Synthesis of Biomolecules Flashcards
is the creation of fatty acids from Acetyl CoA and NADPH
fatty acid synthesis
fatty acid synthesis is the creation of fatty acids from ___ and ___
Acetyl CoA
NADPH
Where does fatty acid synthesis takes place
cytoplasm
Most of the acetyl-coA which is converted into fatty acids is derived from ___
carbohydrates
Most of the acetyl-coA which is converted into fatty acids is derived from carbohydrates through what pathway
glycolytic pathway
also provides the glycerol with which three fatty acids can combine
glycolytic pathway
glycolytic pathway also provides the ___ with which three fatty acids can combine
glycerol
glycolytic pathway also provides the glycerol with which ___ can combine with to form triglycerides
fatty acids
glycolytic pathway also provides the glycerol with which three fatty acids can combine with to form ___
triglycerides
what kind of bonds is present in the connection of three fatty acids with glycerol
ester bonds
final product of the lipogenic process
triglycerides
much like ___-oxidation, straight chain fatty acids occurs via the six recurring reactions until the 16-carbon palmitic acid is produced
Beta
much like B-oxidation, ___ synthesis acids occurs via the six recurring reactions until the 16-carbon palmitic acid is produced
straight fatty acids
much like B-oxidation, straight chain fatty synthesis acids occurs via the six recurring reactions until the 16-carbon ___ acid is produced
palmitic
what enzyme performs the reaction of straight chain fatty acid synthesis
fatty acid synthase II (FASII)
in general contain multiple enzymes that act as one complex
FAS II
present in prokaryotes, plants, fungi, and parasites and in mitochondria
FASII
which organelle is FASII present in
mitochondria
in animals and some fungi such as yeast, the same reactions for fatty acid synthesis occurs on what synthase
Fatty acid I (FASI)
large dimeric protein with all of the enzymatic activities required to create a fatty acid
FASI
which is more efficient
FAS II
FAS I
FAS II
which FAS allows for the formation of more molecules
FAS I
FAS that allows the formation of medium chain fatty acids via chain termination
FAS I
FAS I allows the formation of what length of fatty acids via chain termination
medium chain
FAS i allows the formation of medium-chain fatty acids via ___
chain termination
contribute to taste and texture of foods
fats
3 carbon backbone of fats
glycerol
string of carbon and hydrogen atoms
fatty acids
what is released when glycerol and fatty acid forms a bond
h20
2-5 carbons of fatty acids
short cain fatty acids
6-12 carbons of fatty acids
medium chain fatty acids
13+ carbons fatty acids
long chain
fatty acids with only single bonds
saturated fatty acids
fatty acids that packs well
saturated fatty acids
fatty acids that is solid at room temperature
saturated fatty acids
the ___ the fatty acid chain, the more solid it is at room temperature
longer
1 or more double bonds in fatty acid chain
unsaturated fatty acid
has a kink in the molecule; do not pack together; liquid at room temp
unsaturated fatty acids
are unsaturated fatty acid with one double bond
monounsaturated fatty acid
are unsaturated fatty acid with two or more double bond
polyunsaturated fatty acids
another name for the methyl end of the fatty acid chain
omega end
double bond 3 carbons from the metyl end
omega 3-fatty acid
double bond 6 carbons from the metyl end
omega-6 fatty acids
fatty acids that are usually polyunsaturated
omega-3 fatty acids
omega-3 fatty acids include
a-linoleic acid
eicospentanaenoic acid
docosahexaneoic acid
marine sources of omega 3
DHA
EPA
marine source of DHA and EPA
microalgae
omega 3-fatty acid in plants
ALA
ALA in found in
plants (flax seeds, walnuts, ganola, soybean)
which omega-3 fatty acid is converted by the body into other omega-3 fatty acid
ALA to EPA and DHA
conversion of ALA to EPA and DHA is inefficient/efficient process
inefficient
omega-6 fatty acids include
linoleic acid
arachidonic acid
linoleic acid is found in what source
safflower
corn
soybean
arachidonic acid is found in
fish
meat
eggs
conversion of omega-6 fatty acid to another omega-6 fatty acid
linoleic acid to arachidonic acid
essential fatty acids
linoleic acid
arachidonic acid
