Biochemistry Samplex Test 3

Glycosaminoglycans (GAG’s) are long, unbranched heteropolysaccharide chains that are generally composed of repeating disaccharide units. Which among the following GAG’s is mainly found on synovial fluid and vitreous humor; and plays an important role in permitting cell migration during morphogenesis and wound repair? 

After acquiring your Physician PRC license, you decided to go on moonlighting. At the OPD, a mother brought her 4 year old child who presented with short stature, hypermobile joints and widelyspaced teeth. Upon chest examination, you heard a grade 4/6 systolic murmur. You are suspecting a mucopolysaccharidoses syndrome and upon knowing that the patient has NO CNS abnormality, you already know that the patient is suffering from? 

Myoglobin is a heme protein found in heart and skeletal muscle. It acts as reservoir of oxygen in the said locations and releases oxygen in times of hypoxia. The residue of which amino acid is responsible for myoglobin’s oxygen-binding capacity? 

Which among the following amino acids is a weak base, and therefore has no charge on neutral pH? 

On a research laboratory, you are asked to determine the linear sequence of a specific protein. While doing so, you recalled that the kind of bond you least likely to break is the? 

These are specialized group of proteins required for the folding of many species of proteins. They can also “rescue” proteins that have become thermodynamically trapped in a misfolded dead-end by unfolding hydrophobic regions. 

Hemoglobin A1C (HbA1C) is being used in clinics to monitor a diabetic patient’s compliance in taking his/her medications. On what amino acid residue does glycosylation of erythrocytes occur? 

α1-antitrypsin is said to be a protective factor against developing emphysema. What proteolytic enzyme does this substance inhibit? 

In bioenergetics, the measure of heat content of the reactants and products is called Enthalpy. What unit is used to describe it? 

The electron transport chain (ETC) is the final common pathway by which electrons from the different fuels of the body flow and create energy. What complex of ETC is also an essential part of the Kreb’s Cycle? 

Uncouplers are substances that increase the permeability of the inner mitochondrial membrane to protons. Which among the following statements is/are true about ETC in the presence of uncouplers? 

Lactose is from? 

Glucose is the main fuel of most of the cells in the body. Before it can be utilized, some cells need specific transporters to mediate its use. Which among the following glucose transporters is/are present in the brain? 

Phosphofructokinase 1 (PFK1) is the rate-limiting step for Glycolysis. Which among the following statements is/are true about this enzyme? 

Pyruvate Dehydrogenase enzyme deficiency is the most common biochemical cause of congenital lactic acidosis. Which among the following substances is/are needed by this enzyme as co-factor/s? 

Gluconeogenesis pathway is technically the reverse of Glycolysis. They just differ in three enzymes. Which among the following groups of enzymes is PRESENT in Gluconeogenesis and NOT in the later? 

Cellulose is the primary structure of a plant cell wall. Being a stool-former, it is an important part of human diet and is said to be protective from colon cancer. What kind of glycosidic bond is present in cellulose that humans cannot digest? 

During your rotation in the Department of Pediatrics, you encountered a 5-year-old patient with a chief complaint of loose watery stools accompanied by undocumented fever. During PE, patient is febrile with macular rashes on the chest (Rose Spots). CBC showed lymphocytosis and the Widal Test turned out to be positive. You prescribed Chloramphenicol but the mother told you that the patient experienced bleeding in the past when he took the said medication. What kind of abnormality are you thinking of? 

This is a rare neurologic disorder due to abnormal accumulation of Phytanic Acid. 

Which among the following codons is/are “stop codon/s”?