Chapter 24 Nutrition, Metabolism, and Energy Balance Practice Questions

Can fat-soluble vitamins can be toxic if consumed in large quantities?

Yes. This is because in contrast to water soluble vitamins, fat-soluble vitamins are not easily absorbed in the body and therefore we do not easily excrete the excess in urine, instead we store them.

The _______________________ is the energy the body needs to perform only its most essential activities.

basal metabolic rate (BMR) The basal metabolic rate (BMR) is the energy the body needs to perform only its most essential activities, such as breathing and maintaining resting levels of organ function. The lowest metabolic state of the body, however, occurs during sleep.

The initial phase of fatty acid breakdown is known as _____________________.

beta oxidation

The _____________ uses carbohydrates as primary energy.

brain

Proteins are used to build ___________________.

enzymes

Protein malnutrition can result in a moderate anemia. Which of the below-listed vitamins would be most likely to be associated with this condition? a. vitamin C b. vitamin B12 c. vitamin B1 d. vitamin E

vitamin B12

Which of the following fat-soluble vitamins is NOT stored in the body?

vitamin K Vitamin K is the only fat-soluble vitamin that is eliminated by the kidney and, therefore, not stored in the body. One of the leading interventions for calcification is vitamin K, treatment with vitamin K may prevent bone loss and reduce fracture risks. In addition, vitamin K helps with blood clotting (coagulation).

The official medical measurement of obesity is the __________.

BMI BMI (body mass index)

Which of the following is the amount of energy the body needs in order to perform only the most essential activities and is often referred to as the "energy cost of living"?

BMR (basal metabolic rate) The BMR is the only amount of energy required for "housekeeping" activities, which keep us alive.

Which of these happens during the postabsorptive state?

Blood glucose levels are maintained within an adequate range. After glucose levels stabilize after a meal, the body tries to maintain the blood sugar until the next meal.

What is the correct general equation for cellular respiration?

C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP energy Cellular respiration extracts energy from glucose (C6H12O6) to produce smaller energy packets (ATP).

During fasts lasting several weeks, blood glucose is maintained by __________.

During fasts lasting several weeks, blood glucose is maintained by gluconeogenesis by the kidney and liver. Gluconeogenesis (abbreviated GNG) is a metabolic pathway that results in the generation of glucose from non-carbohydrate carbon substrates such as lactate, glycerol, and glucogenic amino acids.

One function of vitamin A is to __________.

Form visual pigments Retinol in the visual pigments is derived from vitamin A.

Which of the following pathways is INCORRECTLY matched with a description? a. Gluconeogenesis: using glucose to build noncarbohydrate structures b. citric acid cycle: aerobic pathway c. glycolysis: anaerobic respiration d. anabolism: building larger molecules from smaller ones

Gluconeogenesis: using glucose to build noncarbohydrate structures Gluconeogenesis is the opposite of that statement; noncarbohydrate sources are used to build glucose. And gluconeogenesis is glucose "being formed" from noncarbohydrate precursors

____________ are considered "good" cholesterol; high blood levels of this cholesterol are thought to be beneficial.

High density lipoproteins (HDLs)

Which brain region is the main integrating center for thermoregulation?

Hypothalamus The hypothalamus is the main homeostatic integration center for thermoregulation.

The main integrating center for thermoregulation is located in the __________.

Hypothalamus The body's "thermostat" is the hypothalamus.

__________ is the conversion of acetyl CoA into ketone bodies.

Ketogenesis Ketogenesis is the conversion of acetyl CoA (fatty acid fragments, not whole fat) into ketone bodies whenever acetyl CoA cannot be oxidized. But a fat molecule must first be broken into fatty acids by another process.

__________ are considered "bad" cholesterol; high blood levels are believed to increase the risk of cardiovascular disease.