typically monounsaturated fatty acid
omega-9 fatty acids
example of omega-9 fatt yacid
oleic acid
two functional groups are on the same side of the double bond
cis configuration
functional groups on opposite sides of double bond carbons
trans
trans fats is made through the process of
partial hydrogenation
remove all double bonds to cis fants
hydrogenation
removes most double bands
partial hydrogenation
partial hydrogenation happens naturally in some animals including
cows and pigs
enzyme present in saliva, stomach
lipase
lipase is secreted by
pancreas
break big fat globules into small fat droptlet
bile salts
micelles have an ____ interior and ___ exterior
hydrophobic
hydrophilic
columnar cells that line the small and large intestines, and are responsible for absorbing nutrients and water from food
enterocytes
micelles in the lumen diffuse what particles into the enterocytes
monoglycerides
then, the monoglycerides reassemble as triglycerides to be assembled as
chylomicron
has an outer membrane of phospholipids and proteins + hydrophobic core ( vitamins ADEK, triglycerides, and cholesterol)
chylomicrons
chylomicrons cannot enter the endothelial cells, it will then enter the lymphatic capillary called
lacteal
chylomicrons dumped into the thoracic duct secretes monoglycerides to what tissues
muscle for energy
adipose tissue for storage
chylomicrons after delivering the products shrink in size and will be engulfed by the
liver
fats that are precursor for hormones called prostaglandins
polyunsaturated fats
stimulate endothelial cells that line blood vessels to release nitric oxide
prostaglandins
released by endothelial cells to decrease resistance to blood flow
nitric oxide
omega-3 fatty acid important in the development of eyes and brain
DHA
what kind of omega fatty acid lowers plasma triglycerides
long-chain omega-3 fatty acids
replacing saturated fat with ___ benefit cardiovascular heat
polyunsaturated fat
fatty acid is synthesized by two enzymes called
acetyl coA carboxylase
fatty acid synthase
fatty acid synthesis takes place in the ___
liver
enzyme that activates acetyl coA for reaction with malonyl ACP
acetyl-coA ACP trancyclase
enzyme that activates malonyl coA for reaction with acetyl ACP
Malonyl coA-ACP trancyclase
enzyme that reacts with aCP-bound acyl chain with chain extending malonyl-ACP
3-ketoacyl ACP synthase
enzyme that reduces the carbon 3 ketone to hydroxyl group
3-ketoacyl ACP reductase
enzyme that eliminates water
3-hydroxyacyl ACP dehydrase
enzyme that reduces C2-C3 double bond
enoyl ACP reductase
ACP stands for
ACYL carrier protein
once a 16:0 carbon fatty acid has been formed, it can undergo a number of modifications resulting in what processes
desaturation and/or elongation
starting with stearic acid (18:0), is performed mainly in the ER by several membrane bound enzymes
elongation
elongation starts with ____ in the ER
stearic acid
stearic acid number of bonds
18, 0 double bonds
the enzymatic steps involved in the elongation process are principally the same as those carried out by __
FAS
same principle as FAS but the four principal successive steps of the elongation are performed by individual proteins, which may be physically assocaited
elongatin process
during fatty acid synthesis, the reducing agent is
NADPH
during fatty acid synthesis, the reducing agent is NADPH, whereas the ___ is the oxidizing agent
NAD
NAD is the oxidizing agent in what kind of oxidation
b-oxidation
breakdown of fatty acids to acety coA
beta-oxidation
consumed during biosynthethic reactions
NADPH
generated in energy-yielding reactions
NADH
is also required for the synthesis of cholesterol from acetyl coA
NADPH
source of NADPH (2)
malate is oxidatively decarboxylated by NADP+-linked malic enzyme to form pyruvate
pentose phosphate pathway
when malate is oxidatively decarboxylated by NADP+ linked malic enzyme to form pyruvate, what is formed
CO2
NADPH
converts glucose into ribose, which is used in the synthesis of nucleotides and nucleic acids
pentose phosphate pathway
fatty acids are formed predominantly from ___ in the liver
carbohydrates
fatty acids are formed from carbohydrates predominantly in the ___ and ___
liver
adipose tissue
fatty acids are formed from carbohydrates predominantly in the ___ during lactation
