Proteins - Summary II Flashcards
(167 cards)
1
Q
The a-chains of collagen are (left/right)-handed helixes
A
left
2
Q
__________ are used in combination with papain in beer chill-proofing
A
Bacterial proteases
3
Q
_______ form the lipovitellin fraction
A
HDLP
4
Q
_______ hydrolyses a-1-4 glycosidic bonds within starch
A
amylase
5
Q
_______ is used as a ________ on inferior meat cuts
A
Papain meat tenderizer
6
Q
________ are water soluble and correspond to blood serum proteins of the chicken.
A
Livetins
7
Q
_______ are activated as the Ca2+ concentration in the ________ increases postmortem.
A
Calpains sarcoplasm
8
Q
The purpose of the process of surimi is to remove strong _______ compounds and pigments as well as ________ proteins that can interfere with the gelation of the myofibrillar proteins
A
flavor water-soluble
9
Q
________ consists of two polypeptide chains of identical sequence termed a1, and another chain termed a2, and is the dominant type in meat
A
Type 1 collagen
10
Q
______ can be inhibited by vitamin C, bi-sulfites, and EDTA
A
Polyphenol oxidase
11
Q
Hydrolysis by ________ results in dextrins, maltose, and maltotriose
A
a-amylase
12
Q
_________ arise from crosslinking between allysine, which is formed by _____ of lysine residue by lysyl oxidase, and an adjacent unmodified lysine residue
A
Lysinorlysine oxidation
13
Q
What causes dark, firm, and dry (DFD) meat?
A
- Lack of glycogen - Early termination of glycolysis - High pH (> 6.0)
14
Q
__________ sequesters the iron and prevents a red discoloration of the meringue due to conalbumin-iron complex.
A
Citric acid
15
Q
_______ is employed in biomedical research by taking advantage of its high affinity for biotin in immunoassays, affinity chromatography, and molecular labelling
A
Avidin
16
Q
From a functional standpoint, ______ proteins such as ______ are known to have good gelling ability.
A
globular ovalbumin
17
Q
The carbohydrate in ________ is present as three polysaccharide chains, each attached to the polypeptide through an asparaginyl residue.
A
ovomucoid
18
Q
Soybean is exceptionally rich in _______ and can serve as a valuable supplement to cereal foods
A
lysine
19
Q
Fish myoglobin contains a _____ residue that is absent in mammalian myoglobin. Myoglobin and other pigments are concentrated in the _____ muscle.
A
cysteine dark
20
Q
Soy protein isolates (SPI)
A
Wheat, corn, barley, rice
21
Q
_______ is the only egg-white protein to contain a free sulfhydryl group
A
Ovalbumin
22
Q
________ converts colloidal pectin to non-colloidal pectin
A
Pectin methyl esterase
23
Q
_________ consists of three identical chains of a1
A
Type III collagen
24
Q
__________________performs more favourably than acetic or citric acid at pH 6.0, but __________ is important in that it sequesters the iron and prevents a red discoloration of the meringue due to conalbumin-iron complex.
A
Potassium acid tartrate citric acid
25
Hydrolysis by ________ results in maltose
B-amylase
26
\_\_\_\_\_\_ is soluble in weak salt solutions and to some extent in water
Phosvitin
27
The solubility of soybean proteins in water is (affected/unaffected) by the pH
strongly affected
28
The delay phase ends when ______ becomes depleted, because _________ alone cannot produce ATP fast enough to match the rate at which it is being hydrolyzed in the cell
CrP anaerobic glycolysis
29
\_\_\_\_\_\_ are bland in flavor, light in color, and have a number of functional properties such as gelation,viscosity,emulsification,water holding capacity,and even some foaming and whipping ability.
Soy protein isolates (SPI)
30
\_\_S is glycinin, the principal protein of soybeans with a built of 12 subunits
11
31
Depletion of ATP results in an inability to dissociate ____ from ____ and hence the muscle cannot relax, which is the onset of \_\_\_\_\_
myosin actin rigor mortis
32
In soybean, the limiting amino acids are the ones containing \_\_\_\_\_\_, which are ______ and \_\_\_\_\_\_\_
sulfur methionine cystine
33
Fe(III) is \_\_\_\_\_, Fe(II) bound to O2 is \_\_\_\_\_, Fe(II) bound to water is \_\_\_\_\_\_
metmyoglobin oxymyoglobin deoxymyoglobin
34
Does the first or second phase of heating release more fluid?
