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Terms in this set (79)

After digesting a cobb salad from chick-fil-a, nutrient molecules enter the bloodstream after absorption occurs in the small intestine. What would be the fate of this nutrient molecule?
Synthesis of macromolecules such as carbohydrates or lipids
Which pathway is catabolic and which is anabolic?
Catabolic glycolysis, Anabolic: protein synthesis
Under standard conditions, why does ethanol turn into acetyl CoA rather than acetyl CoA converted to ethanol?
Ethanol metabolism is irreversible under standard conditions because delta G0' has an overall negative value and NAD+ is present much higher than NADH in the cell.
What are the three requirements for enzymes to be considered "regulatory" in biosynthetic pathways?
1. Present in lower activities than other enzymes
2. Only one essential function in the metabolic pathway.
3. Catalyze the first irreversible reaction.
Why are vitamins important for the body?
Most coenzymes are derived from vitamins, therefore, a deficiency can prevent metabolic reactions.
All sugars enter the body through the kidneys and are proceeded by the liver.
T/F
F
Identify the incorrect statement about glucose
High amounts of ATP are required to move glucose across the plasma
membrane
When insulin is low during the fasting state, what action will GLUT4 take?
none
During the resting state, most glucose carriers are found where?
The membrane of intracellular vesicles
A new drug is created to decrease the rate at which glucose diffuses across the plasma membrane. What will be the most beneficial method to market this medication to type II diabetic patients?
Decrease the rate of receptor autophosphorylation
All major nutrients are degraded to Acyl-CoA
T/F
F
Substrate level phosphorylation occurs in what steps of glycolysis?
7 and 10

