BIOCHEMISTRY EXAM 3 FREQUENTLY TESTED ACTUAL
QUESTIONS WITH CORRECT ANSWERS
Question 1.
What are the building blocks of proteins?
ANSWER
Amino acids
Question 2.
A single amino acid contains at least 1 of what two groups?
ANSWER
i. One amino group & one
ii. carboxyl group
Question 3.
Basic structure of amino acids
ANSWER
Question 4.
What is a chain of amino acids called?
ANSWER
Polypeptide
,Question 5.
What is a large polypeptide called?
ANSWER
Protein
Question 6.
How many amino acids can be synthesized by the body? And what are they called?
ANSWER
i. 10
ii. nonessential
Question 7.
What are the 10 essential amino acids?
ANSWER
-Phenylalanine
-Valine
-Threonine
-Tryptophan
-Isoleucine
-Methionine
-Histidine
-Arginine
-Leucine
-Lysine
,Question 8.
What are the 10 nonessential amino acids?
ANSWER
-Alanine
-Asparagine
-Aspartic acid
-Cysteine
-Glutamic acid
-Glutamine
-Glycine
-Proline
-Serine
-Tyrosine
Question 9.
What are inherited enzyme defects that inhibit metab olism of certain amino acids?
ANSWER
- Aminoacidopathies
Question 10.
What is the disease with the absence of activity of phenylalanine hydrolase (PAH) and is autosomal
recessive, 1 in 15,000?
ANSWER
Phenylketonuria (PKU)
Question 11.
What can phenylketonuria cause?
ANSWER
Brain damage, delayed mental development, microcephaly
, Question 12.
The Phe/Try (phenylalanine/tyrosine) ratio improves the specificity for diagnosing what deficiency?
ANSWER
Phenylketonuria
Question 13.
What is found in the blood and urine of PKU patients? Urine has a musty or mousy odor.
ANSWER
Phenylalanine & metabolites
Question 14.
What semi-quantitative bacterial inhibition assay for phenylalanine was used historically? If sample
contains phenylalanine, bacteria will grow.
ANSWER
Guthrie test
Question 15.
What has replaced the Guthrie test?
ANSWER
Question 16.
What ratio can be helpful in diagnosing PKU?
ANSWER
Phe/Tyr, increased phenylalanine and decreased tyrosine
Question 17.
What inherited autosomal recessive aminoacidopathy is characterized by excretion of tyrosine in
urine?
ANSWER
Tyrosinemia
QUESTIONS WITH CORRECT ANSWERS
Question 1.
What are the building blocks of proteins?
ANSWER
Amino acids
Question 2.
A single amino acid contains at least 1 of what two groups?
ANSWER
i. One amino group & one
ii. carboxyl group
Question 3.
Basic structure of amino acids
ANSWER
Question 4.
What is a chain of amino acids called?
ANSWER
Polypeptide
,Question 5.
What is a large polypeptide called?
ANSWER
Protein
Question 6.
How many amino acids can be synthesized by the body? And what are they called?
ANSWER
i. 10
ii. nonessential
Question 7.
What are the 10 essential amino acids?
ANSWER
-Phenylalanine
-Valine
-Threonine
-Tryptophan
-Isoleucine
-Methionine
-Histidine
-Arginine
-Leucine
-Lysine
,Question 8.
What are the 10 nonessential amino acids?
ANSWER
-Alanine
-Asparagine
-Aspartic acid
-Cysteine
-Glutamic acid
-Glutamine
-Glycine
-Proline
-Serine
-Tyrosine
Question 9.
What are inherited enzyme defects that inhibit metab olism of certain amino acids?
ANSWER
- Aminoacidopathies
Question 10.
What is the disease with the absence of activity of phenylalanine hydrolase (PAH) and is autosomal
recessive, 1 in 15,000?
ANSWER
Phenylketonuria (PKU)
Question 11.
What can phenylketonuria cause?
ANSWER
Brain damage, delayed mental development, microcephaly
, Question 12.
The Phe/Try (phenylalanine/tyrosine) ratio improves the specificity for diagnosing what deficiency?
ANSWER
Phenylketonuria
Question 13.
What is found in the blood and urine of PKU patients? Urine has a musty or mousy odor.
ANSWER
Phenylalanine & metabolites
Question 14.
What semi-quantitative bacterial inhibition assay for phenylalanine was used historically? If sample
contains phenylalanine, bacteria will grow.
ANSWER
Guthrie test
Question 15.
What has replaced the Guthrie test?
ANSWER
Question 16.
What ratio can be helpful in diagnosing PKU?
ANSWER
Phe/Tyr, increased phenylalanine and decreased tyrosine
Question 17.
What inherited autosomal recessive aminoacidopathy is characterized by excretion of tyrosine in
urine?
ANSWER
Tyrosinemia
