EXAM 2: Bioenergetics Flashcards
water has been described as ________ but overlooked
essential
what is the most abundant compound on earths surface
water
properties of water
high specific heat capacity
high heat of vaporization
high specific enthalpy of fusion
high dielectric constant
high surface tension
value for heat of vaporization
40.65 KJ
specific enthalpy of fusion value
333.55 Kj
functions of water
solvent
transportation medium
temperature regulation
lubricant/cushion
respiration
hydrolysis
what three things classify as temperature regulation
thermal conductivity
specific heat
latent heat of vaporization
location of water in the body
intracellular and extracellular
extracellular fluid
blood plasma
interstitial fluid
isotonic solution
same salt concentration as cells and blood
physiological saline
0.9% NaCl
hypotonic solution
a solution that has lower osmotic pressure than another solution to which it is compared
cells swell
hypertonic solution
external solution that has a high solute concentration and low water concentration compared to body fluids
cells shrink
source of body water
drinking water
free water in feed
metabolic or oxidation water
water losses
urine
feces
sweating
insensible
drooling of saliva
respiration
what percent of CHO is water
60%
what percent of fat is water
109%
what percent of proteins is water
40%
urea average of temperate animals
0.6%
urea average of desert animals
22%
desert animals excretes a ______ feces
drier
effects of water restriction on man
increase concentration of blood
decrease volume and difficulty in blood circulation
increase heart rate and rectal temp
increase respiration
tingling and numbness in feet and fingers
effects of water restriction on rats
decrease feed intake
decrease gain
decrease feed efficiency
decrease urine volume
decrease body weight
decrease activity
mammals need water at the rate of __________ the weight of feed consumed
2-3 times
lactation needs ______ the weight of milk produced
4-5 times
retention of 1 gram of protein or glycogen require how much water
3g H2O
Retention of 1g of fat requires how much water
0.1g H2O
are lipids organic or inorganic
organic
a class of compound soluble in organic solvents such as acetone, ether, and chloroform
fats/lipids
characteristics about fats
vary in size and polarity
hydrophobic
require specialized processing during digestion, absorption, transport, storage, and utilization
most prominent fatty acid
triglycerides
carboxylic acid with a long aliphatic tail (chain) which could be saturated or unsaturated
Fatty acids
what are fatty acids derived from
triglycerides and phospholipids
fatty acids serve as am important source of _____
fuel
saturated fatty acids
fatty acid with NO double bond
unsaturated fatty acids
fatty acid with one or more double bonds
two types of unsaturated fatty acids
monounsaturated and polyunsaturated
monounsaturated
fatty acid with ONLY ONE double bond
polyunsaturated
fatty acid with 2 or more double bonds
esters of fatty acids with glycerol
simple lipids
also known as triglycerides
contain fatty acid, nitrogenous base, plus glycerol or sphingosine
phospholipids
phospholipid containing the vitamin choline as its nitrogenous base
lechithin
substances derived from other lipids by hydrolysis
derived lipids
most important derived lipids
free fatty acids
other lipids include
waxes and steroids
esters of long chain fatty acid and high molecular weight alcohols
waxes
steroids
cholesterol
hormones
carotenoids
plant pigments
vitamin D precursors
fatty acids have two ends which are
the carboxylic acid (-COOH) end
the methyl (CH3) end
the carboxylic acid (-COOH) end is the head or the tail
head; beginning
the methyl (CH3) end is the head or the tail
tail
how are fatty acids names
using the position of the first double bond when counted from the methyl or the n-end
majority of fat in animals is
triglycerides
the longer the fatty acid, the _________ the melting point
higher
the more double bonds present, what happens to melting point
decreases
Are lipids hydrophobic or hydrophilic
hydrophobic
why do we need bile
Emulsify fat because lipids do not interact with water
fat yields about how much of its weight in fatty acids and glycerol
90% fatty acid
10% glycerol
glycerol yields ________ when oxidized
4.3 kcal/g
fatty acids yield _______ when oxidized
9.4 kcal/g
The predominant fatty acids in fats ingesting by animals are
palmitic
stearic
oleic
linoleic
how does the melting point of coconut oil vs corn oil
corn: less than 20
coconut: 20-35
are unsaturated fats or saturated fats better for you
unsaturated
What happens to double bonds when iodine increases
the number of double bonds increase
ruminant fat has a higher proportion of ____________ than pork
