Nutritional Biochemistry Study Guide
Steatosis
'fatty liver' occurs when fat accumulates in the liver. Normally, fatty acids serve as the main source of fuel for the liver. When alcohol replaces fatty acids as the livers main source of energy, unused fatty acids accumulate as triglyceride in the liver; steatosis is reversible by reducing alcohol consumption.
2 reactions vit D active form
(undergo 2 hydroxylation reactions): a. In the liver, vitamin D is hydroxylated to 25-hydroxyvitamin D [25(OH)D], also called calcidiol. b. In the kidneys, 25(OH)D is further hydroxylated to 1,25-dihydroxyvitamin D [1,25(OH)2D], the active form calcitriol.
A change in the concentration of enzymes that catalyze fatty acid synthesis has been shown to be a major mechanism for controlling synthesis rate. Give two regulatory means of changing enzyme concentrations:
activation of zymogens and the product of new enzymes through induction
nonessential amino acids
amino acids that can be synthesized by the body
urea cycle fuel
carbamoyl phosphate
urea cycle function
converts toxic ammonia into less toxic urea for excretion from the body
Where in the cell does fatty acid biosynthesis occur?
cytoplasm
Match the terms transamination and deamination to the following: an ammonium ion is produced
deamination
Which of the following processes must occur before amino acids can be metabolized to release energy? a. fermentation b. deamination c. dehydrogenation
deamination
heme iron
derived from hemoglobin; meats are rich in heme iron; more easily absorbed
Cirrhosis
dying liver cells are replaced by fibrous scar tissue; a cirrhotic liver is unable to remove toxins from the blood, regulate CHO metabolism, synthesize hepatic proteins, or covert ammonia to urea. Although diet and lifestyle changes may ameliorate some of the symptoms of cirrhosis, the damage is irreversible, and a liver transplant is often the only treatment option
megaloblastic macrocytic anemia
folate deficiency; characterized by large, fragile red blood cells; characteristic of B12 deficiency
Based on the following conversions, classify each amino acid as glucogenic or ketogenic. aspartate ------ oxaloacetate:
glucogenic
Describe the two fates of glycerol after it has been converted to an intermediate glycolysis:
glycerol can be converted to pyruvate and contribute to cellular energy production or be converted to glucose
iodine deficiency
goiter and cretinism
chronic kidney disease
have difficulty maintaining appropriate levels of calcium and phosphorus in the blood. The kidneys are not able to adequately reabsorb calcium or hydroxylate vit D, so calcium and 1,25(OH)2D supplements are often necessary. restriction of phosphorus/phosphate
transferrin
iron in plasma must be bound to a carrier protein
ferritin
is a protein that stores iron in the body. can sequester or release iron, depending on the body's needs.
iodine
is a trace element; seafood is good source; table salt
Alcoholic hepatitis
is characterized by inflammation and swelling of the liver. This condition can produce irreversible damage and can even be fatal.
calcium homeostasis
is regulated by parathyroid hormone PTH and vit D.
tyrosine
is synthesized from an essential amino acid precursor - phenylalanine
The clinic nurse is evaluating a man wearing a diabetic medic alert band, who appears confused, with hot, dry, flushed skin. His respirations are deep and fast, and he says he is nauseated. His breath smells fruity. What diabetes-related medical condition is this man exhibiting?
ketoacidosis
Based on the following conversions, classify each amino acid as glucogenic or ketogenic. leucine ------ acetyl CoA:
ketogenic
Define the 3 stages of alcoholic liver disease.
steatosis alcoholic hepatitis cirrhosis
What is the storage form of fat in the body?
triglycerides
liver
urea cycle takes place
amino acid functions
1. They are the building blocks for the synthesis of proteins 2. They provided carbon and nitrogen atoms for the synthesis of other biomolecules 3. They can be sources of energy
vitamins that act as steroid hormones
A and D
What substances are produced by the digestion of proteins?
Amino acids
Name the alternate pathway for ethanol metabolism that is activated by heavy ethanol consumption.
At moderate concentrations, ethanol is metabolized by alcohol dehydrogenase. However, large does invoke another pathway called Microsomal Ethanol Oxidizing System (MEOS) in the endoplasmic reticulum of the liver.
what mechanism exists in the body from transporting insoluble lipids
Chylomicrons are lipoprotein aggregates found in the lymph and the bloodstream.
synthesized when skin is exposed to sun
D
Why do the 2010 dietary guidelines define "moderate" alcohol intake as two drinks per day for men, but only one for women?
