Hormones (The primary messenger) arrives at the exterior of a cell to stimulate the snythesis of _________ (The secondary messenger) inside the cell.
The two main hormones that can be primary messengers are...
adrenalin (epinephrine) and glucagon
The binding sites for the hormones in on the _____ of the cell, facing the _________.
The hormone receptor binds to another protesin in the membrane called the....
The active form of glycogen phosphorylase kinase is the
"a" form with phosphate attached
Adenylate cyclase is located in the ___ , facing the ______ of the cell.
If the Phosphorylation and Dephosphorylation cascades are abbreviated PhosC and DephosC respectively, then the cAMP-dependent many protein kinase
turns on PhosC and turns off DephosC
For a protein that has a "b" form, that form always is the ___ form.
Caffeine is an inhibitor of ___ .
cyclic nucleotide phosphodiestersae
Comparing the phosphorylation and dephosphorylation cascades, the example with more steps in the sequence is the ___ cascade. Having more steps is ___ for responding to an emergency.
The reaction (cAMP -> AMP) is catalyzed by
The letter "G" in the name "G protein" stands for ___ .
The direct function of G protein itself is to
activate adenylate cyclase
The dephosphorylation cascade is initiated by increases in the concentration of ___ .
The many-protein kinase (protein kinase A) which initiates the phosphorylation cascade is itself activated when it binds is..
The enzyme catalyzing the opposite effects of the cAMP-dependent many protein kinase is the
many phosphoprotein phosphatase
Phosphorylation of enzymes (activates or inhibits enzymes?)
either of the above, depending on the specific example
Adrenalin and glucagon lead to similar effects in liver because they both...
generate the same secondary messenger
The substrate of adenylate cyclase is
One direct substrate of the cAMP-dependent many-protein kinase (protein kinase A) is ___ .
glycogen phosphorylase kinase
Adrenalin initiates a series of reactions which inhibits glycolysis step 10 in the ___ .
The cycle by which glucose is converted into lactate in muscles, then converted back into glucose in the liver, and finally transported back to the muscles is the ___ cycle.
The regulated steps in glycolysis are all strongly ________.
are all strongly downhill (in the glycolysis direction)
An example of an enzyme which is inhibited by its own product is ___ .
Organ(s) which contain the enzyme for bypass III of gluconeogenesis include the ___ .
The regulated steps in glycolysis are steps ___ .
1,3, and 10
The concentration of glucose in the blood in a normal healthy human being is ___ mM.
Insulin causes GLUT4 transporters in muscle cells to move from the ___ .
cytoplasm to the plasma membrane
The reaction pyruvate -> lactate includes a ___ conversion.
C=O -> H-C-OH
When S-init is much less than Km, the Michaelis-Menten relationship simplifies to the form of a ___.
sloped straight line which intersects the origin
Muscles lack receptors for ___ .
In muscle hexokinase, its Km is much ___ than the [substrate], so its active site is nearly always ___ suibstrate
smaller; filled with
The organ which is responsible for maintaining a relatively constant level of glucose in the blood is the ___ .
An organ which uses glucose but not fatty acids as a fuel is the ___ .
An example of an enzyme which is inactivated by phosphorylation is ___ .
liver pyruvate kinase
The type of glucose transporter that is regulated by endocytosis and exocytosis occurs in the _____.
For an enzyme or transporter to be under substrate-level control, its Km should be ___ the typical physiological concentration of that substrate.
Diabetics have blood glucose concentrations which are too
Caffeine is bad for the diabetic because it ___ the blood glucose level because it ___ the enzyme which catalyzes cAMP -> AMP.
increases (glucose) ; inhibits (cAMP -> AMP)
Diabetes leads to circulatory problems by
stimulating cell proliferation in artery walls caused by leukotrienes secreted by macrophages responding to glycosylated collage AND
inhibiting recycling of serum lipoproteins by receptors in the liver's outer membrane because the lipoproteins are glycosylated
The official death rate attributed to diabetes is underestimated, because diabetes also indirectly contributes to deaths which have been listed as being caused by
Desensitization refers to
a lowering of the concentration of insulin receptors
Desensitization is usually associated with a _____ of insulin in the blood
an excess of insulin in the blood
The glycosylation of blood vessel proteins occurs...
without an enzyme in all people, but faster in people with high blood glucose levels
Which of the following is NOT a long-range complication of diabetics?
amenia (loss of blood cells)
The best meal plan for the diabetic is toThe best meal plan for the diabetic is to
eat six small sized meals spaced about 2.5 to 3 hrs apart
The primary harmful effect of diabetes glucose effects in the blood is
damage to blood vessels
The most reliable test for diabetes is the concentration of
glycosylated Hb at any time during the day
Stress is bad for the diabetic because it activates the adrenalin (epinephrine) cascade which
breaks down glycogen into glucose
There are two types of diabetes. Type II is characterized by
adult onset and decreased sensitivity to the supply of insulin
the enzyme which is capable of conerting ATP into cAMP is on the _____ side of the plasma membrane with it's active site facing the _________.