LDLs LDLs increase the risk for cardiovascular disease. Foods that contain a high amount of LDLs include: -Butter. -Ghee. -Hard margarines. -Lard, dripping and goose fat. -Fatty meat and meat products such as sausages. -Full fat cheese, milk, cream and yogurt. -Coconut and palm oils and coconut cream.

__________ acts to suppress appetite by inhibiting __________, which is the most powerful known appetite stimulant.

Leptin; neuropeptide Y Leptin acts to suppress appetite by inhibiting neuropeptide Y, which is the most powerful known appetite stimulant. Leptin, is a hormone released from the fat cells located in adipose tissues, that sends signals to the hypothalamus in the brain. This particular hormone helps regulate and alter long-term food intake and energy expenditure, not just from one meal to the next. *Leptin is found in green tea, almonds, and broccoli

Which coenzyme is "reduced" in both glycolysis and the Krebs cycle?

NAD NAD is reduced (add a proton) to NADH in both glycolysis and the Krebs cycle. *This to give their electrons higher energy for the electron transport reactions and to produce carbohydrates.

__________ is the energy (kilocalories consumed) that the body uses to perform only its most essential activities.

The basal metabolic rate (BMR) The basal metabolic rate (BMR) is the energy (kilocalories consumed) that the body uses to perform only its most essential activities, such as breathing and maintaining resting levels of organ function, not all ongoing activities.

Which statement describes the citric acid cycle? a. This process joins 2 pyruvic acid molecules into a molecule of glucose. b. This process produces some ATP and carbon dioxide in the mitochondrion. c. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. d. This process converts pyruvic acid to acetyl CoA. e. This process splits glucose in half and produces 2 ATPs for each glucose.

This process produces some ATP and carbon dioxide in the mitochondrion. The citric acid cycle breaks down carbon molecules, releasing carbon dioxide and forming some ATP.

Which statement describes the electron transport chain? a. This process joins 2 pyruvic acid molecules into a molecule of glucose. b. This process produces some ATP and carbon dioxide in the mitochondrion. c. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. d. This process converts pyruvic acid to acetyl CoA. e. This process splits glucose in half and produces 2 ATPs for each glucose.

This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. In the electron transport chain, electrons move from one electron carrier to another, eventually reaching oxygen. The released energy is used to make ATPs.

The hormone responsible for setting the basal metabolic rate is __________.

Thyroxine Thyroxine is the body's major controller of metabolism.

During glycolysis, glucose must be activated by how many ATP molecules?

Two Glucose must be activated by two ATP molecules forming fructose-1,6-bisphosphate.

Which of the following is a characteristic of the citric acid (Krebs) cycle? a. The citric acid cycle generates a rich supply of the reduced coenzymes, NADH and FADH2. b. Pyruvic acid directly enters the citric acid cycle. c. The citric acid cycle occurs in the cytosol of the cell. d. The citric acid cycle is an anaerobic pathway.

a. The citric acid cycle generates a rich supply of the reduced coenzymes, NADH and FADH2. The citric acid cycle occurs in the inside (matrix) of the mitochondria

Which of the following is an example of catabolism? a. cellular respiration b. using amino acids to make a protein c. lipid synthesis d. absorbing nutrients into the blood from the intestines

a. cellular respiration Catabolism is the breaking "pulling apart" of a molecule.

Which of the following is NOT a physiological response to hypothermia? a. dehydration b. reduced heart rate c. reduced respiratory rate d. shivering e. drowsiness

a. dehydration Dehydration is typically associated with heat exhaustion or heat stroke, not hypothermia.

As proteins are broken down for energy, __________ is generated; the liver then converts this potentially toxic intermediate into __________.

ammonia; urea Urea is the main nitrogenous breakdown product of protein metabolism, and the urea produced in the liver is transported to the kidneys and finally excreted as a waste product in urine. The urea is produced from ammonia and carbon dioxide.

Which of the following factors makes it harder for an obese person to lose weight?

an increase in alpha receptors (the kind that favors fat accumulation) in fat cells. Fat cells of overweight people sprout more alpha receptors, which make it easier for fat cells to accumulate fat.