Differs between genders: for a given amount of alcohol, women tend to have a higher blood alcohol concentration than men. This is partly due to the smaller size and lower total body water of women. However, women have lower activity of a stomach enzyme that metabolizes alcohol, allowing faster absorption of ingested alcohol into the blood.
In your reading assignment, the relationship between alcohol and cardiovascular disease risk is described as a "J-shaped" curve. Explain.
Dose response curve; blood pressure effects of alcohol vary according to chronicity and amount of intake. On the other hand, short-term lowering of blood pressure by alcohol is known. A J shaped relation between alcohol and blood pressure has been suggested with moderate drinkers having a lower blood pressure level, with the lowest levels in consumers of 1 to 3 drinks per day.
How does ethanol absorption from the GI tract differ from absorption of macronutrients?
Ethanol does not need to be digested to smaller end products to be absorbed; can be absorbed in the stomach, so blood alcohol levels will begin to rise within minutes of ingestion; rate of absorption of ethanol factors - whether alcohol is consumed with food as well as the type and amount of food will affect ethanol's rate of absorption. In any case, ethanol is always metabolized much more slowly than it is absorbed.
What hydrogen-transporting coenzymes play important roles in the oxidation of fatty acids?
FAD and NAD+
What is the role of NAD+ and FAD in β-oxidation?
Function as electron carriers.
What are the products of triglyceride digestion?
Glycerol, fatty acids, monoglycerides
Describe how heavy ethanol consumption leads to "fatty liver." •
Heavy ethanol consumption leads to an accumulation of NADH, which in turn, disrupts normal liver metabolism: High concentrations of NADH favor the conversion of pyruvate to lactate. Buildup of lactic acid may disrupt acid/base homeostasis. o Excessive acetyl CoA can also lead to the formation of acidic ketone bodies which worsen acidosis. • High concentrations of NADH inhibit fatty acid oxidation and stimulate fatty acid biosynthesis. o Accumulation of triglycerides in the liver can result in steatosis "fatty liver"
A 7.48 mg sample of blood lipid was found to contain 1.87 mg of protein. Use figure 14.4 to classify this lipid:
It is an LDL
For the pathway MEOS, list 2 ways this pathway differs from "normal" ethanol metabolism. •
MEOS does not result in the production of ATP, but it is the body's attempt to eliminate dangerous acetlyaldehyde. • Breakdown of alchol by the ethanol-oxidizing pathway also generates many reactive oxygen species (ROS).
Which coenzyme acts as an electron-acceptor in the normal metabolism of ethanol? NAD+ ; when ethanol is oxidized, NAD+ is reduced to NADH.
NADH can enter the electron transport chain for ATP production ETOH is a more concentrated source of energy than CHO; it provides 7 kcals/g compared to 4 kcals/g for CHO
What 16-C fatty acid is formed from de novo fatty acid synthesis
Palmitate
Why can the liver convert glucose to fatty acids but cannot convert fatty acids to glucose?
The human body can convert glucose to fatty acids, but it cannot convert fatty acids to glucose. Our cells contain no enzyme that can catalyze the conversion of acetyl CoA to pyruvate, a compound required for gluconeogenesis.
In what organ of the body is urea synthesized?
The liver
Why is ethanol intake during pregnancy potentially harmful to the fetus?
The liver of a fetus does not contain the enzymes necessary to breakdown ethanol, so ethanol that crosses the placenta and enters the fetus can lead to deformities and mental retardation typical of fetal alcohol syndrome. Fetal Alcohol Spectrum Disorder (FASD) pg 3 of Alcohol Alert
amino acid sources
The maintenance of the body proteins must occur constantly in the body because tissue proteins break down regularly from normal wear and ear, as well as from diseases and injuries. The amino acids used in this maintenance come from: 1. proteins that are eaten and hydrolyzed during digestions 2. the boy's own degraded tissue 3. the synthesis in the liver of certain amino acids
glucogentic amino acid
The skeleton of an amino acid that is degraded into pyruvate or intermediates of the citric acid cycle can be used to make glucose and is classified as a glucogenic amino acid.
Why is the oxidation of fatty acids referred to as the fatty acid spiral rather than the fatty acid cycle?