when a hormone arrives on the scene in the bloodstream it causes a _______ change in the receptor which cuases a _______ change in the g-protein subunits.
the conformational chaing in the g-protein subunits causes G-alpha to release ____ into the cytoplasm and bind ____ in its place. also replacing G-Alpha with ________
G-alpha w/ GTP bound
When adenylate cyclase catalyzes the reaction that converst ATP into cAMP _________ is released
The adenylate cyclase reaction is very favorable because
it tries to replanish the depleted PPi
what two hormones cause the same effect in liver cells (stimulating breakdown of glycogen into glucose)?
adrenalin and glucagon
both the adrenalin and glucagon receptor bind to _____ which in turn activate _______.
when the receptors bind its respective hormone, the receptor changes _______ and affects the G protein in a way that will indirectly change the conformation of _______, causing it to activate.
The secondary messenger cAMP is produced either by binding...
adrenalin to the liver cell
glucagon to the liver cell
enzyme 3 = ?
the active form is called
the "a" form
the inactive form is called
the "b" form
glycogen phosphrylase kinase
Enzyme 2 activates enzyme 3 by...
removing a phosphate from ATP and pasting it onto enzyme 2
enzyme 1 =?
cAMP-dependent many proteins kinase
things that remove phosphate groups from something and paste it somewhere else.
enzyme 2 kinase name=?
glycogen phosphorylase kinase kinase
the inactive form of enzyme 1 is a tetramer containing...
two catalytic subunits (C) and two regulatory subunits (R)
the inactivated enzyme 1 dissociates into..
2 monomeric C catalytic subunits and a single R2 dimer
how many cAMPs are bound to the inactivated enzyme 1 dimer?
in the first amplification, it take ___ bound cAMP to convert one cAMP-dependent many-protein kinase coomplex into the active ____ form.
5C2R2 + 20(cAMP) -> 10C + 5R2(cAMP)4
20 cAMP molecules created by one activated adenylate cyclase enzyme molecule are depicted by turning on...
10 cAMP-dependent many-protein kinase subunits
additional ___x amplifications are proposed for each subsequent step in the cascade.
when adrenal gland stop secreting adrenalin, the concentration of _______ arriving at the liver is decreased.
3',5'-cAMP is broken down to 5'-AMP by cleaving ...
the ester bond between the phosphate group and the hydroxyl group
cAMP can build up faster than it is broken down as long as...
hormones are bound to the outside of the cell
One hormones stop binding to the cell there ultimately will be a net breakdown of...
the enzyme catalyzing cAMP breakdown is called
cyclic nucleotide phosphodiesterase
a drug whose ring structure resembles the adenine sidechain of cyclic AMP is...
_______ can function as a competitive inhibitor of cyclic nucleotide phosphodiesterase
Levels of cAMP are arrtificially _____ in the liver cells of a coffee drinker
the feeling of "high energy" after you drink a cup of coffee is generated by artificially high amounts of ______ being released by the liver into the bloodstream.
______ produces the opposite effects of adrenalina or glucagon.
the purpose of insulin is to...
stimulate liver to take excess glucose out of the bloodstream and to store that in the form of glycogen.
insulin stimulates a ______ cascade
glycogen synthase's activated from is .... (phosphory.ated or dephosphorylated)
insulin stimulates an increase in the active form of _______ inside the cell.
enzyme 5 can be regulated by binding to....
an inhibitor ( a phosphorylated protein)
the inhibitor that binds to enzyme 5 is called....
phosphoprotein phosphatase inhibitor
enzyme 1 turns on enzyme ___ in the phosphorylation cascade and turns off enzyme ___ in the dephosphorylation cascade.
enzyme 1 indirectly turns off enzyme 5 in the dephosphorylation cascade by...
converting the phosphoprotein phosphatase inhibitor into its active phosphorylated form, which binds to enxyme 5 and inactivates it.
enzyme 5 turns on enzyme ___ in the dephosphorylation cascade but also turns off enzymes ___ and ____ in the phosphorlyation cascadae.
2 & 3
the phosphorlyation and dephosphorlyation cascades are in a delicate competitive balance which respoonds to relative concentrations of _______, ______ and _______ in the bloodstream.
adrenalin, insulin and glucagon
the _____ has the special function of "buffering" the level of glucose in the bloodstream, trying to maintain that concentration at a ___ mM level.
Skeletal muscle uses glucose and fats to manufacture _____ for use in muscle contraction under both aerobic and anaerboic conditions.
