biochem 2 chris part, Biochem 2 Ch 20, Biochem 2 bonus test, Biochem 2 Ch 21

The ΔG^0' values are determined under standard biochemical and reflect the energy either required, or released, as a particular reaction proceeds. Given the ΔG^0' values below, determine the overall ΔG^0' for the following reaction: creatine + ATP yields creatine phosphate + ADP The half reactions are: ATP + H2O yields ADP + inorganic phosphate ΔG^0' = -7.3kcal/mol Creatine phosphate + H2O yields creatine + inorganic phosphate ΔG^0' = -10.3kcal/mol

+3.0 kcal/mol

During exercise, stimulation of the TCA cycle results principally from which one of the following?

Stimulation of the flux through several enzymes by a decreased 4. NADH/NAD ratio

A sedentar 75 kg male is trying to lose weight and has begun a calorie restricted diet. He has reduced his daily intake by 10 g of carbs, 10g fat, 10 g proteins, and 10 g of ethanol. By what percentage has this man reduced his daily intake as compared to what he would reuiqre to maintain his current weight?

10%

Glycolysis generates energy such that cells have a source of energy to survive. Starting with glyceraldehyde 3-P and synthesizing one molecule of pyruvate, the net yield of ATP and NADH would be which one of the following?

2 ATP, 1 NADH

SOD is one of the body's primary defense mechanism against oxidative stress. Enzyme catalyzes which of the following reactions?

2O2 +2H --> H2O2 + O2

Glycogen is the body's storage form of glucose. When glycogen is degraded, glucose 1-P is formed. Glucose 1-P can then be isomerized to glucose 6-P. Starting with glucose 1-P and ending with two molecules of pyruvate, what is the yield of glycolysis in terms of ATP and NADH formed?

3 ATP, 2 NADH

A 25 year old female with hashimoto's thyroiditis is being treated with thyroid hormone replacement and is now euthyroid. She wishes to lose some of the weight she gained while she was in a hypothyroid state. In order to help her lose weight, her dietitian must determine her daily enery expenditure in order to determine a diet with fewer calories than her DEE. The patient weighs 70 kg is moderately active ( 1 to 2 hours of exercise 5 days per week) and is currently consuming 2700 calories per day. If the patient is to lose 1 lb per week, she would need to reduce her daily consumption by how many calories?

800 calories

Active transport is necessary to move compounds into or out of the cell or mitochondria. Transport work can occur when ATP donated its phosphate group to a transport protein, thereby altering the conformation of that protein. Which one of the following mechanisms allows this conformational change to occur?

A again of ionic interaction, which alter tertiary and/or quaternary structure of the protein

Which one of the following would be expected for a patient with an OXPHOS disease?

A high NADH:NAD+ ratio in the mitochondria

In order for a cell to carry out its biologic functions, the intracellular reactions need to be directed to follow a certain pathway. Which one statement best describes the direction of a chemical reaction will follow?

A reaction with positive free energy will proceed in the forward direction if the substrate concentration is raised high enough.

Succinate dehydrogenase differs from all other enzymes in the TCA cycle in that it is the only enzyme that displays which one of the following characteristics?

A. It is embedded in the inner mitochondrial membrane.

When athletes expend vast amounts of energy, they are sometimes seem on the sidelines using supplemental oxygen. More than 90% of the O2 we breathe is used for the generation of which one of the following?

ATP

Dinitrophenol, which was once tested as a weight-loss agent, acts as an uncoupler of oxidative phosphorylation by which mechanism?

Allowing for proton exchange across the inner mitochondrial membrane

The majority of calories in the US diet are derived from carbohydrates, which can contain a variety of glycosidic bonds. Which one of the following carbohydrates contains glucosyl units linked though alpha-1,6 glycosidic bonds

Amylopectin

In order for cells to function properly, energy is required. For most cells, energy is derived from high energy phosphate bonds of ATP, which is produced through oxidative phosphorylation. Which one of the following is a key component of oxidative phosphorylation?

An ATP synthase to synthesize ATP

A pyruvate carboxylase deficiency will lead to lactic acidemia because of which one of the following?

An accumulation of acetyl-CoA in the mitochondria

At birth, a full-term male neonate was found to result from an X-linked dominant mutation of the α-subunit of E1 in the PDC. Compared with a healthy neonate in the same dietary state, what would be the consequences of this mutation?

An increase in plasma concentrations of lactate and pyruvate

A patient has increased her dietary fiber intake in an effort to decrease constipation. She has recently noticed abdominal cramping and bloating as well as increased flatulence. Which one of the following best explains why this is happening?

Bacteria in the colon can convert fiber to H2, CO2, and methane.

a lipid panel is ordered for a patient as a screening tool to help determine CV disease risk. The patient is told to fast for 12 hours before significantly reduced amounts in the blood?