The word cycle implies that the product is identical to the starting material, which is not the case. The fatty acyl product of a trip through the sequence has two fewer carbon atoms than the starting material.
goiter
Thyroid stimulating hormone (TSH) secreted by the pituitary stimulates the thyroid gland in the next to take up iodine from the blood for synthesis of thyroid hormones. If dietary iodine intake inadequate, the thyroid gland in the neck can become enlarged in a futile attempt to make more thyroid hormones.
Why is ketosis frequently accompanied by acidosis?
Two of the ketone bodies are carboxylic acids, which lower blood pH.
Why are vitamin toxicities usually associated with fat soluble vs water soluble vitamins?
Water soluble vitamins are easily excreted by the kidneys, so toxicities from megadoses are not a likely as for fat soluble vitamins which can be sequestered and stored by body fat.
Why is fat considered "a more concentrated source of energy" than carbohydrate or protein?
When energy is needed, triglycerides are mobilized from storage, and fatty acids are oxidized to yield ATP. One gram of fat provides 9Kcal of energy compared to 4Kcal of CHO and PRO (4Kcal of energy per gram). Provides a very concentrated source of energy.
ketosis
When ketonemia, ketonuria, and acetone breath exist simultaneously
Is any amino acid both glucogenic and ketogenic?
Yes; isoleucine, tryptophan, phenylalanine, and tyrosine
ketogenic amino acid
Amino acids with skeletons that are degraded into acetyl CoA or acetoacetyl CoA cannot be converted into glucose but can, in addition to energy production, be used to make ketone bodies ad fatty acids.
What are ketone bodies?
Are three compounds formed from acetyl CoA: acetoacetate, B-hydroxybutyrate, and acetone.
Ketonuria
At a level about 70 mg/100mL of blood, the renal threshold for ketone s bodies is exceeded, and ketone bodies are excreted in the urine.(ketones in the urine)
Why can't fatty acids directly serve as fuel for the brain?
Brain cells are bathed in cerebrospinal fluid and do not obtain nutrients directly from the blood because of the blood-brain barrier. Red blood cells cannot oxidize fatty acids because red blood cells have no mitochondria, the site of fatty acid oxidation.
Where in the cell does β-oxidation take place?
Mitochondria
protein turnover
the continuing process in which body proteins are hydrolyzed and resynthesized. The turnover rate, or life expectancy, of body proteins is a measure of how fast the proteins are broken down and resynthesized. The turnover rate is usually expressed as a half-life.
List two general sources of intermediates for the biosynthesis of amino acids:
the glycolysis pathway and the citric acid cycle.
What happens to the products of triglyceride digestion inside intestinal mucosal cells?
During digestion, triglycerides are hydrolyzed to glycerol, fatty acids, and monoglycerides (one fatty acid attached to glycerol). Phosphoglycerides are also hydrolyzed to their component substances. These smaller molecules, along with cholesterol, are absorbed into cells of the intestinal mucosa, where resynthesis of the triglycerides and phosphoglycerides occurs.
vitamins C, E, beta carotene, and several trace minerals act as antioxidants. What is oxidative damage?
E, C, beta carotene, and several trace minerals act as important antioxidants in the body. Free radicals are atoms or molecules with one or more unpaired electrons. An atom with an unpaired electron will be very reactive. In an attempt to become part of a paired set, free radicals will react with molecules such as DNA, proteins, lipids, etc., potentially leading to damage of these molecules. Normal biological processes, such as the electron transport chain, will generate free radicals. Several vitamins and trace minerals counter free radical damage by preventing free radical formation or by converting free radicals to more stable molecules. Trace minerals (selenium, magnesium, copper, zinc) function as part of metalloenzymes that counter oxidative damage.
cretinism
In areas without adequate iodine in soil or salt iodization, iodine deficiency during pregnancy may result in a birth defect; is characterized by mental retardation and dwarfism, and cretins are frequently also deaf and mute.
What is meant by the "activation" of fatty acids for β-oxidation?
In order to move from the cytosol into the mitochondria, fatty acids must first be activated. Activation involves conversion of the fatty acid into a molecule of fatty acyl CoA.
urea cycle important
Is a metabolic pathway in which ammonia is converted to urea. Ammonia is toxic, so it must be removed from the body. By the urea cycle, ammonia is converted to urea. Urea is less toxic than ammonia, so it can circulate in the blood unit it is removed by the kidneys. Urea takes place in the liver; after formation of urea in the liver; urea diffuses into the blood; kidneys filter blood and excrete urea in the urine.
