Test: Biomacromolecules (NCERT) - NEET MCQ

• In triglyceride form, lipids can be absorbed by the jejunum is incorrect regarding triglycerides.
• Triglycerides are a type of fat (lipid) found in your blood. When you eat, your body converts any calories it doesn't need to use right away into triglycerides.
• The triglycerides are stored in your fat cells. Later, hormones release triglycerides for energy between meals.

• The apoenzyme is the protein part of a conjugated enzyme, and the coenzyme is the non-protein part.
• The combination of the apoenzyme and the coenzyme results in the formation of a functional enzyme which is called holoenzyme. Enzymes help speed up chemical reactions in the human body.
• They are essential for digesting food, nerve function, muscle, respiration, and among thousands of other roles.
• Conjugation of enzymes to antibodies involves the formation of a stable, covalent linkage between an enzyme. 
• Coenzymes, support the functions of enzymes. 
• The coenzymes share electrons with the enzymes, rather than lose or gain electrons.

Nucleoside is compound formed by the union of a nitrogen base with a pentose sugar. It is a component of nucleotide. Each nucleotide is composed of three units; a nitrogen base, a pentose sugar and a phosphate group.

The nucleoside combines with a phosphate group at 5'position by an ester bond to form a nucleotide or nucleoside monophosphate.

So, the correct option is 'both (a) and (c)'

Sucrose is a disaccharide.
Disaccharides: Two monosaccharides combine to form a disaccharide. Examples of carbohydrates having two monomers include Sucrose, Lactose, Maltose.

Sources of Carbohydrates:

• Simple sugars are found in the form of fructose in many fruits.
• Galactose is present in all dairy products.
• Lactose is abundantly found in milk and other dairy products.
• Maltose is present in cereal, beer, potatoes, processed cheese, pasta, etc.
• Sucrose is naturally obtained from sugar and honey containing small amounts of vitamins and minerals.

Cytosine (C) is a pyrimidine i.e, a nitrogenous base. A combination of a nitrogenous base (purine or pyrimidine) with a pentose sugar is known as a nucleoside. Thus the combination of cytosine with ribose sugar results in the formation of a nucleoside called as cytidine, Similarly, The combination of cytosine with deoxyribose sugar is called as deoxycytidine.

• Maltose is a disaccharide made up of two units each of glucose.
• The two units of glucose are joined together covalently by an O-glycosidic bond which is formed when a hydroxyl group on one sugar reacts with the anomeric carbon on another.

Acidic amino acids have an extra carboxylic group (mono-amino dicarboxylic), e.g., glutamate (glutamic acid or Glu), asparate (aspartic acid or Asp).

Basic amino acids have an additional amino group without forming amides (diamino monocarboxylic), e.g., arginine (Arg), lysine (Lys).

• Cellulose is the most abundant organic polymer on Earth.
• Cellulose is an important structural component of the primary cell wall of green plants, many forms of algae and the oomycetes.

• Phytochromes are pigment molecules that act as photoreceptors and are found in plants.
• Enzymes are biocatalysts that cause a change in the rate of a chemical reaction.
• Chloroplasts are cell organelles that are present mostly in plant cells and help capture sunlight and in photosynthesis.
• Proteins are biomolecules formed of long amino acid chains that are necessary for a cell to function.
• Proteins are involved in carrying out nearly all the functions of a cell.

• Magnesium is at the centre of the porphyrin ring in chlorophyll.
• Chlorophyll is the green colored pigment which is present in the plastid.
• It is located in the thylakoid membranes of the plastids.
• It has a molecular formula of C₅₅H₇₂O₅₅N₄₄Mg. Magnesium is centrally located in the chlorophyll.
• It consists of porphyrin ring which has magnesium ion in the center.
• The two types of chlorophyll are chlorophyll a and b.
• Chlorophyll a has a porphyrin ring with the side chain of the methyl group and a phytol chain.
• Chlorophyll b has a porphyrin ring with the side chain of aldehyde group and a phytol chain.
• It acts like an accessory pigment.

