BIOCHEMESTRY
1-Glycine reaction is normally mediated by: a) Acetyl Coenzyme A b) UDP Glucoronyl tranferase c) PAPS- Phosphoadenosine-5-Phosphosulfate d) Sulfotranferase e) GST-Glutathione S-Transferase 2- Abundant element in the interstitial fluid may include: a) Potassium b) Sodium c) Magnesium d) Calcium e) Chloro 3- Which is responsible for N in vivo? a) Argenine b) Tryptophan c) Guanine d) Thiamine e) Leucine 4- Enzyme that enables DNA fragments from different sources to be joined: a) DNA polymerase b) DNA gyrase c) DNA ligase d) RNA transferase e) None of the above 5- Which of the followings are types of RNA? I- RNAt - RNA transferase II- RNAm – RNA mensager III-RNAr – RNA ribossome a) I only b) III only c) I and II only d) II and III only e) All are correct
6- Which vitamin is/are fat-soluble? I- Vitamin E II- Vitamin K
III- Vitamin B a) I only b) III only c) I and II only d) II and III only e) All are correct 7-Which of the following vitamin is not water-soluble? a) Vitamin B b) Vitamin C c) Vitamin D d) Folic acid e) Riboflavin 8- The most abundant metal ion in human body a) Iron b) Magnesium c) Aluminum d) Phosphorous e) Potassium 9- Which of the following is considered the normal potassium serum in human body? a) 2.0 to 3.5mEq/L b) 3.5 to 5.0mEq/L c) 5.0 to 7.5mEq/L d) 3.5 to 7.5mEq/L e) 3.0 to 6.0mEq/L 10- Which of the following is considered normal sodium serum in human body? a) 35 to 47 mEq/L b) 147 to 150 mEq/L c) 135 to 147mEq/L d) 75 to 135 mEq/L e) 125 to 145 mEq/L 11- Which of the following is considered as essential vitamin for breast-feed babies? a) Vitamin A b) Vitamin B c) Vitamin C d) Vitamin D e) Vitamim E
12- Which of the following hormone acts on cell wall? a) Insulin b) Prolactin
c) Cortisol d) Estrogen e) Alanine
13- Which of the following vitamins has tetrahydrofolate coenz yme activity based on its pteridine ring? a) Thiamine b) Vitamin D c) Vitamin K d) Folic acid e) Pyridoxine
14- What is correct regarding the formation of proteins? a) Formed by condensation of peptic bond b) Geometric sequence of amino acids c) The formation occurs by complexation of amino acids d) Proteins are formed from carbohydrates e) None of the above is right 15- Which is the strongest endogenous analgesic-pain producer in human body? a) Leukotriene b) Enkephalin c) Bradykinin d) Cytokine e) Angiotensin 16- Which of the following is considered the FIRST precursor of vitamin A formation? a) Retinoic acid b) Caroteno c) Cobalt d) Calciferol e) Pantothenic acid
17- Biological catalysts responsible for supporting almost all of the chemical reactions that maintain human life process: a) Nucleic acid b) Amino acids c) Carbohydrates d) Oligopeptides e) Enzymes 18- Which of the following statements is/are correct regarding enz ymes? I-Enzymes are proteins
II- Enzymes are catalyst because they are never altered during a reaction III- Michaelis-Menten theory describe the enzymatic reactions a) I only b) III only c) I and II only d) II and III only e) All are correct 19- Zwintter ion reacts with a substrate as: a) Neutral ion b) Proton acceptor ion c) Proton donor ion d) Anionic e) Cationic 20- Correct statements regarding mutation may include: I- Cell division II- Change in genotype III- Change in DNA replication altering the gene a) I only b) III only c) I and II only d) II and III only e) All are correct 21- Which pyrimidine base is not present in DNA? a) Thiamine b) Adenine c) Uracil d) Cytosine e) Guanine 22- The codon sequence Adenine-Guanine-Cytosine-Uracil is seen in I- RNAs II- DNAs III- Both DNAs and RNAs a) I only b) III only c) I and II only d) II and III only e) All are correct
23- Shaped network present in the cell between nucleus and cell wall: a) Ribossomes
b) Endoplasmic reticulum c) Mitocondria d) Cell membrane e) Nucleotide
24- The Michaelis-Menten equation-Enzymatic reactions will appears ZERO order when: a) The substrate concentration is much smaller than Km b) When Km is much smaller than the substrate concentration c) When Vmax is much smaller than Km d) When Vmax is much larger than Km e) When Km approaches Vmax
