Proteins Flashcards
1
Q
Protein definition
A
Substances made of amino acids.
2
Q
Peptide
A
When two or more amino acids join
3
Q
Elements in proteins
A
Carbon, Hydrogen, Oxygen, Nitrogen, Sulfur
4
Q
Nitrogen in proteins
A
16%
This content allows us to differentiate between proteins and other substances
Used to measure total protein
5
Q
Amino acids
A
- Building blocks of proteins
- chemical properties determine biological function
- synthesized in body or ingested
6
Q
MILL PATH TV (essential amino acids)
A
Methionine Isoleucine Leucine Lysine Phenylalanine Arginine (semi) Tryptophan Histidine Threonine Valine
7
Q
R group
A
Area of structure that differentiates amino acids
8
Q
Glycine
A
Smallest and simplest amino acid
- used as sweetener
- used as sleep aid
9
Q
Peptide bond
A
Formed when molecule of water removed from two amino acids
10
Q
Peptide bond (biruet)
A
Used to measure total protein
-color is proportional to number of bonds)
11
Q
Amino acids structure
A
Amino group (N) (Base) Carboxyl (C) (Acid) R group (function)
12
Q
Protein in serum (amino acid #)
A
100-150 amino acids
13
Q
Amphoteric
A
Containing two ionizable sites
can serve as acid or base to provide buffering capacity to body
14
Q
Proton accepting group
A
NH2
15
Q
Proton donating group
A
COOH
16
Q
Proton donating group
A
COOH
17
Q
Buffering capacity of proteins
A
Comes from terminal groups
allow amino acid to pick up or release H+
18
Q
Protein in alkaline solution
A
Amino acid acts as an acid and releases H+
19
Q
Protein in acidic solution
A
Amino. acid acts as a base and absorbs H+
20
Q
Isoelectric point (pI)
A
pH at which the amino acid or protein has no net charge
21
Q
protein pH range
A
5.5-8.0
22
Q
pH > pI
A
net negative charge
23
Q
pH < pI
A
net positive charge
24
Q
Primary structure
A
Number and types of amino acids in protein
“beads on string”
25
sickle cell disease
Valine is substituted for glutamic acid in hgb A (forms hgb S)
26
secondary structure
regularly repeating structures stabilized by hydrogen bonds
27
secondary structure (3 types)
alpha-helix
beta-pleated sheets
random coils
28
tertiary structure
overall shape/conformation
-folding of R-groups of other amino acids
determines function
29
quarternary structure
two or more polypeptide chains to form a protein
30
ex of quarternary structure
Hemoglobin
- 4 polypeptide chains
- CK
- iron containing heme groups
31
denaturation
disruption of native folded structure of protein. disrupts function of protein
32
causes of denaturation
- heat
- change in pH
- mechanical
- chemicals
- enzymatic activity
- UV light
33
globular proteins
- compact, coiled, tightly folded
- soluble in water
- transporters, enzymes, messengers
34
globular protein examples
- albumin
- hemoglobin
- immunoglobulines
35
fibrous proteins
- form long protein filaments (asymetrical)
- insoluble (R groups)
- tendons, bones, muscle
36
fibrous protein examples
- collagen, elastin
- keratin
- fibrin
- myosin
37
conjugated proteins
consist of protein and nonprotein (prosthetic) groups.
| metalloprotein, lipoprotein, glyco, muco, nucleo...etc
38
metalloproteins
metal ion attached
39
metalloprotein examples
ferritin (Fe)
ceruloplasmin (Cu)
Hemoglobin (complex metal)
40
Lipoproteins
lipids and proteins
| -HDL, VLDL, cholesterol, triglycerides
41
glycoproteins
-sugar group attached
| simple protein and carbohydrates
42
glycoprotein examples
- haptoglobin
| - a1-antitrypsin
43
mucoproteins
large, complex carbohydrates
44
mucoprotein example
mucin
45
nucleoprotein
simple protein and nucleic acids (RNA, DNA)
46
nucleoprotein example
chromatin
47
protein metabolism location
originates in digestive tract
48
protein metabolism process
amino acids are absorbed from intestines into blood, become part of amino acid pool in body.