The second
35
\_\_\_\_\_\_\_\_ enzymes are found in papaya
Papain
36
\_\_S fraction is composed of a-conglycinin and low molecular weight polypeptides
2
37
The innermost part of the endomysium consists primarily of _____ collagen, which forms a sheet-like \_\_\_\_\_\_\_\_\_
Type IV non-fibrous network (group 2)
38
The principal component of \_\_S is B-conglycinin, a sugar containing globulin
7
39
If isolated and hydrated, _____ will form a very viscous solution
gliadin
40
The major globular protein in albumen is \_\_\_\_\_\_\_
ovalbumin
41
The portion of the soybean that contains mostly carbohydrates is the \_\_\_\_\_
hull
42
\_\_\_\_\_\_\_\_\_\_ causes loss of cloud in citrus juice
Pectin methyl esterase
43
\_\_\_\_\_\_\_\_\_\_\_ are important to "dextrinize" the disrupted starch granules in baking
a-amylases
44
Which pH would result in the formation of a transparent gel?
7.0 \> pH \> pI
45
With _______ electrostatic repulsion at _____ ionic strength or at 7.0 \> pH \> pI, three dimensional networks form a transparent gel.
decreasing low
46
\_\_\_\_\_\_\_\_ is a multi-type serine protease inhibitor with a molecular weight of 50 kDa, and comprises seven domains conferring trypsin,chymotrypsin,and elastase inhibitory activity.
Ovoinhibitor
47
\_\_\_\_\_\_\_ exhibits enzymatic activity over a broad range of temperatures, and can withstand boiling water for 1-2 minutes
Lysozyme
48
In collagen, hydrogen bonding occurs between the ____ of a _____ and the _____ of the adjacent X residue on another chain
N-H glycine C=O
49
The _________ account for the low congealing temperature of polar fish of Arctic regions
antifreeze serum glycoproteins
50
The _____________ was used as a consumer friendly alternative for the functional modification of egg white proteins and in particular \_\_\_\_\_\_\_, the major egg white protein.
Maillard reaction ovalbumin
51
If ______ proteins are hydrated, it forms a very tough elastic mass (like chewing gum)
Glutenin
52
\_\_\_\_\_\_\_\_\_ significantly improves the foaming, gelling, and emulsifying properties of egg white proteins
Dry heating
53
\_\_\_\_\_\_\_\_\_\_\_\_ are characterized by large numbers of lysinorlysine and desmosine crosslinks
Elastin fibers
54
\_\_\_\_\_\_ is preferred as a gelling agent since it only contains trace amounts of \_\_\_\_\_\_, and therefore it has a good _______ stability
Egg white lipids oxidative
55
Pasteurization denatures the __________ network, thus resulting in the longer whip time.
ovomucin-lysozyme
56
The final phase of conversion of muscle to meat is referred to as ______ or \_\_\_\_\_\_\_\_
aging rigor resolution
57
\_\_\_\_\_\_ makes up the insoluble granules in egg yolk
HDLP
58
\_\_\_\_\_\_ and ______ contain sulphur in the form of cysteine and cystine
Glutenin gliadin
59
Gel strength and cohesiveness are ________ at pH values close to isoelectric point where net charge is minimal
minimal
60
When bottled or canned beer is kept below 10oC, a ____ can form because of interactions between _________ and _________ in beer
haze proteins tannins
61
Lipovitallin can be separated into two components, that differ by their ______ content
phosphorus
/
62
\_\_\_\_\_\_\_\_, which makes up ~10% of total yolk protein, is the most highly phosphorylated protein known to date.
Phosvitin
63
The components of \_\_S also comprise the soybean trypsin inhibitors
2
64
Animals overexpressing the inhibitor \_\_\_\_\_\_\_, postmortem protein degradation is reduced
calpastatin
65
\_\_\_\_\_\_\_\_\_\_ hydrolyses a-1-6 glycosidic bonds in starch
Pullulunase
66
\_\_\_\_\_\_\_\_ causes an increase in the time period required to whip egg whites.
Pasteurization
67
The _____ and _____ portions of the soybean contain high levels of protein
cotyledon hypocotyl
68
\_\_\_\_\_\_\_\_ readily coagulates, a process which is observed when egg white sets on heating
Ovalbumin
69
Protease inhibiting proteins are present in soybeans as ______ inhibitors
trypsin
70
\_\_\_\_\_\_\_ initiate myofibrillar degradation, resulting in release of actin, myosin, and other proteins from the \_\_\_\_\_\_, which may then be hydrolyzed by the \_\_\_\_\_\_.
