AMINO ACIDS AND PROTEINS Flashcards
(126 cards)
1
Q
building blocks of proteins
A
amino acids
2
Q
amino acids provide ____ of the total body energy requirement
A
12-20%
3
Q
amino acids contain at least one ____ and ____ group
A
N-terminal end amino group; C-terminal end carboxylic group
4
Q
what links amino acids together to form a polypetide
A
peptide bonds
5
Q
what differentiates amino acids from one another
A
chemical composition of their R group
6
Q
these cannot be synthesized by the body and must be obtained from the diet
A
essential amino acids
7
Q
example of proteolytic enzymes that cleave dietary proteins into constituent amino acids
A
pepsin and trpysin
8
Q
give 10 essential amino acids
A
histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, valine, arginine
9
Q
it is a class of inherited errors of metabolism in which there is an enzyme defect that inhibits the body’s ability to metabolize certain amino acids
A
aminoacidopathies
10
Q
what is the enzyme deficient in phenylketonuria
A
phenylalanine hyroxylase (converts phenyalanine to tyrosine)
11
Q
odor of urine in phenylketonuria
A
mousy
12
Q
deficient enzymes in tyrosinemia
A
type I: fumarylacetoacetate hydrolase
type 2: tyrosine aminotransferase
type 3: 4-hydroxyphenylpyruvate dioxygenase
13
Q
deficient enzymes in alkaptonuria
A
homogentisate oxidase
14
Q
deficient enzymes in MSUD
A
branched-a ketoacid decarboxylase
15
Q
deficient enzymes in isovaleric acidemia
A
isovaleryl coA- dehydrogenase
16
Q
deficient enzyme in homocystinuria
A
cystathione B-synthase
17
Q
deficient enzyme in cystinuria
A
none; it only has a defect in amino acid transport
18
Q
what AA accumulate in MSUD
A
leucine, isoleucine, valine
19
Q
what AA are defectively reabsorbed in cystinuria
A
lysine, ornithine, cysteine, arginine
20
Q
Why are proteins amhoteric/ampholytic
A
because they can be acidic or alkaline depending on the body ph
21
Q
at ph <3.5 proteins behave as
A
cation
22
Q
at ph >3.5 proteins behave as
A
anion
23
Q
what is isoelectric point
A
it is the ph at which proteins do not have a net charge (zwitterions)
24
Q
what comprises proteins
A
carbon, hydrogen, oxygen, nitrogen, sulfur
25
what percentage of nitrogen do proteins have
16%
26
Analogy:
Intracellular proteins: ____
_____: ribosomes attached in the rer
free ribosomes
| extracellular
27
which organ synthesizes proteins
liver
28
severe or chronic liver diseases cause a ___ in plasma protein concentration leading to ____
decrease; hypoproteinemia
29
proteins comprises ___ of the cell's dry weight
50-70%
30
what differentiates proteins from lipids and carbohydrates in terms of storage
proteins do not have a designated storage depot in the body
31
negative nitrogen balance: catabolism ___ anabolism
| positive: anabolism ___catabolism
> ; >
32
conditions where a negative nitrogen balance is seen
excessive tissue destruction such as burns, wasting disease, high fever, starvation
33
conditions where a positive nitrogen balance is seen
growth, pregnancy, repair processes
34
protein is a transport carrier for susbtances such as
bilirubin, heme, hemoglobin, iron, copper, drugs, hormones
35
it is the most flexible transport protein
albumin
36
it is the consequence of low osmotic pressure
edema
37
how many g of albumin is excreted in the urine per day when there is nephrotic syndrome
3-4 grams
38
it is the linear sequence of amino acids and determines the identity of the protein
primary structure
39
it involves the winding of the polypeptide chain
secondary structure
40
what are the common secondary structures
alpha-helix,beta pleated, bend conformation
41
it is the actual 3D conformation of the protein
tertiary structure
42
what protein structure is affected by denaturation
secondary, tertiary and quaternary
43
factors causing denaturation
heat, strong acid/alkali, enzymatic reactions, exposure to urea and other subs, exposure to UV
44
transport proteins: (3)
