Glycogen is a branched chain polymer of α-D-glucose units in which chain is formed by C1—C4 glycosidic linkage whereas branching occurs by the formation of C1-C6 glycosidic linkage. Structure of glycogen is similar to ______.
Glycogen is a branched chain polymer of αD glucose units in which chain is formed by C1−C4 glycosidic linkage whereas branchin occurs by the formation of C1−C6 glycosidic linkage. Structure of glycogen can be shown below similar to the sturcture amplopectin.
Which of the following polymer is stored in the liver of animals?
If blood glucose levels become too low, glucagon (pancreatic hormone) is released, which causes the liver to convert the stored glycogen back into glucose, and release it into the bloodstream.
Sucrose (cane sugar) is a disaccharide. One molecule of sucrose on hydrolysis gives _________.
Proteins are found to have two different types of secondary structures viz. α-helix and β-pleated sheet structure. α-helix structure of protein is stabilised by :
In α-helix, hydrogen bonds are present between –NH group of one amino acid residue to the >C= O group of another aminoacid residue.
Which of the following is NOT a culinary use of oil in the food industry?
Flavor, texture and shortening are all major culinary uses of oil in the food industry.
Dinucleotide is obtained by joining two nucleotides together by phosphodiester linkage. Between which carbon atoms of pentose sugars of nucleotides are these linkages present?
The correct answer is option A
Nucleotides are joined together by phosphodiester linkage between 5′ and 3′ carbon atoms of pentose sugar.
Nucleic acids are the polymers of ______________.
Nucleotides are organic molecules that serve as the monomer units for forming the nucleic acid polymers deoxyribonucleic acid and ribonucleic acid, both of which are essential biomolecules within all life-forms on Earth.
Which of the following statements is not true about glucose?
The correct answer is Option C.
Glucose is an aldohexose having structural formula.
Glucose on heating with HI produces n hexane.
Glucose does not give 2,4. DNP test due to its existence as cyclic structure shown below :
It is present in pyranose form, as shown below
Pyranose means pyran (membered ring containing oxygen) like structure.
Each polypeptide in a protein has amino acids linked with each other in a specific sequence. This sequence of amino acids is said to be ____________.
The primary structure of a protein refers to the sequence of amino acids in the polypeptide chain. The primary structure is held together by peptide bonds that are made during the process ofprotein biosynthesis.
DNA and RNA contain four bases each. Which of the following bases is not present in RNA?
Thymine is one of the four nucleobases in the nucleic acid of DNA that are represented by the letters G–C–A–T. The others are adenine, guanine, and cytosine. Thymine is also known as 5-methyluracil, a pyrimidine nucleobase. In RNA, thymine is replaced by the nucleobase uracil.
Which of the following B group vitamins can be stored in our body?
The correct answer is option D
The body has a limited capacity to store most of the B-group vitamins except B12 and folate, which are stored in the liver.
Which one of the following bases is not present in DNA?
Quinoline is an alkaloid, it is not present in DNA. DNA has four nitrogen bases in adenine, guanine, cytosine and thymine
Three cyclic structures of monosaccharides are given below which of these are anomers.
Structures (I and II) differ only in the position of OH at C2 and hence are anomers.
Which of the following reactions of glucose can be explained only by its cyclic structure?
Due to absence of free OH group at C2 cyclic structure of glucose pentacetate cannot revert to open chain aldehydic form and hence cannot form an oxime.
Optical rotations of some compounds along with their structures are given below which of them have D configuration.
The correct answer is Option A.
I, II and III structures have D configuration with -OH group on the lowest asymmetric carbon is on the right side which is comparable to (+) glyceraldehyde.
Structure of a disaccharide formed by glucose and fructose is given below. Identify anomeric carbon atoms in monosaccharide units.
The correct answer is option C
'a' carbon of glucose and 'b' carbon of fructose
Carbon adjacent to the oxygen atom in the cyclic structure of glucose or fructose is known as anomeric carbon. As shown in the structure above ‘a’ and ‘b’ are present adjacent to an oxygen atom. Both carbons differ in configurations of the hydroxyl group.
Three structures are given below in which two glucose units are linked. Which of these linkages between glucose units are between C1 and C4 and which linkages are between C1 and C6?
The correct answer is Option C.
(i) The first structure is lactose, the linkage is (A) C1−C4 glycosidic linkage.
(ii) The 2nd structure has C1−C6 linkages.
(iii) The 3rd structure has C1−C4 linkages.
Carbohydrates are classified on the basis of their behaviour on hydrolysis and also as reducing or non-reducing sugar. Sucrose is a __________.
The correct answer is option B & D.
One of the common disaccharides is sucrose which on hydrolysis gives an equimolar mixture of D−(+)− glucose and D−(−) fructose. These two monosaccharides are held together by a glycosidic linkage between Cl of α- glucose and C2 of β- fructose. Since the reducing groups of glucose and fructose are involved in glycosidic bond formation, sucrose is a non-reducing sugar.
Proteins can be classified into two types on the basis of their molecular shape i.e., fibrous proteins and globular proteins. Examples of globular proteins are :
The correct answer is A and C.
The structure of protein which results when the chain of polypeptides coil around to give a spherical shape are known as globular protein. These proteins are soluble in water, e.g., insulin and albumin are globular protein.
Which of the following carbohydrates are branched polymer of glucose?
The correct answer is option B,D
Amylopectin is insoluble in water and constitutes about 80−85% of starch. It is a branched-chain polymer of −D− glucose units in which chain is formed by C1−C4 glycosidic linkage whereas branching occurs by C1−C6 glycosidic linkage. Glycogen: The carbohydrates are stored in the animal body as glycogen. It is also known as animal starch because its structure is similar to amylopectin and is rather more highly branched.
Which of the following monosaccharides are present as five membered cyclic structure (furanose structure)?
The correct answer is option A,C.
It also exists in two cyclic forms which are obtained by the addition of −OH at C5 to the group. The ring, thus formed is a five-membered ring and is named as furanose with an analogy to the compound furan. Furan is a five-membered cyclic compound with one oxygen and four carbon atoms.
In fibrous proteins, polypeptide chains are held together by ___________.
The correct answer are options B & D,
In fibrous proteins, polypeptide chains are held together by hydrogen and disulphide bonds, in parallel manner. Due to which fibre-like structure is obtained. Such proteins are generally known as fibrous proteins. These proteins are generally insoluble in water e.g., keratin, myosin.
Which of the following are purine bases?
Which of the following terms are correct about enzyme?
The correct answer is option A,D
Life is possible due to the coordination of various chemical reactions in living organisms. This occurs with the help of certain biocatalysts called enzymes. Almost all the enzymes are globular protein.
Options A,B are correct.
In lysine,the amino group is attached to alpha carbon which makes it alpha amino acid and it has more amino groups as compared to -COOH groups, thus basic.