insufficient quantities can limit synthesis and lower levels of essential proteins
49
nitrogen storage
no designated storage depots in body
50
healthy nitrogen balance
intake and excretion are equal
51
positive nitrogen balance
intake exceeds loss
52
who has positive nitrogen balance
pregnant women, children, adults recovering from illness
53
negative nitrogen balance
loss exceeds intake
54
who has negative nitrogen balance
excessive tissue destruction; burns, wasting disease, high fevers or starvation
55
protein synthesis location
synthesized in liver with exceptions
56
protein synthesis exceptions
immunoglobulins
hemoglobin
protein hormones
coagulation factors
57
enzyme funciton
catalyze chemical reactions
58
enzyme examples
- transaminases
- dehydrogenases
- phosphates
59
hormone function
messengers that control actions of specific cells or organs
60
hormone examples
insulin, growth hormone, cortisol
61
transport hormone function
transport ions and molecules across biological membranes
62
transport hormone examples
hemoglobin, albumin, transferrin
63
immunoglobulin function
mediate humoral response to identify and neutralize foreign invaders
64
immunoglobulin examples
IgG, IgM, IgA
65
structural protein function
structure of cells and tissues
66
structural protein examples
collagen, elastin, keratin
67
storage protein function
reserves of metal ions and amino acids
68
storage protein example
ferritin (stores Fe)
69
energy protein
reserve source of energy
70
osmotic force proteins
maintain water distribution between cells and tissue, interstitial compartments and vasculature
71
osmotic force protein example
albumin
72
how proteins maintain osmotic pressure
proteins don't cross capillary membranes. water is absorbed into venous space.
if protein content is low, more water can pass through membrane and osmotic pressure will be low
73
result of low osmotic pressure
edema
74
aminoacidopathies
rare
| enzyme defect that inhibits body's ability to metabolize certain amino acids
75
aminoacidopathy abnormalities
problem with enzyme activity
| membrane transport system for amino acids
76
result of aminoacidopathies
buildup of toxic amino acids
| byproducts of amino acid metabolism in blood
77
IEM
inborn error of metabolism (metabolic defects from birth)
78
why do we not care about IEM in utero
mom's system will make up for any error in metabolism
79
PKU
-IEM
absence of deficiency of phenylalanine hydroxylate
-increased formation of phenylalanine metabolites
80
PKU dietary restrictions
meat, fish, nuts, dairy
| calculated amounts of cereal, starch, fruit, veg, milk substitutes
81
result of PKU
build up of phenylpyruvic acid
| -decreased tyrosine
82
enzyme deficiency in PKU
phenylalanine hydroxylase
83
Tyrosinemia
accumulation of excess tyrosine in the plasma producing urine overflow
84
tyrosinemia urine
excess tyrosine or degredation products
85
tyrosinemia smell
boiled cabbage
86
tyrosinemia enzyme deficiency
tyrosine transaminase
87
tyrosinemia types
type 1, type 2, type 3
88
Alkaptonuria enzyme
homegentisic acid oxidase
89
alkaptonuria urine
black urine, dark
| alkaline
90
homogentisic acid oxidase
used i ncatabolism of phenyalanine and tyrosine
91
adult alkaptonuria
ochronosis, alkaline urine, arthritis, liver, cardiac disorders
92
maple syrup urine disease
thick, dark, sweet urine
| elevated valine, leucine, isoleucine
93
MSUD enzyme
branched chain keto acid decarboxylase
94
maple syrup urine disease diagnosis
within 11 days of live, or else severe intellectual disability
95
cystinuria
elevated cystine in urine
defect in renal tubular reabsorption of cystine
(not an enzyme deficiency)
96
two modes of cystinuria
- reabsorption of all 4 amino acids (cystine, lysine, arginine, ornithine) is affected
- reabsorption of cystine and lysine
97
cystinuria result
kidney stones and crystals
98
cystinosis
inherited lysosomal storage disease resulting in cystine deposits in lysosome cells throughout the body