Chylomicrons

A balanced diet contains antioxidant molecules that help to protect cells from free- radical injury. Which of the following foods contain high levels of antioxidants?

Citrus Fruits

All physiologic processes in living cells require energy transformation. Which one of the following would be considered biochemical work using the high-energy phosphate bonds of ATP?

Converting toxic compounds to nontoxic compounds in the liver.

Isolated intact mitochondria were incubated with a high-salt solution, which is capable of disrupting noncovalent interactions between molecules at a membrane surface. After washing the mitochondria, pyruvate and oxygen were added to initiate electron flow. Oxygen consumption was minimal under these conditions because of the loss of which one of the following components for the ETC?

Cytochrome C

Because glucose has several metabolic routes it might take once it arrives in the cytoplasm, which one of the following reactions would commit the glucose to following glycolytic pathway?

Fructose 6-P to fructose 1,6-bisP

The facilitative transporter that is most responsible for transporting fructose from the blood into cells is which one of the following

GLUT 5

A 4-week-old baby is being seen by the pediatrician because of frequent vomiting after meals and tenderness in the abdomen. Upon examination, the physician noted an enlarged liver and a hint of cataract formation in both of the child's eyes. A urine dipstick test for a reducing sugar gave a positive result. Blood glucose levels were slightly below normal. The compound that reacted with the urine dipstick test was most likely which one of the following?

Galactose

Considering the child discussed in the previous question, measurement of which single intracellular metabolite would allow a determination of the enzyme deficiency?

Galactose 1-P

A man with type 1 diabetes neglects to take his insulin injections while in a weekend vacation. Cells found within which tissue will be most greatly affected by this mistake?

Galactose and glucose

After digestion of a piece of cake that contains flour, milk, and sucrose as its primary ingredients, the major carbohydrates products that enter the blood are which of the following?

Glucose, galactose, fructose

Fructose is the second most common sugar in the human adult diet and its metabolism parallels glycolysis. Which one of the following substances is found in both the fructose metabolic pathway and the glycolytic pathway?

Glyceraldehyde 3-P

A 35 year old sedentary male patient weighing 120 kg was experiencing angina (chest pain) and other signs of coronoary artery disease. his physician in consultation with a registered dietitian, conducted a 3 day dietary recall. The patient consumed an average of 585 g of carbs, 150 g of protein, and 95 g of fat each day. In addition he drank 45 g of alcohol. The patient's diet is best described by which of one of the following?

He had a fat intake within the range recommended in current dietary guidelines

A 10-year-old patient had 3 days of severe diarrhea after developing a viral gastroenteritis. Now, whenever she drinks milk, she experiences nausea, abdominal pain, and flatulence. She never had this happen before after drinking milk. Which one of the following would be the best advice for this patient?

Her ability to drink milk should return in a few days.

25 year old woman presents with chronic fatigue. A series of blood tests suggest that her RBC count is low because of iron-deficiency anemia. The deficiency would lead to fatigue because of which one of the following?

Her decrease in Fe-S centers is impairing the transfer of electrons in the ETC

A patient, Mr. P., has suffered a heart attack. As a consequence, his heart will display which one of the following changes?

Increased intracellular H+ concentration.

An individual taking xenobiotics, such as alcohol, medications, and other foreign chemicals, can increase their risk for free radical injury through which one of the following mechanisms?

Induction of enzymes containing cytochrome p450

An accumulation of hydrogen peroxide in a cellular compartment can be converted to dangerous radical forms in the presence of which metal?

Iron

A patient is trying to lose weight and wonders what her ideal number of calories per day might be. A dietician is helping her by estimating the BMR, the DIT, and physical activity. The BMR is best estimated by consideration of which of the following?

It is equivalent to the calroic requirement of our major organs and resting muscle

Atherosclerosis can narrow the coronary arteries, leading to decreased blood flow and hypoxia of cardiac cells (cardiomyocytes). This causes the patient to experience angina. Which one of the following is likely to occur in the cardiomyocytes during the hypoxic event?

Lactate cannot be used as a fuel

A runner wanted to "carb load" just before a race, and she wanted to pick something to eat that has a high glycemic index. Which one of the following foods should the runner pick?

Malted milk balls

A patient has a genetic defect that causes intestinal epithelial cells to produce disaccharidases of much lower activity than normal. Compared with a normal person, after eating a bowl of oatmeal and milk sweetened with table sugar, this patient will exhibit higher levels of which of the following?

Maltose, sucrose, and lactose in the stool.

