that constantly release bile and do not necessitate a gallbladder for storage

Dogs, since canids have a much shorter colon and bile builds up in this organ instead of the gallbladder

Cows, since ruminant animals rely mainly on fermentative processes for digestion

Horses, since equines are hindgut fermenters that constantly release bile and do not necessitate a gallbladder for storage

Which describes the main similarity between forestomach fermenters and monogastrics?

Enzymatic hydrolysis of feedstuffs contributes the main source nutrients

Feedstuffs consumed are similar for both species

Fermentation is the major role in digestion for both as both species have an elaborate GI tract microflora

Functions of the digestive systems after the stomach are similar

Functions of the digestive systems after the stomach are similar

Palatability of feed in the pre-absorptive phase vs. in the immediate post-absorptive phase is impacted by:

Control of satiety to prevent overconsumption

Avoidance of toxic feed ingredients

Initiation of salivary secretions followed by neural stimulatory feedback

Preference for more highly digested feed ingredients

Initiation of salivary secretions followed by neural stimulatory feedback

The _________is the longest section of the small intestine and contributes to bile acid resorption

Jejunum

Duodenum

Ileum

Ileum

_______ refers to digestion that is performed via host-derived enzymatic hydrolysis

Allo-enzymatic

Auto enzymatic

Auto enzymatic

Trypsin inhibitors in colostrum protect maternally-derived immunoglobulins (antibodies) from digestion allowing transfer to the offspring

True

False

True

Volatile fatty acids (VFAs) are a main product of alloenzymatic fermentation

True

False

True

Briefly describe the ways in which regurgitation by the esophagus is important for digestion in ruminant (i.e., cow) animals?

Regurgitation by the esophagus is important for digestion in ruminant animals because they can regurgitate, chew, and re-swallow food to maximize nutrient extraction at the beginning of the digestion process.

Briefly describe the ways in which regurgitation by the esophagus is important for digestion in non-ruminant (i.e., flamingos ) animals?

it is used to feed their offspring. Flamingos and penguins produce esophageal "milk" to nourish their young, while pigeons create crop "milk" for the same purpose. Unlike ruminants, which regurgitate to aid their own digestion, non-ruminants regurgitate to provide essential nutrients to their offspring

List and briefly describe three of the four functions of the mouth in digestion across species.

Prehension (gathering of feed)

Salivary secretions (lubricate the feed to form a bolus to aid in swallowing)

Chewing, grinding, and tear (reduce particle size and swallowing)

Which enzyme is secreted by Chief cells in the stomach of young animals for the denaturation of kappa-casein to aid in curdling of milk?

Mucins

Rennin

Pepsin

Trypsin

Rennin

Which enzyme is secreted to protect stomach mucosa and lubricates ingesta?

Mucins

Rennin

Pepsin

Trypsin

Mucins

What is secreted in the stomach produced in parietal cells of fundic region. It activates pepsinogen, and initiations hydrolysis of peptide bonds?

Mucins

Rennin

HCl

Pepsin

Trypsin

HCl

Which enzyme cleaves peptide bonds if aromatic amino acids and a stomach secretion?

Mucins

Rennin

Pepsin

Trypsin

Pepsin

The purpose of salivary amylases released in the mouth is to ____

Break down polysaccharides of starch or glycogen to smaller polysaccharides

Break down proteins to polypeptides

Breakdown small peptides to amino acids in the epithelium of the small intestine

Emulsion fat for absorption in the upper GI tract

Break down polysaccharides of starch or glycogen to smaller polysaccharides

Connection to environment (lumen of GI tratc is outside body)

Anatomical features

Motility

Digestion

Absorption

Excretion

Protection

Biological functions performed by the GI tract that influence nutrition and nutrient acquisition across all animal species

What type of crude protein is most rapidly degraded to ammonia in the rumen

metabolizable protein (MP)

Non-protein nitrogen (NPN)

Rumen degraded protein (RDP)

Rumen undegraded protein (RUP)

Non-protein nitrogen (NPN)

In addition to the R group (or side chain), the main structural components of alpha-amino acids include:

An alpha carbon

A carboxyl group

An alpha amino group

All the above

All the above

The following steps provide an accurate description of urea synthesis

2 ammonia compounds react with bicarbonate to form urea

2 ammonia compounds react with carbonic acid to form urea

reversible reaction that requires vitamin B6 to transfer ammonia groups between carbon chains

the 2 ammonia compounds in urea originate from different substrates in different cellular compartments

the 2 ammonia compounds in urea originate from different substrates in different cellular compartments

Deamination is the ________

Addition of ammonia to a carbon group to prevent ammonia toxicity

Reversible reaction that requires vitamin B6 to transfer ammonia groups between carbon chains

Removal of ammonia from amino acids without transfer to another compound leaving free ammonium ions

Conversion of ammonia to nitrate to prevent ammonia toxicity

Removal of ammonia from amino acids without transfer to another compound leaving free ammonium ions

Which term best describes the protein structure that forms an alpha helix?

Secondary

Primary

Quaternary

Tertiary

Secondary

In most animals cysteine can be used to synthesize enough taurine, however, a taurine deficiency in cats can cause blindness

True

False

True

The D- and L-isomers of amino acids differ in the configuration of the compound around the alpha carbon but the two forms exhibit equal activity as both isomers can be incorporated into proteins.

True

False

False

The term "limiting amino acid" refers to the non-essential amino acid in a given feedstuff that contributes the lowest amount when expressed as a percent of the animal's requirement.

True

False

False

Amino acid transport occurs via active transport across the brush border membrane of the small intestine

True

False

True

Feeding a combination of the nutritionally essential amino acid methionine and the non-essential amino acid cysteine to non-ruminant animals changes the rate at which methionine and cysteine are incorporated into proteins.

True

False

False

In the ________ , transported for _______ exhibit higher levels of expression more proximally while amino acids transports are expressed more distally.

Small intestine, peptides, amino acids

Amino acids, peptides, small intestine

peptides , amino acids, small peptides

Small intestine, peptides, amino acids

In avian species what is nitrogen excreted as _______

Ammonia

Uric acid

Urea

Uric acid

In aquatic species what is nitrogen excreted as _____

Ammonia

Uric acid

Urea

Ammonia

bacterial digestion of ___________ involves attachment, release of proteolytic enzymes, followed by proteolytic activity, and simultaneous incorporation of _____ into microbial crude protein (MCP).

Rumen degradable protein (RDP)

Proteolytic

Essential vs. Non-essential vs. conditionally essential amino acids

Essential amino acids are amino acids that can't be produced in adequate quantities to meet the needs of the animal. They are derived from the diet of the animal.

Non-essential amino acids are amino acids produced in sufficient quantities by the animal. They can be made from intermediates of metabolic pathways or other essential amino acids.

Conditionally essential amino acids are usually non-essential but become essential in certain circumstances.

In addition to the alpha carbon, the main structural components of alpha-amino acids include:

A carboxyl group and a carbon ring structure

A multiple carbon side chain with an attached carboxylic acid

A carboxyl amino group

A multiple carbon side chain with an attached amino acid

A carboxyl amino group

Feeding a combination of the nutritionally essential amino acid methionine and the non-essential amino acid cysteine to non-ruminant animal accomplishes which of the following?

Spares ½ of the methionine requirements, since cysteine is derived from methionine

Alters the requirement of additional nutritionally, essential amino acids

Changes the rate at which methionine and cysteine are incorporated into proteins

Increases absorption of both met and cys from the small intestine

Spares ½ of the methionine requirements, since cysteine is derived from methionine

In addition to urea, which compound serves to transports ammonia between body organs

Glutathione

Hydroxyproline

Proline

Glutamine

Glutamine

Transamination describes

Additions of ammonia to a carbon group to prevent ammonia toxicity

Conversion of ammonia to nitrate to prevent ammonia toxicity

Removal of ammonia from amino acids without transfer to another compound leaving free ammonium ions

Reversible reaction that requires vitamin B6 to transfer ammonia groups between carbon chains

Reversible reaction that requires vitamin B6 to transfer ammonia groups between carbon chains

The D- and the L- isomers of amino acids differ in the configuration of the compound around the alpha carbon that affects light diffraction. The biological activity of the two form are:

Equal as both isomers can be incorporated into protein by mammalian cells

Unequal as only the D-isomer can be incorporated into protein by mammalian cells

Equal as light diffraction does not affect protein synthesis

Unequal as only the L-isomer is incorporated into proteins, but the D-isomer can be used in other pathways from some amino acids and partially spare the L-isomer form