99
homocystinuria
autosomal IEM
| defective metabolism of methionine
100
homocystinura result
failure to thrive, thrombosis, death
101
PKU markers
mousy odor
102
Amino acid analysis
evaluated patients with IEM
103
amino acid specimen collection
```
draw 6-8 hour fast (avoid dietary proteins)
heparine tube
remove plasma
avoid WBC and hemolysis
Perform immediately or freeze
-can use urine, chromatography
```
104
acute phase reactants
rapid and coordinated change/response
105
acute phase reactants intiation
intiated by tissue damage
| -infection, inflammation, RA, trauma, burns
106
negative acute phase reactant
proteins will decrease
107
positive acute phase reactants
proteins will increase
108
acute phase reactant protein
proteins needed to deal with tissue damage will be generated, whereas other proteins will be inhibited
109
prealbumin
TTR
| migrates ahead of albumin in protein electrophoresis
110
prealbumin visibility
not visible in low concentration
111
prealbumin job
transport thyroid hormones, retinol (vitamin A)
112
negative acute phase proteins
prealbumin
albumin
transferrin
113
where is prealbumin made
liver
114
increased prealbumin
steroids, alcoholism, chronic renal failure
115
decreased prealbumin
hepatic damage
acute phase inflammatory response
tissue necrosis
poor nutrition
116
PEM
protein energy malnutrition
| sensitive marker of poor nutritional status
117
prealbumin reference range
195-350 mg/dl
118
albumin synthezised where
synthesized in liver
119
albumin amount in plasma
protein present in highest concentration in the plasma 60%
120
albumin functions
- maintenance of colloid osmotic pressure
- buffer pH
- negatively charged, acts as magnet for water (pulls into vascularature)
- negative acute phase protein
- transport various molecules (bilirubin, meds, hormones)
121
albumin reference range
3.5-5.0 mg/dl
122
increased albumin
hyperalbuminemia
dehydration
steroids
excessive albumin infusions
123
decreased albumin
```
hypoalbuminemia
liver disease
malabsorption
diarrhea
renal disease
inflammation
dilution by polydipsia/IV fluids
```
124
makes up 90% of alpha 1 proteins
a1 antitrypsin
125
a1 antitrypsin
acute phase reactant
| inflammatory response.
126
decreased a1 antitrysin
emphysema, congential cirrhosis
127
increased a1 antitrysin
inflammatory reactions, contraceptive use
128
main fetal protein
alpha fetoprotein (AFP)
129
a1 antitrysin synthesis
in liver
130
no a1 antitrypsin present
emphysema.
131
job of a1 antitrypsin
cleans byproducts of macrophages in lungs
132
excess AFP
spina bifida, neural tube issue
133
AFP decreased
down syndrome
134
haptoglobulin
acute phase reactant
binds hemoglobin
indicator of hemolysis
135
increased haptoglobulin
inflammatory disease
RA
burns
nephrotic syndrome
136
decreased haptoglobulin
hemolytic anemia
| liver disease
137
a1 globulins
AFP
a1 antitrypsin
a1 acid glycoprotein
138
why we want to bind free hemoglobin
hemoglobin can be oxidized into a free radicals
139
a2 globulins
haptoglobin
cerruloplasmin
a2 macroglobulin
140
cerruloplasmin function
acute phase reactant
| binds 90% of copper
141
increased cerruloplasmin
inflammation
infection
pregnancy
tissue damage
142
decreased cerruloplasmin
malnutrition
liver disease
wilson's disease
(copper deposits throughout body especially eyes)
143
a2 macroglobulin function
acute phase reactant
protease inhibitor, trysin, pepsin, plasmin
associated with coag cascade
144
increased a2 macroglobulin
- nephrotic syndrom
- oral contraceptives
- hormone replacement
145
decreased a2 macroglobulin
pancreatitis
| advanced prostate cancer
146
beta globulins
```
transferrins
hemopexin
B-lipoproteins
B-microglobulin
fibrinogen
complement
CRP
```
147
transferrin function
transport iron
prevent iron loss
negative acute phase reactant
148
increased transferrin
- iron deficiency
- anemia
- hepatitis
- pregnancy
- HRT
149
decreased transferrin