Which lipoprotein contains the most cholesterol? a. IDL b. LDL c. chylomicron d. VLDL e. HDL

b. LDL LDLs are about 45% cholesterol. This is why Low-density lipoproteins (LDLs are considered the "bad cholesterol". Moreover, the liver is responsible for producing cholesterol.

Which of the following substances is considered a provitamin? a. vitamin D b. iron c. niacin d. beta-carotene

beta-carotene Beta-carotene is considered a provitamin because the body can convert it to vitamin A through digestion.

Which of the following statements about "redox" reactions in human metabolism is correct? a. Oxidized substances lose oxygen. b. Oxidized substances gain energy. c. Coenzymes accept hydrogen. d. The substance being reduced loses an electron

c. coenzymes accept a hydrogen In a "redox" reaction, coenzymes accept hydrogen. They are now reduced.

Which of the following is a micronutrient? a. carbohydrate b. protein c. mineral d. lipid

c. mineral

Which nutrients function primarily as an energy source for cells?

carbohydrates Carbohydrates are needed in relatively large amounts to supply glucose, the main energy source for body cells.

Which nutrient molecule CANNOT be used in the oxidative pathways? a. glucose b. fatty acids c. cholesterol d. protein

cholesterol No cell uses cholesterol as a fuel that it oxidizes to create energy for itself. Oxidative pathways involve energy production.

Vitamins may also function as _______________.

coenzymes

Which hormone promotes protein catabolism? a. cortisol b. thyroid hormone c. glucagon d. insulin

cortisol Cortisol is increased in catabolic states and may work to increase protein breakdown in muscle tissue and to increase amino acid uptake in liver for gluconeogenesis. As one of the "stress" hormones, cortisol is involved in helping cope with turning to protein and fat breakdown in order to spare limited glucose available if one is injured and unable to eat (post-absorptive state).

Which of the following is NOT a characteristic of glycolysis? a. The final products of glycolysis includes two molecules of pyruvic acid b. Glycolysis produces a net gain of 2 ATP molecules per glucose molecule. c. Glycolysis occurs in the cytosol of a cell. d. Glycolysis requires oxygen

d. Glycolysis requires oxygen Glycolysis cycle may occur in both anaerobic or aerobic conditions

Which element below is considered a trace mineral? a. phosphorus b. sodium c. chlorine d. chromium e. potassium

d. chromium is considered a trace mineral. Impaired glucose metabolism occurs without chromium.

Which of the following would decrease body temperature? a. shivering b. dilation of cutaneous blood vessels c. enhanced thyroxine release d. eating a large meal

dilation of cutaneous blood vessels When blood vessels in the skin dilate, heat from blood in the skin is more likely to dissipate into the environment. This would lead to cooling of the body.

Which statement describes glycolysis? a. This process uses energy captured from electrons flowing to oxygen to produce most of the ATPs in cellular respiration. b. This process produces some ATP and carbon dioxide in the mitochondrion. c. This process joins 2 pyruvic acid molecules into a molecule of glucose. d. This process converts pyruvic acid to acetyl CoA. e. This process splits glucose in half and produces 2 ATPs for each glucose.

e. This process splits glucose in half and produces 2 ATPs for each glucose. In glycolysis, glucose is split into two molecules of pyruvic acid. The released energy is stored in ATP and the electron carrier NADH.

What protein (purine)-rich food should be limited to prevent a reoccurrence of uric acid kidney stones?

eggs eggs are high in cholesterol and should be consumed in moderation or not at all become vegan!

Glucose _____________.

exclusive energy source for neurons (brain).

Most vitamins __________.

function as coenzymes in the body Most vitamins function as coenzymes or parts of coenzymes in the body. Coenzymes help catalyze chemical reactions.