mammary glands
important intermediary in the conversion of carbohydrates into fatty acids and cholesterol
pyruvate
conversion of pyruvate into acetyl coA happens in the
mitochondria
acetyl coA needs to be transported into the ___ where the synthesis of fatty acid and cholesterol ocurs
cytosol
to obtain cytosolic acetyl coA, ___ is removed from citric acid cycle and carried across the inner mitochondrial membrane into the cytosol
citrate
produced by the condensation of acetyl coA with oxaloacetate
citrate
citrate is produced by what process by acetyl coa and oxaloacetate
condensation
cleaves the citrate in the cytosol to form acetyl coA and oxaloacetate
ATP citrate lyase
ATP citrate lyase cleaves the citrate into __ and __
acetyl coA
oxaloacetate
the oxaloacetate in the cytosol can then be used for ____
gluconeogenesis
the oxaloacetate in the cytosol can then be used for gluconeogenesis in the __
liver
the oxaloacetate in the cytosol can then be return to the mitochondrion as ___
malate
is carboxylated by acetyl coA carboxylase into malonyl coA
cytosolic acetyl coA
first committed step in synthesis of fatty acids
carboxylation of acetyl coA carboxylase into malonyl coA
where does fatty acid synthesis occurs
cytoplasm
endoplasmic reticulum
two molecules that play roles in moving the acetyl coA in the mitochondrion across the membrane
citrate
acetylcarnitine
when free acetyl coA accumulates in the mitochondrion it combines with ___ and be transported out to the cytoplasm
carnitine
starting with two acetyl coA, one is converted into ___ by carboxylation
malonyl coA
starting with two acetyl coA, one is converted into malonyl coA by carboxylation by the enzyme
acetyl coA carboxylase
the only regulatory enzyme in the fatty acid synthesi
acetyl coA carboxylase
both acetyl coA and malonyl Coa have their coA portions replaced by a carrier protein known as ___
acyl carrier protein
both acetyl coA and malonyl Coa have their coA portions replaced by a carrier protein known as ACP to form
acetyl ACP
malonyl ACP
joining of acetyl ACP with malonyl ACP splits out the ___ that was added
carboxyl
is reduced to hydroxyl using NADPH
ketone
ketone is reduced to hydroxl using ___
nadph
in contrast to the hydroxylated intermediate of beta-oxidation, the beta-intermediate here is in what configuration
d-configuration
what is removed from the carbons 2 and 3 of the hydroxyl intermediate to produce a trans-double bonded molecule
water
water is removed from the carbons 2 and 3 of the hydroxyl intermediate to produce what molecule
trans double bonded
what is hydrogenated to yield a saturated intermediate
double bond
the process cycles with the addition of another malonyl ACP to the growing chain until ultimately an intermediate with how many carbons are produced
16 carbons
its regulation involves both allosteric control and covalent modification
acetyl coA carboxylase
Acetyl coa carboxylase is phosphorylated by both
AMP kinase
protein kinase
stimulated by phosphatases activated by insulin binding
dephosphorylation
what proces activates the enzymes and favors its assembly into a long polymer
dephosphorylation
acts as an allosteric activator that may also favor polymerization
citrate
allosterically inactivates polymerization; reversal of citrate effects
palmitoyl coA
make fatty acids longer than 16 carbons
elongation
elongation make fatty acids longer than 16 carbon occurs in where
endoplasmic reticulum
elongation make fatty acids longer than 16 carbon occurs in the ER and is catalyzed by enzymes describe as
elongases
organelle that can also elongate fatty acids aside from ER
mitochondria
starting materials of elongation of FA in mitochondria is generally ___ than 16 carbons
shorter
group that is used to add two carbons
malonyl group
process where it is similar to those in cytoplasm but the coA is attached to the __ and not ACP
intermediates
process that employs the fatty acid synthase complex
cytoplasmic synthesis of fatty acid
cytoplasmic Fatty acid synthesis employs fatty acid complex but enzymes in these organelles are ___ and not part of a complex
separable
fatty acids are synthesized in what form
saturated form
enzyme that catalyze the formation of cis-double bonds in mature fatty acids
