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Clinical chemistry > AMINO ACIDS > Flashcards

AMINO ACIDS Flashcards

Amino Acids

1
Q

what is a peptide bond

A

is a bond formed when an amino group of one amino acid links with the carboxyl group of another

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2
Q

what name is given to the side chain

A

R

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3
Q

what is an alpha carbon

A

is the carbon that joins the amino group(-NH2) and the carboxyl group (-COOH)

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4
Q

outline the classes/classifications of amino acids

A
  1. Neutral amino acids
  2. Acidic amino acids
  3. Basic amino acids
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5
Q

mention the 4 subcategories of neutral amino acids

A
  1. Aliphatic amino acids
  2. Aromatic amino acids
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6
Q

what is the difference between aliphatic amino acids and aromatic amino acids?

A

Aliphatic amino acids have non-polar and hydrophobic R-group (does not mix well with water) while aromatic amino acids have a benzene ring in their side chain

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7
Q

mention any 4 examples of aliphatic amino acids

A
  1. glycine
  2. alanine
  3. valine
  4. leucine
  5. serine
  6. isoleucine
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8
Q

mention 2 examples of aromatic amino acids

A
  1. phenylalanine
  2. tyrosine
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9
Q

what are heterocyclic amino acids

A

they contain a cyclic R-group

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10
Q

mentiowhat are the examples of heterocyclic amino acids

A

1.histidine
2.tryptophan

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11
Q

what are imino acids

A

contains the NH2 and COOH groups attached to the alpha carbon and the NH2 is part of the R group

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12
Q

what are the examples of s containing amino acids

A
  1. cysteine
  2. methionine
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13
Q

what are acidic amino acids

A

these amino acids contains two -COOH groups and one -NH2 group/ also known as monoaminodicarboxylic acids

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14
Q

what are the examples of acidic amino acids

A
  1. Aspartic acid
  2. Glutamic acid
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15
Q

what are basic amino acids

A

are AA that contains -COOH group and two -NH2 groups. thus they are called diamino monocarboxylic acids

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16
Q

what are exaples of basic amino acids

A
  1. Arginine
  2. Lysine
  3. Hydroxylysine
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17
Q

Mention 3 nutritional classification of Amino acids

A
  1. Essential amino acids
  2. Non essential amino acids
  3. Semi essential amino acids
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18
Q

What are semi-essential amino acids

A

these are growth promoting factors since they are not synthesised in sufficient quantity during growth

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19
Q

what are examples of semi essential amino acids

A
  1. arginine
  2. histidine
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20
Q

what are essential amino acids

A

are the ones that can not be synthesized by the body, the diet is the source

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21
Q

what are the examples of essential amino acids

A
  1. leucine
  2. arginine
  3. lysine
  4. methionine
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22
Q

what are non-essential amino acids

A

are the ones that can be synthesized by the body

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23
Q

mentions any 5 sources of amino acids

A
  1. soy protein
  2. pork
  3. eggs
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24
Q

explain the functions of amino acids

A
  1. some amino acids areare converted to carbohydrates and are called glucogenic amino acid
  2. specific amino acids give rise to specialized products
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25
Q

mention the amino acids that adds up to form a product and mention the product

A
  1. tyrosine forms hormones such as thyroid hormone
  2. Tryptophan can synthesise a vitamin called niacin
  3. glycine, arginine and methionine sythesize creatine
  4. glycine is used for the stnthesis of haem
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26
Q

physical properties of amino acids

A
  1. are colorless amd crystalline, more solubke in water than in polar substances\
  2. they have high melting point, usually more than 200 oc
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27
Q

chemical properties of amino acids die to carboxylic group

A
  1. Amino acids forms esters with alcohols, reaction with Na2CO3 releases a free ester
  2. Amino acids forms amines by decarboxylation catalyzed by decarboxylase
  3. AA are reduced to amino alcohols in presence of aluminum hydride
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28
Q

chemical properties of amino acids die to Amino group

A
  1. The NH_2 group reacts with HCL forming salts
  2. AA reacts with acyl anhydrides (benzoyl chloride) gives acyl amino acids
  3. AA reacts with CO2 forming carbaminoacid anion
  4. H2O2 reacts with NH_2 to form ammonia (NH4
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29
Q

define aminoacidopathies

A

Inherited errors of metabolism enzyme defect that inhibits the body’s ability to metabolize certain amino acids.