Calpains sarcomere proteosome
71
Type I collagen is associated with \_\_\_\_\_\_\_
epimysium
72
The _________ occurs because the muscle cells still function adequately as long as ATP levels remain high, and hence the muscle remains pliable and undergoes lengthening when subjected to stretch.
delay phase
73
The role of the added salt in surimi is to ______ the _______ proteins.
solubilize myofibrillar
74
In skeletal muscle cells, the ubiquitous calpains tend to be concentrated in the \_\_\_\_\_\_\_\_\_
Z-discs
75
During the separation of ovalbumin from albumen, _________ is transported with ovalbumin into the filtrate resulting from half- saturation with ammonium sulfate.
ovotransferrin
76
As ATP levels continue to fall, there is a continuous increase in the number of _____ cross-bridges with _____ that are locked because of a lack of ATP.
myosin actin
77
\_\_\_\_\_\_\_\_ hydrolyses a-1-4 glycosidic bonds from the non-reducing end of starch
B-amylase
78
Desmosine crosslinks are derived from ____ lysine chains
four
79
\_\_\_\_\_\_\_\_ is a phosphoglycoprotein, with a molecular weight of about 44.5 kDa.
Ovalbumin
80
Ovotransferrin is also known as \_\_\_\_\_\_\_\_
conalbumin
81
The antifreeze effects of serum glycoproteins are attributed to the ______ residues as well as the _____ side chains of the peptide moiety
disaccharide methyl
82
Active mitochondrial respiration at a ___ ph reduces the fraction of __________ in the tissue
higher oxymyoglobin
83
\_\_\_\_\_\_\_\_\_ is absent in some mollusks and in Antarctic fish with colorless blood.
Hemoglobin
84
The \_\_\_\_\_\_, formerly known as \_\_\_\_\_\_\_\_\_\_,are proteins which possess the ability to agglutinate red blood cells.
lectins hemagglutinins
85
What is the consequence of reduced oxymyoglobin in the tissue?
The color of DFD meat ranges from slightly dark to extremely dark or nearly black
86
Lipoxygenase and polyphenol oxidase, which is responsible for \_\_\_\_\_\_, are _______ enzymes
browning oxidoreductase
87
\_\_\_\_\_\_\_\_\_ is made of an apoprotein that also binds riboflavin, a B group vitamin
Flavoprotein
88
During storage of eggs, ________ converts to S- a more stable form with increased resistance to denaturation.
ovalbumin
89
\_\_\_\_\_\_ are usually manufactured by using alcohol to remove the soluble carbohydrates from the de-oiled soy flakes, resulting in a protein with (high/low) solubility incapable to ____ or \_\_\_\_\_\_\_\_
SPC low gel emulsify fat
90
What are the three types of glycoside hydrolases?
1) Enzymes that hydrolyze glycosidic bonds 2) Invertases 3) Lactases
91
\_\_\_\_\_\_\_ is a phosphorus-rich, lipid-free protein that is strongly associated with lipovitellin
Phosvitin
92
Separation and purification of _______ is commonly performed by half-saturating the egg white with \_\_\_\_\_\_\_, followed by the addition of ________ to ____ the pH to its isoelectric point
ovalbumin ammonium sulfate sulfuric acid lower
93
\_\_\_\_\_\_\_\_ are lipid-free globular glycoproteins represent about 10% of egg-yolk total solids.
Livetins
94
Depletion of ATP reduces the ability of the _________ to reduce the ___________ concentration to the submicromolar range, and thereby maintain the muscle in a _____ state
calcium pump protein sarcoplasmic Ca2+ resting
95
\_\_\_\_\_\_\_\_ catalyzes the oxidation of phenolic compounds (mono and/or diphenols) in the presence of _____ to give \_\_\_\_\_\_, which polymerize into ______ pigments (desirable or undesirable)
Polyphenol oxidase (PPO) O2 quinones melanin
96
A _____ cocktail from ____________ is used to partially break down glutens to reduce mixing time and making them more extensible
protease Aspergillus oryzae
97
\_\_\_\_\_\_\_\_\_ is the most easily heat-denatured egg protein but it is less susceptible to surface denaturation than ovalbumin.
Ovotransferrin
98
\_\_\_\_\_\_ are wheat proteins that consist of a heterogeneous group of proteins, which are crosslinked by (intra/inter)molecular disulfide bonds
Glutenins inter
99
After the exhaustion of CrP, creatine kinase, and adenylate kinase, what becomes the dominant metabolic pathway for the generation of ATP?
Anaerobic glycolysis utilizing glycogen reserves stores in the muscle
100
Which amino acid is virtually absent from collagen?