25- Which vitamin can be classified as hormone? a) Vitamin D b) Vitamin D3 c) Vitamin E d) Vitamin K e) Vitamin B12 26- False statement regarding vitamin D3 metabolism include: a) Vitamin C facilitates absorption of vitamin D3 in the liver b) Hydroxylation of D3 is in kidney c) Hydroxylation of is D3 in the liver d) Parathyroid hormone activate metabolism of vitamin v itamin D3 in the kidney e) Skin activates synthesis of vitamin D3 by sunlight
27- Hydrolysis of fixed oils may yields: a) Saturated + Unsaturated acids b) Glycerol + Fatty acids c) Glucose + Fatty acids d) Fatty acids + Triglycerideos e) None of the above
28- Example of compound that is phospholipid include: a) Glycogen b) Leucine c) Lecithin d) Hyaluronic acid e) Phenylalanine 29- In an enzymatic reaction, addition of competitive inhibitor leads to: a) Increase the rate of reaction b) Decrease the rate of reaction
c) Same rate of reaction d) Decrease rate and increase substrate concentration e) Decrease both rate and substrate concentration
30- Which of the following is the end products of ANAEROBIC reactions? a) Pyruvic acid b) CO2 c) CO2 + H2O d) Lactic acid e) Proteins
31- Which of the following is the end products of AEROBIC reactions? a) Pyruvic acid b) CO2 c) CO2 + H2O d) Lactic acid e) Proteins
32- Which of the following is an essential aminoacid? a) Histadiol b) Cysteine c) Methionine d) Aspartane e) Glutamine
33- Which of the following is NOT an essential aminoacid? a) Methionine b) Argenine c) Leucine d) Triptophan e) Glycine
34- Which of the following is the end product of proteins? a) Amino acids b) Urea c) Uric acid d) Purine e) Phosphorous 35-Purine may be the end product of: a) Amines b) Aminoacids
c) Uric acid d) Proteins e) Enzymes 36- In the typical cell, mitochondria may contains: I- Enzymes of Kreb’s cycle II- Enzymes of respiratory pathway as well cytochrome o xidase III- Enzymes of fatty acid cycle a) I only b) III only c) I and II only d) II and III only e) All are correct 37- Which of the following is the main carbohydrate of body blood? a) Sorbitol b) Mannitol c) Frutase d) Glucase e) Lactase 38- The presence of mitochondria in the living cell can be detected by: a) Neutral reagent b) Jenus green c) Morquis reagent d) Methylen blue e) Phenolphthalein 39- Which of the following is the only disaccharide NOT synthesized during human metabolism? a) Lactose b) Maltase c) Fructose d) Glucose e) Cellulose 40- The conversion of β-carotene to vitamin A is carried out in: a) Pancreas b) Spleen c) Liver d) Adrenal cortex e) Nefrons
41- Keratin is an example of:
a) Protein b) Peptin c) Scleroprotein d) Albuminoid e) C and D are correct 42- The metabolic degradation of hemoglobin takes place principally in: a) RBCs b) Reticulun Endothelial c) Liver d) Kidney e) Pancreas 43- Degradation of hemoglobin in mammal involve: a) Formation of bile pigments b) Formation of urobilinogen c) Formation of biliverdin d) Non-oxidative cleavage of phosphirin ring e) All are correct 44- Non-protein portion of hemoglobin consist of: a) Ferrous complex of protophorphirin IX b) 3 Heme unit surrounding an iron atom c) 4 Heme unit surrounding a ferric ion d) 4 Pyrrole rings linked through a Fe³+ mol. e) All are correct 45- Which of the following amino acid is an important precursor of hemoglobin? a) Alanine b) Proline c) Leucine d) Glycin e) Histadin 46- Which of the following is an important enzymatic reaction involved in muscular contraction? a) Glucose-6-phosphatase reaction b) Glycogenolysis c) ATP-Creatine phosphokinase reaction d) Enolase reaction e) Glucogenolysis
47- Protein disnaturation may happen due to: a) Exposure to air b) Shaking
c) Increase in temperature d) Chemical reagents e) All are correct 48- Which of the following enzyme is responsible for the synthesis of DNA? a) DNA polymerase b) DNA gyrase c) DNA ligase d) RNA transferase e) None of the above