- inflammation
- malignancy
- nephrotic syndrome
- malnutrition
- marker of PEM
150
hemopexin function
binds free heme
151
increased hemopexin
- inflammation
- diabetes
- melanoma
- pregnancy
152
decreased hemopexin
-hemolytic anemia (hemopexin is used up)
153
b-lipoprotein function
transport lipids
154
increased b-lipoproteins
- heart disease
- athreosclerosis
- diabetes
- hypothyroidism
155
decreased b-lipoproteins
malnutrition
156
b-microglobulin function
component of immune system
| -HLA molecules (blood matching for donation)
157
increased b-microglobulin
- RA
- lupus
- renal failure
158
fibrinogen function
- forms a fibrin clot when activated by thrombin
| - acute phase reactant
159
increased fibrinogen
pregnancy, oral conctraceptive
160
decreased fibirnogen
excessive coagulation
161
complement function
immune response
| acute phase reaction
162
increased complement
inflammation
163
decreased complement
malnutrition
| hemolytic anemima
164
CRP function
acute phase reactant
165
increased CRP
tissue necrosis
cardiac disease
bacterial infection
RA
166
high snesitivity, low specificity
CRP testing
167
immunoglobulin structure
heavy chain
antigen binding site
disulfide bonds
carbohydrate side chains
168
immunoglobulin synthesis
mature B cells in plasma
169
majority of protein synthesis
liver
170
y globulins
- IgG
- IgA
- IgM
- IgD
- IgE
171
majority of immunolgobuin
IgG
172
IgG function
antibodies
173
increased IgG
- liver disease
- infection
- parasitic disease
- RA
174
decreased immunoglobins
immunodeficiency disorders
175
IgA function
antibodies in secretion
| ex. colostrum
176
increased IgA
- liver disease
- infection
- autoimmune disease
177
decreased IgA
depressed protein synthesis
178
largets immunoglobulin
IgM
179
IgM function
early response antibodies
180
increased IgM
toxicoplasmosis
181
decreased IgM
hereditary
182
IgD fucntion
antibodies
183
increased IgD
infection
liver desase
connective tissue disorders
184
IgE function
allergy antibodies
185
increased IgE
not diagnostic
inflammatory disease
allergens
186
myoglobin
found in skeletal/cardiac muscle
187
myoglobin function
carry oxygen to muscles
188
myoglobin and tropronin
used to help rule out MI
189
troponin
cardiac biomarker
190
increased myoglobin
muscle disease, crush injuries
191
myglobin size
can pass through the nephron and damage kidney
192
brain natriuretic peptide (BNP) function
fluid homeostasis
| distinguishes AMI and CHF
193
fetal fibronectin
used to help predict short term delivery risk of premature delivery
194
total protein reference range
6.5-8.3 mg/dl
195
lower total protein
```
hospital patients (0.5 lower)
age (decline)
```
196
artificial increased total protein
increased tourniquet application (by 0.5 mg/dl)
197
hyperproteinemia ref range
total protein over 8.3 mg/dl
198
causes of hyperproteinemia
-dehydration --> decreased water = increased protein
(vomiting, diarrhea, diabetes)
-excess gamma globulins
(multiple myeloma, waldestron's)
199
hypoproteinemia ref range
total protein <6.5 mg/dl
200
negative nitrogen balance
hypoproteinemia
201
causes of hypoproteinemia
- excessive loss (renal disease)
- decreased intake
- decreased synthesis (liver disease)
- acceleration of protein catabolism
202
A/G ratio equation
(calc. globulin)= (total protein)-(albumin)
203
A/G ratio reference range
1.0-1.8
204
low AG ratio
- overproduction of globulins
| - decreased albumin
205
high AG ratio
-underproduction of globulins
206
fibrinogen tube and specimen
green top: plasma
207
(Protein methodology) Kjedahl method principle
Digestion of protein, measurement of nitrogen content
| -assume nitrogen content is 16%
208
Refractometry (total protein)
Measurement of refractive index due to solutes in the serum
| -assume nonprotein solids are in same concentration as the serum
209
Biuret (tot protein) principle
Formation of violet-colored compound chelate between Cu2- ions (cupric) and peptide bonds.