Unequal as only the L-isomer is incorporated into proteins, but the D-isomer can be used in other pathways from some amino acids and partially spare the L-isomer form

The pool size of free amino acids within a cell is relative large, which increases osmotic load and disrupts acid-base balance

True

False

False

The liver is the major site of urogenesis for excretion via the kidney

True

False

True

Deamination is the removal of ammonia from amino acids without transfer to another compound leaving free ammonium ions

True

False

True

Advantages of microbial fermentation

Fully utilize low quality feed to maximize nutrient absorption

Microbes can turn nitrogen containing compounds into proteins (NPNs)

Disadvantage of microbial fermentation

Protein can be degraded to nitrogen, causing it to be unutilized by the animal to nitrogen, causing it be be utilized by the animal

Microbial fermentation can create methane gas and waste products can lead to nitrogen leaching in the soil.

Advantages of uric acid excretion

Very insoluble so the animal can devote less water to the formation of it

Less toxic than ammonia

A lower incidence of milk fever (hypocalcemia) in dairy cows has been attributed to _____

Excess consumption of phosphorus in feed ingredients fed during the dry, transition phase which increases buffering capacity making the cow acidotic, which depletes Ca ions

Reduced consumption of dietary Ca in the dry, transition phase which increases active absorption of Ca in the intestine and resorption from bone

Feeding a positive DCAD (dietary cation-anion difference) electrolyte balance diet which increases mobilization of Ca and P from skeleton reserves

Excess consumption of dietary Ca in the dry, transition phase which reduces active absorption of Ca in the intestine and resorption from bone

Reduced consumption of dietary Ca in the dry, transition phase which increases active absorption of Ca in the intestine and resorption from bone

Animals fed raw-rock phosphorus ingredients directly from strip-mines would likely____

experience weakened bones and teeth from fluoride impurities in the mined product

experience stronger bones and teeth from fluoride impurities in the mined product

alleviate concerns for pollution of surface waters since the P is natural

experience no consequences as fluoride is not a required nutrient

experience weakened bones and teeth from fluoride impurities in the mined product

Vitamin D acts on GI tract tissue to increase _____

synthesis of Ca-ATPase, a protein involved with Ca transport

conversion of 25-OH Vitamin D to 1α, 25(OH)2D3

Ca transport via synthesis of 1 alpha hydroxylase

Ca transport via activation of Na-K ATPase

synthesis of Ca-ATPase, a protein involved with Ca transport

The most direct involvement of parathyroid hormone in regulation of serum Ca occurs by:

all answers are correct

synthesis of proteins, calmodulin and calbindin, in the duodenum to increase Ca absorption

activation of enzymes in the liver to convert 25-OH D into a more active form of vitamin D

activation of enzymes in the kidney to convert 25-OH D into a more active form of vitamin D

activation of enzymes in the kidney to convert 25-OH D into a more active form of vitamin D

Early deficiency symptoms in growing animals fed P deficient diets are displayed as a reduction in ______

inability to walk due to failure of muscle contraction

protein synthesis and bone mineralization

protein synthesis

bone mineralization

protein synthesis and bone mineralization

The most common target tissues for action of 1α, 25(OH)2D3 include:

GI Tract, bone, and liver

skin, GI tract and bone

small intestine, bone and thyroid gland

GI Tract, bone and kidney

GI Tract, bone and kidney

The major biochemical reactions requiring biotin are reactions involving:

additions of carboxyl groups to substrates

scavenging free radicals that cause membrane damage

post-translational modifications of extracellular matrix proteins to form crosslinks

modifications of heme proteins to bind Fe atoms, hence the origin of biotin as Vitamin H

additions of carboxyl groups to substrates

The chemical reaction that links a functional role of vitamin K to the extracellular matrix of bone involves additions of ____

hydroxyl groups to 25-hydroxyl vitamin D to form the active vitamin D metabolite

Ca binding to P ions to form hydroxyapatite crystals

carboxylic acid to glutamate residues in osteocalcin protein

carboxylic acid to glutamate residues in osteocalcin protein

Before Vitamin D3 acts to regulate Ca homeostasis, the compound must be____

hydroxylated in the kidney to form 25(OH)D3 then in the liver to form 1α, 25(OH)2 D3

