Case Scenario: A 3-month-old infant presents with failure to thrive, lethargy, and metabolic acidosis. Laboratory results show elevated methylmalonic acid levels. Genetic testing confirms methylmalonyl-CoA mutase deficiency, affecting the metabolism of odd-chain fatty acids and branched-chain amino acids. Which of the following best describes the function of methylmalonyl-CoA mutase, a cobalt-dependent enzyme?

Case Scenario: A 65-year-old male presents with fatigue, paresthesia (numbness and tingling in hands and feet), and memory impairment. Blood tests reveal elevated homocysteine levels and macrocytosis. His physician suspects a vitamin B12 deficiency affecting methyl group transfer in amino acid metabolism. Which of the following enzymes requires cobalt-containing vitamin B12 to facilitate the conversion of homocysteine to methionine?

A 45-year-old vegan presents with fatigue, tingling in their hands and feet, and difficulty walking. Blood tests reveal macrocytic anemia and elevated homocysteine levels. Which of the following best explains the role of cobalt (Co³⁺) in vitamin B12 (cobalamin) function?

A 62-year-old male with a history of recurrent urinary tract infections (UTIs) is admitted with sepsis due to multi-drug resistant Escherichia coli. The infection is found to be resistant to β-lactam antibiotics. His physician explains that bacterial β-lactamase enzymes, which break down antibiotics, often rely on transition metals for their function. Which of the following transition metals is a cofactor in Type II β-lactamases, enabling bacterial resistance to β-lactam antibiotics?

Case Scenario: A 50-year-old alcoholic presents with ataxia, confusion, and slurred speech. Bloodwork reveals elevated acetaldehyde levels and zinc deficiency. The physician explains that Zn²⁺ is essential for an enzyme responsible for metabolizing alcohol. Which of the following zinc-containing enzymes is most directly involved in alcohol metabolism?

A 35-year-old male with a rare genetic disorder presents with delayed wound healing, immune dysfunction, and growth retardation. Laboratory tests reveal low zinc (Zn²⁺) levels. His physician explains that zinc plays a crucial role in stabilizing transcription factors involved in gene expression and immune function. Which of the following protein structures is primarily stabilized by Zn²⁺ and plays a role in DNA/RNA binding and gene regulation?

Case Scenario: A 55-year-old male welds metal for a living and presents with tremors, rigidity, and difficulty walking. His symptoms resemble Parkinson’s disease, but he has no history of neurodegenerative disorders. Laboratory tests reveal elevated manganese levels. Which of the following best describes the neurological effects of manganese toxicity?

 A 50-year-old male with uncontrolled diabetes mellitus presents with hypoglycemia despite fasting. Laboratory tests show elevated gluconeogenic activity. His physician explains that manganese-dependent enzymes are involved in gluconeogenesis, helping maintain glucose levels during fasting. Which of the following Mn-dependent enzymes is directly involved in gluconeogenesis?

A 45-year-old woman presents with fatigue and poor wound healing. Her dietary history suggests a severe deficiency in trace elements, including manganese. The physician explains that manganese is crucial for enzymatic functions, particularly in mitochondrial metabolism and antioxidant defense. Which of the following Mn-dependent enzymes plays a critical role in detoxifying reactive oxygen species (ROS) in the mitochondria?

A 60-year-old male with a recent bacterial pneumonia infection presents with persistent fever and leukocytosis despite antibiotics. His physician suspects an impaired immune response, possibly due to reduced myeloperoxidase activity in macrophages, linked to iron dysregulation. What is the primary role of iron in myeloperoxidase within macrophages?