The level of oxidative damage to mitochondrial DNA is 10 times greater than that to nuclear DNA. This could be because of which of the following

Mitochondrial DNA lacks histones

Many biologic reactions are oxidation-reduction reactions that use a biologic electron carrier. Which one of the following statements correctly describes reduction of one of these electron carriers, NAD+ or FAD

NAD+ accepts two electrons as a hydride ion to form NADHL

A deficiency in which one of the following compounds would lead to an inability to produce coenzyme A?

Pantothenate

ATP is the cells' major energy-carrying molecule, and in order for a cell to survive, the call must be able to regenerate ATP when ATP levels drop. Which one of the following statements accurately describes an aspect of ATP metabolism?

Phosphate groups repel each other, which in ATP leads to strained bond formation

A patient diagnosed with thiamin deficiency exhibited fatigue and muscle cramps. The muscle cramps have been related to an accumulation of metabolic acids. Which one of the following metabolic acids is most likely to accumulate in a thiamin deficiency?

Pyruvic acid

A patient with type 1 diabetes has neglected to take his insulin before eating a carb rich meal. Which of the following tissues will metabolize glucose under these conditions?

RBC Yes Brain Yes Skeletal Muscle No Adipose Tissue No

Nitroglycerin and other medications used for treating erectile dysfunction work by forming NO. In high concentrations, NO can produce RNOS that are involved in which one of the following diseases?

Rheumatoid Arthritis

A patient with alcoholism developed pancreatitis that affected his exocrine pancreatic function. He exhibited discomfort after eating a high-carbohydrate meal. The patient most likely has a reduced ability to digest which one of the following?

Starch

The red blood cells require ATP in order to maintain ion gradients across their membrane. In the absence of these ion gradients, the red blood cells will swell and burst, bringing about a hemolytic anemia. Red cells generate their energy via which one of the following?

Substrate-level phosphorylation

A distance runner is training for her half marathon and as part of the training is allowing her muscles to use the fatty acids as a fuel source. Fatty acids are converted to acetyl-CoA in the mitochondria, at which point the acetyl-CoA can be oxidized in the TCA cycle to generate reduced cofactors. Which one of the following correctly describes how the Acetyl-CoA is metabolized in the mitochondria?

Substrate-level phosphorylation generates one high-energy phosphate bond during the cycle

A newly diagnosed patient with diabetes avoided table sugar because he knew he had "sugar diabetes," but he continued to consume fruits, fruit drinks, milk, honey, and vegetables, with the result being poor diabetic control. The diet the patient was following contained carbohydrate primarily in which form? Choose the one best answer.

Sucrose

Patient with chronic granulomatous disease complaining of fever, dermatitis, and diarrhea. The genetic form of this disease results in the inability to generate what?

Superoxide

You diagnose patient with ALS, and you discover that his father also has the disease. The patient most likely had a mutation that to the inability to detoxify which of the following?

Superoxide

An individual displays lactic acidemia as well as a reduced activity of a- ketoglutarate dehydrogenase activity. The most likely single enzymatic mutation that leads to these changes would be in which one of the following proteins?

The E3 subunit of pyruvate dehydrogenase

All cells require energy to survive, and the laws of thermodynamics need to be followed within biologic systems. Which one of the following energetic terms or phrases is defined correctly?

The change in enthalpy of a reaction is a reaction is a measure of the total amount of heat can be released from the changes in the chemical bonds.

Metformin is a medication used in treating diabetes mellitus type 2. One of its actions is to decrease hepatic gluconeogenesis. A theoretical concern with this medication was lactic acidosis, which in practice does not occur in patients taking metformin. Which one of the following explains why lactic acidosis does not occur with the use of this medication?

The heart uses lactate as fuel.

Rotenone, an inhibitor of NADH dehydogenase, was originally used for fishing. When it was sprinkled on a lake, fish would absorb it through gills and die. It was used in U.S. as an organic pesticide for tomato plants. It was considered nontoxic to mammals and birds neither of which can readily absorb it. What effect would rotenone have an ATP production by heart mitochondria, if it could be absorbed?

There would be a 95% reduction in ATP production

Glucose is the body's universal fuel, which can be used by virtually all tissues. A major role of glycolysis is which one of the following?

To generate energy

Every human cell has the capacity to use glycolysis for energy production. Which one of the following statements correctly describes an aspect of glycolysis?

Two molecules of ATP are used in the beginning of the pathway

ATP is the cells' major chemical form of energy, and often it is converted to ADP during reactions, thereby releasing energy to allow the reaction to proceed in the forward direction. The highest energy phosphate bond in ATP is located between which of the following groups?

