Biomolecules Quiz-10

Biomolecules Quiz-10

Dear Readers,

NEET is the most famous and important medical entrance examination held in our country. This exam is an objective type, an offline test which includes 4 sections namely– Physics, Chemistry, Botany, and Zoology. The maximum marks that can be scored are 720 marks and have 180 questions. About half of the paper consists of questions from Biology, as the NEET exam essentially focuses on capacitating students to go for seats in medical courses. One of the most significant and crucial sections in the NEET exam is of Biology. It comprises of theories, descriptions, discoveries, diagrams, definitions, explanations of differences, and relations. The majority of the topics covered in the NEET syllabus are from the NCERT syllabus of Class 11 & 12 and other related sources become part of the rest of the syllabus. Clear Exam curates a list of articles selected by professionals who recommend the highly vital topics for NEET exams. The table below takes you directly to the respective topic where the in-depth article and the MCQs are available for an easy and productive learning experience. Prior to solving NEET question papers or practicing mock tests, you must ensure to study the basic concepts in NEET and practice a few sample questions related to this exam. Students will be covered for all their studies as the topics are available from basics to even the most advanced. .

Q1.   Michaelis Menten constant (km) is equal to

•  The rate of enzymatic activity
•  The rate of reaction
•  Substrate concentration at which the reaction attains half of its maximum velocity
•  Substrate concentration at which the rate of reaction is maximum

Solution
(c) Michaelis Menten constant (km) is equal to the substrate concentration at which the velocity of the reaction is half maximum. It is inversely proportional to the enzyme activity

Q2.   Arrange the steps of catalytic action of an enzyme in order and choose the correct option. I. The enzyme releases the products of the reaction and the enzyme is free for another substrate. II. The active site of enzyme is in close proximity of the substrate and breaks of chemical bonds of the substrate. III. The binding of substrate induces the enzyme to alter its shape fitting more tightly around the substrate. IV. The substrate binds to the active site of the enzyme fitting into the active site.

•  IV, III, II, I
•  III, II, I, IV
•  IV, II, I, III
•  II, I, IV, III

Solution
(a)

Q3.   Which of the following statements are correct for polysaccharides? I. The polysaccharides are found as a part of the acid insoluble pellet II. These are long chains of sugars III. They are threads containing different monosaccharides as building blocks IV. Cellulose is a polymeric polysaccharide consisting of only one type of monosaccharide i.e., fructose

•  All are correct
•  All are correct except IV
•  III and IV
•  Only IV is correct

Solution
(b) Cellulose is a polymeric polysaccharide consisting of only one type of monosaccharide, i.e., glucose

Q4.   Which of the following secondary metabolites are used as drugs?

•   Vinblastin and curcumin
•  Anthocyanin
•  Gums and cellulose
•  Abrin and ricin

Solution
(a) Vinblastin and curcumin are used as drugs

Q5.   One strand of DNA has sequence of nucleotide 3’ ATTCGCTAT 5’ then other strand of DNA has

•  3’ TAAGCGATA 5’
•  5’ TAGCACGTA 5’
•  5’ TAGCACGTA 3’
•  5’ TAAGCGATA 3’

Solution
  (d) In a double stranded DNA, the sequence of nucleotides is complementary to each other, i.e., A pair with T and G pair with C. So, the sequence of nucleotide for 3’ ATTCGCTAT 5’ will be 5’ TAAGCGATA 3’.

Q6.   Cellulose is made up of

•  Branched chain of glucose molecule linked by α-1, 4 glycosidic bond in straight chain and β-1, 6 glycosidic bond at the site of branching
•  Branched chain of glucose molecule linked by α-1, 6 glycosidic bond in straight chain and β-1, 4 glycosidic bond at the site of branching
•  Unbranched chain of glucose molecule linked by β-1, 4 glycosidic bond
•  Unbranched chain of glucose molecule linked by α-1, 6 glycosidic bond

Solution
(c) Cellulose is made up of unbranched chain of glucose molecule linked by β-1, 4 glycosidic bond.

Q7.   Select the wrong statement.

•  The building blocks of lipids are amino acids
•  Majority of enzymes contain a non-protein part called the prosthetic group
•  The thylakoids are arranged one above the other like a stack of coins forming a granum
•  Crossing over occurs at pachytene stage of meiosis-I

Solution
(a) Amino acids are organic acids (with carboxylic group (-COOH) and having amino group (-NH_2) generally attached to α-carbon or next to the carboxylic group. Carboxylic group provides an acidic property to the amino acid, while amino group gives it a basic reaction. Amino acids are building blocks of proteins and enzymes.

Q8.   One turn of DNA has nucleotide pairs

•  8
•  100
•  6
•  10

Solution
(d) These are five forms of DNA, B.DNA is most common. A-DNA – 11 pairs B-DNA – 10 pairs C-DNA – 9.33 pairs D-DNA – 8 pairs Z-DNA – 12 pairs

Q9.   The given graph shows the effect of substrate concentration on the rate of reaction of the enzyme green gram-phosphatase. What does the graph indicate?

•  The rate of enzyme reaction is directly proportional to the substrate concentration
•  Presence of an enzyme inhibitor in the reaction mixture
•  Formation of an enzyme-substrate complex
•  At higher substrate concentration, the pH increase

Solution
(b) In given graph, initial rate of enzymatic reaction increases but after sometime began to show down due to presence of an enzyme inhibitor.

Q10.   Find out the wrongly matched pair.

•  Primary metabolite – Ribose
•  Secondary metabolic – Anthocyanin
•  Protein – Insulin
•  Cellulose – Heteropolymer

Solution
(d) Cellulose is the most important structural component of the cell wall of plants. It is a linear polymer of β-D glucose units connected through β-1, 4-glycosidic linkage. The linear chains form microfibrillae or bundles of parallel chains held together by hydrogen bonds.