Why can the liver convert glucose to fatty acids but cannot convert fatty acids to glucose?
The required enzymes are missing.
Chylomicron -
a lipoprotein aggregate found in the lymph and the bloodstream; are lipoprotein particles containing lipids from the diet (mostly triglycerides) and a small amount of proteins; lipoprotein made in intestinal cells; delivers dietary fat to tissues after a meal. (contain triglycerides, phosphoglycerides, and cholesterol) Formed: endoplasmic reticulum in the absorptive cells (enterocytes) of the small intestine (intestinal mucosa cells) Function: transport lipids absorbed from the intestine to adipose, cardiac, and skeletal muscle tissue, where their triglyceride components are hydrolyzed by the activity of lipoprotein lipase and the released free fatty acids are absorbed by the tissue. Chylomicrons pass into the lymph system and then into the bloodstream. They are modified by the liver into smaller lipoprotein particles, the form in which most lipids are transport to various parts of the body by the blood stream.
Name the compound that enters the urea cycle by combining with ornithine:
carboxyl phosphate
ketone bodies with diabetes
diabetes mellitus, like a long fast or starvation, also produces an imbalance in CHO and lipid metabolism. Even though blood glucose reaches hyperglycemic levels, a deficiency of insulin prevents the glucose from entering tissue cells in sufficient amounts to meet cellular energy needs. The resulting increase in fatty acid metabolism leads to excessive production of acetyl CoA and a substantial increase in the level of ketone bodies in the blood of poorly controlled diabetes.
ketone bodies during fasting
fatty acids from stored fats become the body's primary energy source. With a minimum amount of cellular glucose available, the level of glycolysis decreases, and a reduced amount of oxaloacetate is synthesized. In addition, oxaloacetate is used for gluconeogenesis to a greater than normal extent as the cells react to make their own glucose. The lack of oxaloacetate reduces the activity of the citric acid cycle. As a result of these events, more acetyl CoA is produced by fatty acid oxidation than can be processed through the citric acid cycle. As the concentration of acetyl CoA builds up, the excess is converted within the liver to three substances called ketone bodies: acetonacetate, Beta-hydroxybutyrate, and acetone.
what are the products of triglyceride digestions
glycerol, fatty acids, monoglycerides
folate
is the form of the vitamin naturally present in foods
iron deficiency
is the most common deficiency; menstruating women and children
non heme iron
present in beans, spinach iron enriched foods
What tissues utilize ketone bodies to meet energy needs?
the brain, heart, and skeletal muscles.
carbon skeleton fates
1. Used to synthesize glucose by gluconeogenesis 2. Converted to fatty acids for triglyceride storage in adipose tissue 3. After the amine group of an amino acid is removed, the remaining carbon skeleton can be converted to pyruvate, acetyl CoA, or one of several intermediates of the citric acid cycle.
precursor molecule for synthesis
7-dehydrocholesterol (precursor); when exposed to ultraviolet rays from the sun, it is converted to vitamin D3 (cholecalciferol)
list the major types of lipoprotein
: Chylomicrons, very low-density lipoproteins, low-density lipoprotein, high-density lipoproteins
ketonemia
A concentration higher than about 20 mg/100 mL of blood(ketones in the blood)
How is the fatty acid prepared for catabolism? Where in the cell does fatty acid activation take place?
A fatty acid is first converted to a fatty acyl CoA, a high-energy compound. This occurs in the cytoplasm of the cell.
Describe the 2 reactions of normal ethanol metabolism by hepatocytes. Include the substrates, products, and enzymes involved.
ADH (alcohol dehydrogenase) ALDH (acetaldehyde dehydrogenase) Ethanol is broken down in the liver by a series of oxidation reactions. Step takes place in the cytoplasm when the enzyme alcohol dehydrogenase catalyzes the conversion of ethanol to acetylaldehyde. (acetylaldehyde can condenses with amino groups of nucleic acis and proteins, causing damage to cells) Acetaldehyde is highly toxic, it is quickly metabolized to acetyl CoA by the enzyme acetaldehyde dehydrogenase. This step takes place in the mitochondria of the liver.
Vitamin C is important for the synthesis of:
Collagen, a structural protein of skin, bone, cartilage, and other connective tissue. L-carnitine, the molecule that facilitates transport of fatty acids into mitochondria for beta oxidation. Neurotransmitters such as norepinephrine.
Briefly describe ethanol's effects on the central nervous system.