apotrasferrin, apoceruloplasmin, albumin
45
structural proteins (3)
collagen, elastin, keratin
46
what are simple proteins
contain a peptide chain which on hydrolysis yields only amino acids
47
example of fibrous proteins
fibrinogen, troponin, collagen
48
example of globular proteins
globin enzyme, peptide hormone, albumin
49
what are conjugated proteins
proteins composed of an apoprotein and a non protein moiety (prosthetic group)
50
```
give examples of the ff:
metalloproteins
lipoproteins
glycoprotein
mucoprotein
nucleoprotein
```
metalloproteins: ferritin, flavoprotein, hemoglobin, ceruloplasmin
lipoprotein: vldl ldl hdl chylomicrons
glycoprotein: haptoglobin, and alpha-1 antitrypsin
mucoprotein: mucin
nucleoprotein: chromatin
51
these are the most frequently analyzed of all the proteins
plasma proteins
52
plasma proteins are divided into:
albumin and globulin
53
the blood panel for plasma protein analysis consists of
total protein
albumin
globulin
A:G ratio
54
this is a sensitive marker of nutritional status
pre albumin
55
pre albumin is the transport protein for:
T4 and retinol
56
why is pre albumin used to confirm is sample is really CSF
pre albumin crosses the CSF more easily compared to other proteins
57
albumin comprises __% of the plasma protein mass
50%
58
albumin transports:
bilirubin, fatty acids, calcium, magnesium, drugs, Salicyclic acid, dyes
59
albumin is responsbile for 80% of _____ of the ___
colloid osmotic pressure; intravascular fluid
60
is albumin a neg or pos APR
neg
61
lowest plasma levels of albumin is seen in
nephrotic syndrome
62
conditions where hypoalbuminemia is seen
malnutrition and malabsorption
liver dx
protein losing enteropathy or GI los
renal dx (nephrotic syndrome or glomerulonephritis)
acute dx states
mutation resulting from an autosomal recessive trait causing analbuminemia and bisalbuminemia
hemodilution, increased capillary permeability, and sepsis
63
hyperalbuminemia is seen in what conditions
dehydration
| excessive albumin infusion
64
globulins are group of proteins consisting of
alpha 1, alpha 2, beta, and gamma fractions
65
what does A1 antitrypsin inhibit?
it inhibits neutrophil elastase which are released by WBC to fight infection
66
it is the major inhibitor of protease activity (preventing self destruction of tissues)
A1 antitrypsin
67
A1 antitrypsin is deficient in conditions such as
emphysematous pulmonary disease and juvenile hepatic cirrhosis
68
where is A1 fetoprotein synthesized
it is synthesized initially in the fetal yolk sac and then by the fetal parenchymal cells of the liver
69
when does the concentration of AFP peaks in the fetus
13th week of gestation
70
Physiologic increase of AFP: ___
Pathologic increase of AFP: ____
Pathologic decrease of AFP: _____
pregnant women with twins
neural tube defects (spina bifida and anencephaly), low folate
down syndrome and trisomy 18
71
QUAD marker
high HCG and inhibin A and low maternal serum AFP and urinary estriol
72
AFP is used as a tumor marker for ___
hepatic and gonadal cancer
73
A1 - acid glycoprotein (orosomucoid) contains the highest percentage of __ and ___
CHO and sialic acid
74
why is orosomucoid negatively charged even in acid solution
because it has a low isoelectric point 2.7 and due to high sialic acid content
75
orosomucoid provides a useful diagnostic tool for ___
neonates with bacterial infecitons
76
A1 acid glycoprotein has high affinity to ___ and binds ___
progesterone ; quinidine
77
A1- antichymotrypsin binds and inactivates ____
prostate specific antigen
78
A1- antichymotrypsin is an integral component of ___ found in Alzheimer's dx
amyloid plaques
79
what does A1-antichymotrypsin inhibits
serine proteases like; cathepsin C, pancreatic elastase, chymase and chymotrypsin
80
it transports lipids and is the major component of hdl
A1- lipoprotein
81
this inhibits serine proteases
inter-alpha-trypsin inhibitor
82
