NDT Chapter 7: Metabolism

TCA cycle

repetitive series of eight metabolic reactions, located in cell mitochondria, that metabolizes acetyl CoA for the production of carbon dioxide, high energy GTP, and reduced coenzymes NADH and FADH2

glucose from glycogen degradation in muscle is used for energy by the muscle cells is an example of _____________

short term fasting

glycogen degradation in the liver helps maintain blood glucose levels is an example of _____________

short-term fasting

Which meal would be most likely to increase the use of ketones for energy? -spinach and cheese omelet with bacon -spinach and cheese omelet with buttered whole wheat toast -spinach and cheese omelet with a plain bagel -spinach and cheese omelet with an orange

spinach and cheese omelet with bacon

megadosing

taking a dose of a nutrient that is 10 or more times greater than the recommended amount

proteolysis

the breakdown of dietary proteins into single amino acids or small peptides that are absorbed by the body

catabolism

the breakdown, or degradation, of larger molecules to smaller molecules

example of anabolic hormones

insulin

Fill in the blank about metabolic hormones. ____________ promotes storage of macronutrients. -Cortisol -Insulin -Epinephrine -Glucagon

Insulin

Which of the following statements is correct regarding the hormonal control of metabolism during the fed state? -Glucagon from the pancreas stimulates protein synthesis, glycogen synthesis, and lipogenesis when blood glucose levels are low. -Insulin released from the pancreas stimulates glycogen synthesis, lipogenesis, and protein synthesis. -Epinephrine from the adrenal glands stimulates glycogen synthesis and protein degradation, but it has little to no effect on lipid metabolism. -Cortisol from the adrenal glands stimulates protein synthesis, gluconeogenesis, and lipolysis.

Insulin released from the pancreas stimulates glycogen synthesis, lipogenesis, and protein synthesis.

In the absence of oxygen, the pyruvate produced through glycolysis is converted to -acetyl CoA. -lactate. -NADH. -oxaloacetate.

lactate

________________ is the process in which excess glucose or amino acids are converted into fatty acids to be stored as a triglyceride in the adipose cells

lipogenesis

Fatty acids are cleaved from the glycerol backbone to yield free fatty acids in a process called _______________

lipolysis

fatty acids are converted to ketone bodies that can be utilized for fuel by all cells and tissues except red blood cells is an example of _____________

long term fasting

the liver utilizes single amino acids from the catabolism of muscle for gluconeogenisis is an example of _____________

long term fasting

acetyl CoA

metabolic intermediate resulting from the reaction between coenzyme a, which is derived from the b vitamin pantothenic acid, and two carbon acetate semicolon sometimes referred to as acetyl coenzyme A

Adenosine Diphosphate (ADP)

metabolic intermediate that results from the removal of one phosphate group from ATP

major minerals

minerals that the body requires an amounts of at least 100 mg per day and of which the total amount present in the body is at least 5 g

ultra trace minerals

minerals the body requires an amounts less than 1 mg per day

trace minerals

minerals the body requires an amounts less than 100 mg per day and of which the total amount present in the body is less than 5 g

Most lipogenesis -occurs when individuals consume an excess of glucogenic amino acids -occurs in adipose cells. -occurs when acetyl CoA is converted into glycerol, which is in turn attached to fatty acid chains. -occurs in liver cells

occurs in liver cells

coenzyme

organic (carbon-containing) co-factor; many coenzymes are derived from b vitamins

Which of the following might result in low levels of oxaloacetate? -consuming excess kilocalories from carbohydrate, protein, and fat -a low carbohydrate diet or starvation conditions -eating a high-carbohydrate diet -consuming insufficient dietary protein

a low carbohydrate diet or starvation conditions

adenosine monophosphate (AMP)

a low-energy compound that results from the removal of two phosphate groups from ATP

glycolysis

a sequence of chemical reactions that converts glucose to pyruvate

beta oxidation (fatty acid oxidation)

a series of metabolic reactions that oxidize free fatty acids, leading to the end products of water, carbon dioxide, and ATP

electron transport chain

a series of metabolic reactions that transport electrons from NADH or FADH2 through a series of carriers, resulting in ATP production

albumin

a serum protein, made in the liver, that transports free fatty acids from one body tissue to another

co-factor

a small, non-protein substance that enhances or is essential for enzyme action;

carnitine

a small, organic compound that transports pretty fatty acids from the cytosol into the mitochondria for oxidation