Ethanol acts as many sites in the brain, including the reticular formation, cerebrum, and cerebellum; also affects the activity of several neurotransmitters including the principle inhibitory neurotransmitter gamma-aminobutyric acid (GABA); chronic heavy consumption of alcohol can alter brain chemistry so that a person may present with severe withdrawal symptoms when alcohol is stopped. Symptoms of withdrawal may include tremors, rapid breathing and pulse, spikes in blood pressure, hallucinations, and seizures.
What molecule supplies the carbon atoms for fatty acid synthesis?
Fatty acid synthesis occurs by way of a rather complex series of reactions catalyzed by a multi-enzyme complex called the fatty acid synthetase system. This system is made up six enzymes and an additional protein, acyl carrier protein (ACP), to which all intermediates are attached. Large input of energy is stored in the synthesized fatty acids and is one of the reasons it is so difficult to lose excess weight due to fat. After synthesis, the fatty acids are incorporated into triglycerides and stored in the form of fat in adipose tissues. The liver is the most important organ involved in fatty acid and triglyceride synthesis. It is able to modify body fats by lengthening or shortening and saturating or unsaturating the fatty acid chains. The only fatty acids that cannot be synthesized by the body are those that are polyunsaturated. However, linoleic acid (two double bonds) and linolenic acid (three double bonds) from the diet can be converted to other polyunsaturated fatty acids. This utilization of linoleic and linolenic acids as sources of other polyunsaturated fatty acids is the basis for classifying them as essential fatty acids for humans. The human body can convert glucose to fatty acids, but it cannot convert fatty acids to glucose. Our cells contain no enzyme that can catalyze the conversion of acetyl CoA to pyruvate, a compound required for gluconeogenesis. However, plants and some bacteria do possess such enzymes and convert fats to CHO as part of their normal metabolism.
What substance supplies the carbons for fatty acid synthesis?
Fatty acids are built two carbons at a time and broken down two carbons at a time.
Describe how glycerol from hydrolyzed triglycerides can enter cells to be metabolized for energy.
Glycerol from hydrolyzed triglycerides can enter cells to be metabolized for energy. In the cytoplasm of cells, glycerol is converted to dihydroxyacetone phosphate. Dihydroxyacetone phosphate is an intermediate in the glycolysis pathway. Thus, glycerol can enter glycolysis as dihydroxyacetone phosphate to be converted to pyruvate. Pyruvate can then be further catabolized for energy, or it can be converted to glucose by gluconeogenesis
fat mobilization
Is the process of hydrolyzing triglycerides to produce fatty acids and glycerol, both of which can be used for energy in muscle cells? - The hydrolysis of stored triglycerides followed by the entry of fatty acids and glycerol into the bloodstream. - The process by which stored triglycerides are hydrolyzed to release glycerol and fatty acids into the bloodstream. When body cells need fatty acids for energy, the endocrine system is stimulated to produce several hormones, including epinephrine, which interact with adipose tissue. Earlier we saw that epinephrine stimulates the conversion of glycogen to glucose. In the fat cells of adipose tissue, epinephrine stimulates the hydrolysis of triglycerides to fatty acids and glycerol, which enter the bloodstream. In the blood, mobilized fatty acids form a lipoprotein with the plasma protein called serum albumin. In this form, the fatty acids are transported to the tissue cells that need them. The glycerol produced by the hydrolysis of the triglyceride is water soluble, so it dissolves in the blood and is also transported to cells that need it.
What term is used to denote the breakdown and resynthesis of body proteins?
Protein turnover
Name four important biomolecules other than proteins that are synthesized from amino acids?
Purines and pyrimidines, heme, choline, ethanolamine
Based on the following conversions, classify each amino acid as glucogenic or ketogenic. tyrosine ------ acetoacetyl CoA:
ketogenic
deamination reaction
Removal of an amine functional group from an amino acid. With deamination, the amine group of the amino acid is replaced by a ketone group so that the amino acid becomes a keto acid. This phase of amino acid catabolism uses the glutamate produced in stage 1. The enzyme glutamate dehydrogenase catalyzes the removal of the amino group as an ammonium ion and regenerates alpha-ketoglutarate, which can again participate in the first state (transamination). This reaction is the principal source of NH4+ in humans. Because the deamination results in the oxidation of glutamate, it is called oxidative deamination. The NADH produced in this second state enters the electron transport chain and eventually produces 2.5 ATP molecules. Other amino acids in addition to glutamate may also be catabolized by oxidative deamination. The reactions are catalyzed by enzymes in the liver called amino acid oxidases. In each case an alpha-keto acid and NH4+ are the products.
which cells utilize fatty acids over glucose to satisfy their energy needs
Resting muscle and liver cells.
acetone breath
The concentration of acetone in the blood reaches levels that cause it to be expelled through the lungs, and the odor of acetone can be detected on the breath.Also, excessive alcohol consumption can cause ketone bodies to be produced with acetone on the breath.
