Aromatic amino acids (tyrosine,

NEET 2020 o
phenylalanine, tryptophan).
Quick Revision Key Notes o A particular property of amino acids is
BIOMOLECULES the ionizable nature of –NH2 and –
COOH groups. @ Isoelectric pH &
Covering 2 to 4 MCQs in NEET
Zwittor ion
Biomentors Classes Online, Mumbai
o In solutions of different pHs, the
© All right reserved structure of amino acids changes.
Copyright - Biomentors 4. Lipids
These notes only for Biomentors online subscribers o Generally water insoluble.
1. Trichloroacetic acid (Cl3CCOOH) à o A fatty acid has a carboxyl group
Used to analyse chemical composition of living

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attached to an R group.
tissue o The R group à Generally 1 carbon to

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Acid-soluble pool à 19 carbons
Compounds found have molecular weights o Palmitic acid has 16 carbons

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ranging from 18 to around 800 daltons (Da) o Arachidonic acid has 20 carbon atoms

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approximately. @ Micro molecules o Fatty acids
Retentate or the acid-insoluble fraction à

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§ Saturated (without double bond)
Only four types of organic compounds i.e., § unsaturated (with one or more
proteins, nucleic acids, polysaccharides and C=C double bonds).
lipids. @ Macro molecules except Lipid
Except lipids, all have molecular weights @ § Most simple lipid is glycerol
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which is trihydroxy propane.
10000 daltons and above. o Many lipids have both glycerol and
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2. All the carbon compounds present in living fatty acids.

tissues à ‘Biomolecules’.
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o Oils have lower melting point (e.g.,

3. Amino acids à gingely oil)
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Organic compounds o Some lipids have phosphorous and a

Have an amino group and an acidic group on phosphorylated organic compound
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the same carbon i.e., the alpha-carbon. Hence, à Phospholipids à Found in cell
they are called α-amino acids. membrane.
They are substituted methanes.
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§ Example - Lecithin
There are four substituent groups o Neural tissues have lipids with more
Hydrogen, Carboxyl group, Amino group and A
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complex structures.
variable group designated as R group.
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5. Nitrogen Base à
Based on the nature of R group there are many o Heterocyclic rings
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amino acids. o Nitrogen bases – adenine, guanine,

In proteins à only of 20 types of amino acids . cytosine, uracil, and thymine.
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The R group à o Nitrogen base + sugar àNucleosides.

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o Adenosine, guanosine, thymidine,

uridine and cytidine are nucleosides.
o Nucleotide = Nucleoside +Phosphate
o Nucleotides à Adenylic acid, thymidylic
acid, guanylic acid, uridylic acid and
The chemical and physical properties of amino
cytidylic acid
acids determined by à Amino group, o Nucleic acids like DNA and RNA consist
carboxyl group and the R functional groups.
of nucleotides only.
Based on number of amino & carboxyl groups,
o DNA & RNA à Genetic material.
o Acidic (e.g., glutamic acid), 6. PRIMARY AND SECONDARY METABOLITES
o Basic (lysine) and
o Neutral (valine) amino acids.
 o Primary metabolites à Have 11. The GLUT or SLC2A family are a protein family
identifiable functions and play roles in that is found in most mammalian cells.
normal physiological processes. 12. GLUT is a type of uniporter transporter protein.
§ Proteins, amino acids, nucleotides, 13. Glucose transporter type 4 (GLUT-4) is a protein
carbohydrates, lipids etc. encoded, in humans, by the SLC2A4 gene.
o Secondary metabolites à Not clear 14. GLUT4 is the insulin-regulated glucose
understanding about the role or transporter found primarily in adipose tissues
functions of all the ‘secondary and striated muscle (skeletal and cardiac).
metabolites’ in host organisms. 15. Collagen is the most abundant protein in
§ Many useful to ‘human welfare’ animal world
§ Some secondary metabolites have 16. Ribulose bisphosphate Carboxylase-Oxygenase

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ecological importance. (RuBisCO) is the most abundant protein in the
§ e.g., rubber, drugs, spices, scents, whole of the biosphere.

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pigments, alkaloids, flavonoids, 17. POLYSACCHARIDES
rubber, essential oils, antibiotics, o Long chains of sugars.

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coloured pigments, scents, gums, o Threads containing different

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spices. monosaccharides as building blocks.