A substance that is said to be reduced has ___________ an electron.

gained

__________ is the key hormone regulator of the postabsorptive state.

glucagon Glucagon raises the blood glucose level and is the key hormone used to handle the postabsorptive (fasting) state. Glucagon is released by the alpha cells in the pancreas and is used for energy "reserve".

The process of forming glucose from noncarbohydrate molecules is known as _______________________.

gluconeogenesis

In the postabsorptive state, __________. a. insulin serves as the main regulatory hormone b. glucose is the main energy source c. anabolism exceeds catabolism d. glycogen is broken down to release glucose

glycogen is broken down to release glucose

The formation of glycogen to store glucose is known as _______________.

glycogenesis

The cleavage of glycogen to release glucose is known as _______________________.

glycogenolysis

Which of the following processes takes place in the cytosol of a eukaryotic cell? a. electron transport chain b. citric acid cycle c. acetyl coA formation d. ATP production by ATP synthase d. glycolysis

glycolysis Glycolysis, the breakdown of glucose into two molecules of pyruvic acid (later converted to acetyl coA), takes place in the cytosol, outside the mitochondria.

What is the correct sequence of steps as energy is extracted from glucose during cellular respiration?

glycolysis → acetyl CoA → citric acid cycle → electron transport chain Glycolysis produces pyruvic acid, which enters the mitochondrion. There, it is converted to acetyl CoA, which enters the citric acid cycle. Electron carriers bring electrons from the first three steps to the electron transport chain, and ATP is made.

A low-density lipoprotein contains __________.

high lipid content The higher the percentage of a lipid in a lipoprotein, the lower the density. LDL usually contain a large amount of cholesterol and lipids.

The role of __________ is to transport excessive cholesterol from peripheral tissue to the liver, where it is broken down and becomes part of bile.

high-density lipoproteins (HDL) The role of high-density lipoproteins is to transport excessive cholesterol from peripheral tissue to the liver, where it is broken down and becomes part of bile.

The hormone that controls essentially all events of the absorptive state is __________.

insulin Rising blood glucose levels after a carbohydrate-containing meal act as a humoral stimulus that prompts the beta cells of the pancreatic islets to secrete more insulin (the insulin will be quick to decrease blood glucose levels). Absorptive state is during the time of "eating". In this moment the liver is "storing" energy for later moments of post-absorptive state.

In the absorptive state, __________. a. glycogen is broken down to release glucose b. catabolism exceeds anabolism c. insulin serves as the main regulatory hormone d. fats are the main energy fuel

insulin serves as the main regulatory hormone

Cyanide acts as a poison by __________.

interfering with the flow of electrons in the electron transport chain. Cyanide acts as a poison by interfering with the flow of electrons in the electron transport chain.

Which of the following is considered a long-term regulator of feeding behavior? a. blood concentrations of amino acids and fatty acids b. leptin levels c. cholecystokinin (CCK) levels d. stimulation of stretch receptors

leptin levels Leptin, is a hormone released from the fat cells located in adipose tissues, that sends signals to the hypothalamus in the brain. This particular hormone helps suppress appetite as well as regulate and alter "long-term food intake" and energy expenditure, not just from one meal to the next.

Essential nutrients refer to nutrients that are __________.

limited in synthesis and therefore should be consumed. Essential nutrients are substances the body cannot make fast enough to meet the body's needs, so our diet must provide them.

Triglyceride synthesis in liver in known as _________________.

lipogenesis

Which of the following is NOT catabolic? a. glycolysis b. lipogenesis c. lipolysis d. beta oxidation of fatty acids

lipogenesis Lipogenesis is an anabolic process (synthesis/ building triglycerides), all other options are catabolic reactions.

Gluconeogenesis happens most commonly in the __________.

liver

The _____________ uses fats/lipids as primary energy.

liver

Prolonged high protein intake can lead to __________.

loss of bone mass Prolonged high protein intake can lead to loss of bone mass due to pH imbalance.