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30
Q

the abnormalities of acidopathies exist in two forms, explain them

A
  1. the activity of a specific enzyme in the metabolic pathway
  2. in the membrane transport system for amino acids e.g Cystinuria
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31
Q

explain how the guthie test is done

A

The infant’s blood is collected on a piece of filter paper Small disc of the 4 filter paper is punched out and placed on an agar plate containing Bacillus subtilis and beta-2 thienylalanine The beta-2-thienylalanine inhibits bacterial growth, but in the presence of phenylalanine leaked from the disk, the bacteria still grow
The presence of phenylalanine from the disks overcomes the inhibition and bacteria grow

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31
Q

what are yhe characteristics of phenylketonuria

A
  1. Compounds may be present in blood and urine giving it a characteristic musty odor
  2. In infants and children, it may cause retarded mental development and microcephaly
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31
Q

How is phenylketonuria caused

A

Results from absence of activity of phenylalanine hydroxylase that catalyzes conversion of phenylalanine to tyrosine

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32
Q

list the aminoacidopathies

A
  1. Phynylketonoria
  2. Tyrosinemia
  3. Alkaptonuria
  4. Maple syrup urine disease
  5. Isovaleric acidemia
  6. Homocystinuria
  7. Citrullinemia
  8. Argininosuccinic aciduria
  9. Cystinuria
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33
Q

What is tyrosinemia

A

it is an Inborn metabolic disorders of tyrosine catabolism, characterized by the excretion of tyrosine and tyrosine catabolites in urine

Tyrosine is an amino acid that takes part in the production of dopamine

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34
Q

How is tyrosinemia diagnised

A

diagnosis criteria include an elevated tyrosine level using tandem MS/MS. coupled with a confirmatory test for an elevated level of the abnormal metablite succinylacetone

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35
Q

What are the characteristic of alkaptonuria (1)

A

Characterized by the patients urine turning brown when mixed with air due to accumulation of homogentisic acid thus oxidized and produce color.

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36
Q

what causes alkaptonuria

A

Caused by the lack of enzyme Homogentisate oxidase, required for metabolism of tyrosine and phenylalanine

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37
Q

how to diagnose alkaptonuria in the lab

A

In clinical laboratory when patient urine is mixed with ferric chloride, it turns black.

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38
Q

what is maple syrup urine disease [MSUD]

A

Results from reduced activity of the enzyme branched-chain α-keto acid decarboxylase, affecting the metabolism of leucine, isoleucine and valine

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39
Q

Explain the diagnosis of MSDU

A

A modified Guthrie test is performed where the inhibitor is 4-azaleucine.
A microfluorometric assay involves filter paper specimen treated with methanol and acetone to denature the hemoglobin.
Leucine dehydrogenase is added and the fluorescence of the NADH produced in the subsequent reaction is measured at 450 nm after excitation at 360nm
Levels above 4mg/dl is indicative of MSUD, MS/MS is also used in testing for MSUD

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40
Q

what causes isovaleric acidemia

A

Results from a deficiency of the enzyme isovaleryl-CoA dehydrogenase, preventing normal metabolism of the branched-chain amino acid leucine

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41
Q

what are the characteristics of isovaleric acidemia

A

Characteristic feature is a unique odor of sweaty feet caused by the buildup of isovaleric acid

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42
Q

what is homocystinuria

A

Homocystinuria is an inherited metabolic disorder characterized by an abnormal accumulation of homocysteine in the blood and urine. Results from lack of the enzyme cystathionine β-synthase necessary for the metabolism of the amino acid methionine
Leading to elevated plasma and urine levels of methionine and of the precursor homocysteine

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43
Q

What is type I citrullinemia

A

Is a metabolic defect caused by the lack of the enzyme argininosuccinic acid synthetase , leading buldup of citrulline and ammonia in the blood.