Calorimeter

a special instrument in which food can be burned and the amount of heat that is released can be measured; this process demonstrates the energy (caloric) content of the food

lactate ( lactate acid)

a three carbon compound produced pipe from pyruvate and oxygen deprived conditions

vitamins

organic micronutrient compounds essential for regulating body processes; classified as water soluble or fat soluble

molecule donating an electron is __________

oxidized

Which of the following are ketones? -ketoglutarate -citrate -acetoacetate and beta-hydroxybutyrate -oxaloacetate

acetoacetate and beta-hydroxybutyrate

examples of ketone bodies

acetoacetate, beta-hydroxybutyrate, acetone

Excessive ketones are produced when -acetyl CoA is converted to glucose. -oxaloacetate availability falls and TCA cycle activity decreases. -people follow a high-carbohydrate, low-fat diet. -All of the above can prompt the production of ketones.

acetyl CoA is converted to glucose

ketogenic amino acid

an amino acid that can be converted to acetyl CoA for the synthesis of free fatty acids

glucogenic amino acid

an amino acid that can be converted to glucose via gluconeogenesis

dehydration synthesis

an anabolic process by which smaller, chemically simple compounds are joined in a molecule of water is released; also called condensation

Aldehyde dehydrogenase

an enzyme that oxidizes acetaldehyde to acetate

The process of converting excess glucose to glycogen in the liver and muscle is a(n) ______________ reaction

anabolic

amino acids from the amino acid pool are used to replace old proteins is an example of __________________

anabolic processes

excess amino acids are converted to fatty acids and stored as triglycerides in the adipose tissue is an example of __________________

anabolic processes

excess fatty acids combine with glycerol to form triglycerides, which are stored in adipose tissue is an example of __________________

anabolic processes

excess glucose is stored as glycogen in the liver and muscle is an example of __________________

anabolic processes

The bonding of two amino acids to form a dipeptide is _____. -anabolism -ketogenesis -catabolism -phosphorylation

anabolism

alcohol dehydrogenase (ADH)

and inside that converts ethanol to acetaldehyde in the first step of alcohol oxidation

The end product of glycolysis is __________ -lactate -pyruvate -adenosine triphosphate -acetyl CoA

pyruvate

oxidation reduction reactions

reactions in which electrons are lost by one atom or molecule ( it is oxidized) and simultaneously gained by another (it is reduced)

molecule gaining an electron is ____________

reduced

glucose is used as fuel source for red blood cells, brain cells, and other tissues is an example of _____________

both short term and long term fasting

triglycerides in adipose tissue are broken down during lipolysis to provide fatty acids for energy is an example of _____________

both short term and long term fasting

Which cells are capable of utilizing ketone bodies for ATP when glucose is limited? -red blood cells -brain, skeletal muscle, and fat cells -liver cells

brain, skeletal muscle, and fat cells

Acetyl CoA is the "gateway molecule" for energy metabolism because __________. -carbohydrates, protein, and fats can all be catabolized into acetyl CoA before entering the TCA cycle -It facilitates the transport of glucose into cells -it can be produced with or without oxygen -it is produced only from the body's preferred carbohydrate energy source

carbohydrates, protein, and fats can all be catabolized into acetyl CoA before entering the TCA cycle

dietary carbohydrate from a meal is digested and absorbed as monosaccharides, mainly glucose is an example of __________________

catabolic processes

dietary fat from a meal is digested and absorbed as monoglycerides, free fatty acids, and glycerol is an example of __________________

catabolic processes

dietary protein from a meal is digested and absorbed as single amino acids is an example of __________________

catabolic processes

glucose is used as the primary fuel for energy is an example of __________________

catabolic processes

phosphorylation

the addition of one or more phosphate groups to a chemical compound

keto acid

the chemical structure that remains after a deamination of an amino acid

lipolysis

the enzyme driven catabolism of triglycerides into free fatty acids and glycerol

de novo synthesis

the process of synthesizing a compound "from scratch"

