Biochem 2023 Paper Variant PDF

COLLOQ 3 BIOCHEM (PAPER VARIANT) 09.10.2023 In total 85 points can be gained in Colloq 3 1. Which statement about lipoproteins is correct? a) ApoA1 is necessary for the elimination of cholesterol from peripheral tissue b) Chylomicrons are involved in the endogenous transport pathway...

COLLOQ 3 BIOCHEM (PAPER VARIANT) 09.10.2023 In total 85 points can be gained in Colloq 3 1. Which statement about lipoproteins is correct? a) ApoA1 is necessary for the elimination of cholesterol from peripheral tissue b) Chylomicrons are involved in the endogenous transport pathway of lipoproteins c) TAGs are major component of LDL particle d) Exogenous lipid transport pathway ensures TAGs utilization from muscles and adipocytes 2. Which statement about carnitine-acylcarnitine shuttle is correct? a) This shuttle ensures the transport of TAGs in the cells b) Translocase ensures carnitine transport in the mitochondrial matrix c) Genetic mutations in enzymes of this system would lead to weight loss d) Carnitine can be derived from food and synthesized in the liver 3. Which statement about the oxidation of fatty acids is correct? a) Alpha oxidation eliminates the methyl group at a carbon atom b) Beta-oxidation occurs in mitochondria and peroxisomes c) Beta oxidation occurs only in the liver, skeletal muscle, adipocytes, and heart. d) Fatty acids for oxidation are mobilized from lipid droplets in adipose cells covered with albumin. 4. Which statement about ketogenesis is correct? a) Elevated levels of insulin stimulate ketogenesis b) The most common ketone body produced in a human body is acetone c) Ketogenesis occurs in mitochondria of liver cells and kidney cells d) Substrate for ketone body synthesis is Acetyl-CoA that comes from fatty acids mobilized from adipocytes 5. Which statement about fatty acid biosynthesis is correct? a) The substrate acetyl-CoA comes primarily from beta oxidation b) Every cell is capable of synthesizing fatty acids in mitochondria c) Pentose phosphate pathway provides reduction of cofactors that are required in fatty acid biosynthesis d) Fatty acids with more than 18C are synthesized in peroxisomes 6. Which statement about the biosynthesis of triacylglycerides is correct? a) TAGs are stored in every cell as a main energy source for this cell b) The most common enzyme used in TAG synthesis is acyl transferase  c) TAGs are synthesized in mitochondrial matrix d) TAGs have a polar head and non-polar tails 7. Which statement about cholesterol biosynthesis is correct? a) HMG-CoA lyase is the rate limiting enzyme of cholesterol synthesis pathway b) Synthesis of cholesterol takes place during the fed state c) Cholesterol is necessary for the synthesis of peptide hormones d) Most of the cholesterol is supplied by diet 8. Which statement about glycerol metabolism is correct? a) Glycerol is converted to glycerol-3-phosphate by enzyme glycerol dehydrogenase b) Glyceroneogenesis occurs only in the liver and kidneys c) Most of the glycerol 3-phosphate is formed from an intermediate of glycolysis dihydroxyacetone phosphate (DHAP) d) During transamination, alanine is formed from glycerol 9. Which statement about amino acid synthesis is correct? a) Glutamate is the main donor of amino groups for the synthesis of new amino acids b) Amino acid synthesis is facilitated during fasting period c) Essential amino acids are synthesized after the meal d) Synthesis of amino acids takes place in mitochondria 10. Which statement about transamination is correct? a) It takes place primarily in mitochondria b) ALT levels in blood will increase after an intensive workout c) Oxaloacetate is the most common amino group acceptor d) It is necessary only for amino acid catabolism 11. Which statement about deamination is correct? a) Typical substrate for deamination reactions is alanine b) Deamination is performed only in tissues that produce urea c) The amino group is transferred to another molecule as a result d) Is necessary for elimination of waste products after amino acid use for production of energy 12. Which statement about the urea cycle is correct? a) Reactions of this cycle take place both in mitochondria and in the cytosol b) It is performed in every cell after protein degradation c) In case of liver failure, the level of urea in bloodstream will increase d) The fifth reaction of urea cycle is transamination 13. Which statement about glucose-alanine cycle is correct? a) It describes amino group transfer between the brain and the liver b) It involves gluconeogenesis that ensures energy for muscle tissues c) The cycle includes the deamination reaction d) Alanine is synthesized from glucose for further use in proteins 14. Which statement about purine metabolism is correct? a) Uric acid formation releases ammonium b) The main form of nitrogen excreted from human body is uric acid c) The breakdown of purines results in the common intermediate xanthine d) In purine catabolism, inositol is a common intermediate 15. Which statement about heme metabolism is correct? a) During heme catabolism, a green compound called bilirubin is formed b) Heme is a porphyrin ring produced from succinyl-CoA and glycine c) Synthesis includes repeated condensations of isoprenoid units that form the ring structure d) Heme can be synthesized in bile duct 16. Which statement about hormones is correct? a) Steroid hormones have blood plasma transport proteins b) Eicosanoids are wide action range neurohormones c) Peptide hormones are water-soluble and have a long half-life d) Biogenic amines are only locally active neurotransmitters 17. Which statement about hormone signal transduction is correct? a) Steroid hormones are active only when bound to a transport protein b) Changes caused by steroid hormones will be faster than triggered by other hormones c) Binding to the cell membrane receptor usually initiates changes in gene transcription d) Peptide hormones amplify the signal through the secondary messenger system 18. Which statement about insulin is correct? a) Insulin facilitates protein synthesis in the liver b) Insulin facilitates the absorption of macronutrients from the intestines c) Insulin lowers glycolysis activity in adipose tissues d) Insulin increases the availability of glucose by breakdown of storage carbohydrates