saturated fatty acids
chicken fat is the most __________ of the animals fats
unsaturated
Which animal is the most saturated and the less saturated
beef is the most
fish is the least
melting point
useful measure of the hardness of a fat
oils
liquid at room temperature
examples: corn and soybean oil
fats
solid at room temperature
examples: lard and tallow
the more unsaturated, what happens to boiling point
decreases
unsaturated fat adds two atoms of iodine at each double bond
iodine number
the more unsaturated, what happens to the iodine number
increases
number of mg of an alkali as NaOH or KOH required to saponify 1g of fat (indicator of the length of FA chains)
saponification number
when fat is boiled with alkali such as NaOH it is split into
glycerol and alkali salt of FA
shorter the fatty acid chain, what happens to the saponification number
increases
how many carbons is classified as a long FA
more than 12
how many carbons is classified as a short FA
less than 12
Mg of KOH to neutralize free fatty acid in1 gram of fat
measures the hydrolytic rancidity
acid value
acid value increases with ________
rancidity
measures the water-soluble, steam volatile fatty acids present
useful for detecting adulterations in butterfat
reichert-meissel number
fatty acids of 12 carbons or less are volatile in _______
steam
fatty acids with 6 carbons or less are appreciably soluble in ______
water
fats can add __________ at the double bonds
oxygen
Highly unsaturated acids like linseed oil are ready _______ and this reaction produces a _________
oxidized
harder fat
double bonds can add _____ but not as readily as oxygen. this produces a ________ out of a soft unsaturated fat
H2
hard saturated fat
double bonds are susceptible to oxidation by _______
free radicals
essential fatty acids
linoleic
linolenic
arachidonic
essential fatty acids deficiency symptoms
scaly skin
necrosis of tail
growth failure, reproduction and lactation affected
death
Can essential fatty acids be synthesized by the body?
no
without essential fatty acids get cell deterioration which leads to
cell death
early work by _______________ showed that rats on a diet practically devoided of fat developed __________
Burr and Burr
EFA deficiency symptoms
arachidonic may be synthesized from the key EFA _________
linoleic acid
in ruminants, where triglycerides are hydrolyzed
rumen
glycerol is fermented by _______ into ____ acid
microbes; propionic
in nonruminants, the sole site of fat hydrolysis occurs where
small intestine
fat enters the _______ and is emulsified via bile salts
duodenum
the three volatile fatty acids
acetic acid
butyric acid
propionic acid
what are volatile fatty acids used for
to make ATP
Glycerol gets converted into
butyric acid
salts in bile
cholic acid
deoxycholic acid
chenodeoxycholic acid
lithocholic
Which of the four bile salts are most important/common
cholic acid
chenodeoxycholic acid
fat is ______ digestible
highly
Digestibility is influenced by
length of carbon chain
state of saturation
Longer chains over 18 C does what to digestibility
decreases
more saturation does what to digestibility
decreases
Hydrolysis occurs only at
the interface between the lipid droplet and aqueous phase
the larger the interface the more
fat is emulsified
bile salts promote _______
emulsification
Longer than 12 carbons go to what system
lyphatic
Shorter than 12 carbons may enter the __________ directly
portal circulation
glycerol is ______ soluble
water
Monoglycerides and insoluble FA are emulsified to form a submicroscopic complex called ________
micelle
micelle is absorbed by what cells
epithelial that line the mucosa of the intestinal tract
While still in mucosal cells, the longer chained fatty acids and monoglycerides are converted back into ________
triglycerides
Chylomicrons give blood a milky appearance called
lipemia
Chylomicrons are absorbed into what system via thoracic duct
lymphatic
What long chained FA and monoglycerides are converted to when surrounded by lipoprotein
chylomicrons
lipid in the body is stored mainly in the ________ form
triglyceride
most storage of lipids occurs in what tissue
adipose
lipid deposited in the adipose tissue can be two sources
dietary
synthesized by the animal
Any substance capable of forming acetyl CoA is a potential source of
carbon atoms for the process of FA synthesis (lipogenesis)
types of fat
white
brown
glycerol by itself is metabolized as a
CHO
catabolism of fatty acids
enters glycolytic pathway via alpha glycerol phosphate
catabolized to pyruvate
condenses with CoASH to form acetyl CoA
enters citric acid cycle for complete oxidation
during complete catabolism of glycerol,how many ATP are formed
22
ketosis body chemical situation
high blood ketones
high urine ketones (spill out of blood)
