Biochemistry LE 5: Nucleic Acid Chemistry and Metabolism

What are the three major components of nucleic acids?

Base, pentose, and phosphate

What is the characteristic of pyrimidine bases?

One six-member ring with nitrogen at positions N1 and N3

What is the difference between uracil and thymine?

Uracil is found in RNA, while thymine is found in DNA

What is the structure of purine bases?

Two fused rings with nitrogen at positions 1, 3, 7, and 9 Signup and view all the answers

What is the function of the amino group in adenine?

It is located at C6 Signup and view all the answers

What is the mnemonic used to remember the pyrimidine bases?

CUT the PIE Signup and view all the answers

What is the characteristic of guanine?

It has an amino group at C2 and oxygen group at C6 Signup and view all the answers

What is the difference between cytosine and uracil?

Cytosine has an amino group at C4, while uracil has an oxygen group at C4 Signup and view all the answers

What is the function of kinase in the salvage pathway of pyrimidine nucleoside to a nucleotide?

To convert nucleoside to nucleotide Signup and view all the answers

What is elevated in rapidly dividing cells like tumor cells?

Deoxythymidine kinase Signup and view all the answers

What is the product of the reaction catalyzed by deoxythymidine kinase?

dTMP + ADP Signup and view all the answers

What is the enzyme involved in the salvage pathway of pyrimidine base to a nucleotide?

Phosphoribosyltransferase Signup and view all the answers

What are the three components of a nucleotide?

Base, sugar, phosphate Signup and view all the answers

What is the final degradation product of Cytosine and Uracil?

β-alanine Signup and view all the answers

What is the final degradation product of Thymine?

β-aminoisobutyric acid Signup and view all the answers

What happens when there is an increase in the degradation of pyrimidines?

It does not lead to a disease state Signup and view all the answers

What is the sugar found in a ribonucleoside?

Ribose Signup and view all the answers

What is the base that replaces Thymine in ribonucleosides?

Uracil Signup and view all the answers

What is the type of bond between the base and sugar in a ribonucleoside?

Glycosidic bond Signup and view all the answers

What is the suffix used to name purine nucleosides?

-osine Signup and view all the answers

What is the bond between the sugar and phosphate group in a nucleotide?

Ester bond Signup and view all the answers

What is the term for the rotation of the base and sugar in a nucleotide?

Syn and anti conformations Signup and view all the answers

What is the abbreviated form of Adenosine monophosphate?

AMP Signup and view all the answers

What is the term for the combination of a base, sugar, and phosphate group?

Nucleotide Signup and view all the answers

What is the most likely diagnosis of the child in the case described?

Severe Combined Immune Deficiency (SCID) Signup and view all the answers

What is the likely deficient enzyme in the case of SCID?

Adenosine deaminase Signup and view all the answers

What is the mechanism of action of the drug used in the long-term management of SCID?

Inhibits xanthine oxidase Signup and view all the answers

What is the symptoms of Von Gierke's Disease associated with?

Gout Signup and view all the answers

What is the biochemical basis of gout in Von Gierke's Disease?

Overproduction of glucose-6-phosphate Signup and view all the answers

What is the likely cause of the patient's symptoms in Case 7?

Gout Signup and view all the answers

What is the likely underlying cause of the patient's gout in Case 7?

Overproduction of uric acid Signup and view all the answers

What is the significance of the absent thymic shadow on the chest X-ray?

Indicates an absent thymus Signup and view all the answers

What is the primary cause of elevated uric acid levels in the patient's blood and urine?

Deficiency in HGPRT Signup and view all the answers

What is the purpose of prescribing allopurinol to the patient?

To inhibit xanthine oxidase Signup and view all the answers

What is the characteristic of Lesch-Nyhan Syndrome?

Elevated uric acid levels in blood and urine Signup and view all the answers

What is the cause of the orange sand in the patient's diaper?

Uric acid crystals Signup and view all the answers

What is the effect of HGPRT deficiency on hypoxanthine and guanine levels?

Increased levels Signup and view all the answers

What is the mechanism of action of allopurinol in addition to inhibiting xanthine oxidase?

Inhibiting purine nucleoside phosphorylase Signup and view all the answers

What is the characteristic of von Gierke's Disease?

Hypoglycemia with elevated lactate, uric acid, and triglyceride levels Signup and view all the answers

What is the reason for the patient's irritability and respiratory distress in von Gierke's Disease?

Hypoglycemia Signup and view all the answers

What is the relationship between HGPRT deficiency and uric acid production?

HGPRT deficiency increases uric acid production Signup and view all the answers

What is the consequence of elevated uric acid levels in the patient's blood and urine?

Formation of uric acid crystals Signup and view all the answers