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44
Q

what is type II citrullinemia

A

Is a metabolic defect that results from the mutation of gene encoding CITRIN

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45
Q

What is argininosuccinic aciduria (ASA)

A

Results from the lack of the enzyme argininosuccinic acid lyase, preventing the conversion of argininosuccinic acid ito arginine. (the conversion of argininosuccinic acid causes build up of the amino acid citrulline and amonia in the blood.

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46
Q

what is cystinuria

A

a defect in the amino acid transport system.

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47
Q

characteristics of cystenuria

A

it is characterized by the inability of the kidney to reabsorb cystine leading to accumualtion ofthe amino acid

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48
Q

what does the statement cystine precipitates in kidneys and form stones mean

A

The statement “cystine precipitates in kidneys and forms stones” means that the amino acid cystine, which is normally dissolved in urine, crystallizes and forms solid masses or stones in the kidneys. This condition is often associated with a genetic disorder called cystinuria, where the kidneys excrete an excessive amount of cystine into the urine. When the concentration of cystine in the urine is too high, it exceeds its solubility limit and begins to form crystals, which can aggregate into stones. These cystine stones can cause pain, urinary tract infections, and may lead to kidney damage if not treated1

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49
Q

How is cystinuria diagnosed

A

Clinically diagnosed by testing the urine forcystine using cyanide nitroprusside

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50
Q

Why must specimens for amino acid analysis be collected after fasting?

A

To avoid contamination from dietary amino acids that could affect the analysis results

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51
Q

What is the importance of using heparin tubes with prompt separation

A

It prevents contamination from platelets and white cells, as well as hemolysis, ensuring sample integrity

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52
Q

How does the concentration of aspartic acid and glutamic acid in WBC compare to plasma?

A

It is 100 times higher in WBC than in plasma, which can impact the accuracy of the analysis if contaminated

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53
Q

What should be done with the sample after collection for amino acid analysis?

A

Deproteinize (removing proteins from biological samples) within 30 minutes and analyze immediately, or freeze at −20°C to −40°C to preserve it for later analysis

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54
Q

Where are most proteins synthesized and secreted in the body?

A

Most proteins are synthesized in the liver and secreted by hepatocytes, except for immunoglobulins which are produced by plasma cells

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55
Q

How is the information for protein synthesis encoded?

A

The information is encoded in genes, which provide the protein its unique amino acid sequence

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56
Q

What processes allow for the genetic code to be read and proteins to be synthesized?

A

The processes of transcription and translation enable the genetic code to be read and proteins to be synthesized

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57
Q

What is the difference in the synthesis location of intracellular proteins and proteins made by the liver for secretion

A

Intracellular proteins are mostly synthesized on free ribosomes, while proteins made by the liver for secretion are synthesized on ribosomes attached to the rough endoplasmic reticulum

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58
Q

What role do glucagon and cortisol play in protein metabolism

A

Glucagon and cortisol assist in controlling protein catabolism.

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59
Q

Which hormones assist in controlling protein synthesis?

A

Thyroxine, growth hormone, insulin, and testosterone assist in controlling protein synthesis.

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60
Q

At what rate does protein synthesis occur

A

Protein synthesis occurs at the rate of approximately two to six peptide bonds per second

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61
Q

How can proteins be classified based on their shape and size?

A

Proteins can be classified as fibrous or globular based on their shape, and as small, medium, or large based on their size.

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62
Q

What defines a protein as a globular protein?

A

A protein is classified as a globular protein when the axial ratio of its length to width is less than 10.

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63
Q

Describe the shape and solubility of globular proteins.

A

Globular proteins are approximately spherical in shape and are generally water-soluble.

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64
Q

Can you provide examples of globular proteins?

