Protein Flashcards
1
Q
Composed of C, H, O, N, and sometimes S
A
Protein
2
Q
Only nutrient that can make new cells and rebuild tissue.
A
Protein
3
Q
Basic material of every body cell.
A
Protein
4
Q
Composed of amino acids linked by peptide bonds.
A
Protein
5
Q
Greek word that means “holding first place” and term coined by Mulder (Dutch Scientist) in 1840.
A
Protein
6
Q
Molecule w/ a central carbon to which an amino group, a carboxyl group and a functional group are attached.
A
Amino acid
7
Q
How many amino acid are needed by the human body?
A
20
8
Q
How many from the 20 AA are considered essential, which must be supplied by the diet?
A
10
9
Q
General structure of AA
A
central carbon, amino group, a carboxyl group and a functional group
10
Q
AA classification
A
Functional groups, Pathway of catabolism, essentiality
11
Q
Functional groups
A
Basic, acidic, neutral
12
Q
Basic Functional group AA
A
lysine, arginine, histidine
13
Q
acidic Functional group AA
A
aspartic acid, glutamic acid
14
Q
neutral Functional group AA
A
glycine, serine, threonine, etc
15
Q
2 pathway of catabolism
A
glucogenic, ketogenic
16
Q
AA that can be catabolized to produce glucose (gluconeogenesis)
A
glucogenic
17
Q
AA that can be catabolized to produce acetyl-CoA (-> ketone bodies) and ipids
A
ketogenic
18
Q
3 classifications of Essentiality of AA
A
essential, nonessential, conditionally essential
19
Q
Indespensable AA
A
Essential
20
Q
Dispensable
A
Nonessential
21
Q
Indispensable at certain life stages
A
Conditionally essential
22
Q
Essential AA
A
(PVTTIMHALL) Phenylalanine, valine, threonine, tryptophan, isoleucine, methionine, histidine, arginine, leucine, lysine
23
Q
Conditionally essential
A
Proline, serine, tyrosine, cysteine, taurine, glycine
24
Q
Nonessential
A
Glutamate, alanine, aspartate, glutamine
25
Protein classification
structure, shape, composition
26
4 levels of protein structure
primary structure, secondary structure, tertiary structure, quaternary structure
27
Classification of protein by shapes
fibrous, globular, membrane
28
Proteins which are long coiled or folded chains of AA bound in parallel line and insoluble in water and dilute salt solutions; serve in structural roles
Fibrous
29
Protein which are coiled, tightly wound structure & roughly spherical; relatively water soluble; constitute most of the soluble proteins in the cell
Globular
30
Proteins associated with various membrane systems; insoluble in aqueous solutions; more hydrophobic AA
Membrane
31
Example of Fibrous protein
keratin
32
Example of globular protein
hemoglobin
33
Example of membrane protein
phospholipid membrane
34
Protein classification by composition
simple, conjugated, derived
35
Protein which are primary components are AA
simple
36
Proteins which are composed of AA and other components
conjugated
37
Proteins which are products of partial hydrolysis
derived
38
Examples of simple proteins
albumin (egg white), globulins (egg yolk), glutenins or glutelins (wheat, rice), prolamines (wheat, corn) scleroproteins (bones, connective tissues)
39
protein source with amino acid score: 100%
animal origin
40
Biological functions of protein
Enzymes - to accelerate rates of biological reactions
Regulation of body processes - to assist in the ability of other proteins to carry out their functions (hormones)
Storage - to provide reservoir like hemoglobin
contraction and motility - for muscles
structure - to provide strength like collagen and keratin
protection - to enhance immunity like immunoglobulins
41
amino acid score of animal origin
100%
42
Examples of conjugated proteins
glycoproteins, lipoproteins, nucleoproteins, phosphoproteins, metalloproteins, hemoproteins, flavoproteins, mucoproteins
43
General functions of protein
1. body building or structural
2. essential for growth
3. source of energy (secondary)
4. regulator of body processes
5. transport of certain substances
44
Examples of derived proteins
Primary - edestan, myosan, metaproteins, coagulated proteins
Secondary - proteoses, peptones, and peptides
45
protein source with true digestibility: 95-98%
animal origin
46
true digestibility of animal origin
95-98%
47
protein source which concentrations increase after cooking
animal origin
48
protein source which includes pulses, cereal & cereal products
plant origin
49
protein source with amino acid present, could be 1 or more limiting amino acids
plant origin
50
plant origin examples
pulses, cereal & cereal products
51
how many limiting amino acid present in a plant origin?
