Amino Acids

Question 0

Means that amino acids contain both acidic and basic groups

Answer 0

Amphoteric (zwitterion)

Question 1

Amino acids may have a positive, negative, or neutral charges, depending on the _____

Answer 1

pH

Question 2

pH>7.4 , when a base is added to the amino acid resulting molecule has a _______ charge

Answer 2

Negative

Question 3

pH=7.4 , internal transfer of a hydrogen ion from the -COOH group to the -NH2 group results in a _________ charge

Answer 3

Neutral

Question 4

pH<7.4 decrease in pH by adding an acid results in a _______ charge

Answer 4

Positive

Question 5

Defined as the pH at which net charge is zero; i.e. There are equal numbers of positive and negative charges

Answer 5

Isoelectric point

Question 6

If pH > pl

Answer 6

Amino acid has a negative charge

Question 7

If pH < pl

Answer 7

Amino acid has a positive charge

Question 8

Proteins act in vivo as a _______ _______ due to their acid-base properties

Answer 8

Mild buffer

Question 9

Four essential amino acids

Answer 9

Leucine. Isoleucine, Valine, Methionine, Tryptophan, Phenylalanine, Threonine, Lysine

Question 10

Formed when the alpha amino group of one amino acid is covalently linked with the alpha-carboxyl group of a second amino acid

Answer 10

A peptide bond

Question 11

The formation of glucose from non-carbohydrate sources, such as amino acids, glycerol, or fatty acids

Answer 11

Gluconeogenesis

Question 12

Starting and ending products of gluconeogenesis

Answer 12

S: amino acids/glycerol/fatty acids
E: glucose

Question 13

The process of amino group removal or transfer to make different amino acids

Answer 13

Transamination

Question 14

Starting and ending products of transamination (2 of them)

Answer 14

S: glutamic acid/Oxaloacetate
E: alanine/aspartate

Question 15

The removal of the amino group, forming toxic ammonia

Answer 15

Deamination

Question 16

Starting and ending products of deamination

Answer 16

S: Ammonia
E: Urea

Question 17

Organ in which the metabolic/catabolic pathways occur in the body

Answer 17

liver

Question 18

occurs when the plasma levels of the amino acid are normal, but the renal reabsorptive mechanism is defective

Answer 18

Renal Aminoaciduria

Question 19

______ plasma levels and _______ urine levels of amino acids in renal aminoaciduria

Answer 19

normal; increased

Question 20

Defect in renal tubular reabsorption of cystine, ornithine, lysine, and arginine; most common error of amino acid transport

Answer 20

cystinuria

Question 21

Three primary renal aminoacidurias

Answer 21

cystinuria, hartnup disease, and fanconi syndrome

Question 22

prone to renal calculi made of cystine; cystine crystals on urine microscopic

Answer 22

lab findings in cystinuria

Question 23

Increased urinary excretion of neutral monocarboxylic amino acids

Answer 23

Hartnup Disease

Question 24

Patients have a nicotinamide (vit B) deficiency, so they can have pellagra (red, scaly rash), plus neurological and muscular abnormalities

Answer 24

Clinical features of hartnup disease

Question 25

renal dysfunction of the proximal convoluted tubule

Answer 25

Fanconi Syndrome

Question 26

polyuria, dehydration, hypokalemia, acidosis, osteomalacia, cannot reabsorb necessary nutrients, bowing of the legs, low weight/height, abdominal distention, enlargement in wrist and ankle joints

Answer 26

clinical features of fanconi syndrome

Question 27

plasma level of one or more amino acids exceeds the rena threshold

Answer 27

overflow aminoaciduria

Question 28

______ plasma levels and _______ urine levels of amino acids in overflow aminoaciduria

Answer 28

Increased; Increased

Question 29

Due to a deficiency or absence of phenylalanine hydroxylase enzyme

Answer 29

Phenylketonuria (PKU)

Question 30

spastic movements and seizures, sever mental retardation if untreated, eczema, feeding difficulties, vomiting, delayed mental/social development, hypopigmentation, Increased serum phenylalanine, Decreased serum tyrosine, increased urine phenylpyruvic acid

Answer 30

Clinical features of PKU

Question 31

Due to fumarylacetoacetase deficiency

Answer 31

Type I Tyrosinemia

Question 32

causes cirrhosis and renal damage leading to fanconi, elevated serum and urine tyrosine levels, elevated methionine in serum

Answer 32

Clinical features of Type I tyrosinemia

Question 33

Due to tyrosine aminotransferase deficiency

Answer 33

Type II Tyrosinemia

Question 34

skin lesions, ocular abnormalities (corneal dystrophy), elevated serum and urine levels of tyrosine, tyrosine crystals in urine, serium methionine NOT increased

Answer 34

clinical features of Type II Tyrosinemia

Question 35

due to 4-hydroxyphenylpyruvate dioxygenase deficiency

Answer 35

Type III Tyrosinemia

Question 36

mild mental retardation, seizures, periodic loss of balance and coordination, increased serum tyrosine

Answer 36

Type III Tyrosinemia

Question 37

caused by a defect in the enzyme homogentisic acid oxidase

Answer 37

Alkaptonuria

Question 38

homogentisic acid inreases in serum and urine, urine turns brown/black when exposed to light and air or when alkali is added, ocular ochronosis

Answer 38

clinical features of Alkaptonuria

Question 39

most commonly caused by a defect of CBS (cystathionine beta synthase)

Answer 39

homocystinuria

Question 40

both methionine and homocystine are increased in serum and urine, ocular (lens displacement) and skeletal abnormalities (knock knee), cardiovascular problems (thromboli due to sticky platelets), pigeon chest

Answer 40

clinical features of homocystinuria

Question 41

due to a defect in the enzyme alpha-ketoacid decarboxylase; also known as branched chain aminoaciduria due to excretion of the branched chain amino acids valine, leucine, and isoleucine

Answer 41

Maple Syrup Urine Disease (MSUD)

Question 42

symptoms include hypoglycemia, ketoacidosis (blood and urine), lethargy, poor appetite, vomiting, convulsions, detected by the 11th day of life, maple syrup odor, increased ketone bodies

Answer 42

MSUD clinical features

Question 43

Amino acids can be measured using 3 screening methods

Answer 43

Thin layer chromatography (TLC), photometric screening tests, and Guthrie test

Question 44

three quantitative testsf for the presence of aminoacidurias

Answer 44

ion exchange chromatography, gas liquid chromatography (GLC), and high performance liquid chromatography (HPLC)