A

Myoglobin
haemoglobin
ribonuclease

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65
Q

What characterizes a protein as a fibrous protein?

A

A protein is classified as a fibrous protein when the axial ratio of its length to width is more than 10

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66
Q

What are the main functions of fibrous proteins and are they water-soluble

A

Fibrous proteins are structural proteins that are generally insoluble in water

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67
Q

Describe the structural arrangement of fibrous proteins

A

Fibrous proteins consist of long cable-like structures built entirely of either helical or sheet arrangements.

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68
Q

Can you provide examples of fibrous proteins?

A

α-keratin and collagen

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69
Q

explain the fuctional properties of amino proteins

A
  1. Defense proteins: Immunoglobulins involved in defense mechanisms.
  2. Contractile proteins: Proteins of skeletal muscle involved in muscle contraction and relaxation.
  3. Respiratory proteins: Involved in the function of respiration, like haemoglobin, myoglobin, cytochromes.
  4. Structural proteins: Proteins of skin, cartilage, nail
  5. Enzymes
  6. Hormones
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70
Q

What is the role of immunoglobulins?

A

Immunoglobulins are defense proteins involved in the body’s immune response mechanisms

71
Q

What function do contractile proteins serve in skeletal muscles?

A

Contractile proteins are involved in muscle contraction and relaxation

72
Q

Which proteins are associated with respiration

A

Haemoglobin, myoglobin, and cytochromes are respiratory proteins involved in the function of respiration

73
Q

Where are structural proteins typically found?

A

Structural proteins are found in skin, cartilage, and nails

74
Q

What is the function of enzymes in the body?

A

Enzymes act as catalysts to accelerate chemical reactions in the body

75
Q

What is the role of hormones?

A

Hormones regulate various physiological processes and activities in the body

76
Q

What are simple proteins and what do they yield upon complete hydrolysis?

A

Simple proteins yield only amino acids upon complete hydrolysis. Examples include protamines, histones, albumin, and globulin.

77
Q

: What distinguishes conjugated proteins from simple proteins?

A

Conjugated proteins contain a non-protein prosthetic group in addition to amino acids. Examples are nucleoproteins and glycoproteins.

78
Q

How are derived proteins formed?

A

Derived proteins are formed from native proteins by the action of heat, physical forces, or chemical factors, resulting in coagulated proteins, peptides, and peptones

79
Q

what are conjugated proteins

A

these are proteins which in addition to aminio acids contain a non protein called prosthetic group in their structure

80
Q

explain the primary structure of proteins

A

contains linear sequence of amino acids held together by peptide bonds

81
Q

explain the secondary structure of amino acids

A

Repeating structures stabilized by hydrogen bonds between AAs within a CHON
Common secondary structures include α-helix, β-pleated sheet, and turns, most serum proteins forming a helix

82
Q

explain the tertiary structure ofproteins

A

These are three dimensional structures of proteins,
Results from interaction of side chains and is stabilized by hydrogen bonds, ionic attraction, and disulfiide bonds

83
Q

What constitutes the primary structure of a protein

A

The primary structure is the linear sequence of amino acids in a protein, held together by peptide bonds.

84
Q

What are common types of secondary structures in proteins?

A

: Common secondary structures include the α-helix, β-pleated sheet, and turns

85
Q

How is the tertiary structure of a protein stabilized

A

The tertiary structure is stabilized by interactions of side chains, including hydrogen bonds, ionic attractions, and disulfide bonds

86
Q

explain the quatenaty structure of protein

A

Results from interaction of more than one protein molecules or subunits

87
Q

What is the quaternary structure of a protein?

A

The quaternary structure refers to the arrangement of multiple polypeptide chains (subunits) in a multi-subunit complex1

88
Q

How is the quaternary structure of a protein held together?

A

It is stabilized by non-covalent interactions such as hydrogen bonds, hydrophobic interactions, ionic bonds, and sometimes disulfide bonds between the subunits1

89
Q

Is the quaternary structure of a protein determined by the gene corresponding to the protein?