low blood glucose
depleted glycogen reserves
what group of animal is ketosis common in
ruminants
biochemical cause of ketosis
don’t have a good source of glucose causing us to use lipids
in ruminants, ketosis or acetonemia is a pregnancy disease in _________
dairy cows
sheep
Ketosis occurs shortly after calving or lambing due to
high nutrient demand in late gestation
stress of birth
nutrient demand in lactation
possible hormonal changes
symptoms of ketosis in ruminants
decreased feed intake
decreased milk production
cant stand (glucose deficient in brain–coma and death)
is there a cure for ketosis
not known
ketosis prevention
Feed extra energy late in gestation
Lipids (micelles) absorption occurs via
passive diffusion
why doesn’t feeding glucose to ruminants work
it’s converted to VFA’s then to acetate
large part of ATP in nonruminants come from
glucose
large part of ATP in ruminants come from
VFA
measure of energy values of food and feedstuffs for animals
direct energy measurements
indirect energy measurements
TDN stands for
total digestable nutrients
examples of direct energy measurements
digestbile energy
metabolizable energy
net energy
example of indirect energy estimates
TDN
order of energy distribution in the body
gross energy
digestible energy
metabolizable energy
net energy (m/p)
net energy production
between gross energy and digestable energy, what is lost
fecal energy
Between digestible energy and metabolizable energy what is lost
urinary and gas
between metabolizable energy and net energy(m/p) what is lost
heat increment
between net energy and net energy production what is lost
energy for maintence
the total amount of heat that is released when a substance is completely oxidized in a bomb calorimeter containing 25-30 atmospheres of o2
measured in calories
gross energy
digestible energy
attempts to measure gross metabolic functions
Fecal energy reflects
undigested food
bacteria cell residue
metabolic energy from endogenous sources
digestible energy equation
DE=GE-Fecal Energy
Energy loss as gaseous product digestion results primarily from
microbial metabolism in the rumen
metabolizable energy
provides a more satisfactory measure of nutritive value than TDN or DE
poultry metabolizable energy is more easily determined than DE because
feces and urine are excreted as one product
metabolizable energy equation
ME=GE-(Fecal energy +UE+GPD)
ruminant gaseous losses are _______ than urinary
greater
gaseous losses of energy are greater on
roughages
urinary energy losses in pigs and cattle
2-3% pig
4-6% cow
in ruminants, an average figure is around _______ of the total energy intake
8%
low quality forages yield a _________ percentage loss of energy as methane
greater
portion available for sustenance of life and productive purposes-tissue, maintenance and growth, milk, eggs, wool, and work
net energy
The continual outgo of heat from the body, which is minimum in the postabsorptive state in a thermoneutral environment and increases the amount of food consumed
heat increment
two parts of heat increment
heat of fermentation
heat of nutrient metabolism
produced in the GI tract as a result of microbial action
much larger in ruminants than nonruminants
cannot be determined directly
heat of fermentation
heat above the basal metabolism that occurs in the utilization of the absorbed nutrients
heat of nutrtient metabolism
factors affecting heat increment
kind of food fed
balance of diet
effect of temperature on HI
what class of nutrients has the lowest GE and which has the highest
lowest= carbs
highest= protein
why does heat increment reduce at low temps
at below or lower critical temperature HI is reduced because of its use for the maintenance of body temp
by shifting acetic to ________ should increase efficiency
propinoic
b/c lowest heat lost
fraction of net energy expended to keep the animal in energy equilibrium
animals tissues aren’t gaining or losing
the net energy of maintenance
What is net energy composed of
basal metabolism
voluntary activity
heat to warm body or cool the body
basal metabolism
the function of body size
energy expended by animals under basal conditions
Energy expended by the animal under basal conditions include
thermoneutral environment
resting conditions
post-absorptive state
sexual repose
consciousness
basal metabolism is used for
circulation
respiration
kidney function
general musculature (highest percentage)
amount of energy needed to replace the energy expended in getting up, moving about to obtain food, grazing, drinking, laying down
voluntary activity
The extra heat needed to keep the animal’s body warm when the environment is below the critical temperature
energy to keep the body cool, extra energy expended by the animal when the environmental temperature is above the zone of thermal neutrality