Liver cells have receptors for each hormone in their ________.
outer plasma membrane
Muscle cells have receptors for insulin so that they can build up...
their small supply of glycogen when appropriate
muscle cells have receptors for adrenalin so they can convert...
glycogen back into glucose during an emergency
Muscles do not have receptors for....
Bypass III (gluconeogensis) occurs in the _____ and not the _____.
muscles do not express the gene for _________, because it the enzyme catalyzes bypass III.
muscle cells do contain the DNA gene which codes for that enzyme since all cells of a human being are derived from...
the same original fertilized egg cell.
the gene for the phosphatse is ________ in muscle cells.
not turned on.
liver and muscle cells both have receptors for...
Muscles need _______ to be stimulated
the liver needs ______ to be stimulated.
the liver needs _____ to be inhibited.
different enzyme forms are called = ?
iso-enzymes or isozymes
the human body has at least ___ genes coding for pyruvate kinase (step 10 of glycolysis)
in liver, the gene that is expressed produces an isozyme that is capable of being phosphorylated by the _____.
cAMP-dependent "many-protein" kinase
the isozyme of pyruvate kinase which is expressed in muslce cells is not capable of being phosphorylated because...
of differences in the presence of ser and thr sidechains in its sequence, or their environments in the tertiary structure.
muscle pyruvate kinase is _________ in the presence of adrenalin
liver pyruvate kinase is _______ in the presence of adrenalin.
step 1 of glycolysis is....
conversion of glucose into G6P
in muscles, the gene that is expressed in step 1 of glycolysis produces the enzyme called.....
in liver, the gene that is expressed in step 1 of glycolysis produces the enyme called...
the best design for the liver enzyme is to make step 1 of glycolysis is directly
proportional to the level of glucose in the blood
making the velocity of step 1 directly proportional to the concentration of the substrate (glucose) is a mechanism called....
"substrate level control"
vint=constant x S-init
(k-cat x E-tot)
Vinit is _______ to s init
glucose binds ______ tightly to muscle hexokinase than to liver glucokinase.
it takes only about ___mM glucose to half-saturate the muscle iso-enzyme.
it takes ___mM glucose to half-saturate the liver iso-enzyme
the glucose concentration giving a velocity that is 1/2 of V-max is numerically equal to the value of ____.
Muscle hexokinase , but not liver glucokinase is allosterically _______ by its own product G6P
insulin initiates a series of events leading to "export" of glucose transporters to the plasma membrane on the ......
exterior of muscle and fat cells
the glucose transporter is called...
GLUT 4 is stored in the ....
membrane of small sacs called vesicles
exocytosis is when..
you move something from the inside to the cell to the outside
endocytosis is when..
you move something from the outside of the cell to the inside
insulin facillitates conversion of glucose into glycogen not only by activating glycogen synthase, but also by increasing the concentration of active _________.
in the cori cycle, muscle lactate goes to the ....
lactate + NAD -> pyruvate + NADH
the complete cycle of moving organic molecules from the muscle to the liver and then back to the muscles is called the....
The cost of the cori cycle is...
4 ATPs per glucose
__-__% of americans are afflicted by diabetes
_______ deaths per year from diabetes in 1995
___th greatest cause of death by disease (diabetes)
The cofactor permanently bound to pyruvate oxidative decarboxylase is
A metabolite having the same ratio of C:H:O found in glucose is
Three cofactors are strongly bound to PDH. The two cofactors which diffuse thru solution, temporarily binding to PDH, are
NAD+ and CoA
The PDH cofactor which is described as being an "electron sink" is
The three major molecules in the process converting pyruvate to ethanol are pyruvate CH3-C(=O)-COOH -> acetaldehyde CH3-C(=O)-H -> ethanol (CH3-CH2-OH). The enzymes which accomplish this are
pyruvate decarboxylase and alcohol dehydrogenase
Which of the following cofactors participates directly in both of the oxidation/reduction reactions occurring during fermentation of glucose to ethanol?
NAD+ / NADH
Conversion of glucose into two lactates is best characterized as no net
oxidation or reduction..
Which of the following statements about PDH is FALSE?
The multienzyme complex is located in the mitochondrial matrix.
Both NAD+ and a flavin nucleotide act as electron acceptors.
The carbon of the methyl group (CH3) of pyruvate is converted into CO2.
Two types of cofactors participating in PDH have an SH form.
The carbon of the methyl group (CH3) of pyruvate is converted into CO2.
The reason why yeast cells convert pyruvate to ethanol and CO2 under anaerobic conditions is
to recycle NADH back to NAD+
Consider the sequence of enzymes E1 -> E2 -> E3 in the pyruvate dehydrogenase complex. E3 is..
Which of the 5 cofactors (CoA, TPP, lipoic acid, FAD, NADH) contain(s) a sulfur atom somewhere in its structure:
CoA, TPP, and lipoic acid
Vitamins are precursors for...