49- Which pyrimidine base is not present in RNA sequence? a) Uracil b) Thiamine c) Cytosine d) Guanine e) Adenine
50- Which of the following is the predominant intracellular element? a) Sodium b) Magnesium c) Potassium d) Calcium e) Phosphorous
51- Which of the following is the only polysaccharide NOT synthesized during human metabolism? a) Maltase b) Sucrose c) Glucose d) Cellulose e) Frutose
52- Heparin synthesized in the body and can be classified as: a) Monosaccharideo b) Polysaccharide c) Disaccharide d) Oligosaccharide e) Aminoacid 53- Sucrose is a disaccharide formed from two molecules of monosaccharide: a) Glucose + frutose
b) Glucose + glucose c) Glucose + galactose d) Frutose + frutose e) Galactose + galactose 54- Enzymes that catalyze the transfer of one group to other group is called: a) Oxidoreductase enzymes b) Transferase enzymes c) Hydrolyses enzymes d) Isomerasis enzymes e) Lyasis enzymes 55- Catabolism of carbohydrates is a process characterized by: I- Consume of energy II- Release stored energy from carbohydrates III-Glycogenolysis is an example of carbohydrates catabolism reaction a) I only b) III only c) I and II only d) II and III only e) All are correct 56- The formation of glucose from non-carbohydrates sources such as lactate and Kreb’s cycle metabolites is an anabolic process called: a) Glycogenolysis b) Glycolysis c) Glycogenesis d) Gluconeogenesis e) None of the above 57- GLYCOGENESIS is a process characterized by: a) The breakdown of glycogen into glucose b) The transformation of glucose to glycogen c) The breakdown of sugar into pyruvate d) The breakdown of sugar into lactate e) The formation of glucose from non-carbohydrates sources 58- Which of the following reactions is controlled by the pancreatic hormone INSULIN? a) Glycogenolysis b) Glycolysis c) Glycogenesis d) Gluconeogenesis e) Anaerobic glycolysis 59- Correct statements regarding RNA messenger may include: a) Carrier activated aminoacids to the ribosome b) Specifies aminoacids sequence templant for protein synthesis
c) Enable DNA fragments to be joined d) Synthesize RNA e) Carrier the genetic information for all the other cells
60- Element found in the center of vitamin B12-cyanocobalamin: a) Iron b) Zinc c) Cobalt d) Magnesium d) Calcium
61- Beriberi is caused by deficiency of which of the following vitamins? a) Thiamine b) Riboflavin c) Niacin d) Pyridoxine e) Folic acid
62- Which of the following is the most important vitamin in pregnancy? a) Cyanocobalamin b) Folic acid c) Pantothenic acid d) Pyridoxine e) Niacin
63- Which of the following vitamin is derivated from the amino acid tryptophan? a) Thiamine b) Riboflavin c) Niacin d) Pyridoxine e) Folic acid
64- Which of the following vitamin has its chemical structure related to PABA? a) Cyanocobalamin b) Folic acid c) Pantothenic acid d) Pyridoxine e) Niacin 65- Vitamin that requires an intrinsic factor to be carried out to ileum in order to suffer absorption from the small intestine: a) Cyanocobalamin
b) Folic acid c) Pantothenic acid d) Pyridoxine e) Niacin 66- Which of the following vitamin is the precursor of collagen synthesis? a) Vitanin A b) Vitamin B c) Vitamin C d) Vitamin D e) Vitamin E 67- Correct statements concerning vitamin E include: I- It is a lipid soluble vitamin stored in adipose tissues II- It is absorbed from the small intestine III- Widely used in pharmaceutical formulations as antioxidant agent a) I only b) III only c) I and II only d) II and III only e) All are correct 68- Which of the following compounds are considered the building blocks of nucleic acids? a) Nucleotides b) Nucleosides c) Monosaccharides d) Purines e) Amino acids 69- Proteins are formed from: a) Purines b) Carbohydrates c) Amino acids d) Monosaccharides e) Nucleosides
CORRECT ANSWERS BIOCHEMESTRY
1- A Comments:
Glycine reaction is a reaction mediated by acetyl Coenzyme A.
