Test: Polysaccharides & Nucleic Acids - ACT MCQ

The complementary base pairs of guanine with cytosine and adenine with thymine connect to one another using hydrogen bonds. In addition to holding the DNA strands together, the hydrogen bonding between the complementary bases also sequester the bases in the interior of the double helix. Since, the option of Guanine and Cytosine is not provided. Hence, the correct option is Option C. 

Cellulose is made up of Glucose like starch . Cellulose is composed of a long chain of at least 500 glucose molecules. Cellulose is these a polysaccharide chains are arranged in parallel arrays to form cellulose microfibrills.

• Carbohydrates containing two to ten monosaccharide molecules are oligosaccharides.
• Oligosaccharides are formed when two or more monosaccharides join together by O-glycosidic bonds.
• Examples include sucrose, lactose and maltose. Specific enzymes are used to catalyze the glycosidic bonds in olgosaccharides and each sugar must be specific to each enzyme used for each new glycosidic bond.

Explanation:

• DNA nucleotides are attached by the Hydrogen bond.
• A nucleotide is the basic unit of polynucleotide chain of DNA (deoxyribonucleic acid) or RNA (Ribonucleic acid).
• The nitrogenous bases are found in the strand's inward direction. 
• The nitrogenous bases of the two antiparallel strands form hydrogen bonds, resulting in the formation of two helical strands.
• The nitrogenous bases used in DNA (double-stranded helical structure) are adenine (A), cytosine (C), guanine (G), and thymine (T).
• Adenine is joined to thymine with two hydrogen bonds, whereas guanine is joined to cytosine by three hydrogen bonds.

Thus, DNA nucleotides are attached by Hydrogen bond.

In a DNA molecule, the two strands are not parallel, but intertwined with each other. Each strand looks like a helix. The two strands form a "double helix" structure, which was first discovered by James D. Watson and Francis Crick in 1953. In this structure, also known as the B form, the helix makes a turn every 3.4 nm, and the distance between two neighbouring base pairs is 0.34 nm. Hence, there are about 10 pairs per turn. The intertwined strands make two grooves of different widths, referred to as the major groove and the minor groove, which may facilitate binding with specific proteins.
So, the correct answer is '3.4 nm'

The antiparallel strands of a DNA molecule that one strand turns anti-clockwise, the phosphate group of two DNA strands, at their ends, share the same position, the phosphate groups at the start of two DNA strands are in the opposite position and one strand turns clockwise.

Uracil is energetically less expensive to produce than thymine, which may account for its use in RNA. In DNA, however, uracil is readily produced by chemical degradation of cytosine, so having thymine as the normal base makes detection and repair of such incipient mutations more efficient.

According to Chargaff’s rule, the amount of adenine is always equal to that of thymine and the amount of guanine is always equal to that of cytosine.

A = T(120), G = C(120)

The total number of nucleotides would be 120 × 4 = 480.

• The chain of nucleotides joined together by phosphodiester bonds is known as nucleic acids.
• Nucleic acids are large biomolecules that play essential roles in all cells and viruses.
• A major function of nucleic acids involves the storage and expression of genomic information.
• Deoxyribonucleic acid, or DNA, encodes the information cells need to make proteins.

Bacterial cell walls are made of peptidoglycan (also called murein), which is made from polysaccharide chains cross-linked by unusual peptides containing D-amino acids. Bacterial cell walls are different from the cell walls of plants and fungi which are made of cellulose and chitin, respectively.

Glycogen is a branched polymer of glucose. It is readily soluble in water. It consists of alpha D glucose units, mostly linked by 1-4 glycosidic linkage, and is highly branched via frequent 1-6 linkages.

• A nucleoside does not contains phosphate group.
• A nucleoside consists simply of a nucleobase (also termed a nitrogenous base) and a five-carbon sugar (ribose or 2'-deoxyribose) whereas a nucleotide is composed of a nucleobase, a five-carbon sugar, and one or more phosphate groups.

A homopolysaccharide is a polysaccharide that includes the same type of monosaccharide. Glycogen, Cellulose, Starch, and Inulin are examples of important homopolysaccharides.

The correct option is Option B.

DNA is a polymer. The monomer units of DNA are nucleotides, and the polymer is known as a "polynucleotide." Each nucleotide consists of a 5-carbon sugar (deoxyribose), a nitrogen containing base attached to the sugar, and a phosphate group.

RNA is a linear polymer of nucleotides linked by a ribose-phosphate backbone. Polymerization of nucleotides occurs in a condensation reaction in which phosphodiester bonds are formed. Such ordering can provide conditions that promote the nonenzymatic polymerization of RNA strands under prebiotic conditions.

• Nucleic acid i.e. DNA and RNA is a polymer of nucleotide.
• Nucleotides are organic molecules consisting of a nucleoside and a phosphate.
• They serve as monomeric units of the nucleic acid polymers - deoxyribonucleic acid and ribonucleic acid, both of which are essential biomolecules within all life-forms on Earth.