When you eat a large meal and take in excess energy, __________. -fat is pulled from the adipose tissue so the excess carbohydrate in the meal can be spared -the rate of glucose oxidation increases and more fat is stored -the rate of protein oxidation decreases and glycogen becomes preferred as a fuel -the rate of fat metabolism increases to decrease storage in the adipose tissue

the rate of glucose oxidation increases and more fat is stored

lipogenesis

the synthesis every fatty acid from non lipid precursors, such as ketogenic amino acids or ethanol

Gluconeogenesis

the synthesis of glucose from non-carbohydrate precursors, such as glucogenic amino acids and glycerol

anabolism

the synthesis of larger molecules from smaller ones

carbon skeleton

the unique side group that remains after deamination of an amino acid semicolon also referred to as a ketoacid

Which of the following statements is correct regarding the anabolic reactions that occur during the fed state? -During the fed state, glycogen synthesis is favored to store excess glucose as glycogen in the liver and the muscle. -During the fed state, excess amino acids are used for energy production after they have first been deaminated. -During the fed state, gluconeogenesis is favored to raise blood glucose levels. -During the fed state, beta-oxidation of fatty acids is favored to raise blood glucose levels.

During the fed state, glycogen synthesis is favored to store excess glucose as glycogen in the liver and the muscle.

T/F Body fat is the only option for storing energy consumed in excess of short-term energy needs

FALSE

T/F Glycolysis yields a net of four ATP that can be used as energy for the cell.

FALSE

Which of the following statements correctly describes carbohydrate metabolism during the fasting state? -In the later stages of the fasting state, fatty acids can be converted to glucose to supply the brain and red blood cells with fuel. -Excess glucose is converted to a fatty acid, attached to a glycerol backbone, and stored as a triglyceride in adipose tissue in the fasting state. -Muscle glycogen stores are depleted early in the fasting state. -Liver glycogen stores are utilized to supply the blood with glucose even during long-term fasting

Muscle glycogen stores are depleted early in the fasting state.

T/F Every cell of the body is metabolically active

TRUE

What is pyruvic acid? -a six-carbon molecule transformed from glucose -a three-carbon molecule formed from the breakdown of glucose during glycolysis -a three-carbon molecule that enters the TCA cycle when there is a lack of oxygen -None of these answers is correct.

a three-carbon molecule formed from the breakdown of glucose during glycolysis

Of the approximately 160,000 kcal reserves in the body of a well-nourished 70-kg male -about 75% is from triglycerides, and most of the remaining 25% is from glycogen. -triglycerides account for about 50%, and glycogen and protein each about 25%. -triglycerides, glycogen, and protein each account for about 33%. -about 85% is from triglycerides, and most of the remaining 15% is from protein.

about 85% is from triglycerides, and most of the remaining 15% is from protein.

Ketone production by the liver increases when __________. -total energy intake exceeds output -glycogen stores are high -excess fat is eaten -carbohydrate is depleted

carbohydrate is depleted

Glucagon, epinephrine, and cortisol are -coenzymes. -anabolic hormones. -catabolic hormones. -cofactors

catabolic hormones.

Complete the statement about protein catabolism. Amino acids contain nitrogen, which must be removed via oxidative ____________ in order for the carbon skeleton to be used for energy -proteolysis -deamination -urea synthesis -glycolysis

deamination

Fill in the blank about metabolic reactions. In the process of ____________, water is always released -dehydration synthesis -hydrolysis -phosphorylation -oxidation-reduction

dehydration synthesis

ketones are by-products of ______________

fat catabolism

The process in which glucose is broken down to yield pyruvate and energy is called ____________

glycolysis

Choose the item that lists the steps involved in glucose oxidation in the correct order. (Assume an aerobic environment is present -glycolysis, TCA cycle, electron transport chain -glycolysis, pyruvate conversion to lactate, Cori cycle -glycolysis, electron transport chain, TCA cycle -electron transport chain, TCA cycle, glycolysis

glycolysis, TCA cycle, electron transport chain

Which of the following is the correct sequence in the breakdown of glucose to provide ATP? -TCA cycle, oxidative phosphorylation, glycolysis -glycolysis, TCA cycle, oxidative phosphorylation -glycolysis, oxidative phosphorylation, beta-oxidation -oxidative phosphorylation, TCA cycle, glycolysis

glycolysis, TCA cycle, oxidative phosphorylation

anabolism is critical for ______________

growth, repair, maintenance, and synthesis of chemical products essential for human functioning

