MCQs in Biochemistry

Chapter 1: Introduction to biochemistry

 

1 - Which of the following prevents uric acid synthesis by inhibiting the enzyme xanthine oxidase:

 

  1. Aspirin
  2. Allopurinol
  3. Colchicine
  4. Probenecid

 

 

 

 

 

 

 

 

The answer is: B

 

 

2 - Which one of the following is required for crystallization and storage of the hormone insulin:

  1. Mn++
  2. Mg++
  3. Ca++
  4. Zn++

 

 

 

The answer is: D

 

3- Oxidation of which of the followings substances in the body yields the most calories:

  1. Glucose
  2. Glycogen.
  3. Protein.
  4. Lipids.

 

 

 

The answer is: D

 

4- Milk is known to be deficient in which vitamins?

  1. Vitamin C
  2. Vitamin A
  3. Vitamin B2
  4. Vitamin K

 

 

 

 

The answer is: A

 

5- Milk is known to be deficient of which mineral?:

  1. Phosphorus.
  2. Sodium.
  3. Iron.
  4. Potassium.

 

 

 

 

The answer is: C

 

6- The synthesis of prostaglandinsis is inhibited by:

  1. Aspirin.
  2. Arsenic.
  3. Fluoride.
  4. Cyanide.

 

 

 

 

The answer is: A

 

7- HDL is known to be synthesized and secreted from:

  1. Pancreas.
  2. Liver.
  3. Kidney.
  4. Muscle.

 

 

 

 

The answer is: B

 

8- What are the cholesterol esters that enter cells through the receptor-mediated endocytosis of lipoproteins hydrolyzed?:

  1. Endoplasmin reticulum.
  2. Lysosomes.
  3. Plasma membrane receptor.
  4. Mitochondria

 

 

 

 

The answer is: B

 

9- Which of the following is  a phospholipids that is localized to a greater extent in the outer leaflet of the membrane lipid bilayer?:

  1. Choline phosphoglycerides.
  2. Ethanolamine phosphoglycerides.
  3. Inositol phosphoglycerides.
  4. Serine phosphoglycerides.

 

 

 

 

The answer is: A

 

10- All the following processes occur rapidly in the membrane lipid bilayer EXCEPT:

  1. Flexing of fatty acyl chains
  2. Lateral diffusion of phospholipids
  3. Transbilayer diffusion of phopholipids
  4. Rotation of phospholipids around their long

 

 

 

 

 

 

The answer is: C

 

11- Which one of the following statements is correct about membrane cholesterol:

  1. The hydroxyl group is located near the centre of the lipid layer.
  2. Most of the cholesterol is in the form of a cholesterol ester
  3. The steroid nucleus form forms a rigid, planar structure.
  4. The hydrocarbon chain of cholesterol projects into the extracellular fluid

 

 

 

 

 

The answer is: C

 

12- Which one is the heaviest particulate component of the cell?:

  1. Nucleus
  2. Mitochondria
  3. Cytoplasm
  4. Golgi apparatus.

 

 

 

 

The answer is: A

13- Which one is the largest particulate of the cytoplasm?

  1. Lysosomes.
  2. Mitochondria.
  3. Golgi apparatus.
  4. Entoplasmic reticulum.

 

 

 

 

 

The answer is: B

 

14- The degradative Processess are categorized under the heading of:

  1. Anabolism
  2. Catabolism
  3. Metabolism
  4. None of the above

 

 

 

 

The answer is: B

 

15- The exchange of material takes place:

  1. Only by diffusion
  2. Only by active transport
  3. Only by pinocytosis
  4. All of the above

 

 

 

 

 

The answer is: D

 

16- The average pH of Urine is:

  1. 7.0
  2. 6.0
  3. 8.0
  4. 5.0

 

 

 

 

The answer is: B

 

17- The pH of blood is 7.4 when the ratio between H2CO3 and NaHCO3 is equal to:

  1. 1:10
  2. 1:20
  3. 1:25
  4. 1:30

 

 

 

 

 

The answer is: B

 

18- The phenomenon of osmosis is opposite to that of which of the following:

  1. Diffusion
  2. Effusion
  3. Affusion
  4. Coagulation

 

 

 

 

 

The answer is: A

19- The surface tension in intestinal lumen between fat droplets and aqueous medium is decreased by which of the following:

  1. Bile Salts
  2. Bile acids
  3. H2SO4
  4. Acetic acid

 

 

 

 

 

The answer is: A

 

20- Which one of the following is located in the mitochondria?