converted by UVB light to the active form

hydroxylated in the kidney to form 1α, 24(OH)2 D3 then 1α, 25(OH)2 D3

hydroxylated in the liver to form 25(OH)D3 then 1α, 25(OH)2 D3 in the kidney

hydroxylated in the liver to form 25(OH)D3 then 1α, 25(OH)2 D3 in the kidney

Most typical feed ingredients contain sufficient amounts of Mn, so a deficiency is not common. Exceptions where Mn deficiencies are observed usually involve:

Diets based on ingredients that have been stored for over 8 months

Feeding programs based on feed ingredients that have been heat damaged

Diets with deficient levels of biotin

Secondary deficiencies caused by excessive levels of another mineral

Secondary deficiencies caused by excessive levels of another mineral

Calcium absorption

is driven mainly by Na absorption and water flux

requires active transport regulated by Na-K ATPase activity

requires active transport regulated by vitamin D

involves both active and passive absorption

involves both active and passive absorption

Feeding raw eggs creates a deficiency of biotin because __________

excess levels of Mn in the yolk inhibits SOD activity

the excess fat in egg yolk requires more biotin for carboxylation reactions

a protein, avidin, binds biotin making it unavailable

excessive levels of carotenoids (yellow pigments) interfere with biotin absorption

a protein, avidin, binds biotin making it unavailable

Which statement best describes the relationship between Ca and P in mineralized tissue

Ca and P form hydroxyapatite crystals that are deposited within bone collagen matrix

Ca and P are chelated and deposited in the rough endoplasmic reticulum of bone cells

Ca and P ions adhere to specific amino acids in collagen to stabilize the tertiary structure of collagen

Ca and P are independently deposited as mineral salts in bone

Ca and P form hydroxyapatite crystals that are deposited within bone collagen matrix

Early signs of vitamin K deficiency would likely be detected as _____

an increase in time required for blood coagulation

tetany due to Ca deficiencies

a decrease in time required for blood coagulation

a change in bone mass

an increase in time required for blood coagulation

The net effect on body acid-base balance following resorption of bone hydroxyapatite is _____

elimination of H ions by the kidneys as the excess Ca is excreted

elimination of OH ions by the kidneys as the excess P is excreted

an increase in serum Ca buffer

elimination of H ions by the kidneys as the excess P is excreted

elimination of H ions by the kidneys as the excess P is excreted

Synthesis of the metabolically active form of vitamin D (1, 25(OH)2 D3 is inhibited in the ______

liver upon stimulation by PTH

skin with UV light exposure

bone tissue upon stimulation by FGF23

kidney upon stimulation by FGF23

kidney upon stimulation by FGF23

Bones provide structural support for protection of vital tissues and for locomotion, and also serve a role in storage of Ca and P. The resorption of Ca and P from bone involves cellular and endocrine processes to:

reabsorb the entire bone mineral and organic matrix

prevent new bone from being deposited

remove Ca as needed

remove P as needed

reabsorb the entire bone mineral and organic matrix

he active role for Vitamin K in blood coagulation involves ____

gamma carboxylation of glutamate residues in several proteins found in blood

transport of Ca to binding sites on several proteins found in blood

oxidation-reduction reactions with Fe in platelets

oxidation-reduction reactions with Fe in the heme proteins

gamma carboxylation of glutamate residues in several proteins found in blood

Energy strand - ATP

Cell membranes (RNA and DNA)

Acid base balance in blood

Nucleic acids

Cofactor for numerous enzymes

Protein phosphorylation

Biological functions of P other than its role in bone mineral

Phytic acid is found in plant sources and is primarily associated with ______

Decreased availability of phosphorus

Inhibition of vitamin K activity

Inhibition of vitamin D activity

Increased available of phosphorus

Decreased availability of phosphorus

Describe role of FGF23 if dietary phosphorus is supplied at an amount that exceeds the animals requirements

FGF23 comes from bone, decreases 1a, 25 (oh)2D3 in the kidneys, and translationally regulates NaPi-2a/c.

This protein transports phosphorus into the kidneys, so now this protein is moved, P will excreted rather than reabsorbed