Tryptophan
101
\_\_\_\_\_\_ can hydrolyze all the way to glucose
Glucoamylase
102
\_\_\_\_\_\_\_\_\_\_\_ are produced using minimum heat and homogenization followed by spray drying, or by using a water-wash process at an (acid/base) pH to remove soluble \_\_\_\_\_\_\_, followed by neutralization
Functional soy concentrations acid sugars
103
As in all legumes, the bulk of soybean proteins are \_\_\_\_\_\_\_, characterized by their solubility in _____ solutions.
globulins salt
104
\_\_\_\_\_\_\_\_ appear to be important in the foaming properties of albumin
Ovoglobulins
105
\_\_\_\_\_\_\_ binds to titin, and carries 3 unique sequences
Calpain 3
106
Egg white is more _____ to heat treatment when the pH is adjusted to 7.6 using lactic acid, hydrochloric acid or potassium acid tartrate.
stable
107
\_\_\_\_\_\_\_ is specific to skeletal muscles
Calpain 3
108
During mashing in the brewing process, ______ hydrolyze starch to give ______ for yeast and produce CO2 and \_\_\_\_\_\_\_
amylases maltose ethanol
109
\_\_\_\_\_\_\_\_ can be heated at 100 °C under acidic conditions for long periods without any apparent changes in its physical or chemical properties.
Ovalbumin
110
\_\_S also contains gamma-conglycinin, the enzymes (B-amylase and lipoxygenase), and hemagglutinins
7
111
The two types of soybean trypsin inhibitors are the _______ inhibitor (large), and the ________ inhibitor (small)
Kunitz Bowman-Birk
112
What is the major problem with all microbial sources as a source of protein?
Their high nucleic acid content, which cannot be handled by our livers in excessive amounts if consumed on a substantive scale (liver damage, gout)
113
In the delay phase, the level of ATP remains at \>95% of the initial level, indicating that the rate at which _________ is nearly equal to the rate at which it is \_\_\_\_\_\_\_\_\_
ATP is generated consumed
114
If maltose is desired in corn syrup production, __________ and __________ enzymes are used
B-amylase pullulanase
115
\_\_\_\_\_\_\_\_ is also present as a component of the egg-yolk proteins, differing only by its carbohydrate prosthetic group.
Ovotransferrin
116
\_\_\_\_\_\_\_ has a very acidic activity optima (pH 1.8), which somewhat limits its use
Pepsin
117
The portion of the soybean that contains the most lipids is the \_\_\_\_\_
cotyledon
118
Upon gelation after heating to 40-50oC, some of the water previously associated with the myofiber is apparently forced out by shrinkage of the \_\_\_\_\_\_\_, thus accounting for some of the loss of fluid observed over this temperature range.
endomysium
119
Following a-amylase, corn syrup production uses _______ to break down \_\_\_\_\_\_\_
glucoamylase glucose
120
The triple helix of collagen is also stabilized by H-bonds involving the _______ residues
hydroxyproline
121
The enzyme ______ has served as an indicator for the adequacy of the heat treatment given to soybean meal
urease
122
\_\_\_\_\_\_ are calcium-activated proteases that are most active in the _____ pH range and are regulated by a variety of factors, including calcium, phospholipids, and calpastatin, a widely distributed calpain-specific protein inhibitor.
Calpains neutral
123
What happens initially with the cessation of blood flow that occurs at slaughter? How long does this last?
Myofibers utilize the oxygen bound to myoglobin to support aerobic metabolism (5 minutes)
124
Elastic lacks ______ and _______ AA
hydroxyproline hydroxylysine
125
\_\_\_\_\_\_\_ cause rapid and complete loss of the _____ owing to the degradation of troponin-T, titin, and nebulin as well as other minor proteins closely associated
Calpains Z-discs
126
Premature browning may occur as a result of the greater sensitivity of _______ and ________ to thermal denaturation as compared to \_\_\_\_\_\_\_\_\_\_
metmyoglobin oxymyogloin deoxymyoglobin
127
The addition of _______ in surimi further enhances the gel-forming abilities
paramyosin
128
The shrinkage of the __________ generates a substantial force that expels a large amount of fluid from the myofibers in the second phase as compared to the first phase.
perimysial fibers
129
Unlike calpains, _______ are maximally active at the _____ pHs characteristic of meat in the ______ phase
cathepsins acidic resolution
130
Corn syrup production starts with _________ to break _____ and ___________ to smaller units
a-amylase amylose amylopectin
131
The main content of protein in soy is found in storage sites called ________ or \_\_\_\_\_\_\_\_\_\_, which are subcellular structures that range in diameter from 2 to 20 um.
protein bodies aleuronic grains
132
The soybean storage proteins were extracted and characterized for the first time by ______ & ______ in 1898, and they named the extracted protein \_\_\_\_\_\_.