A

The quaternary structure is not directly determined by the gene; it results from the way protein subunits assemble post-translation1.

90
Q

Which type of protein does not typically have a quaternary structure?

A

Proteins composed of a single polypeptide chain, such as myoglobin, do not have a quaternary structure1

91
Q

Factors that can cause protein denaturation include

A
  1. heat
  2. hydrolysis by strong acids or alkalis
  3. enzymatic action
  4. exposure to urea or other substances
  5. exposure to ultraviolet light may cause protein denaturation
92
Q

mention 5 functions of proteins

A
  1. All biochemical reactions are catalyzed by enzymes, which contain protein.
  2. The structure of cells and the extracellular matrix that surrounds all cells is largely made of the protein group collagens.
  3. The transport of materials in body fluids depends on proteins such as transferrin, receptors for hormones are transmembrane proteins,
    4.Transcription factors, needed to initiate the transcription of a gene, are proteins.
    5.Proteins make up antibodies, which are a major component of the immune system.
  4. Proteins by means of exerting osmotic pressure help in maintenance of electrolyte and water balance in body.
93
Q

STUDY QUESTIONS
1. Describe the classification of proteins with suitable examples.
2. What are proteins? Classify them giving suitable examples in each group.
3. What is the primary structure of proteins? Discuss the biochemical functions of proteins.
4.Classify proteins, give their biological importance.
5.What are proteins? Describe biological importance of proteins.
Describe the structure of proteins

A
94
Q

Plasma proteins are the most measured proteins during protein analysis, as a result they are divided into two mention them.

A
  1. albumin
  2. Globulin
95
Q

What are the two main groups into which plasma proteins are divided?

A

Plasma proteins are divided into two groups: Albumin and Globulin

96
Q

What are the components measured in a blood protein panel?

A

A blood protein panel measures total protein, albumin, globulin, and the albumin/globulin (A/G) ratio.

97
Q

What types of analysis are performed on plasma proteins?

A

Both qualitative and quantitative analyses are performed on plasma proteins.

98
Q

list the methods perfomed in quantitative methods during protein analysis

A
  1. physical methods
    i.e dye binding, direct absorbance measurement
  2. Activity measurement
    i.e Binding proteins, protease inhibitors, coagulationfactors
  3. Immunoassays
99
Q

mention 5 qualitative techniques perfomed during protein analysis

A
  1. Electrophoresis
  2. Chromatography
  3. Genetic analysis
  4. Functional assay
  5. mass spectroscopy
100
Q

how does insulin work in the body

A

Insulin is a hormone produced by the pancreas that plays a vital role in regulating blood sugar levels in the body. Here’s how it works:

Production: Insulin is made by beta cells in the pancreas1.
Release: When blood sugar levels rise, such as after eating, the pancreas releases insulin into the bloodstream1.
Action: Insulin helps cells throughout the body absorb glucose from the bloodstream, which they use for energy1.
Storage: It also signals the liver to store excess glucose as glycogen for later use1.
Balance: By facilitating the uptake and storage of glucose, insulin keeps blood sugar levels within a normal range1.
Without sufficient insulin or if cells become resistant to insulin, blood sugar levels can rise, leading to conditions like diabetes23. Managing insulin levels is crucial for maintaining overall health and preventing long-term complications.

101
Q

how does glucagon work in the body

A

Glucagon is a hormone that plays a crucial role in maintaining blood glucose levels. Here’s how it functions in the body:

Production: Glucagon is produced by alpha cells in the pancreas.
Release: It is released when blood glucose levels fall too low or during prolonged fasting1.
Glycogenolysis: Glucagon prompts the liver to convert stored glycogen into glucose and release it into the bloodstream, a process known as glycogenolysis.
Gluconeogenesis: It also stimulates gluconeogenesis, which is the production of glucose from non-carbohydrate sources, such as amino acids3.
Blood Sugar Regulation: By increasing blood glucose levels, glucagon prevents hypoglycemia and ensures a steady supply of energy for the body1.
Glucagon’s actions are critical, especially during fasting or vigorous exercise, to provide the body with the necessary glucose to function properly. It works in concert with insulin, which lowers blood glucose levels, to maintain glucose homeostasis12