ADP to ATP
If a cell lacks the enzyme triose phosphate isomerase, which of the following is a possible result?
Only one pyruvate molecule will be made
High levels of ATP will inhibit what enzyme in glycolysis?
PFK
Why is glycolysis regulated by ATP only in Red blood cells?
RBCs do not have mitochondria or nuclei.
During a diseased state, a cell is producing an excess amount of glucose-6-phosphate. What would you expect to see from this point on?
Hexokinase will be inhibited in the peripheral tissue, preventing the rest of the glycolysis cycle
What enzyme is responsible for the conversion of 1,3 Bisphophoglyerate to 2,3- Bisphoglycerate?
bisphosphoglycerate mutase
The keto form is more energetically stable than the enol form of what reaction?
pyruvate tautomerism
In muscles, glucose-6-phosphate is a common intermediate among?
Pentose phosphate pathway
Glycolysis
gluconeogenesis
If a scientist wants to increase the rate of glucokinase in the pancreas, what should he do?
Decrease the production of Fructose 6 phosphate.
Pyruvate dehydrogenase catalyzes oxidative decarboxylation.
T/F
T
Step 3 of oxidative decarboxylation of pyruvate by PDH involves what type of reaction?
esterification
Allosteric regulation of PDH involves
Inhibition by acetyl CoA and NADH
Activation by AMP
The conversion of GTP to GDP occurs at what enzyme of the TCA cycle?
succinyl co-a synthase
The purpose of the glycerol phosphate shuttle
To move FADH2 across the inner mitochondrial membrane
Jake performed an experiment where he added lab-made carbon dioxide to an incubation chamber along with the two cells. If both cells were extracted from a eukaryotic species, how many carbons will be produced during the Krebs cycle if Jake added 6 carbons for three trials of his experiment?
0
A three-week-old infant was diagnosed with a respiratory disease that decreases electron transport across the inner mitochondria membrane. A biochemist did extensive research on this patient and discovered electrons were specifically not being transferred to molecular oxygen. What part of the Electron Transport Chain is responsible for the patient's disease?
Complex IV
The respiratory chain contains: flavoproteins, Iron-copper proteins, Cytochromes, coenzyme Q, and protein-bound copper.
T/F
F
After the successful creation of a drug that is identical to CoQ and increases the reaction rate of ubiquinone in the electron transport chain, you celebrate like there is no tomorrow. Unfortunately, the next day, the FDA emails you explaining that your drug patent was denied for one particular reason. What could be a reason for such denial?
You created a drug that is water soluble, instead of lipid-soluble like the actual CoQ
The rate-limiting step of the electron transport chain is?
there isn't one
A small business company is promoting its most popular weight loss pill to customers by providing actual weight loss proof on social media. One client lost over 30lbs in 2 months, and another client lost 50lbs in the same period. However, what the company is not advertising is the side effects. Both clients were rushed to the ED for extreme exhaustion and fatigue. What could be a reason for this?
the weight loss pill prevents protons flow, no ATP is generated in the body
Proton pumping is fueled by the exergonic reactions in the ETC
T/F
T
What causes conformational transitions (tight, open, loose) within ATP synthase?
Rotating gamma subunit
If 36 ATP are generated by complete oxidation of glucose, how many ATP are produced by phosphorylation in glycolysis and TCA?
4
In a controlled mice experiment, a biochemist did not realize he was increasing the levels of lactic acid in his group of mice. After every trial, 1 to 2 mice would die with no apparent cause to the biochemist. The goal of the experiment was to decrease the level of ATP in the body to increase glycolysis. What was the cause of death in the mice?
During anaerobic metabolism, a decrease in ATP leads to the accumulation of lactic acid which ends in cell death
Which is an example of a physiological uncoupler?
thyroxin
The brain can consume fat to supply ATP if glucose is low
T/F
F
Hexokinase is bypassed by what enzyme?
glucose-6-phosphatase
The Cori cycle can be defined as?
Lactate is released into the blood by muscles and by cells that lack a
mitochondria
If oxaloacetate is missing from the cell, what would you expect to happen?
TCA and gluconeogenesis would not function properly
A common allosteric regulator for phosphofructokinase and fructose- 1,6- bisphosphatase is?
F26BP
Synthesis of glycogen from glucose occurs in the cytosol and requires energy supplied by ATP.
T/F
T
Glycogen has two reducing ends, at C1 and C_____?
Glycogen only has one reducing end
Dr. James has a patient with low glucose levels even after eating high carbohydrate-containing meals. Dr. James decided to use a drug that converts fatty acids to glucose to help his patient. After 6 months of being on this drug, the patient still does not have increased glucose levels. What could be a reason for this?
Fatty acids cannot make glucose
What protein serves as a primer for glycogen synthesis?
glycogenin
Glycogen degradation is initiated by?
glucagon in the liver
Oxidation of 3 molecules of glucose by pentose phosphate pathway results in the production of _____
3 molecules of pentose, 6 molecules of NADPH, and 3 molecules of CO2
The liver metabolizes fructose faster than glucose
T/F
T
in the pentose phosphate pathway, the two major products are
Ribose 5 phosphate and NADPH
Which enzyme is responsible for the conversion of Xyluolse-5 phosphate to glyceraldehyde 3 phosphate
transketolase
4 major organs play a dominant role in energy metabolism: heart, liver, muscle, and brain.
T/F
F
A 45-year-old man presents for a physical. He has a BMI of 27, serum cholesterol of 254 mg/dL, and fasting blood glucose of 185 mg/dL. After confirming this fasting blood glucose level on a follow-up visit, you prescribe metformin for him and explain that this drug will help lower his blood glucose levels by doing what?
Inhibiting transcription of gluconeogenesis enzymes
What can favor high superoxide formation?
A high proportion of electrons carriers in the reduced state
Alcohol metabolism follow what type of kinetics
zero order
What phase of xenobiotics metabolism make xenobiotics water soluble for excretion?
II
the committed step of a metabolic pathway is _____
the step of the pathway which controls the overall efficiency of the pathway
between fats and carbs, which would store more energy per gram, and by how much
fats store twice as much energy per gram as carbs
under almost all metabolic conditions, the source of fuel for the human brain is
glucose
under long-term starvation conditions, the brain uses _____ as an energy source
ketone bodies
when is energy stored in ATP?
when a phosphate group is added to ADP
what is the correct comparison of the Km of hexokinase and glucokinase?
Km of hexokinase < Km of glucokinase
what is considered a waste product of cellular respiration
carbon dioxide
during cellular respiration, in which locations is NADH produced?
cytosol, mitochondria
Flavoproteins are common in the mitochondria and chloroplasts
T/F
T
flavoproteins are modified vitamin B2, and include FAD and FMN
T/F
T
NADH and FADH2 are electron carrier molecules
T/F
T
What products of glucose oxidation are essential for oxidative phosphorylation?
NADH, FADH2
predict the outcome of a mitochondrial membrane that is more permeable to hydrogen ions than normal
increasing the levels of inorganic phosphate in the mitochondrial matrix
Cyanide is a poison that inhibits the electron transport chain by creating a strong and stable bond with Fe-Cu center in cytochrome C oxidase (complex IV). What is the immediate consequence of cyanide poisoning?
prevent the reduction of oxygen
rotenone is added to a culture of muscle cells. this leaves _____ reduced
E1
in a patient with liver cirrhosis who is also fasting, which structure will prevent hypoglycemia?
kidney cortex

People with cirrhosis are not able to mobilize glucose out of the body's reserves, and they can easily develop low blood sugar
a mutant form of glucokinase has a significantly lower Km. following a meal, this would result in
hypoglycemia
in humans, which of the following compounds cannot be utilized to synthesize glucose
acetyl coa
The active form of glycogen synthase is _____, the active form of glycogen phosphorylase is _____
dephosphorylated, phosphorylated
rate limiting step in pentose phosphate pathway
glucose-6-phosphate dehydrogenase
the ppp is utilized for all of the following except
formation of atp
how does nadph maintain a reductive environment
by regenerating reduced form of glutathione
which cell type has the GLUT transporter with the lowest Km and why is it so beneficial
RBCs, always need glucose to maintain membrane stability
a man comsumes a large breakfast. which of the following will have elevated activity in his liver after breakfast
cytoplasmic glucokinase
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