ISOENZYMES ISOENZYMES (ISOZYMES) Isoenzymes are the physically distinct forms of the same enzyme. Isoenzymes differ from each other structurally, electrophoretically and immunologically. Isoenzymes possess quaternary structure and are made up of two or three different subunit (mutimeric). Isoenzymes catalyze the same reaction and act on same substrate, but with different Km and Vmax values i.e. […]
Histones Q. 1 Histone acetylation causes? A >Increased Heterochromatin formation B >Increased Euchromatin formation C >Methylation of cystine D >DNA replication Q. 1 Histone acetylation causes? A >Increased Heterochromatin formation B >Increased Euchromatin formation C >Methylation of cystine D >DNA replication Ans. B Explanation: Increased Euchromatin formation [Ref: Lippincott’s Biochemistery 3/e p406, 420; Harper biochemistry 28/e
HISTONES Histones Most abundant chromatin Protein. Histones are divided into- Core Histone Linker Histone 5 classes- H1, H2A, H2B (Lysine), H3 and H4 (arginine). Linker histone- is loosely bound to nucleosome. Modifications- Acetylation of H3 & H4 Acetylation of histones associated with chromosomal assembly during DNA replication. Phosphorylation of H1 is associated with condensation of
Organization of DNA in the cell Q. 1 Total number of base pairs in human haploid set of chromosome A 3 million B 3 billion C 33 billion D 5 million Q. 1 Total number of base pairs in human haploid set of chromosome A 3 million B 3 billion C 33 billion D 5 million Ans. B Explanation:
Organization of DNA in the cell Read More »
ORGANIZATION OF DNA IN THE CELL Organization of DNA in the cell Genome in the prokaryotes is loosely packed. In eukaryotes, DNA is well organized inside the nucleus. Levels of organization of DNA is– DNA Double helix Nucleosomes form of chromatin are of- 10nm chromatin fibril– In eukaryotics, Nucleosomes are separated by spacer DNA to
Organization of DNA in the cell Read More »
Bile Acid Synthesis Q. 1 Secondary bile acids are synthesised by: A Liver B Intestine C Both liver and intestine D Pancreas Q. 1 Secondary bile acids are synthesised by: A Liver B Intestine C Both liver and intestine D Pancreas Ans. B Explanation: Bile acids are synthesized in the liver. Bile acids are divided
Bile acid synthesis Read More »
METABOLISM OF PURINE Q. 1 The purines salvage pathway is for: A Hypoxanthine and Xanthine B Hypoxanthine andAdenine C Adenine and Guanine D Xanthine and Guanine Q. 1 The purines salvage pathway is for: A Hypoxanthine and Xanthine B Hypoxanthine andAdenine C Adenine and Guanine D Xanthine and Guanine Ans. B Explanation: Hypoxanthine andAdenine Q.
Metabolism Of Purine Read More »
Bile acid synthesis BILE ACID SYNTHESIS The primary bile acids are produced from cholesterol in liver. Primary bile acids are- Cholic acid Chenodexycholic acid glycocholic acid, glycochenodeoxycholic acid, taurocholic acid. Secondary bile acids produced from cholesterol in intestine. Secondary bile acids are- Deoxycholic Acid Lithocholic Acid Cholesterol converted to 7 Hydrocholesterol by 7 α- Hydroxylase.
Bile acid synthesis Read More »
METABOLISM OF PURINE METABOLISM OF PURINE Purine nucleotides are synthesized- Adenosine monophosphate (AMP) Guanosine monophosphate (GMP) Purine nucleotides synthesized by 2 pathways- De novo synthesis Salvage pathway De novo synthesis– It is synthesis in liver. It takes place in cytoplasm. Precursors for de novo synthesis are – Glycine provides C4, C5 and N7 Aspartate provides
Metabolism Of Purine Read More »
Hemochromatosis Q. 1 MOST common mutation seen in heriditary hemochromatosis is: A C282Y B H63D C TFR2 D SLC11A3 Q. 1 MOST common mutation seen in heriditary hemochromatosis is: A C282Y B H63D C TFR2 D SLC11A3 Ans. A Explanation: The most common mutation in hereditary hemochromatos is a homozygous G to A mutation resulting