2- B Interstitial fluid is situated between parts or in the interspaces of a tissue theref therefore ore outsid outsidee the cells. cells. Sodium Sodium is the most most abundan abundantt elemen elementt outsid outsidee the cells cells therefore in the interstitial fluid. Comments:
3- A Comments:
Argenine is an essential amino acid responsible for N.
4- C DNA ligase is an enzyme that enables en ables DNA fragments from different sources to be joined. Comments:
5- E Comments:
All, RNA transferase, RNA mensager and RNA ribosome are types of RNAs.
6- C Comments:
All vitamins B and vitamin C are water-soluble.
7- C Comments:
Vitamin A, D, E and K are fat-soluble vitamins.
8- A Comments:
Iron is the most abundant metal ion in human body.
9- B Comments: Normal
potassium serum in human body range between 3.5 to 5.0mEq/L.
10- C Comments: Normal
sodium serum in human body range between 135 to 147mEq/L
11- D Comments:
The most essential vitamin for breast-feed babies is vitamin D.
12- A Comments:
Insulin is a hormone that acts on cell wall
13- D Folic acid is a vitamin B9 that has tetrahydrofolate coenzyme activity based on its pteridine ring. Comments:
14- A Proteins are formed by a reaction between amino acids called condensation between peptid bonds. Comments:
15- C Comments:
Bradykinin is the strongest endogenous analgesic-pain producer in human
body. 16- B Comments:
Vitamin A is formed from retinoic acid that is formed from beta-caroteno.
17- E Enzymes are biological catalysts responsible for supporting almost all of the chemical reactions that maintain human life process, and accelerate reactions by lowering the energy of the transition state.
Comments:
18- E Enzymes Enzymes are protei proteins ns or biolog biologica icall cataly catalysts sts respons responsibl iblee for suppor supportin ting g almost all of the chemical reactions. They are called catalyst because are never altered during a reaction. Michaelis-Menten theory describes the enzymatic reactions.
Comments:
19- A Zwintter ion is a neutral ion with two charges, positive and negative, that reacts neutrally with a substrate.
Comments:
20- D Mutation is a permanent transmissible change in the genetic material, usually in a single gene. Comments:
21- C Comments:
Uracil is only present in RNAs.
22- A The codon sequence Adenine-Guanine-Cytosine-Uracil is seen in RNAs only. DNAs differ only in the presence of Thiamine instead of uracil.
Comments:
23- B Endopl Endoplasm asmic ic reticu reticulum lum is a shaped shaped networ network k presen presentt in the cell cell between between nucleus and cell wall. Comments:
24- E The Michaelis-M Michaelis-Menten enten equation-Enzy equation-Enzymatic matic reactions reactions will appears appears ZERO order when Km approaches Vmax and FIRST order when the substrate concentration is smaller than Km. Comments:
25- B Comments:
Vitamin D3 man be classified as hormone
26- A Comments:
Vitamin C does not interfere with absorption of vitamin D3 in the liver.
27- B Comments:
Glycerol and fatty acids are the end products of hydrolysis of fixed oils.
28- C Comments:
Lecithin is a phospholipid
29- C Addition of competitive inhibitor in an enzymatic reaction does not alter the rate of reaction. Comments:
30- D Comments:
Pyruvic acid is the end product of anaerobic reactions
31- C Comments:
CO2 and H2O are the end products of aerobic reactions.
32- C Histadiol, cysteine, aspartame and glutamine are examples o f non-essential amino acids Comments:
33- E Comments:
Glycine is not an essential amino acid.
34- B Comments:
Urea is the end product of proteins.
35- C Comments:
Purine is the end product of uric acid.
36- E Enzy Enzyme mess of Kreb Kreb’s ’s cycl cycle, e, enzy enzyme mess of resp respir irat ator ory y path pathwa way y as well well cytochrome oxidase and enzymes of fatty acid cycle are present in the mitochondria structure of the cell. Comments:
37- D Comments:
Glucase is the main carbohydrate present in the human blood.
38- B Jenus green is a laboratory test that detects the presence of mitochondria in the living cell 39- A Comments:
Maltase Maltase and cellulose are both carbohydrates carbohydrates not synthesized synthesized during human meta metabol bolis ism, m, howev however er malt maltas asee is disa disacc ccha hari ride de and and cell cellul ulos osee is a polys polysac accha chari ride de carbohydrate. Comments:
40- C β-carotene is the precursor of vitamin A. The transformation reaction happens in the liver by oxidation.
