Exam 1 Flashcards
Nutrition
the study of applied biochemistry and physiology
diet formulation
applied nutrition and economics
Nutrient
essential in diet
nutrient allocation
what is the most effective way to utilize a source of nutrition
metabolism
sum of all biochemical reactions in body
catabolism
degradation: breakdown of nutrients and other complex molecules
anabolism
biosynthesis: building of complex molecules
how to enzymes increase the rate of reaction?
interact with reactants and products to increase likelihood of reaction occurring
enzyme
biological catalyst
proenzyme/zymogen
enzymes produced by body in inactive form
autoenzymatic
mammal produces own enzymes
alloenzymatic
microbes in animals GI tract produce enzymes
what are the three calorie providing nutrients
carbohydrates
protein
lipids
protein
macromolecule made of amino acids
T/F essential amino acids can be synthesized by the body
FALSE. non essential amino acids can be synthesized by the body
carbohydrate
end product of photosynthesis(base energy source)
non structural carbohydrates
easy to digest
T/F mammals produce enzymes to break down structural carbohydrates
FALSE. Mammalian enzymes can not digest structural carbohydrates
lipids
soluble in fats/oils, there are two essential fatty acids
what are the two main challenges for water
when its hot access to water must increase
when its too cold water may freeze
minerals
inorganic rocks
macro vs. micro minerals
macro measures as percent of diet
micro measured in ppm or ppb
vitamins
fat-soluble: A,D,E,K
water soluble
digestive physiology
-diet selection
-animals ability to derive nutritional benefit from a food
diet selection
how an animals physical features impact the food they choose
mouth functions
Mastication(mechanical breakdown of food)
Mixing of food
purpose for mixing of food in mouth
oral health
feed lubrication
CHO and lipid digestion
T/F particle size and digestion are inversely related
TRUE. as particle size decreases surface area increases
Function of esophagus
transport food from mouth to stomach
functions of stomach(5)
Storage
Mixing
Secretion
Digestion
Absorption
storage(stomach)
control flow of digesta
extent of digestion equals?
Kd/(Kd + Kp)
Kd and Kp relation to extent of digestion
as Kp increases EOD decreases
as Kd increases EOD increases
what is mixing(stomach)
physical processing of digesta
what is secreted by the stomach
acid
enzymes
buffer
mucus
purpose of acid in stomach
denature proteins
kill microbes
lower pH
what form are most stomach enzymes produced in
zymogens(inactive)
purpose of buffer in stomach
-raise pH
-coat stomach surface
-prevent acid/enzyme from destroying stomach surface
purpose of mucus in stomach
-coat stomach surface
-prevent acid/enzyme from destroying stomach surface
types of digestion
chemical
enzymatic
chemical digestion duties
denature protein
activate zymogens
what is enzymatic digestion/ what does it do
hydrolytic(inserting H2O) enzymes –> break bonds
-Digest lipids
-Proteins
what is absorbed in stomach
H2O
Alcohol
Cu, Fl, Mo
Aspirin
4 Regions of Stomach
Esophageal region
Cardiac
Gastric
Pyloric
what is the function of the gastroesophageal sphincter
prevent stomach acid from entering esophagus
what is the function of the pyloric sphincter
controls Kp into duodenum
which stomach regions have folds of rugae
Cardiac and gastric regions
what are the three types of stomach glands
cardia
oxyntic(peptic)
pyloric
what does the cardia gland produce
mucus and buffer
what does the oxyntic gland produce
acids and enzymes
what does the pyloric gland produce
acids, enzymes, and endocrine products
what endocrine products are produced by pyloric gland
gastrin
somatistatin
what are some exocrine products
mucus
buffer
acid
enzymes/zymogens
primary functions of small intestine
digestion
secretion
absorption
immunity
what is the purpose of digestion
preparation of ingested food for absorption
how is feedstuff digested in the small intestine
it is hydrolyzed(cleaved by H2O through hydrolytic enzymes)
what components are proteins broken into
amino acids
dipeptides
tripeptides
what are non structural carbohydrates broken into
monosaccharides
what components are lipids broken into
monoacylglycerides
2 fatty acids
goal of small intestine
avoid being digested while digesting and absorbing nutrients
what is the area in the middle of the intestinal tract
lumen
how does surface area impact rate of passage
as surface area increases, rate of passage slows
what it the pH of the duodenum
5-6
what is secreted into the duodenum
zymogens
buffer
bile salts
mammalian enzymes
what section of the SI has the most structures to increase surface area
proximal jejunum
where is peak absorption
proximal jejunum
pH of Jejunum
7-7.5
exocrine products from pancreas
enzymes
buffer
endocrine products from pancreas
glucagon
insulin
when is glucagon produced?, and by what cells
produced when blood glucose is low by a-cells
when is insulin produced and by what cells?