Describe how ketone bodies may be formed:
The ketone bodies are carried by the blood to body tissues, mainly the brain, heart, and skeletal muscle, where they may be oxidized to meet energy needs. Under normal conditions: the concentrations of ketone bodies in the blood averages a very low 0.5 mg/100mL.
transamination reaciton
The transfer of an amino group from one molecule to another. In the tissues, amino groups freely move from one amino acid to another under the catalytic influence of enzyme called aminotransferases, or more commonly, transaminases - enzyme that catalyze the transfer of amine groups. A key reaction for amino acids undergoing catabolism is a transamination involving the transfer of amino groups to an alpha-ketoglutarate. The carbon skeleton of the amino acid remains behind and is transformed into a new alpha-keto acid. A second important example of transamination is the production of aspartate, which is used in stage 3, urea formation. The net effect of the transamination reactions in the catabolism of amino acids is to use nitrogen from a variety of amino acids to form glutamate and aspartate.
essential amino acids:
Those amino acids that must be obtained from the diet because the body cannot produce them are called essential amino acids.
Match the terms transamination and deamination to the following: a keto acid is produced from an amino acid.
Transamination and deamination
ketoacidosis
Two of the ketone bodies are acids, and their accumulation in the blood as ketosis worsens results in a condition of acidosis (a low blood pH) called; it is caused by ketone bodies in the blood (a low blood pH due to elevated levels of ketone bodies). If it is not controlled, the person becomes severely dehydrated because the kidneys excrete excessive amounts of water in response to low blood pH. Prolonged ketoacidosis leads to general debilitation, coma, and even death.
Where are ketone bodies formed?
liver
urea formation
Urea cycle - a metabolic pathway in which ammonium ions are converted to urea. The ammonium ions released by the glutamate dehydrogenase reaction are toxic to the body and must be prevented from accumulating. In the urea cycle, which occurs only in the liver, ammonium ions are converted to urea. This compound is less toxic than ammonium ions and can be allowed to concentrate until it is convenient to excrete it in the urine. The urea cycle process the ammonium ions in the form of carbomoly phosphate, the fuel for the urea cycle. This compound is synthesized in the mitochondria from ammonium ions and bicarbonate ions. Energy for the synthesis of one molecule of carbamoly phosphate is derived from two molecules of ATP. After urea is formed, it diffuses out of liver cells into the blood, the kidneys filter it out, and it is excreted in the urine. Normal urine from an adult usually contains 25-30 g of urea daily, although the exact amount varies with the protein content of the diet. The direct excretion of NH4+ accounts for a small but important amount of total urinary nitrogen. Ammonium ions can be excreted along with acidic ions, a mechanism that helps the kidneys control the acid-base balance of body fluids.
Define β-oxidation "Process"
a pathway in which fatty acids are broken down into molecules of acetyl CoA. beta-oxidation is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH2, which are co-enzymes used in the electron transport chain. It is named as such because the beta carbon of the fatty acid undergoes oxidation to a carbonyl group.
describe what is meant by the term fat mobilization
is the process of hydrolyzing triglycerides to produce fatty acids and glycerol, both of which can be used for energy in muscle cells.
folic acid
is the synthetic form used in supplements and fortified foods
iron
trace element required by many enzymes and other proteins.
List two vital functions performed by transaminases:
transaminases are used in the biosynthesisis of amino acids and in the transfer of nitrogen atoms from amino acids when the disposal of nitrogen is necessary.
Match the terms transamination and deamination to the following: new amino acids are synthesized from other amino acids
transamination
Match the terms transamination and deamination to the following:. an amino group is removed from an amino acid and donated to a keto acid.
transamination
Chylomicron remnant
what's left of a chylomicron after it has delivered dietary fatty acids to tissues; once chylomicrons have delivered dietary fat to the body's they are called chylomicron remnant; are taken up by the liver where they are converted to VLDL.