Term
| How many amino acids are used in making protein? |
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Definition
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|
Term
| How many amino acids are considered dietary essentials? |
|
Definition
|
|
Term
| What is the main role of proteins in the diet? |
|
Definition
| providing amino acids for protein synthesis & other areas of metabolism |
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Term
| Hemoglobin and albumin are examples of what type of protein? |
|
Definition
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|
Term
True or False
Adipose tissue is high in protein content |
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Definition
|
|
Term
| What regions of the body are highest in protein content? (3) |
|
Definition
Blood (RBCs)
Connective Tissue
Eye Lens |
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Term
| Our body's protein requirement could really be considered to be a _____ requirementq |
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Definition
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Term
| Which is higher in protein content: pork, beef, turkey or chicken? |
|
Definition
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Term
| Percent protein content of animal products is generally ______ than plants |
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Definition
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Term
| What is the monomeric unit of a polypeptide? |
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Definition
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Term
| What amino acid does NOT contain a chiral alpha-carbon? |
|
Definition
|
|
Term
| What is the general structure of an amino acid? |
|
Definition
central alpha-carbon
amine functional group
carboxylic acid functional group
hydrogen
'R' side chain (varies) |
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|
Term
| What are the two types of amino acids in the body? Which are mainly used to make proteins? |
|
Definition
standard & non-standard
-standard are typically used to make proteins |
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|
Term
| How are non-standard amino acids usually formed? |
|
Definition
post-translational modification of other AA's
or
as intermediates in metabolic pathways of standard AA's |
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|
Term
| Which enantiomer of amino acids is more commonly found in nature? Where is the NH2 group found in this case? |
|
Definition
| L-form (NH2 group on the left) |
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Term
|
Definition
| AA's with a protonated amino group, deprotonated carboxylate group |
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|
Term
True or False
Zwitterions have an overall positive charge (assuming the R group is neutral) |
|
Definition
False
They have no overall charge |
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Term
| At physiological pH will free amino acids present themselves in their 'traditional' form or as a zwitterion? |
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Definition
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|
Term
| Why are zwitterions more water-soluble? |
|
Definition
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Term
| Amino acids are linked by _____ bonds between the ______ of one AA and the ______ of another |
|
Definition
peptide bonds
carboxyl
amino |
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|
Term
True or False
'peptide' and 'protein' can be used interchangeably |
|
Definition
|
|
Term
| How many AA's are found in a polypeptide? How many polypeptides constitute a biologically active protein? |
|
Definition
>50 AA's in a polypeptide
1 or more polypepties in a protein |
|
|
Term
| What is the primary protein structure? |
|
Definition
|
|
Term
| What is the tertiary protein structure |
|
Definition
interactions between side chains
e.g. disulfide bonds, globule formation |
|
|
Term
| What is the secondary protein structure? |
|
Definition
| hydrogen bonds forming helixes & pleated sheets |
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|
Term
| What is the quaternary protein structure? |
|
Definition
| accumulation of multiple globules |
|
|
Term
True or False
Denaturation affects primary, secondary, tertiary and quaternary structure |
|
Definition
False
Primary protein structure is not affected |
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|
Term
| What is the protein found in eggs? |
|
Definition
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Term
| Which AA's are considered essential in humans? (9) |
|
Definition
Lysine
Threonine
Isoleucine
Leucine
Methionine
Phenylalanine
Tryptophan
Valine
Histidine |
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|
Term
| What is a conditionally indispensable amino acid? |
|
Definition
not normally required in the diet, but supplementation might be required under certain conditions
e.g. phenylketonuria requires Tyrosine |
|
|
Term
| What is an acquired indispensable amino acid? |
|
Definition
| might become indispensible in states of metabolic disorder or stress |
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|
Term
| What are non-essential amino acids? |