  1. Cytochrome oxidase
  2. Succinate dehydrogenase
  3. Dihydrolipoyl dehydrogenase
  4. All of the above

 

 

 

 

 

The answer is: D

 

21- The most active site of protein synthesis is the:

  1. Nucleus
  2. Ribosome
  3. Mitochondrion
  4. Cell sap

 

 

 

 

 

The answer is: B

 

22- The fatty acids can be transported into and out of mitochondria through:

  1. Active transport
  2. Facilitated transfer
  3. Non-facilitated transfer
  4. None of the above

 

 

 

 

 

The answer is: B

 

23- Mitochondrial DNA is known as:

  1. Circular double stranded
  2. Circular single stranded
  3. Linear double helix
  4. None of the above

 

 

 

 

 

The answer is: A

 

24- The absorption of intact protein from the gut in the foetal and newborn animals takes place by which of the following mechanisms:

  1. Pinocytosis
  2. Passive diffusion
  3. Simple diffusion
  4. Active transport

 

 

 

 

 

The answer is: A

 

 

25- The cellular organelles called “suicide bags” are:

  1. Lysosomes
  2. Ribosomes
  3. Nucleolus
  4. Golgi’s bodies

 

 

 

The answer is: A

 

26- From the biological viewpoint, solutions can be grouped into:

  1. Isotonic solution
  2. Hypotonic solutions
  3. Hypertonic solution
  4. All of the above

 

 

 

 

The answer is: D

 

27- Bulk transport across the cell membrane is accomplished by:

  1. Phagocytosis
  2. Pinocytosis
  3. Extrusion
  4. All of the above

 

 

 

 

The answer is: D

 

28- The ability of the cell membrane to act as a selective barrier depends upon:

  1. The lipid composition of the membrane
  2. The pores which allow small molecules
  3. The special mediated transport systems
  4. All of the above

 

 

 

 

The answer is: D

 

29- Which of the following is true regarding carrier protein:

  1. Transport only one substance
  2. Transport more than one substance
  3. Exchange one substance to another
  4. Perform all of these functions

 

 

 

 

The answer is: D

 

30- A lipid bilayer is permeable to:

  1. Urea
  2. Fructose
  3. Glucose
  4. Potassium

 

 

 

 

 

The answer is: A

 

31- which of the following is true regarding Golgi complex:

  1. Synthesizes proteins
  2. Produces ATP
  3. Provides a pathway for transporting chemicals
  4. Forms glycoproteins

 

 

 

 

 

The answer is: D

 

32- The following points about microfilaments are all correct EXCEPT:

  1. They form cytoskeleton with microtubules
  2. They provide support and shape
  3. They form intracellular conducting channels
  4. They are involved in muscle cell contraction

 

 

 

 

 

The answer is: C

 

33- The following substances are cell all inclusions EXCEPT:

  1. Melanin
  2. Glycogen
  3. Lipids
  4. Centrosome

 

 

 

 

 

The answer is: D

 

34- Fatty acids can be transported into and out of the cell membrane by which of the following mechanisms:

  1. Active transport
  2. Facilitated transport
  3. Diffusion
  4. Osmosis

 

 

 

 

 

The answer is: B

 

35- Enzymes catalyzing electron transport are present mainly in the:

  1. Ribosomes
  2. Endoplasmic reticulum
  3. Lysosomes
  4. Inner mitochondrial membrane

 

 

 

 

 

The answer is: D

 

36- Mature erythrocytes do not contain:

  1. Glycolytic enzymes
  2. HMP shunt enzymes
  3. Pyridine nucleotide
  4. ATP

 

 

 

 

 

The answer is: C

 

 

37- In mammalian cells rRNA is mainly produced in the:

  1. Endoplasmic reticulum
  2. Ribosome
  3. Nucleolus
  4. Nucleus

 

 

 

 

 

The answer is: C

 

38- Genetic information of nuclear DNA is transmitted to the site of protein synthesis by:

  1. rRNA
  2. mRNA
  3. tRNA
  4. Polysomes

 

 

 

 

 

The answer is: D

 

39- The powerhouse of the cell is:

  1. Nucleus
  2. Cell membrane
  3. Mitochondria
  4. Lysosomes

 

 

 

 

 

The answer is: C

 

 

40- The digestive enzymes of cellular compounds are confined to:

  1. Lysosomes
  2. Ribosomes
  3. Peroxisomes
  4. Polysomes

 

 

 

 

The answer is: A