Osborne Campbell glycinin
133
The ________ group of collagen are stabilized and strengthened by the intra and intermolecular covalent crosslinks
striated and fibrous
134
The main AA in elastin is \_\_\_\_, and large amounts of _______ are also found
glycine proline, alanine, nonpolar aliphatic AA
135
Fish with dark-colored flesh have more free ______ than fish with light-colored flesh
histidine
136
\_\_\_\_\_\_ is a wheat protein that requires alcohol for solubilization
Gliadin
137
\_\_\_\_\_\_\_\_ hydrolyses a-1-4 and a-1-6 glycosidic bonds in starch
Glucoamylase
138
At ____ ionic strength or at pH values near the pI, proteins aggregate to from a turbid gel composed of random aggregates.
high
139
\_\_S is a dimer of glycinin
15
140
During the \_\_\_\_\_\_\_\_\_\_\_, partial degradation of the structure of the myofilament framework by endogenous _______ enzymes occurs.
resolution phase proteolytic
141
\_\_\_\_\_\_\_\_ hydrolyze the methyl ester linkages of pectin
Pectin methyl esterase
142
\_\_\_\_\_\_\_\_\_\_ have almost equal ability to form cheese clots like chymosin
Fungal proteases
143
\_\_\_\_\_\_\_\_ is a hydrophobic prolamine
Gliadin
144
\_\_\_\_\_\_\_ consists of heterogeneous group of proteins which (are/are not) crosslinked, and contain extensive (intra/inter)molecular disulfide bonds and free SH groups
Gliadin are not intramolecular
145
The second step in the gelation of surimi is the formation of \_\_\_\_\_\_\_\_\_\_, characterized by the conversion of the loose network to an ordered, non-transparent gel that is more cohesive and elastic
kamaboko
146
Fish muscle tissue has a high content of \_\_\_\_\_\_, which is derived from \_\_\_\_\_, but lacks a ______ group
taurine cysteine carboxyl
147
\_\_\_\_\_\_\_\_\_\_\_ are likely to be involved in restoring elastin fibers to their original shape and size following deformation
Desmosine
148
It is custom to characterize soybean protein fractions by their \_\_\_\_\_\_\_\_\_
sedimentation constants
149
\_\_\_\_\_\_ is a strongly basic minor albumen protein
Avidin
150
\_\_S is highly heterogeneous
7
151
The denaturation temperature of albumen proteins is highest in \_\_\_\_\_\_\_\_, and lowest in \_\_\_\_\_\_\_\_
ovalbumin ovotransferrin
152
\_\_\_-lipovitellin (0.48% phosphorus), and \_\_\_\_-lipovitellin (0.27 phosphorus)
a f
153
Apart from papain, other popular tenderizing enzymes are _____ (from figs), ______ (from pineapple) and microbial proteases
ficin bromelain
154
\_\_\_\_\_\_\_ forms the lipovitellenin fraction
LDLP
155
\_\_\_\_\_\_\_ can be used to clear turbidity (chill haze) in beer
Papain
156
\_\_\_\_\_\_\_ are wheat proteins that are soluble in dilute alkali or acid
Glutenin
157
Type I, III, and some Type V is associated with the \_\_\_\_\_\_\_
perimysium
158
\_\_\_\_\_\_\_ contributes to the formation of S-S bonds in gluten in dough, without having to add chemical oxidizers
Lipoxygenase
159
Glucose isomerase converts an _______ to a \_\_\_\_\_\_\_\_\_\_
aldose ketose
160
The main portion of the soybean is the \_\_\_\_\_\_\_
cotyledon
161
The ______ may last up to 12 hours
delay phase
162
A _____ increase in toughness occurs over the range of 40- 50 °C, attributed to thermal denaturation of ___ and \_\_\_, which shrink and form a ____ within the myofiber that accounts for the increased toughness.
sharp actin myosin gel
163
Ovomucoid can be precipitated from albumen after the removal of ______ and ______ by complete saturation with _______ or by the addition of excess \_\_\_\_\_.
ovalbumin ovotransferrin ammonium sulfate alcohol
164
Lysozyme has optimum activity for ______ foods
low-acid
165
Among the egg-white proteins, ______ is unique in its resistance to heat coagulation.
ovalbumin
166
Paramyosin is a protein that is similar to ______ that is present in the ____ filaments of all invertebrates
myosin thick
167
\_\_\_\_\_\_\_ is added when clarity is desired (ex: apple juice)
Pectin methyl esterase