In the PDH reaction series, the bond between the C=O and COOH groups of pyruvate is weakened by ___ the electron density in that bond. The group responsible for this effect is a ___ .
decreasing ; N+ in TPP
Two types of amino acids having a direct one-step input into the TCA cycle are
asp and glu
Feature(s) shared by the TCA cycle and beta oxidation (breakdown of FA's) include
(1) "growing" a carbonyl group, and (2) a cyclic-like process
Citric acid, which occurs at the beginning of the citric acid cycle, contains ___ carbon atoms and ___ carboxyl groups.
6 C's ; 3 COOH
Which cofactor is required for conversion of succinate to fumarate in the citric acid cycle?
In terms of numbers of high energy compounds directly produced, the dominant high-energy product of the TCA cycle itself is
Pathways(s) NOT located in the mitochondrion :
Production of ATP or GTP is seen in
glycolysis and the TCA cycle
NADH is produced in
glycolysis, PDH, and the TCA cycle
The products of one trip thru the TCA cycle are 2 CO2's and
3 NADH, 1 GTP, and 1 FADH2
If both carbons of the entering acetyl group from acetyl-CoA are radioactively labelled, and if the TCA cycle runs only once, the number of radioactive CO2 molecules released will be
The reaction used to convert alpha-ketoglutarate into succinyl-CoA resembles
the PDH process
An enzyme which catalyzes the reaction X + Y + ATP(or GTP) -> X-Y + ADP(or GDP) + Pi is called a
When citrate is bound to the enzyme aconitase, the two CH2-COOH groups are
The translocation reaction which moves ATP from the matrix to the intermembrane space derives its energy from
the presence of the proton gradient
Which of the following does NOT participate in electron transport that begins with transfer of electrons from succinate to FAD?
Ubiquinone (coenzyme Q = CoQ) picks up electrons (e-) from
both complexes I and II
Complex III receives e- directly from ___ and passes them on directly to ___ .
(from) ubiquinone ; (to) cyt c
Consider proteins in the electron transport chain which might be called cyochrome c reductase or cytochrome c oxidase. The protein which would appear AFTER cyt c in an electron transport chain is cytochrome c
The location of the F1 portion of ATP synthase is _____ of the inner mitochondrial membrane
on the matrix side
In eukaryotes, aerobic respiration requires an intact ____ membrane.
mitochondrial inner membrane
Highly mobile electron carrier(s) in the electron transport chain include(s)
cytochrome c and coenzyme Q
A protein complex which is not involved in pumping protons out of the matrix is complex
The role of gradient dissipation is to force
the F1 complex to release newly synthesized but tightly bound ATP
diabetes is the...
inability of cells to take up glucose from blood. = high concentration of blood glucose.
cost of diabetes per yr?
glycosylation of proteins do not require...
an enzyme catalyst
glycosylation rxn occurs at ...
amino groups (N-terminus and lysine sidechains)
the rate of the glycosylation rxn depends on...
the concentration of glucose in the blood
the primary harmful effect of diabetes is...
damage to blood vessels
plasma leaks into..
the lymph system
lymph flows through lymph nodes to filter _____ out of the plasma.
diabetes glycosylation of lysine interfere with the formation of a proper...
macrophages bind to glucose-collagen units and release...
leukotrienes stimulate neighboring cells to....
divide and proliferate to secrete new collagen
the new and extra collagen thicken and stiffen the walls of the _____, decreasing their elasticity and blood flow.
lipoproteins are particles used to transport...
nonpolar lipids thru the blood
lipoproteins contain ...
nonpolar TAG's coated by amphipathic phospholipids and particular proteins plus additional cholesterol to fill in gaps and help the particle.
the major serious symptoms of diabetes are...
amputation of limbs
early-stage symptoms of diabetes are...
what causes increased urination in diabetics?
osmostic pressure effects, extra water leaves the kidneys to enter the glucose-rich urine.
mid-stage symptoms of diabetes are?
numbness in hands and feet
baseline of healthy glucose conc.
80-120 units (mg/dl)
healthy: max amount of glucose right after a meal does not exceded ____ units
healthy: within 2 hrs after a meall, level has dropped to a value below _____.
healthy individual has ___-____% glycosylation
risk factors for diabetes? (6)
type 1 diabetes has a ___ onset
type 1 diabetes is _____-dependent
when you have type 1 diab, you have no ____ in your body
type 2 diabetes has a ____ onset
NIDDM stands for
Non-insulin-dependent diabetes melittus
in early stages of dia. 2, you have high than normal ______ levels.
the problem in early stages with dia. 2 is not lower insulin but...
diminished response (lower sensitivity) to insulin
type 2 possibilities are ... (5)
low secretion of insulin
low conc. of functional insulin receptors
defects in the dephosphorylation cascade
low total level of glucose transporters
defect in exocytosis cascade that release GLUT 4 to surface membrane of tissues