desaturases
desaturases are found where
endoplasmic reticulum
what kind of organism have limited desaturated fatty acids that they can make
animals
animals are limited in desaturated fatt yacids due to the inability to catalyze reactions beyond what carbons
carbons 9 10
humans can only make what kind of fatty acids at this point
oleic acid (18)
humans cannot snthesize what fatty acids
linoleic acid
linolenic acid
set of biochemical processes by which the amino acids are produced
amino acid synthesis
humans can only synthesize how many proteins
11 out of 20
in time of accelerated growth, ___ can be considered an essential amino acid
histidine
conditionally essential amino acids
Arginine
Cysteine
Glycine
Glutamic acid
Histidine
Proline
Serine
not normally required in the diet but must be supplied exogenously to specific populations that do not synthesize it in adequate amounts
conditionally essential
amino acids produced in the body
nonessential amino acids
catalyzes the reductive amination of a-ketogluarate to glutamate
glutamate dehydrogenase
glutamate dehydrogenase catalyzes the reductive ___ of a-ketoglutarate to glutamate
amination
glutamate dehydrogenase catalyzes the reductive amination of a-ketoglutarate to _____
glutamate
process that takes place in the synthesis of most amino acids
transamination
transamination establishes the __ of an amino acid
chilarity
synthesized by the transamination of pyruvate and oxaloacetate (2)
alanina
aspartic acid
synthesized from NH4+
glutamine
are derived from glutamate
proline and arginine
formed from 3-phosphoglycerate
serine
precurose of glycine and cysteine
serine
serine is the precursor of
glycine
cysteine
synthesized by the hydroxylation of phenylalanine
tyrosine
tyrosine is synthesized by the hydroxylation of ___
phenyalanine
the pathways for the biosynthesis of essential amino acids are much more complex than the non essential ones
T/F
True
amino acids derived from a-ketoglutarate are (4)
glutamic acid
glutamine
proline
arginine
enzyme involved in the synthesis of amino acid from a-ketoglutarate
aminotransferase
formed by the amination of a-ketoglutarate
glutamic acid
a-ketoglutarate + ____ ⇌ glutamate
NH+4
concentration of a-ketoglutarate is dependent on the
activity and metabolism iwthin the cell
what organism has citrate synthase inhibited by the a-ketoglutarate feedback inhibition
e.coli
enzyme involved in the condensation reaction initiating the Citric Acid Cycle
citrate synthase
citrate synthase is strongly inhibited by what feedback inhibition in e coli
a-ketoglutarate
citrate synthase is also inhibited by what concentration
high ATP concentration
amino acids derived from E4P and PEP
phenylalanine
tyrosine
tryptophan
E4P
erythrose-4-phosphate
phenylalanine, tyrosine, and tryptophan arise from ___
chorismate
condensation of ___ from PEP/E4P happens
3-deoxy-d-arabino-heptulosonic acid-7-phosphate (DAHP)
three isoenzymes in the amino acid synthesis using E4P, PEP
AroF
AroG
AroH
regulates AroF isoenzyme
tyrosine
regulates AroG isoenzyme
phenylalanine
regulates AroH isozenyme
tryptophan
The rest of the enzyme in the common pathway (conversion of DAHP to chorismate) appear to be synthesized constitutively except for
shikimate kinase
can be inhibited by shikimate thorugh linear mixed-type inhibition
shikimate kinase
what amino acids are biosynthesized from prephenate
tyrosine
phenylalanine
biosynthesized from prephenate
tyrosine
phenylalanine
process mediated by PheA and TyrA specific chorismate mutase-prephenate dehydrogenase
conversion of prephenate to an amio acid intermediate
uses a simple dehydrogenase to convert prephenate to phenylpyruvate
PheA
uses NAD-dependent dehydrogenase to make 4-hydroxyphenyl pyruvate
TyrA
can also be inhibited at the transcriptional level by the TyrR repressor
tyrosine
involves conversion of chorismate to anthranilate using athranilate synthase
tryptophan biosynthesis
enzyme requiring either glutamine as the amino group donor or ammonia itself
anthranilate
encodes the first subunit, which binds to chorismate and moves the amino group from the donor to chorismate
trpE
encodes the second subunit, which facilitates the transfer of the amino acid group from glutamine
trpG
amino acids derived from oxaloacetate/aspartate are:
lysine
asparagine
methionine
threonine
isoleucine
aspartate can be converted to (4)
lysine
asparagine
methionine
threonine
also gives rise to isoleucine
threonine
the aspartate pathway uses _-aspartic acid as the precursor for the biosynthesis of one-fourth of the building block amino acids
L
its biosynthesis frequently involves the transaminaition of oxaloacetate
aspartate
enzyme that catalyzes the phosphorylation of aspartate and initiates its conversion to other amino acids
aspartokinase
aspartokinase is broken up to 3 isozymes
AK-I, AK-II, and AK-III
AK feedback initiated by threonine
AK-I
AKs that are inhibited by lysine
AK-II and AK-III
AK that catalyzes the phosphorylation of aspartic acid which is the committed step in this biosynthetic pathway
AK-III
AK becomes downregulated by the presence of what amino acids
threonine
lysine
Lysine is synthesized from aspartate from what pathway
diaminopimelate (DAP) pathway
initial two stages of the DAP pathway is catalyzed by what enzymes (2)
aspartokinase
aspartate semialdehyde dehydrogenase
aspartokinase and aspartate semialdehyde dehydrogenase play a key role in the biosynthesis of what amino acids (3)
lysine
threonine
methionine
two bifunctional aspartokinase/homoserine dehydrogenase
ThrA MetL
the biosynthesis of __ originates with aspartate using a transaminase enzyme
asparagine
enzyme that produces asparagine, AMP, glutamte and pyrophosphate from aspartate, glutamine, and ATP
transaminase enzyme
how many asparagine synthetases are found in bacteria
2
2 asparagine synthethases found in bacteria
AsnC
autogeneously regulated asparagine synthethases in becteria, which is where the product of a structural gene regulates the expression of the operon in which the genes reside
AsnC
the stimulating effect of AsnC on AsnA transcription is downregulated by what amino acid
asparagine
AsnC autoregulation is not affected by what amino acid
asparagine
this amino acid biosynthesis by the trans-sulfuration pathway starts with aspartate, including relevant enzymes such as aspartokinase, aspartate-semialdehyde dehydrogenase, homoserine dehydrogenase, etc.
methionine
this biosynthesis is subject to tight regulation with a repressor protein called MetJ
methionine
in cooperation with corepressor protein S-adenosyl-methionine, this mediates the repression of methionine’s biosynthesis
MetJ
regulator for MetE and MetH gene expression and functions as transativator for these genes
MetR
MetR transcriptional activity is regulated by ___, which is the metabolic precursor or methionine
homocysteine
metabolic precursor of methionine
homocysteine
what vitamin can repress MetE gene expression, which is mediaed by MetH holoenzyme
vitamin B12
in plants and microorganisms, ___ is synthesized from aspartic acid via a-aspartyl semialdehyde and homoserine
threonine
precursor of threonine
homoserine
high levels of what amino acid result in low levels of homoserine synthesis
threonine
in plants and microorganisms, what amino acid is biosynthesized from pyruvate and alpha-ketoglutarate
isoleucine
amino acids deerived from 3-phosphoglycerate (3)
serine
glycine
cysteine
first amino acid to be produced in the family of amino acids derived from 3-phosphoglycerate
serine
modified to both glycine and cysteine
serine
both glycine and cysteine is regulated by the available concentration of ___ in the cell
serine
is biosynthesized from serine, catalyzed by SHMT
glycine
genes required for the synthesis of this amino acid are coded for the cys regulon
cysteine
effective inducers of cysteine regulon is ___
n-acetyl-serine
amino acid derived from pyruvate
alanine
valine
leucine
the result of glycolysis, can feed into both the TCA cycle and fermentation process
pyruvate
produced by transamination of one molecule of pyruvate using two alternate steps
alanine
what amino acids are converted to become alanine
glutamate
valine
is produced by a four enzyme pathway
valine
synthesis pathway that diverges from valine pathway beginning with a-ketoisovalerate
leucine
like valine, this amino acid regulates the first step of its pathway by inhibiting the action of a-isopropylmalate synthase
leucine
synthesized by a diversion from the valine synthetic pathway, so the feedback inhibition of valine can also inhibit its synthesis