one or more limiting amino acids
52
protein source with true digestibility in natural foods: 70-85%
plant origin
53
true digestibility of plant origin
70-85%
54
bioavailability of protein in pulses
20-25%
55
bioavailability of protein in flour
7-12%
56
meat alternative made from soy protein and other ingredients to simulate various kinds of meat
meat analogues
57
textured vegetable protein (TVP) and tofu
meat analogues examples
58
Capacity of food proteins to provide nitrogen and essential AA for human growth and functions
Protein quality
- checks AA content & efficiency of digestion
- lower protein quality means more intake of protein
59
What highlights nitrogen balance
Protein quality
60
reflects the equilibrium between protein intake and losses
nitrogen balance
61
Nitrogen balance
equilibrium: intake = output
positive nitrogen balance: intake > output (children, pregnant, convalescing person/recovering)
negative nitrogen balance - intake < output (underwent surgery, fever, immobility, shock, burns)
62
Factors affecting protein utilization
1. AA balance
2. emotional stress
3. caloric intake
4. inborn errors of metabolism
5. food processing
63
How to determine protein quality
1. biological value
2. amino scoring
3. protein digestibility
4. protein conc.
5. protein/energy ratio
64
refers to percentage of nitrogen absorbed from the dietary protein actually used by the body
biological value
-higher BV -> higher N retained; means the food is supplying essential AA
65
Formula of biological value
BV = (N retained) / (N absorbed) = ((Dietary N - (Urinary N - Fecal N)) / Dietary N - Fecal N) x 100
66
BV of some foods
Egg: 100
Milk: 93
Rice: 86
Fish, beef: 75
Corn: 72
Peanut flour: 56
Wheat gluten: 44
67
Calculation of the proportion of each EAA in protein or diet relative to reference protein
AA Scoring
68
Value of the limiting AA with the lowest score in a protein
AA score (chemical score)
69
Formula of AA score
AA score = (mg of EAA in 1g of food protein) / (mg of EAA in 1g of reference protein)
70
Measure of the amount of protein available for absorption after digestion that is dependent on the shape (fibrous or globular), presence of dietary factors, and heat treatment
Protein digestibility
71
A variation of protein digestibility that has been developed
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
72
provides adequate amounts of essential amino acids to adequately support human protein synthesis
plant combination
73
official assay for evaluating protein quality in human nutrition
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
74
complementary proteins of Kanin + Munggo Guisado
High Met (rice) + Low Met (beans)
75
Chemical score of limiting AA multiplied by its true digestibility
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
76
Complementary proteins of mais con yelo
High Lys (milk) + Low Lys (corn)
77
PDCAAS Formula
PDCAAS = ((mg of 1st limiting AA in 1g test protein) / (mg of the same AA in 1g reference protein)) x TD (%) x 100
TD is true fecal digestibility of the test protein
78
excellent protein combinations of grains and legumes
-rice + beans
-pea soup + toast
-lentil curry +rice
79
to rate the overall quality of protein based on the amount of essential AA contained
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
80
excellent protein combinations of grains and dairy
-pasta + cheese
-rice pudding
-cheese sandwich
81
Based on the AA that is in the shortest supply when compared to the reference (scoring) protein
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
82
This scoring pattern is based on the IAA requirements of preschool-age children
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
83
excellent protein combinations of legumes and seeds
-garbanzo beans + sesame seeds
-hummus (dip or soup)
84
Digestibility of protein is factored into the score by way of fecal digestibility
Protein Digestibility Corrected Amino Acid Score (PDCAAS)
85
addition of protein rich food to a regular diet to increase protein content and quality
protein supplementation
86
PDCAAS Example
common digestibility percentages include 98% for egg protein; 95% for casein, soy and collagen; 91% for wheat protein
87
increase protein content and quality
addition of protein rich food to a regular diet
88
How to interpret PDCAAS
If a protein is completely missing just one essential AA, the PDCAAS is 0.
If a protein with a low amount of one essential AA ha a PDCAAS of 20, then the protein provides only 20% of that particular AA when compared to the scoring pattern.
Thus, only 20% of this protein is possible available for protein synthesis in the human body.