102
Q

what 5 methods are used to measure serum/plasma total protein

A

Biuret method
Direct spectroscopy
Folin-Ciocalteu (Lowry)
Dye binding
Refractomertic methods
Turbidimetric methods
kjeldahl method

103
Q

explain how the kjeldahl method work

A

sample is digested with an acid to convert nitrogen in the protein to ammonium ion and measure. The ammonium value is maltiplied by a factor of 6.25 to calculate the total protein. the method is impractical for routine use

104
Q

What is the Biuret method used for?

A

It’s used for measuring protein concentration

105
Q

What happens to cupric ions in the Biuret method?

A

Cupric ions ((Cu^{2+})) complex with peptide bonds in proteins.

106
Q

what wavelength is the absorbance change measured in the Biuret method?

A

The absorbance change is measured at 540nm.

107
Q

What does the change in absorbance indicate in the Biuret method?

A

It indicates the amount of protein, proportional to the number of peptide bonds

108
Q

For what type of samples is the Biuret method particularly sensitive?

A

It’s sensitive for high protein concentrations such as serum and plasma.

109
Q

What factors can affect the accuracy of serum protein determination by the Biuret method?

A

The presence of bilirubin and lipemia can affect the accuracy

110
Q

What UV absorbance range is used to measure protein contents in biological samples?

A

The UV absorbance range of 200 to 225nm and 270 to 290nm.

111
Q

On which molecular structures does the absorbance at 280nm depend

A

The absorbance at 280nm depends on the aromatic rings of tyrosine and tryptophan

112
Q

How is direct spectroscopy used in liquid chromatography?

A

It is used to monitor protein and peptide elution.

113
Q

What is the basis for using dye binding to measure protein concentration?

A

It is based on the ability of most proteins in serum to bind dyes.

114
Q

Can you list some dyes that are used to stain proteins?

A

Coomassie brilliant blue, Bromophenol blue, Ponceau S, amido black 10B, and lissamine green.

115
Q

How does Coomassie brilliant blue 250 indicate protein concentration

A

It binds to protein, causing a shift in the absorbance maximum of the dye from 465 to 595 nm, and the increase in absorbance at 595 nm is used to determine the protein concentration.

116
Q

how does refractometric method work

A

it is used to measur econcentration of protein

117
Q

what test is laboratory refractometry employed to test

A

total urine protein

118
Q

what factors may interfere with refractometric method

A

salts, glucose, low molecular weight compounds

119
Q

How are nephelometric methods related to turbidimetric methods?

A

Both methods are used to assess the formation of masses, but the specific measurement technique may differ. Nephelometry typically measures the light scattered by the particles, whereas turbidimetry measures the decrease in light transmission due to the particles. (Note: This answer is inferred based on common knowledge of nephelometry, as the paragraph does not provide details on nephelometric methods.

120
Q

What reagents are used in turbidimetry

A

Reagents include trichloroacetic acid, sulfosalicylic acid, sulfosalicylic acid combined with sulfonate, benzothonium chloride, and benzalkonium salts.

121
Q

How does turbidimetry measure changes?

A

Turbidimetry measures changes in absorbance caused by the aggregates

122
Q

What does nephelometry measure?

A

Nephelometry measures the light reflected at an angle by particles in a solution.

123
Q

What methods are used to assess albumin in urine

A

Turbidimetric and nephelometric methods are used for qualitative assessment.

124
Q

How can turbidimetric and nephelometric measurements be conducted?

A

These measurements can be carried out as either end point or kinetic methods.

125
Q

What is the total protein concentration in health ambulatory adults

A

6.4 to 8.3

126
Q

total protein of adults at bed rest

A

6.0 to 7.8

127
Q

Q: Why is total protein measurement important

A

It is important for monitoring gross changes in protein levels caused by various disease states

128
Q

When is total protein measurement typically performed?