thermal regulation
net energy for production
net energy required for involuntary work or for tissue gain, or production of milk, eggs, wool etc
homeotherms
an animal that must keep body temp pretty constant to maintain life processes
critical temperature
point at which a homeotherm must initiate additional reactions to maintain normal body temperature
zone of therm neutrality (TNZ)
range where the supporting functions of the body are generating enough heat to maintain body temperature, but not enough to cause stress in the animal
the first law of thermodynamics
law of conservation of energy
“the total energy of a system and its surroundings remain constant. Can change form but cant be created or destroyed”
in animal metabolism we are concerned with the utilization of
chemical energy
oxidation
loss of electrons
reduction
gain of electrons
what mineral is used in energy trapping
phosphorus
two types of bonds of phosphorus
low energy (3kcal)
high energy (7.3kcal)
the compounds in the body that traps energy and later releases it when needed is one that has high energy phosphate bonds called
ATP
in the muscles there is very little_____ but there is a liable source of ____________ used to replenish ATP used
ATP
high energy phosphate
start with one compound and metabolize it to a second compound, the net change in energy will be the same no matter how many steps
law of hess
the step by step process in the metabolism insures the capture of __________% of energy in the useful form of ______the rest in lost in
40-60%
ATP
heat
byproduct of metabolism and is beneficial to the animal in maintain body temperature
heat
the overall ability of the animal body to convert potential energy of food to mechanical work amounts to only _________ percent of its total available energy
20-25
Involves what occurs to nutrients within the cell
intermediary metabolism of CHO
main three steps glucose must go through to make 38 ATP
glycolysis
TCA cycle
Electron transport chain/oxidation
glycolysis
anaerobic (absence of oxygen)
occurs in cytoplasm
more primitive type of metabolism to generate energy; typical of that of microbes
converts 2 glucose into two pyruvate
used in the synthesis of ATP, NAD, FAD, RNA,DNA and others
ribose
important in biosynthetic reactions
NADPH
important in generating ATP in electron transport
NADH
the flow of glucose through glycolysis is regulated by the need for
NADPH and ribose
TCA cycle
aerobic (presence of oxygen)
occurs in mitochondria
more advanced system typical of higher-order organisms
ATP is formed as electrons are transferred from NADH + H+ or FADH2 to O2 by a series of electron carriers called cytochrome
located on the inner membrane of mitochondria
electron transport chain
(process called oxidation phosphorylation)
Having a series of cytochromes generates
more than one ATP
e- of H last from intermediate
the energy liberated and trapped as ATP
oxidation taking place
kinase
consumption or release of phosphorus (ATP)
where is glucokinase found
only in liver
where is hexokinase found
in all cells (muscle)
isomerase
rearrangment of structure within the same compound
what coenzyme do kinase require
Mg2+
about how much ATP is formed in TCA cycle
24 ATP
(~2/3)
Intermediates in TCA are important in the synthesis of
nonessential amino acids
the major source of energy for the ruminant
part of the energy source of the horse
metabolism of VFA’s
the primary VFA
metabolized by muscle and adipose tissue
enters kreb cycle via acetyl CoA
Acetate
the secondary VFA
metabolized by liver
enters kreb cycle via succinyl CoA
only VFA which can yield blood glucose
propinoate
least important VFA
metabolized by the rumen epithelium and liver
butyrate
the major pathway of respiration in aerobic organisms
citric acid cycle
bioenergetic constant: Phosphate bond
7.3 kcal/mole
bioenergetic constant: e- (&H) carried on FAD
yields 2 ATP
bioenergetic constant:e- (&H) carried on NAD
yields 3 ATP
bioenergetic constant:One “turn” of the TCA cycle
yields 12 ATP
bioenergetic constant:One “clipping” of acetyl CoA from FA
yields 5 ATP
blood chemical situation of ketosis
- High blood ketones
- High urine ketones - spill out of blood →urine
- Low blood glucose
- Depleted glycogen reserves
Intermediates provide means whereby amino acids for protein can be
oxidized
used to form GLU for other tissues like the brain
glucogenesis
glucogenesis
glucose from non CHO (primarily protein) occurs in the liver via reverse glycolysis
summary of output from TCA cycle
3 NADH (18 ATP)
1 FADH (4 ATP)
1 GTP (2 ATP)
2 CO2 (4CO2)
how many ATP is produced by glycolysis
4 ATP
net: 2 ATP
net production of ATP in the ruminant
acetate: 10 ATP
propionate: 18 ATP
butyrate: 25 ATP
