Page 60 - General Biochemistry

• Symptoms of biotin deficiency include dermatitis, glossitis, loss of appetite and
nausea.

6. Folic acid

• Folic acid (or folate) plays a key role in one-carbon metabolism.
• which is essential for the biosynthesis of amino acids, purines, and thymidine

monophosphate (TMP), a pyrimidine found in DNA.

Enzymes in
Clinical Biochemistry

• Types of clinical enzymes

• Proenzyme (zymogen) – inactive form of enzyme that becomes active after
example: pepsinogen → pepsin
partial proteolysis

• Isoform – more general term, includes true isoenzymes and pseudoisoenzymes
(posttranslational variations).
Isoenzymes – General Features

• Genetical differences in primary structure. (cytoplasm × mitochondria for
• Catalyze the same reaction.
• May have different subcellular distribution

example).

• May have different tissue distribution.
• May be combined from more subunits.

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