function of group specific globulin
it transports vitamin D and binds actin
83
what are the A1 globulins
haptoglobin, a2-macrogloblulin, apoceruloplasmin
84
what is the function of haptoglobin
it binds the free hemoglobin by its alpha chain
85
haptoglobin is decreased in ___
intravascular hemolysis and hemoglobinuria
86
it is the largest major nonimmunoglobulin protein in plasma
a2- macroglobulin
87
where is a2- macroglobulin primarily found
intravascular space
88
in what condition does the concentration of a2- macroglobulin increases 10x
nephrosis
89
it is a copper binding alpha-2 glycoprotein that has enzymatic activities
apoceruloplasmin
90
where is apoceruloplasmin synthesized
liver (6-8 atoms attached forming ceruloplasmin)
91
what color does it impart to proteins
blue
92
apoceruloplasmin is decreased in what conditions
Wilson's dx, menke's kinky hair syndrome
93
copper deposits in the cornea
kayser fleischer rings
94
what are the B- globulins
Pre-b lipoprotein; transferrin; hemopexin; B-lipoprotein; B2- microglobulin; complement, CRP
95
Analogy:
Pre-b lipoprotein: ___
______: LDL
VLDL trigylcerides
| b-lipoprotein
96
Transferrin comprises ___ of the beta globulin fraciton
90%
97
how many molecules of ferric ion does transferrin transport
2
98
level of transferrin in IDA
normal or increased (paraprotein)
99
what does hemopexin do
it binds the free heme and evaluates early hemolysis
100
B2-microglobulin is a light chain component of MHC class __ which are found in ___
II; nucleated cells
101
B2 microglobulin is recognized by ___
Cd8 or cytotoxic cells
102
functions of complement
cell lysis; opsonization; anaphylaxis; inflammation
103
which complement is present in high concentration in the plasma
c3
104
CRP is named after its ability to bind with the ___ of ___
C-polysaccaride; pneumococci
105
it is used as an early warning test to persons at risk of coronary artery disease
hsCRP
106
it is the most abundant of the coagulation factors
fibrinogen (factor 1`)
107
effect of high levels of fibrinogen in the plasma
it may elevate the ESR which favors rouleaux formation which sediments faster
108
fibrinogen is found between __ and ___ globulin
beta and gamma
109
antibodies in the neonatal serum are of ____ origin
maternal
110
myoglobin is a primary-oxygen carrying protein found in ___ and ___
striated skeletal muscle and cardiac muscle
111
give the onset, peak, and normalize of myoglobin
2-3 hrs; 8-12 hrs; 18-30 hrs
112
myoglobin is not cardiospecific because it is also elevated in ___ and ___
progressive muscular dystrophy and crushing injury
113
which troponins are considered as gold standard tess for acute coronary syndrome
T and I
114
which troponin is present in both cardiac and skeletal muscle; binds calcium to regulate muscle contraction
C
115
Analogy:
Troponin T: ____ ( onset: ___ peaks: ____ normalize: ___
____: myocardium
```
heart muscle (3-4; 10-24; 7 days
Troponin I
```
116
it is a potent vasodilator that promotes natriuresis
natriuretic peptide
117
fibronectin plays a role in ___, ___, ___, ____
cell adhesion, tissue differentiation, growth and wound healing
118
B-trace protein is established as an accurate marker of ___
CSF leakage
119
CTXs is a biochemical marker of ____
bone resorption
120
Cystatin C is an endogenous marker of ___
GFR
121
test used for differential diagnosis of Alzheimers dx
Amyloid b-42 and Tau test
122
test indicating increased likelihood of alzheimer's dx
low AB42 and high Tau test
123
microalbuminuria is increased in ___, ____,___,___
fever, infection, hypertension, diabetic nephropathy
124
it is the presence in CSF of two or more IgG bands in the gamma region
CSF oligoclonal banding
125
other disorders with two or more bands in the CSF: (4)
neoplastic d/o. neurosyphilis, encephalitis, and guillan barre syndrome
126
supporting medium and stain for CSF oligoclonal banding
agarose gel and coomasie brilliant blue stain