A

It is typically performed alongside other tests like serum albumin, liver function tests, or protein electrophoresis.

129
Q

What additional ratio is often calculated during a total protein test?

A

An albumin/globulin ratio is calculated for more information

130
Q

what does high levels of protein associate

A
  1. dehydration
  2. chronic inflammation or infection
  3. multiple myeloma, pregnancy
  4. waldenstorm disease, b cell cancer
131
Q

what does lower protein levels associated with

A
  1. hemorrhage, malabsorption, malnutrition, nephrotic syndrome
  2. burns
  3. liver diseases, agammaglobulinemis
132
Q

What is the role of albumin in plasma?

A

Fluid Balance: Albumin helps regulate fluid balance by preventing excessive fluid from leaking out of blood vessels

Transporter: Albumin acts as a carrier protein for various substances eg steroids, fatty acids

133
Q

Where is albumin found in the body?

A

Albumin is a major component of body fluids, including interstitial fluid, CSF, urine, and amniotic fluid. Half of the total albumin is found in the extravascular space

134
Q

how does increased plasma concentration occur

A
  1. though dehydration
  2. artififactually from prolonged torniques time or specimen evaporation prior to analysis
135
Q

How is albumin concentration calculated

A

Albumin concentration is calculated by subtracting the globulin value from the total protein

136
Q

what does a decrease in abulmin indicate

A
  1. kidney and cardiovascular diseases
  2. dexreased synthesis
  3. increased metabolic turn over
  4. increased metabolic turnover
  5. increased distribution of extravascular fluids
137
Q

How is total globulin concentration determined?

A

Total globulin concentration is determined by a direct calorimetric method using glyoxylic acid, which condenses with globulins in the presence of ( \text{Cu}^{2+} ) and in acetic acid and ( \text{H}_2\text{SO}_4 ), producing a purple color.

138
Q
A
139
Q

how does inflammatory disorders lower albumin

A

by increasing capillary premeability allowing increased distribution of albumin into the exravascular space

140
Q

apart from inflammatory disorders what other factors affect lower abulmin

A

nephrotic syndrome
malnutrition
edema

141
Q

Which dyes have a high affinity for albumin?

A

BCG and BCP have a higher affinity for albumin than other proteins

142
Q

How is the charge of albumin adjusted during testing

A

he pH of the solution is adjusted so that albumin becomes positively charged

143
Q

What happens when albumin binds to an anionic dye

A

The dye has a different absorption maximum than when it is free.

144
Q

How is the concentration of albumin determined

A

By measuring the absorbance of the albumin-dye complex

145
Q

Compare the specificity of methyl orange and HABA for albumin

A

Methyl orange is nonspecific for albumin, while HABA is more specific but has low sensitivity

146
Q

Name some compounds that interfere with albumin binding to HABA

A

Salicylates, penicillin, conjugated bilirubin, and sulfonamides can interfere with the binding.

147
Q

What does the albumin/globulin ratio measure?

A

It measures the amount of albumin in serum divided by the globulins

148
Q

Why is the albumin/globulin ratio used?

A

The ratio is used to identify causes of changes in total serum proteins.

149
Q

How can the albumin/globulin ratio be utilized in a clinical setting

A

It may be used to assess body nutritional status

150
Q

What is an increased albumin/globulin ratio associated with?

A

It is associated with an increase in albumin due to hemoconcentration.

151
Q

What can cause a decrease in globulin levels?

A

A decrease in globulin can be due to SCID, agammaglobulinemia, or transient hypoagammaglobulinemia

152
Q

what does the decrease in albumin/globulin ratio associated with

A
  1. hyperglobulinemia
  2. maldigestion
  3. inflammation
153
Q

What is the basis for protein separation in electrophoresis

A

Proteins are separated based on their electric charge densities

154
Q

How do proteins behave when subjected to an electric current?