produced when blood glucose is high by B-cells
T/F exocrine functions account for approx 85% of pancreatic mass
TRUE
pH of illeum
7.5-7.9
where are kerkring folds more dense
proximal small intestine
villi are found on what structure in SI
kerkring folds
where are enterocytes born
the crypt of villi
how long does it take from an enterocyte being produced to it dying
7 days
what structure is found inside the villus that is important for fat absorption
lacteal
what blood vessel brings oxygenated blood from the heart to the villus
arteriol
what blood vessel takes blood from the villus to the liver
venule
T/F the venule is lacking nutrients
FALSE. the venule is returning from the villi and carrying its nutrients to the liver
what cell makes up 90% of villi cells
enterocytes
what is the purpose of microvilli
increase surface area
what are glycocalyx
hair-like projections on microvilli
what is the purpose of glycocalyx
suspend nutrients to decrease Kp
protect enterocytes from enzymes and bacteria
what is the purpose of the sodium potassium co transport
create electrical gradient
bring nutrients into the cell
where is the Na+ concentration high
outside the cell
where is the K concentration high
inside the cell
what is the ratio of Na+K+ from the sodium potassium pump
3 NA+ out, 2 K+ in
why is it important for the Na+ concentration inside the cell to be low
so the SGLT1 can activate and pump sodium and glucose into the cell without directly using energy
how does the SGLT1 indirectly use energy
it pumps Na+ and glucose in following the concentration gradient which requires no energy. however, the concentration gradient was formed by Na+K+atpase through the use of ATP
what is the primary absorptive cell in SI
enterocyte
T/F cellulose can not be digested by mammalian enzymes
TRUE
is auto enzymatic digestion anaerobic or aerobic
aerobic(uses O2)
what are the products of starch digestion in non ruminants
per 1 glucose: 6 CO2, 6H2O, >34 atp
T/F fermentation is anaerobic
TRUE
products of fermentation
VFA
CO2
CH4
1-4 ATP/microbe
MCP
MPL
vitamins
ammonia
where is energy lost in microbial fermentation, Why?
CH4-energy is being expelled
1-4 ATP- going to microbes
what percent of energy intake is methane
3.5-6%
what products of fermentation are absorbed in the SI
MCP
MPL
vitamins(water soluble + K)
what fermentation products are absorbed in fermentation chamber
ammonia
VFA
what is microbial crude protein
microbes themselves are digested
source of amino acids and energy
what is microbial phospholipid(MPL)
microbe themselves are digested
source of fatty acids and energy
benefits of foregut fermentation
animal receives all benefits of microbial fermentation(MCP, VFA, Vitamins, MPL)
what is the downside of foregut fermentation
easily digested nutrients(ex.starch) will be fermented(lowering their value to the animal)
what are the benefits of hindgut fermentation
mammal has first access to easily digested nutrients and gets them at their maximum value
what are downsides of hindgut fermentation
microbial products are poorly(not) utilized except for VFA the rest are excreted in feces
characteristics of fermentation chambers
Anaerobic
consistent supply of digesta
maintain stable pH(6.2-6.5)
stable temp(39 C)
dark
mixing
–0
how does absorption of VFA affect pH
absorbing VFA lowers pH
why does the fermentation chamber have no humoral defense
so the immune system wont attack the microbes
how long does it take to convert methane to CO2
7-12 years
what is the biogenic carbo cycle
plants consume CO2 and produce glucose and O2—>animal consumes plant for energy and produces CO2 which the plant consumes
types of microbes and their characteristics
bacteria: does most of the work and is most numerous
protozoa: biggest and most likely to die
fungi: fiber digestion
which microbe do we know the most about? the least?