leucine
is the process by which nucleic acids (DNA and RNA) are synthesized and degraded
nucleic acid metabolism
anabolic mechanism generally involving the chemical reaction of phosphate, pentose sugar, and a nitrogenous base
nucleotide synthesis
destruction of a nucleic acid is what kind of reaction
catabolic
nucleotides are classified in either
purine
pyrimidine
purine and pyrimidine are primarily produced in the ___
liver
purine/pyrimidine is larger
pyrimidine is smaller; purine is larger
two nucleotides classified as purines
adenine
guanine
all nucleotide synthesis requires the use of what enzyme
phosphoribosyl pyrophosphate
enzyme that donates the ribose and phosphate necessary to create a nucleotide
phosphoribosyl pyrophosphate (PRPP)
in what synthesis is PRPP turned into inosine monophosphate or IMP
purine
ATP stimulates the production of ___, and vice versa
GTP
excess of either nucleotide could increase the likelihood of
DNA mutations
reacts with glutamine and other chemicals to form cytidine-triphosphate (CTP
UTP
nucleoside that include cytidine, uridine, and thymidine
pyrimidine
the synthesis of any pyrimidine nucleotide begins with the formation of ___
uridine
unlike in purine synthesis, the sugar phosphate group from PRPP is not added to the nitrogenous base until towards the end of the process
pyrimidine sytnhesis
UTP is converted to ___ by CTP synthethase
CTP
activator of pyrimidine synthesis
ATP
inhibitor of pyrimidine synthesis
CTP
in plants and some prokaryotes __ is a product of photosynthesis
glucose
is formed by the breakdown of polymeric forms like glycogen
glucose
polymeric form where glucose is derived from
glycogen
polymeric source of glucose in animals
glycogen
polymeric source of glucose in plants
starch
cleavage of glycogen is called
glycogenolysis
cleavage of strach
starch degradation
photosynthetic organisms are called
photoautothrophs
organisms able to synthesize food directly from carbon dioxide and water using energy from light
photosynthetic organism
use organic compounds, rather than CO2, as a source of carbon
photoheterotrophs
in plants, algae, and cyanbacteria,, photosynthesis releases ___
oxygen
most common type of photosynthesis used by living organisms
oxygenic photosynthesis
type of photosynthesis used mostly by certain types of bacteria, which consume carbon dioxide but do not release oxygen
anoxygenic photosynthesis
CO2 is converted to sugars in a process called
carbon fixation
endothermic redox reaction
carbon fixation
in general outline, photosynthesis is the opposite of___
cellular respiration
process of reduction of CO2 to carbohydrates
photosynthesis
oxidation of carbohydrates or other nutrients to carbon dioxide
cellular respiration
who proposed the general equation of photosynthesis
Cornelis van Niel
general equation of photosynthesis
CO2 carbon dioxide + H2A electron donor + photons/light energy > CH2O carbohydrate + 2 aoxidized electron donor + H2O
apply water as electron donor in Cornelis van Niel’s photosynthesis equation
CO2 + 2 H2O + photons/light energy > Ch2O carbohydrate + O2 + H2O
both a reactant in the light dependent reaction and a product of light independent reaction
water
net equation of photosynthesis
CO2 + H2O + photons > Carbohydrates + O2
two stages of photosynthesis
light independent reactions
light dependent reactions
stage of photosynthesis where light reactions capture the energy of light and use it to make the energy store molecules ATP and NADPH
light dependent reactions
stage of photosynthesis where products of ATP and NADPH are sed to capture and reduce carbon dioxide
light independent reactions
most organisms that utilize oxygenic photosynthesis use ____ for the light dependent reactions
visible light
some organisms use what kind of electromagnetic wave aside from visible light
infrared
far-red radiation
use a simpler method that employs a pigment similar to those used for vision in animals
archaea
changes its configuration in response to sunglight, acting as a proton pump
bacteriorhodposin
bacteriorhodopsin produces ___ more directly, which is then converted to chemical energy
proton gradient
does archaea photosynthesis have co2 fixation and release of oxygen?