In which of the following types of chemical reactions is a compound catabolized by the addition of a molecule of water? -hydrolysis -oxidation -dehydration synthesis -phosphorylation

hydrolysis

The process in which compounds are broken apart with the addition of water is called __________. -dehydration synthesis -oxidation-reduction -phosphorylation -hydrolysis

hydrolysis

_________________ is a back-up source of energy for carbohydrate-deprived cells

ketone production

minerals

naturally occurring elements essential for the formation of blood, bone, many enzymes, and other crucial compounds; classified as major, trace, or ultra Trace

micronutrients

nutrients needed in relatively small amounts to support normal health and body functions.

examples of cofactors

trace minerals such as iron, zinc and copper function as co-factors

what is the function of catabolic hormones

trigger the breakdown of stored triglycerides, glycogen, and body protein for energy

T/F NADH and FADH2 are formed as each acetyl CoA molecule is formed

true

Choose the correct statements about fat metabolism -During β-oxidation, fatty acids are broken down into two-carbon segments. -Lipolysis results in three fatty acids and glycerol. -It requires more steps to convert glucose to energy than it does to convert triglycerides to energy. -Carnitine transports triglycerides across the mitochondrial membrane for oxidation. -Cells can convert fat-derived acetyl CoA to glucose, allowing fatty acids to feed glucose production.

-During β-oxidation, fatty acids are broken down into two-carbon segments. -Lipolysis results in three fatty acids and glycerol.

the electron transport chain is initiated by the electrons donated from _________ and ___________ to yield ___________ and ___________

-NADH -FADH2 -ATP -H2O

What occurs in the body during a short-term fasting state? Select all that apply. -The body shifts to a catabolic state. -Decreased immune function may lead to infection. -Gluconeogenesis increases. -Skeletal and cardiac muscles are broken down for fuel. -Liver glycogen is broken down to increase blood glucose.

-The body shifts to a catabolic state. -Gluconeogenesis increases. -Liver glycogen is broken down to increase blood glucose.

glycolysis occurs in the ____________ and ______________ require oxygen

-cytosol -does not

example of catabolic hormones

-glucagon -epinephrine -cortisol

glycolysis is the breakdown of ________ into two molecules of _______________ and yields 2 ___________ and 2 ___________

-glucose -pyruvate -ATP -NADH

lypolysis is the breakdown of __________ and ___________ to form _____________

-glycerol -fatty acids -acetyl CoA

what is the function of insulin

-increases in the blood after a meal -activates storage enzymes -signals cellular uptake of glucose, fatty acids, and amino acids

Adenosine monophosphate -can be regenerated by adding two phosphate groups to ATP. -is composed of one molecule of adenosine bonded to one phosphate group. -is produced when one phosphate group is released from ATP. -has one high-energy phosphate bond.

-is composed of one molecule of adenosine bonded to one phosphate group.

lipolysis occurs in the ___________ and ___________ require oxygen

-mitochondria -does

acetyl CoA enters the TCA by combining with _____________. When ______________ is low or absent, acetyl CoA is converted into ___________ which can provide fuel to some cells in times of low glucose

-oxaloacetate -glucse -ketones

when oxygen is limited ____________ is converted to ______________. This allows glycolysis to ________________ by providing ______________

-pyruvate -lactate -continue -NAD+

examples of fat soluble vitamins

A, D, E, K

The energy molecule cells use to perform their functions is _____ -CoA -AMD -ADP -ATP

ATP

what is used by cells as a source of metabolic energy

ATP

Which of the following metabolic reactions occurs when a cell requires energy? -ATP gains a phosphate group and becomes ADP. -ADP releases a phosphate group and becomes ATP. -ATP releases a phosphate group and becomes ADP. -ADP gains a phosphate group and becomes ATP.

ATP releases a phosphate group and becomes ADP.

Which of the following statements regarding the TCA cycle is FALSE? -At the end of the TCA cycle, eight hydrogen ions have been transferred to the electron transport chain. -During the TCA cycle, energy is released to NAD+ to form NADH and H+. -During the TCA cycle, eight metabolic reactions have occurred. -Acetyl CoA combines with a two-carbon molecule called malate to form citrate.