89
example of protein supplementation
-Tuna spread + cheese = Tuna Melt Sandwich
-Pasta + Ground Beef + Cheese/Cream = Lasagna
90
Protein concentration (density)
----table----
91
-Tuna spread + cheese = Tuna Melt Sandwich
-Pasta + Ground Beef + Cheese/Cream = Lasagna
example of protein supplementation
92
To describe whether a diet provides adequate amounts of protein
- indicates the amount of protein that the diet provides relative to energy
Protein/Energy Ratio (net dietary protein calories present)
93
protein turnover is composed of
SYNTHESIS where amino acids are joined to form peptides and protein AND DEGRADATION which results in amino acids that are recycled
94
Formula of protein/energy ratio
((metabolizable energy from dietary protein) / (metabolizable energy in diet)) x 100
95
Formula on %protein calories
(protein calories/total kcal intake) x 100
96
amino acids are joined together to form peptides and protein
Synthesis in protein turnover
97
meat analogues examples
textured vegetable protein (TVP) and tofu
98
amino acids are recycled
Degradation in protein turnover
99
Fusarium graminearum
a mycoprotein example of meat analogue
100
dependent on the simultaneous presence of all the amino acids for the specific protein & energy
Protein synthesis
101
102
substances/structures that require protein synthesis
cells, glands, muscles, organs, fluid and secretions
103
a mycoprotein example of meat analogue
Fusarium graminearum
104
metabolic events in Cell Nucleus
105
106
Site of synthesis for these metabolic events:
-DNA serves as templet for mRNA
-mRNA copies DNA code
-mRNA leaves the nucleus
Cell nucleus
107
meat analogue has _____ digestibility
higher
108
metabolic events in Ribosomes in the Cytoplasm
-mRNA attach to ribosome to specify sequence of amino acid
-tRNA collect amino acids from cell fluid and brings these to mRNA which specifies amino acid sequence
-ribosome moves along mRNA as each amino acid is brought by tRNA
-completed protein is released from ribosome and mRNA is degraded
109
110
proteins which contain all essential amino acids in amounts sufficient for growth & maintenance
complete or high biological (HBV) proteins
111
Site of synthesis for these metabolic events:
-mRNA attach to ribosome to specify sequence of amino acid
-tRNA collect amino acids from cell fluid and brings these to mRNA which specifies amino acid sequence
-ribosome moves along mRNA as each amino acid is brought by tRNA
-completed protein is released from ribosome and mRNA is degraded
Ribosomes in cytoplasm
112
113
site of protein synthesis which consists of RNA and protein
Ribosomes
114
all animal origin foods except gelatin
complete or high biological (HBV) proteins
115
proteins which maintain life but do not support growth
partially complete proteins
116
What are the genera principles of protein metabolism?
-amino acid are in dynamic state
-proteins must be supplied to the body on a daily basis
-synthesis of proteins is controlled by DNA
-synthesis of proteins follow the all or none law
-protein utilization is closely interrelated w/ fat & carbohydrate metabolism
-amino acids can be recycled
117
gliadin (wheat) and legumin (legumes)
partially complete proteins
118
amino acids are in a _______ state
dynamic
119
proteins which cannot support life or growth
incomplete proteins
120
zein (corn), gealtin, and most plant proteins
incomplete proteins
121
synthesis of proteins follow the ______ or _______ law
all, none
122
plant combination which provides adequate amounts of essential amino acids to adequately support human protein synthesis
protein complementary
123
synthesis of protein is controlled by
DNA
124
Proteins must be supplied to the body on a ______ basis
daily
125
protein utilization is closely interrelated with _______ & _______ metabolism
fat, carbohydrate
126
__________ can be recycled
amino acids
127
results in amino acids that join the amino acid pool
Protein degradation
128
process of protein degradation
protein -> peptide -> amino acids;
nitrogen - incorporated in niacin & creatinine
129
proteins (ex. proline, glitamate, serine, and threonine) degrade at different rates based on
physiological status and amino acid composition
130
fates of amino acids not used for synthesis
-DEAMINATION (transamination, oxidative deamination, deamination by amino acid oxidase)
-CARBON SKELETONS (oxidized, synthesis of glucose or fatty acids)
131
transamination, oxidative deamination, deamination by amino acid oxidase
DEAMINATION
132
oxidized, synthesis of glucose or fatty acids
CARBON SKELETONS
133
What are the protein (CHON) requirements (g/kg DBW) for each age group?
Infants - 2.75 to 3.00
Children - 1.50 to 2.00
Early Adolescents - 1.50
Older Adolescents - 1.25
Adults - 1.12
134
Protein which is 10-15% of TEA is affected by what factors?
1. Body size
2. Growth
3. Pregnancy and Lactation
4. Aging
135
state of deficit in body protein or in or more of the essential amino acids
protein deficiency
136
signs of protein deficiency
wasting of tissue, weight loss, general weakness and malaise, reduced resistance to infection, dry and scaly skin, delayed wound healing, nutritional edema, hypoproteinemia, and pallor (anemia)
137
results from inadequate dietary protein, energy or both
protein energy malnutrition
138
protein energy malnutrition common in 1-3 years of age can cause
mortality, morbidity, and impairment of physical and mental growth
139
types of prolonged protein energy malnutrition
1. Kwashiorkor
2. Marasmus
140
disease occurs when the next baby is born, inadequate protein intake with fair or normal intake of energy , occurs during weaning stage where foods which lacks amino acids are given to child
Kwashiorkor
141
results from deficiency of both protein and energy (predominantly energy deficiency)
Marasmus
142
characteristics of marasmus
wasting, emaciation, no edema, quiet, apathetic
143
not toxic but taxing to liver, kidneys, and circulatory system
excess protein
144
infants -> increase in ____ and _____ (not to exceed: ___ g/kg/day)
BUN, creatinine, 3
145
excess protein with adequate CHO and fat lead to
adiposity or obesity