more peptide bonds = more color
210
Biuret method specimen
serum or plasma
211
Biuret wavelength
450 nm
212
Spectrophotometer interference
lipids, icteric, hemolysis
213
Biuret requirements
2 peptide bonds
| alkaline medium
214
Dye binding (tot prot)
Protein binds to dye and causes spectral shift in the absorbance (465 nm-595nm)
215
Dye binding (tot protein) notes
unequal dye requires caution
216
Biuret method advantages
simple,automated,precise
217
biuret method disadvantages
hemolysis can elevate RBC proteins.
| lipemia, biirubinemia, turbidity
218
Bromcresol green (albumin dye binding) principle
Albumin binds to dye, causes shift in absorbance
not as specific for albumin
most common
219
Bromcresol purple (albumin dying)
Albumin binds to dye
| Specific, sensitive, precise
220
serum protein electrophoresis clinical application
when tissues responsible for synthesis or clearance of proteins are altered by disease, serum reveals patterns helpful for diagnosis
221
how serum protein electrophoresis separates
Basis of electric charge densities
222
fastest migrating protein
albumin
223
intermediate migrating protein
alpha1, alpha 2, beta-globulins
224
slowest migrating protein
gamma globulines
225
electrophoresis process
migrate on agarose gel, fix proteins, stain for scanning
226
pH buffer for serum protein electrophoresis
pH 8.6
227
why SPE is performed on serum
fibrinogen is absent
228
rate of migration depends on
```
Net electrical charge
pH buffer
pI mobility
size/shape
electrical field
supporting medium
temperature
```
229
isoelectric point of a protein and pH
if pH is greater than pI, specimen will move towards anodes
230
densitometry dyes
Ponceau S, Amido black, Coomaise blue
231
Densitometry protein strips
gel bands are dyed, and passed through optical beam and absorbance is read
232
densitometry wavelength
520-640 nm depending on stain
233
densitometry peaks
more protein = darker bands
234
abbie ____ is attracted to Andy ____ because of his _____ attitude
albumin, anode, positive
235
why is serum electrophoresis
to see if there is a presence of abnormal proteins, or absence of normal proteins
236
densitometry equation
relative %=(absorb. apecific band/absorb. all bands) X 100
237
greater the concentration =
higher the absorbance
238
densitometry absolute concentration
(Relative % of each band) X (Total serum protein)
239
albumin band
dark, tight band
240
gamma globulin bands
many immunoglobulins with different charges
| lighter wider band, short peak
241
albumin relative % (ref range)
53-65
242
albumin absolute concentration (ref range)
3.5-5.0 g/dl
243
a1 globulin relative % ref range
2-5%
244
a1 globulin absolute conc. ref range
0.1-0.3 g/dl
245
a2-globulin % reference range
7-13%
246
a2-globulin absolute conc. ref reange
0.6-1.0
247
B-globulin % ref range
8-14%
248
B-globulin absolute conc. ref range
0.7-1.1 g/dl
249
y-globulin % ref range
12-20%
250
y-globulin absolute conc. ref range
0.8-1.6 g/dl
251
nephrotic syndrome (protein)
protein lost from blood to urine. (damage to kidney)
| decreased albumin, increased a2, B-globulins
252
nephrotic syndrome symptoms
```
edema
blood clots
high cholesterol
foamy urine
fatty/waxy casts
```
253
edema and protein
when albumin leaves through urine, water cannot pass through into vasculature and accumulates into extravascular space
254
y-globulin increase
-immune reaction
-RA
-cirrhosis
-liver disease
metastatic cancer
-bacterial infection
255
y-globulin decrease
- immune deficiency
- manifest in infancy
- monoclonal gammopathy
- immunosuppresive therapy
256
monoclonal increase
- excessive production of single immunoglobulin by single plasma line
- appears as distinct band
- requires further investigation
257
IgM overproduction
Waldenstroms Macroglobulinemia
258
overproduction of any single immunoglobulin
Multiple myeloma
259
bence jones protein
overproduction of light chains on immunoglobulins
260
monclonal
one type of protein
261
polyclonal
multiple types of proteins
262
diffused band
polyclonal
263
cirrhosis
polyclonal increase in y-proteins
| -increased IgA
264
fusion of Beta and gamma bands
"bridging"
occurs in cirrhosis
fast moving gamma prevent resolution of beta
265
hypogammaglobulinemia
low gamma globulins due to reduced antibodies
- immunocompromised
- staining erro