Acetyl CoA combines with a two-carbon molecule called malate to form citrate.

Choose the correct statement about anabolism and catabolism -Growth and repair of body tissues are directly achieved through catabolic reactions. -Anabolism releases chemical energy. -Catabolism provides the energy required for anabolic reactions. -Fetal growth represents a net catabolic state

Catabolism provides the energy required for anabolic reactions

T/F The conversion of dietary Carbohydrate to body fat is less efficient than the conversion of dietary fat to body fat

FALSE

T/F You can speed up your liver's breakdown of alcohol by drinking a beverage containing caffeine

FALSE

Which of the following statements correctly describes lipid metabolism during the fasting state? -Lipogenesis creates triglycerides from excess carbohydrates, proteins, and fats, which are stored during the later stages of the fasting state. -Fatty acids are rapidly broken down from adipose tissues and converted to ketone bodies during the later stages of the fasting state. -Ketogenesis is stimulated by the breakdown of stored muscle glycogen during the early stages of the fasting state. -During long-term starvation, ketone bodies can be used by the red blood cells but not by the brain, which relies on glucose produced by gluconeogenesis

Fatty acids are rapidly broken down from adipose tissues and converted to ketone bodies during the later stages of the fasting state.

Which of the following statements correctly describes protein metabolism during the fasting state? -Beta-oxidation is a series of metabolic reactions in which amino acids are oxidized to yield energy. -Amino acids provide energy at a steady pace throughout the fasting state. -Protein metabolism is halted during the fasting state. -Glucogenic amino acids are used to produce glucose through gluconeogenesis during the fasting state

Glucogenic amino acids are used to produce glucose through gluconeogenesis during the fasting state

What is the fate of glycerol during the process of converting triglycerides to energy? -Glycerol directly enters the TCA cycle. -Glycerol is converted directly to acetyl CoA. -Glycerol (a three-carbon molecule) is converted to pyruvate.

Glycerol (a three-carbon molecule) is converted to pyruvate.

Which of the following occurs in people following a very low-carbohydrate diet? -Ketones are produced. -ATP production becomes more efficient. -Insulin levels increase drastically. -Body glycogen stores are preserved.

Ketones are produced.

Anya skipped breakfast this morning. It is now midafternoon, and she has joined a friend for a late lunch. Although she rarely drinks alcohol, while waiting for her food to arrive, she enjoys a glass of wine. Which of the following statements best describes Anya's body's response to the alcohol? -Gastric ADH oxidizes about 30% to 35% of the alcohol Anya consumes; the rest is absorbed into her bloodstream. -None of the above statements is true. -The microsomal ethanol oxidizing system (MEOS) breaks down about 20% of the alcohol Anya consumes before it is absorbed into her bloodstream. -When the alcohol enters Anya's bloodstream, her muscles quickly take it up for oxidation before her blood alcohol level increases.

None of the above statements is true.

Choose the correct statement about nutrient synthesis. -Cholesterol must be ingested from an individual's diet because it is an essential nutrient. -Gluconeogenesis involves the synthesis of glucose from carbohydrate substrates. -Lipogenesis occurs when an individual consumes excess fat. -Nonessential amino acids (NEAAs) can be synthesized from carbohydrate or fat metabolic intermediates when adequate energy and nitrogen are present in the body

Nonessential amino acids (NEAAs) can be synthesized from carbohydrate or fat metabolic intermediates when adequate energy and nitrogen are present in the body

T/F Certain vitamins are essential for producing energy in the body

TRUE

T/F During a period of extreme starvation, the body will use heart muscle for energy and to help maintain blood glucose levels

TRUE

T/F During prolonged starvation, serum levels of free fatty acids increase sharply

TRUE

T/F Liver synthesis of urea increases as dietary protein intake increases

TRUE

T/F When cells engage in catabolism, chemical energy is released.

TRUE

Which of the following statements regarding the electron transport chain is FALSE? -Water is formed when donated electrons are transferred to oxygen. -ATP is created when protons pass through the ATP synthase complex. -The electron transport chain is the final stage of glucose oxidation. -The electron transport chain takes place in the cytoplasm of the cell.