Two phosphate groups

Which of the following vitamins or enzymes is unable to protest against free-radical damage

Vitamin B6

Mrs.Jones is a sedentary 83yr old who is 5 ft tall and weighs 125 lb. She has been at this weight for about a year. She says that a typical diet for her includes a breakfast of toast (white bread, no butter), a boiled egg, and coffee with cream. For lunch she often has a cheese sandwhich (white bread) and a glass of whole milk. For supper she prefers cream of chicken soup and a slice of frosted cake. Mrs. Jones diet is most likely to be inadequate in which of the following?

Vitamin C

The mechanism of vitamin E as an antioxidant is best described by which one of the following?

Vitamin E participates in the reduction of radicals

A dietitian is counseling a patient with celiac sprue (intolerance to gluten, leading to malabsorption issues in the instestine) who has experienced steatorrhea (fatty stools caused by poor absorption . The dietician in addition to describing appropriate carbs, lipids, and proteins that will not trigger the malabsorption issue, also encourages the patient to take certain vitamins. Which one of the following vitamins is most likely on the list?

Vitamin K

A friend of yours has decided to go on a crash diet consuming only 700 calories per day. You advise your friend that he is at risk for certain dietary deficiencies and inform him of the RDA, which is best described by which of the following?

a reasonable dietary goal for the intake of anutrient by a healthy individual

5 year old boy was eating pain chips from the windowsill in his 125 year old home, and he developed anemia. Blood work indicated high levels of lead, which interfere with heme synthesis. Reduced heme synthesis would have little effect on the function of which of the following proteins or complexes?

complex I

Isolated liver mitochondria are incubated in the presence of a limiting amount of malate. 3 min after adding substrate, cyanide is added, and the reaction is allowed to proceed for another 7 min. At this point, which component of the ETC will be in oxidized state?

complex II

A male patient exhibited a BMI of 33 kg/m2 and a waist circumference of 47 in. what nutrition therapy would be most helpful?

decreased intake of total calories because all fuels can be converted to adipose tissue triacylglycerols

elevated levels of chylomicrons were measured in the blood of a patient. To lower chylomicron levels most effectively you would prescribe a diet that is restricted in which of the following?

fat

A patient with type 2 diabetes mellitus take his insulin shot and then 15 minutes later ingests a meal of bread, potatoes and milk. Which one of the following proteins is supppressed during the absorption of this meal?

glucagon

A patient with celiac sprue needs advice on which foods and what proportions he should ingest them because he still requires a diet containing all essential components. When he eats and digests a mixed meal (carbs, lipids, and proteins) which is likely to occur?

glucose levels increase in the blood

A 45-year old developed DVT and PE. After recovery, the patient was placed on warfarin to prevent future blood cots. The patient was counseled by a dietitian to limit his consumption of which one of the following foods because of the finding that eating the food could interfere with the action of warfarin?

green leafy vegetables

UCPs allow oxidation to be uncoupled from phosphorylation. Assume that a drug company has developed a reagent that can activate several UCPs with the goal being the development of a weight-loss drug. A potential side effect of this drug could be which one of the following?

increase in body temp

a type 2 diabetic whose diabetes is well controlled (as determined by his hemoglobin A1c levels), has taken his insulin and 15 min later eats his evening meal. Which of the following changes will occur as he digests his meal?

increased glucose transport by muscle: Yes VLDL synthesis by the liver:Yes fatty acid synthesis in fat cells: No Glycogen synthesis in the liver: Yes tryacylglycerol storage in the adipose tissue: YEs

A 2 month old baby is exclusively breastfed. Which one of the following anatomic locations contains the most important enzyme needed by this baby for absorption of carbohydrate from this diet?

liver

An athlete is competing in a 400 m dash. Which one of the following is the major source of energy for the muscles used in this competition?

muscle glycogen stores

A patient with cirrhosis is having mental status changes owing to elevated ammonia levels in the blood. In prsecribing a diet to reduce ammonia production in this patient which class of nutrients should be most restricted?

proteins

Isolated liver mitochondria are placed in a weakly buffered solution. Malate is added as energy source, and an increase in oxygen consumption confirms that ETC is functioning within these organelles. Valinomycin and potassium is added. Valinomycin is a drug that allows potassium ions to freely cross the inner mitochondrial membrane. What is effect of valinomycrin on the proton motive force that had been generated by oxidation of malate.

proton motive force will be decreased but to a value greater than zero

A dietitian is counseling a patient with celiac sprue(intolerance to gluten), leading to malabsorption issues in the intestine) and describing a diet with appropriate carbohydrate, fat, and protein content. Once properly absorbed, the major fate of compounds during respiration is?

they are oxidized to generate ATP

a marathon runner is training for a race, the runner exhausts her glycogen stores through an extensive training session and then goes out and eats a large helping of pasta. This is called Carb loading and is designed to

to stimulate glycogen synthesis in liver and muscles