A substance that is said to be oxidized has _______ an electron.

lost *remember oil rig

Minerals may be incorporated into structures to _________________.

make them stronger

The site of electron transport is the __________.

mitochondrial inner membrane (cristae) The inner membrane of the mitochondrion contains the integral proteins necessary for electron transport.

In what organelle would you find acetyl CoA formation, the citric acid cycle, and the electron transport chain?

mitochondrion All of the steps of cellular respiration except glycolysis take place in the mitochondrion.

A kilocalorie is the amount of energy __________.

needed to heat 1 kilogram of water 1°C

A person who is starving is likely to exhibit ___________________.

negative nitrogen balance

Nutritionally incomplete proteins are low in __________.

one or more of the essential amino acids. The 9 essential amino acids are: histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine.

Most of the ATP produced during cellular respiration is produced by ____________.

oxidative phosphorylation during the chemiosmotic process.

The final electron acceptor in the electron transport chain is __________.

oxygen

Cholesterol serves as the _____________________.

precursor to hormones and maintains the fluidity of the plasma membrane

Which of the following would raise body temperature? a. thyroxine b. dilation of cutaneous blood vessels c. sweating d. evaporation

thyroxine Body temperature can be lowered by seeking shade, decreasing activity, sweating, dilation of cutaneous capillaries to radiate heat to the environment, and wearing loose, light-colored clothing. As sweat evaporates from the body, cooling occurs. Mechanisms that raise body temperature include constricting cutaneous capillaries to reduce the loss of heat to the environment, shivering, increasing physical activity, eating, and raising levels of certain hormones such as thyroxine.

A function of the liver during the post-absorptive state is __________.

to mobilize glucose reserves by glycogenolysis The liver mobilizes glucose reserves quickly and efficiently to maintain blood sugar levels for about four hours during the post-absorptive state. Post-absorptive state is during times of "fasting' when the body is relying on using up its energy "reserves".

What is the primary function of cellular respiration?

to regenerate ATP Cellular respiration takes energy from our food nutrients and transfers that energy into a usable form of energy in ATP.

The body's overall rate of energy output is called the ___________________________

total metabolic rate (TMR) The total metabolic rate (TMR) is the rate of kilocalorie (energy) consumption needed to fuel all physiological activities, involuntary and voluntary. Food ingestion induces a rapid increase in TMR. This effect is called food-induced thermogenesis. The basal metabolic rate (BMR) is the energy the body needs to perform only its most essential activities, such as breathing and maintaining resting levels of organ function. The lowest metabolic state of the body, however, occurs during sleep.

The final product of glycolysis is __________.

two molecules of pyruvic acid, two molecules of NAD+, and a net gain of two ATP

Which of the following is NOT an essential role of the liver? a. urea disposal b. protein metabolism c. biotransformation functions d. carbohydrate metabolism

urea disposal Though the liver is involved in creating urea from ammonia and carbon dioxide, it is up to the kidney to eliminate the urea thus formed.

Ammonia, which is a byproduct of protein metabolism, is converted to __________ primarily in the __________.

urea; liver Ammonia produced during protein metabolism is converted into urea in the liver.

A major means for conserving heat is __________. a. enhanced sweating b. increased metabolic rate c. increased convective loss d. vasoconstriction of cutaneous blood vessels

vasoconstriction of cutaneous blood vessels The skin serves as a radiator of heat.

Which of the following is NOT a fat-soluble vitamin? a. vitamin B b. vitamin D c. vitamin K d. vitamin A

vitamin B Vitamin B is a water-soluble vitamin.

Which of the following is NOT correctly matched in regards to BMR (basal metabolic rate)? a. high body temperature (nonfever): higher BMR b. low thyroxine: low BMR c. increased stress: increased BMR d. younger age: lower BMR

younger age: lower BMR The younger a person is, the higher the BMR should be. As a person ages, the BMR declines.