most: bacteria
Least: fungi
peristaltic
moving from proximal to distal
layers of reticulorumen from bottom to top
particle layer
liquid layer
hay mat
gas layer
reticular omasal orifice
hole connecting reticulum to omasum
reticular groove
groove in nursing calves that leads milk directly to omasum to avoid fermentation
what are all places autoenzymatic digestion occurs
-stomach(pig, horse, cow abomasum)
-small intestine(pig, horse, cow)
what places of digestive tract have structures to lower Kp
-stomach(pig, horse, cow-all compartments)
-small intestine(pig, horse, cow)
-large intestine(pig, horse, cow)
where is acid secreted into the lumen in the digestive tract
-stomach(pig, horse, cow abomasum)
where does the animal secrete buffer in intestinal tract
-stomach(pig, horse, cow abomasum)
-small intestine(pig, horse, cow)
exocrine vs. endocrine
exocrine is secreted into digestive tract, endocrine will go to other parts of body
T/F amino acids and glucose are nutrients that supply energy to the body
TRUE. they are proteins and carbohydrates respectively
T/F glucose can transport against its concentration gradient
TRUE. it can transport glucose against its concentration gradient bc nitrogen pulls it along with its gradient
what are the six brushy border enzymes
maltase
isomaltase
glucoamylase
sucrase
fructase
phlorizin hydrolase
what cell produces brushy border enzymes
enterocyte
what moves fructose into cell
GLUT5
what moves glu, gal, fru into blood stream
GLUT2
what enzyme breaks down amylose, and amylopectin
pancreatic a. amylase
what is amylose broken into
maltose
maltotriose
what is amylopectin broken into
maltose
maltotriose
isomaltos
what are maltose, isomaltose, and maltotriose broken into
glucose
what is lactose broken into
glucose
galactose
what is sucrose broken into
glucose
fructose
what are the four disacchrides
lactose
sucrose
maltose
cellubios
what bond is maltose linked by
a. glycosidic
what bond in cellobiose linked by
b. glycosidic
what are the four main polysacchrides
starch
cellulose
hemicellulose
pectin
T/F all polysaccharides are digestible by ME
FALSE. only starch is
two types of starch
amylose
amylopectin
equation for digestibility
D=((intake-feces)/intake) x 100
how does lignin affect carbohydrates
it is 0% digestible, as it increases digestibility for carbohydrates decreases
what does the enzyme phlorizin hydrolase do
cleaves sugars bound to lipids
what does glucoamylase do
hydrolyzes one(1) glucose molecule from starch
where does all glucose, galactose, and fructose absorption occur
Small intestine
difference between amylase and amylopectin
amylase is a. bond at 1,4. chain of 100 glucose
amylopectin is a. bond at 1,4 and 1,6(branch points) similar to glycogen
how do a. glycosidic and b. glycosidic bonds differ, and how does it impact digestibility
a. glycosidic bond at 1,4 straight making molecules connect in spiral and easily removed from one another.
b. glycosidic connects at 1,4 at diagonal making long flat chains that pack tightly together and not easily pulled apart
path of monosaccharides after leaving enterocyte
-travel through blood to liver
-gal, fru metabolized in liver
-glu travels from liver to tissue
-glu turned into ATP, glycogen synthesis, or fat synthesis
what animal is glycogen synthesis most important in
Horse, they do the most exercise
where does glycogen synthesis occur
muscle and liver
where does fat synthesis occur
adipocytes
