Home » Cell Biology – 1 Cell Biology – 1 / Cell Biology Welcome to your Cell biology Identify the statement that is not correct regarding collagen: Collagen is a molecule largely composed of the three amino acids proline, lysine, and glycine. Hydroxylation of amino acids proline and lysine occurs in the lumen of the rough endoplasmic reticulum. Glycosylation of hydroxyproline and hydroxylysine occurs by adding sugar molecules. Alpha chains are synthesized in the rough endoplasmic reticulum. Tropocollagen is formed by cleavage of the N and C terminal. Which step of collagen synthesis does not occur in the endoplasmic reticulum? Pro-alpha chain formation Hydroxylation of proline and lysine residues Glycosylation of hydroxylysine residues Procollagen formation All of them Arrange the steps of collagen synthesis in the correct order: Alpha helix formation, Hydroxylation and Glycosylation, Procollagen, Tropocollagen, Collagen fibrils Collagen fibrils, Procollagen, Alpha helix formation, Hydroxylation and Glycosylation, Tropocollagen Alpha helix formation, Procollagen, Hydroxylation and Glycosylation, Tropocollagen, Collagen fibrils Alpha helix formation, Hydroxylation and Glycosylation, Procollagen, Collagen fibrils, Tropocollagen A 6-month-old boy presents with symptoms of poor feeding, growth issues, and an unusual neck posture during breastfeeding. Upon examination, he has sparse and kinky hair. Laboratory tests reveal low copper and ceruloplasmin levels. The physician suspects an X-linked disorder related to copper metabolism. Which of the following is the most likely cause? Mutation in a gene encoding a protein involved in intestinal copper absorption Gene involved in biliary copper secretion Mutation in the gene encoding fibrillin Mutation in the UGT1A1 gene involved in glucuronidation Mutation in the COL1A1 and COL1A2 genes involved in type 1 collagen synthesis A 20-year-old men arrives with sudden-onset hematuria. He mentions experiencing visual and hearing issues since a young age. His mother has a similar medical history and underwent a kidney transplant at the age of 40. The physician suspects an X-linked connective tissue disorder. Which type of connective tissue component is most likely responsible for this condition? Collagen type 1 Collagen type 2 Collagen type 3 Collagen type 4 Elastin A 10-year-old girl arrives at the emergency room with a left lower arm fracture from a school play. She mentions a history of multiple fractures since a very young age due to her "something related to collagen" condition. Physical examination reveals hypermobile skin and joints, along with unexplained bruising on various body parts. On auscultation at the 5th intercostal area midclavicular line, a late systolic click is heard at the apex of the heart. Which type of collagen is likely affected in this disorder? Collagen type 1 Collagen type 2 Collagen type 3 Collagen type 4 Collagen type 5 During a routine examination, a three-year-old boy with an "elfin" appearance raises concerns. Physical examination reveals a systolic murmur on auscultation at the left second intercostal area close to the sternum. The parents note delayed developmental milestones, higher blood pressure, and shorter stature compared to peers. Genetic analysis confirms a deletion in chromosome 7. Which connective tissue component is most likely affected by this condition? Collagen type 5 Elastin Fibrillin Collagen type 1 Elastase inhibitor A mother delivers a stillborn baby with multiple limp fractures and a hypoplastic thoracic cage. Antenatal ultrasonography revealed fractures, femur shortening, and growth retardation. Which gene mutation is most likely responsible for this condition? CO1LA1 & COL1A2 COL3A1 COL4A1 COL5A1 FBN1 During a routine examination, a three-year-old boy with an "elfin" appearance raises concerns. Physical examination reveals a systolic murmur on auscultation at the left second intercostal area close to the sternum. The parents note delayed developmental milestones, higher blood pressure, and shorter stature compared to peers. Genetic analysis confirms a deletion in chromosome 7. Which connective tissue component is most likely affected by this condition? Alport-syndrome – X-linked Osteogenesis imperfecta – Autosomal dominant Williams syndrome – Autosomal dominant Wiliams syndrome – X-linked Marfan Syndrome - Autosomal dominant Time's up