|
Definition
| they can be synthesized in the body, do not need to be included in the diet |
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Term
| At physiological pH basic amino acids will have a ___ charge on their side chain |
|
Definition
|
|
Term
| Are basic amino acids polar or non-polar? |
|
Definition
|
|
Term
| What are the basic amino acids? |
|
Definition
|
|
Term
| At physiological pH, acidic amino acids will have a ____ charge on their side chain |
|
Definition
|
|
Term
| Are acidic amino acids polar or non-polar? |
|
Definition
|
|
Term
| What are the acidic amino acids? |
|
Definition
Aspartate
Glutamate
Asparagine
Glutamine |
|
|
Term
| Which classification of amino acids are not catabolized in the liver? |
|
Definition
|
|
Term
| Inability to metabolize phenylalanine is a characteristic of what disease? How can we 'spare' the pheylalanine requirement? |
|
Definition
phenylketonuria
-dietary supplementation with tyrosine |
|
|
Term
True or False
All branched chain amino acids are essential |
|
Definition
|
|
Term
| What substance are secreted by the stomach to aid in protein digestion? |
|
Definition
HCl
pepsinogen
parapepsinogen I & II |
|
|
Term
| HCl converts pepsinogen to.... |
|
Definition
|
|
Term
| Protein denaturation via pepsinogen and parapepinogen produces... |
|
Definition
|
|
Term
|
Definition
zymogens (inactive proteins)
-required proteolytic cleavage to form activated enzymes |
|
|
Term
| What enzymes are secreted by the pancreas to aid in protein digestion? |
|
Definition
trypsinogen
chymotrypsinogen
proelastase
procarboxypeptidase |
|
|
Term
| What enzymes are secreted by intestinal mucosa to aid in protein digestion? |
|
Definition
enterokinase
aminopeptidase |
|
|
Term
| If a protein name starts with 'pro' or ends in 'gen', what is required in order for it to become an active enzyme? |
|
Definition
|
|
Term
| Where does the majority of AA absorption occur? |
|
Definition
| proximal portion of the SI |
|
|
Term
| How are AA's absorbed from the small intestine? Which is most common? |
|
Definition
| facilitated diffusion & active transport (most common) |
|
|
Term
| Which are absorbed faster, essential or non-essential AA's |
|
Definition
|
|
Term
| Which transporter typically carries small peptides across the intestinal cell membrane? |
|
Definition
|
|
Term
| What factors are considered when assessing protein quality? |
|
Definition
amino acid balance
digestibility
presence of toxic factors
species consuming the protein |
|
|
Term
| What is the official method in Canada for evaluating protein quality? What is the formula? |
|
Definition
Protein Efficiency Ratio
[wet body weight gain(g)] / [test protein consumed (g)] |
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|
Term
| What protein assessment involves feeding growing rats a diet that has adequate nutrient requirements, except a protein which is fed at 10% of the diet? |
|
Definition
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|
Term
| How can you calculate the protein rating of a food? |
|
Definition
|
|
Term
| How do you calculate Chemical Score? |
|
Definition
| [abundance of 1st limiting AA in test protein] / [abundance of that AA in whole egg] X 100 |
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|
Term
| What factors are considered when measuring Biological Value of a protein? |
|
Definition
| chemical score & digestibility |
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|
Term
If intake of protein is of adequate quantity and quality, nitrogen balance in the following groups will be... (pos. / neg. / neutral)
Children -
Adults -
Elderly - |
|
Definition
Children - positive
Adults - neutral
Elderly - negative |
|
|
Term
| How do you calculate nitrogen balance? |
|
Definition
|
|
Term
| What are some observed clinical results of high-protein diets? |
|
Definition
-short term weight loss is comparable to other diets
-improved insulin sensitivity is sometimes observed
-no linear response between high protein diet & beneficial effects (moderate protein may be better!) |
|
|
Term
|
Definition
A protein & energy deficiency
-low intake of a balanced diet which is slightly deficient in protein
-because all nutrients are balanced, body switches to 'starvation' mode, results in complete loss of body fat |
|
|
Term
|
Definition
-unlimited intake of a diet that is very protein deficient
or
-adequate intake but in a body that cannot maintain protein synthesis |
|
|
Term
| What are some most-translational modifications of proteins that are related to nutrient status? |
|
Definition
phosphorylation
hydroxylation
carboxylation
iodination
ADP-ribosylation reactions |
|
|
Term
Why is hydroxylation important?
What vitamin is involved? |
|
Definition
provides site for x-linking in collagen and elastin
Vitamin C & Copper |
|
|
Term
| Why is carboxylation important? What vitamin is involved? |
|
Definition
provides site for calcium binding (important in blood clotting & maintaining Ca homeostasis)
Vitamin K |
|
|
Term
| Why is iodination important? |
|
Definition
|
|
Term
| What do ADP-ribosylation reactions require? Why are they important? |
|
Definition
niacin
important in DNA repair & regulating protein function |
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