Comments:
41- E Comments:
Keratin is a scleroprotein that also can be called albuminoid.
42- B The metabolic degradation of hemoglobin takes place principally in reticulun Endothelial. Comments:
43- E The degrad degradati ation on of hemogl hemoglobi obin n in mammal mammal involv involvee format formation ion of bile bile pigments, formation of urobilinogen, formation of biliverdin and non-oxidative cleavage of phorphirin ring Comments:
44- A The non-pro non-protei tein n portio portion n of hemogl hemoglobin obin consist consistss of ferrou ferrouss comple complex x of protophorphirin IX. Comments:
45- D Comments:
Glycin is a non-essential amino acid and important precursor of hemoglobin.
46- C ATP-Cr ATP-Creat eatine ine phospho phosphokin kinase ase reacti reaction on is the most most impor importan tantt enzyma enzymatic tic reaction in muscular contraction.
Comments:
47- E Protein derivative products are very sensible and may suffer disnaturation by exposure to air, shaking, increase in temperature and addition of chemical reagents in.
Comments:
48- A Comments:
DNA polymerase is the enzyme responsible for the synthesis of DNA.
49- B Thiamine is the only pyrimidine base not present in RNA sequence; thiamine is only present in DNAs molecule.
Comments:
50- C Potassium is the most predominant intracellular element while sodium is the most predominant extracellular element. 51- D
Comments:
Maltase Maltase and cellulose are both carbohydrates carbohydrates not synthesized synthesized during human meta metabol bolis ism, m, howev however er malt maltas asee is disa disacc ccha hari ride de and and cell cellul ulos osee is a polys polysac accha chari ride de carbohydrate. Comments:
52- B Comments:
Heparin is a polysaccharide carbohydrate naturally synthesized in the body.
53- A Sucrose is a disaccharide formed from two molecules of monosaccharide, glucose and fructose Comments:
54- B Transferase enzymes catalyzes reactions involved in the transfer of one group to other group Comments:
55- D Catabolism Catabolism of carbohydrates carbohydrates is a process process characterize characterized d by release release of energy stored from carbohydrates. Glycogenolysis and glycolysis are examples of carbohydrates catabolism reaction Comments:
56- D Gluconeogenesis is the formation of glucose from non-carbohydrates sources such as lactate and Kreb’s cycle metabolites is an anabolic process called.
Comments:
57- B Glycogenesis is the transformation of glucose to glycogen. It hap pens in the liver and skeletal muscle from glucose consumed in the diet its synthesis is controlled by the pancreatic hormone insulin
Comments:
58- C Glycogenesi Glycogenesiss is an anabolic anabolic reaction reaction that transform transformss glucose glucose to glycogen in the liver and it is controlled by insulin.
Comments:
59- B Comments:
RNA messenger specifies amino acids sequence templant for protein
synthesis. 60- C Comments:
B12-cyanocobalamin has a cobalt molecule in the center of its structural
molecule. 61- A Comments:
62- B
Beriberi is caused by deficiency of thiamine.
Folic acid is one of the most important vitamin to be taken by women that is planning to get pregnant, during pregnancy and in breast-feeding. Comments:
63- C Comments: Niacin
is derivate from the amino acid tryptophan.
64- B Comments:
Folic Folic acid acid is a vitami vitamin n that that has its chemic chemical al struct structure ure simil similar ar to PABA PABA
structure. 65- A Cyanocobalam Cyanocobalamin in is not properly properly absorbed absorbed from the gastro gastro intestinal intestinal tract therefore it requires an intrinsic factor to be carried out to ileum in order to suffer absorption from the small intestine
Comments:
66- C Comments:
Vitamin C is the precursor of collagen synthesis.
67- E Vitami Vitamin n E is a lipid lipid solubl solublee vitami vitamin n stored stored in adipos adiposee tissue tissuess and well absorbed from the small intestine. It is widely used in pharmaceutical formulations as antioxidant agent Comments:
68- A Comments:
Nucleotides are considered the building blocks o f nucleic acids.
69- C Comments:
Proteins are formed from amino acids by condensation conden sation of peptid bond