no
what enzyme in light independent reactions capture Co2 from the atmosphere
RuBisCo (ribulose 1-5,bisphosphate carboxylase)
RuBisCo capturing CO2 from atmosphere is a process called
calvin cycle
calvin cycle uses what intermiediate to release three-carbon sugars
NADPH
calvin cycle releases three carbon sugars which are later combined to form what products
sucrose
starch
overall equation for light indepedent rxn
3Co2 + 9 ATP + 6 NADPH + 6H+ > 3-phosphoglycerate + 9 ADP + 8 Pi + 6 NADP+ + 3H2O
produces the intermediate three-carbon sugar product
carbon fixation
simple carbon sugar produced by photosynthesis is used to build the material ___
cellulose
process in which CO2 combines with a five-carbon sugar, ribulose 1,5-bisphosphate, to yield two molecules of a three carbon compound, glycerate 3-phosphate, in the presence of ATP and NADPH
fixation or reduction of CO2
product of carbon fixation
PGAL or triose phosphate
PGAL is used to regenerate
ribulose 1,5-bisphosphate
the triose phosphate not recycled often condense to form what
hexose phosphates
hexose phosphate ultimately yields
sucrose
starch
cellulose
the sugars produced during carbon metabolism yield carbon skeletons that can be used for metabolic rxns like the production of ___ and ___
amino acids
lipids
metabolic pathway that begins with molecules containing 2 to 4 carbon atoms and ends in glucose molecule containing six carbon atoms
gluconeogenesis
metabolic pathway that results in the generatio of glucose from certain non-carbohydrate carbon substances
gluconeogenesis
where does gluconeogensis occurs mainly in vertebrates
liver
cortex of kidneys
two primary mechanisms to maintain blood sugar levels, avoid low levels
gluconeogenesis
degradation
in ___, because dietary carbohydrates tend to be metabolized by these organisms, gluconeogenesis occurs regardless of fastin low carb diets, exercise, etc.
ruminants
in many other animals, this process occurs during periods of fasting, starvation, low carb diets, or intense exercise
gluconeogenesis
under conditions of prolonged fasting ___ derived from ketone bodies can also serve as a substrate
acetone
relative contribution of gluconeogenesis by the __ is increased in diabetes and prolonged fasting
gluconeogenesis
pathway that is highly endergonic until it is coupled to the hydrolysis of ATP or GTP
gluconeogenesis
gluconeogensis is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, making it effectively ___
exergonic
where is the ATP supplied from when glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP
fatty acid catabolism via beta-oxidation
is pathway consisting of series of eleven enzyme-catalyzed reactions
gluconeogenesis
which organelles does gluconeogenesis occur
mitochondria
cytoplasm
gluconeogensis begins in the ___
mitochondria
gluconeogensis begins in the mitochondria with the formation of ___ by the carboxylation of pyruvate
oxaloacetate
gluconeogensis begins in the mitochondria with the formation of oxaloacetate by the carboxylation of ___
pyruvate
enzyme that catalyzes the formation of oxaloacetate
pyruvate carboxylase
pyruvate carboxylase is stimulated by high levels of ___ and inhibited by ___ and ___
ATP
ADP and glucose
oxaloacetate is reduced to ___ using NADH, a step required for its transportation out of the mitochondria
malate
malate is then oxidized to ___ using naD+ in the cytosol
oxaloacetate
remaining gluconeogensis takes place in the
cytosol
oxaloacetate is decarboxylated and then phosphorylated to form ___ using the enzyme PEPCK
phosphoenolpyruvate
what molecule is hydrolyzed to remove one phosphate in oxaloacetate decarboxylation
GTP
rate limiting step of gluconeogenesis
fructose 1,6-bisphopshate to fructose 6-phosphate
formed from fructose-6 phosphate by phosphoglucoisomerase
glucose-6-phophate
can be used in other metabolic pathways or phosphorylated to form glucose
glucose 6-phosphate
where does glucose form in gluconeogenesis
lumen of endoplasmic reticulum
glucose is shuttled into the cytoplasm by ___ transporters located in the Er’s membrane
endoplasmic reticulum