• Enzyme catalyzing optical or geometrical rearrangement of atomic groupings without altering molecular weight or number of atom is isomerase.
• It converts into from one isomer to the other isomer by changing the intramolecular arrangement by forming or breaking the bond.
• For, example glucose 6 phosphate is changed to fructose 6 phosphate by enzyme isomerase during the process of glycolysis.
• Ligase is a enzyme which is used to join two molecules by establishing covalent bonds.
• Two DNA molecules are joined together by phosphodiester bond in presence of DNA ligase.
• The enzyme cannot be used for the blunt end of the DNA fragments.
• The nature of the bond is covalent as it involves the exchange of electrons.
• Hydrolase are the enzyme which catalyses the splitting of compounds by addition of water.
• Transferases helps to transfer functional group from one molecule to another.

(i) The amino acid is the basic units of proteins and is formed by one carboxyl bond plus one amine group on the side chain.
(ii) On the basis of the compound present, they are divided into various types, for example, simple amino acid, sulphur containing amino acids, basic amino acids, an aromatic amino acid.
(iii) On the given structure CH₃ is present on the side chain, and here the amino acid is alanine and in the second image hydrogen is present as the side chain and so it is the simplest amino acid that is glycine.
(iv) On the third chain, CH₂OH is present and the amino acid is serine.
So, the correct option is 'i - Alanine, ii - Glycine, iii - Serine'

Aromatic amino acids possess cyclic structure in the side chain, e.g., phenylalanine, tryptophan (actually heterocyclic) or tyrosine (having OH group).

Nitrogen bases are heterocyclic compounds. They are of two types, substituted purines and substituted pyrimidines. Purines are larger-sized nitrogen containing biomolecules. They have 9−9-membered double rings. A purine has imidazole ring joined to pyrimidine ring at 44 and 55 positions. It has nitrogens at 1, 3, 7 and 9 positions. There are two types of purines- adenine (A) and guanine (G). Pyrimidines are 6−6- membered rings. A pyrimidine ring has nitrogen at 11 and 33 positions. Pyrimidine bases are of three types-cytosine (C), thymine (T) and uracil (U).

Glucose ans ribose both are carbohydrates. Ribose sugar constitutes RNA nucleotides. Glucose is a hexose sugar while ribose is a pentose sugar.

Lipids are estres of fatty acids and alcohol. These are hydrophobic in nature and they are insoluble in water but are soluble in organic solvents like benzene, ether and chloroform. 
Simple lipids are the esters of fatty acid and glycerol. Fats and oils are the triglycerides of fatty acid and glycerol. 

Biological molecules, also known as biomolecules, are large structures that are responsible for the catalysis, structure and function of the cell. The molecules (C,H, O, N etc.) within the biomolecules are joined by covalent bond because it is strong bond that maintains structural integrity. The biomolecules will then combine to form a functional cell. The examples include peptide bond, glycosidic bond, phosphodiester bond etc.

A. Peptide bond is a type of covalent bond found in polypeptides. So only proteins will show peptide bonds.

B. Ionic bonds result in formation of cation and anion which could hamper the vital activities within the cells.

C. Hygrogen bonds are weak bonds and they do not confer structural integrity to the molecules.

D. Covalent bonds form the backbone of the structure of biomolecules. 

Hence, the correct answer is 'covalent bond'.

The amino acid at the structural and functional unit of protein and they combine through peptide Bond to form proteins. The amino acids have one carboxyl group along with one amino group and a side chain which is different in all the amino acids.

On the basis of the side chain, amino acids are categorised into a variety of types, for example, simple amino acids, sulphur containing amino acids, aromatic amino acids and so on.

• Chitin is a polysaccharide. It is an important component of the cell wall of fungi.
• It is the main constituent of the exoskeleton of the arthropods.
• It is a long chain polymer of N-acetylglucosamine.
• It is the second most abundant homopolysaccharide.
• The cell wall of bacteria is made up of peptidoglycan.
• Algae has the cell wall made up of cellulose.
• Yeast has the cell wall made up of beta-glucan and mannan sugar polymers), 15 - 30 % proteins, 5 - 20 % lipids and a small amount of chitin.

Carbohydrates are also called saccharides because their basic components are sugars. Monosaccharides are those sugars or simple carbohydrate monomers which cannot be hydrolysed further into smaller components. They have a general formula of Cn​H₂n​On​. Depending upon the number of carbon atoms, monosaccharides are of five types : trioses (having 3 carbon atoms, glyceraldehyde), tetroses (having four carbon atoms, e.g., erythrose), pentoses (having five carbon atoms, e.g, ribose), hexoses (having six carbon atoms, e.g.; glucose), heptoses (having seven carbon atoms, e.g., sedoheptulose).