A

Proteins move according to their charge density when placed in an electric current

155
Q

How do proteins acquire a negative or positive charge during electrophoresis

A

Proteins become negatively or positively charged when placed in a buffer with a pH higher or lower than their isoelectric point (pI), respectively.

156
Q

What determines the movement of proteins during electrophoresis?

A

The movement depends on whether proteins are positively or negatively charged, which is influenced by the pH of the buffer relative to the protein’s isoelectric point (pI)

157
Q

How does the pH of the buffer affect protein migration?

A

The further the pH of the buffer is from the protein’s pI, the greater the net charge of the protein, resulting in faster movement in the electric field.

158
Q

What are the five bands produced by serum proteins in electrophoresis?

A

The five bands are albumin, α1-globulins, α2-globulins, β-globulins, and γ-globulins, with albumin traveling farthest towards the anode

159
Q

How are electrophoretic patterns visualized after separation

A

The protein fractions are fixed, denatured, and stained, then visualized or scanned by a densitometer, or the bands can be cut out, eluted, and measured spectrophotometrically.

160
Q

how are proteins identified

A

by reacting a protein and its antibody

161
Q

what are the techniques used to identify proteins

A

radial immunodiffusion
immunoelectrophoresis
immunofixation electrophoresis

162
Q

What are the common durations for collecting specimens in urine protein quantitative methods?

A

Most urine protein quantitative methods are performed on either a 12-hour or 24-hour specimen

163
Q

Why is a 24-hour specimen often preferred in urine protein quantitative tests

A

The 24-hour specimen allows for the observation of circadian rhythmic changes in protein excretion

164
Q

How is the volume of urine measured and recorded during urine protein quantitative testing?

A

The volume of urine collected over the specified time period (either 12 or 24 hours) is carefully measured and recorded

165
Q

How are results reported in urine protein quantitative tests?

A

Results are reported as the weight of protein excreted per 24 hours. This is calculated by determining the amount of protein present in the total volume of urine collected during that time

166
Q

Which methods can be used for urine protein quantification?

A

Turbidimetric methods (using sulfosalicylic acid, trichloroacetic acid, or benzethonium chloride)
Biuret method
Folin-Lowry method
Dye binding method (using Coomassie blue or Ponceau S)

167
Q

What is the most frequently performed chemical test on CSF to determine protein levels?

A

The most frequently performed chemical test on CSF to determine protein levels is protein turbidimetry

168
Q

What are the commonly used techniques for measuring total CSF protein?

A

The two most routinely used techniques for measuring total CSF protein are turbidimetry and dye-binding methods (such as Coomassie brilliant blue).

169
Q

What is the reference interval for CSF protein in patients between 10 and 40 years of age?

A

The reference interval for CSF protein in patients between 10 and 40 years of age is 15 to 45 mg/dL

170
Q

What conditions may lead to increased total CSF proteins?

A

Bacterial, viral, and fungal meningitis
Traumatic tap
Multiple sclerosis
Obstruction
Neoplasm
Disk herniation
Cerebral infarction

171
Q

Why is albumin used as a reference protein in CSF analysis?

A

Albumin is used as a reference protein because it is not synthesized in the central nervous system (CNS). The reference value for the CSF albumin–serum albumin ratio is less than 2.7 to 7.3

172
Q

In which conditions are low CSF protein values typically found?

A

Low CSF protein values are found in conditions such as hyperthyroidism and when fluid is leaking from the CNS.

173
Q

How do we calculate albumin to globulin ratio

A

measures the amount of abulmin in serum and divides it by globulin

174
Q

what is the abulmin to globulin ratio used for

A
  1. used to identify causes of changes in total serum proteins
  2. it may be used to assess body nutritional status
175
Q

what is the clinical signficance of abulmin/globulin ratio

A

associated with increase in albumin due to hemoconcentration

176
Q

what does decrease in albumun/globulin ration signify

A

severe liver disease, maldigestion,inflammation, hyperglobulinemia

Clinical chemistry (13 decks)

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