The electron transport chain takes place in the cytoplasm of the cell

What is the first step in utilizing stored fatty acids for ATP? -The first step is to convert glycerol into acetyl CoA in the mitochondria. -The first step is the hydrolysis of fatty acids from glycerol in the stored triglyceride. -The first step is to transfer high-energy electrons to NAD+. -The first step is to convert fatty acids to acetyl CoA in the mitochondria.

The first step is the hydrolysis of fatty acids from glycerol in the stored triglyceride

nicotinamide adenine dinucleotide

a coat in time form of the b vitamin niacin; NAD readily accepts electrons (hydrogen) from various donors

flavin adenine dinucleotide

a coenzyme derived from the b vitamin riboflavin; FAD readily accepts electrons (HYDROGEN) from various donors

Adenosine Triphosphate (ATP)

a high energy compound made up of the purine adenine, the simple sugar ribose, and three phosphate units;

microsomal ethanol oxidizing system

a liver enzyme system that oxidizes ethanol to acetaldehyde; it's activity predominates at higher levels of alcohol intake

hydrolysis

a catabolic process by which a large, chemically complex compound is broken apart with the addition of water

hydrolysis

a chemical reaction that breaks down substances by the addition of water

Which of the following is a possible fate of acetyl CoA? -broken down to ammonia -conversion to pyruvate -directed into fatty acid synthesis -broken down to urea

directed into fatty acid synthesis

How many acetyl CoA molecules are produced from one 16-carbon-chain fatty acid? -four acetyl CoA molecules -eight acetyl CoA molecules -sixteen acetyl CoA molecules -thirty-two acetyl CoA molecules

eight acetyl CoA molecules

Which of the following CANNOT be synthesized from the metabolic intermediates of either fat or carbohydrate? -fatty acids -glucose -non-essential amino acids -essential amino acids

essential amino acids

T/F NADH and FADH2 are reduced during the reactions in the electron transport chain

false

Which of the following CANNOT be converted to glucose? -glycerol -glycogen -fatty acids -glucogenic amino acids

fatty acids

During short-term fasts, the body uses -amino acids from the breakdown of body proteins for gluconeogenesis. -muscle and liver glycogen for glucose for red blood cells, brain cells, and other body cells. -glycerol from adipose tissue to synthesize ketone bodies. -glucogenic amino acids to synthesize glucose.

glucogenic amino acids to synthesize glucose

The formation of glucose from noncarbohydrate sources such as glucogenic amino acids is called ____________________

gluconeogenesis

What is (are) the major metabolic source(s) of acetyl CoA for a healthy person who is getting an adequate amount of calories? -glucose from glycolysis and the oxidation of fatty acids -glycerol -beta-hydroxybutyrate -amino acids

glucose from glycolysis and the oxidation of fatty acids

Amino acids are unique from other energy-yielding compounds in that -they cannot be converted to glucose (gluconeogenesis). -they contain nitrogen, which must be removed before the remaining compound can be used for energy. -even when consumed to excess, they will not increase the synthesis of fatty acids. -they contain ammonia, which the kidneys convert to urea and excrete from the body in urine

they contain nitrogen, which must be removed before the remaining compound can be used for energy.

ketone bodies

three and four carbon compounds synthesized by the liver when acetyl CoA levels become elevated

Fill in the blank about energy storage. In a healthy adult, the most abundant source of stored energy is ____________. -triglycerides -circulating amino acids -muscle glycogen -stored starch -stored protein

triglycerides

Humans appear to have an unlimited ability to store __________. -glycogen -triglycerides -water -protein

triglycerides

An example of a catabolic reaction would be __________ -condensation -glycogen synthesis in the liver -triglycerides being broken down to fatty acids and glycerol -the conversion of ADP to ATP

triglycerides being broken down to fatty acids and glycerol

T/F The process of converting fatty acids into ATP is called fatty acid oxidation

true

How many carbons does acetyl CoA contain? -two -three -four -six

two

example of water soluble vitamins

vitamin c in the b vitamins

examples of micronutrients

vitamins and minerals

fat soluble vitamins

vitamins that are soluble and fat

water soluble vitamins

vitamins that are soluble in water