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Pigments Carotenoids, o cellulose (Polymer of beta-D-glucose) &
Anthocyanins, etc. Starch (Polymer of alpha-D-glucose)
Alkaloids Morphine, Codeine 18. Cellulose is a homopolymer;
Terpenoides
Essential oils
Monoterpenes,Diterpenes
Lemon grass oil @ Starch is à A store house of energy in plant
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tissues;
Toxins Abrin, Ricin
Glycogen is à A store house of energy in
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Lectins Concanavalin A
Drugs Vinblastin, curcumin
animal tissue
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Polymers Rubber, gums, cellulose 19. Inulin is a polymer of fructose.

20. In Glycogen à The right end is called the
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7. PROTEINS reducing end and the left end is called the non-
o Polypeptides. reducing end.
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o Linear chains of amino acids linked by 21. Starch forms helical secondary structures.
peptide bonds Starch can hold I2 molecules in the helical
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o Polymer of amino acids. portion. The starch-I2 is blue in colour.

o 20 types of amino 22. Cellulose does not contain complex helices and
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o Heteropolymer and not a homopolymer. hence cannot hold I2 .

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8. Dietary proteins are the source of essential 23. Plant cell walls, Cotton fibre, Paper pulp are
amino acids. We get through our diet/food. made of cellulose.
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9. Proteins carry out many functions in living 24. Complex polysaccharides à Have as building
blocks, amino-sugars and chemically modified
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organisms
Protein Functions sugars (e.g., glucosamine, N-acetyl
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Collagen Intercellular ground substance galactosamine, etc.).

Trypsin Enzyme o Exoskeletons of arthropods, (chitin)
Insulin Hormone o These complex polysaccharides are
Antibody Fights infectious agents mostly homopolymers. (2020 – NCERT)
Receptor Sensory reception (smell, taste, 25. NUCLEIC ACIDS:
hormone, etc.) Polynucleotides.
GLUT -4 Enables glucose transport Building block à nucleotide.
into cells
A nucleotide consist of à 3 components
1. N Base, 2. Pentose sugar 3. a phosphate.
10. GLUCOSE TRANSPORTERS are a group of Heterocyclic compounds in nucleic acids are the
membrane proteins that facilitate the transport nitrogenous bases à adenine, guanine, uracil,
of glucose across the plasma membrane. cytosine, and thymine.
 Adenine and Guanine are substituted purines 2 H - bonds between A and T and 3 H - bonds
while the rest are substituted pyrimidines. between G and C.
The sugar found in polynucleotides à either Each strand appears like a helical staircase.
ribose or 2’ deoxyribose. Each step of ascent à a pair of bases.
A nucleic acid containing deoxyribose à DNA At each step of ascent, the strand turns 36°.
A nucleic acid containing ribose à RNA One full turn of the helical strand would
26. STRUCTURE OF PROTEINS involve ten steps or ten base pairs.
Biologists describe the protein structure at four The pitch would be 34Å. The rise per base pair
levels. would be 3.4Å.
The sequence of amino acids à Primary This form of DNA with the above mentioned
structure of a protein. features is called B-DNA.

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The first amino acid à N-terminal amino acid. 29. Biomolecules have a turn over.
The last amino acid à C-terminal amino acid. o Constantly being changed into some

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A protein thread is folded in the form of a helix other biomolecules and also made from
à Secondary structure some other biomolecules.

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In proteins, only right handed helices are o Breaking and making is through

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observed. chemical reactions à metabolism.

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In addition, the long protein chain is also o In other words, metabolites are
folded upon itself à Tertiary structure converted into each other in a series of
This gives us a 3-dimensional view of a protein. linked reactions called metabolic
Tertiary structure is absolutely necessary for the
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o These metabolic reactions is that every
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many biological activities of proteins.
Some proteins are an assembly of more than chemical reaction is a catalysed reaction.
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one polypeptide or subunits. à quaternary

o Proteins with catalytic power are named
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enzymes.
structure of a protein.
30. Metabolic pathways can lead to
Adult human haemoglobin consists of 4
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o More complex structure from a simpler

subunits. @ 2 Alpha & 2 Beta chains
structure (biosynthetic or anabolic
27. NATURE OF BOND LINKING MONOMERS IN A
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pathways)
POLYMER à
o Simpler structure from a complex
In a protein, amino acids are linked à
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structure (catabolic pathways)

by peptide bond
o Anabolic pathways, as expected,
In a polysaccharide monosaccharides are
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consume energy.
linked à by glycosidic bond.
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o catabolic pathways lead to the release of

In a nucleic acid nucleotides are linked à by
energy.
Phosphodiester bond
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o Energy currency in living systems is the

a phosphate moiety links the 3’-carbon of one sugar
bond energy in a chemical called
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of one nucleotide to the 5’-carbon of the sugar of the

succeeding nucleotide. adenosine triphosphate (ATP).
o ATP is energy currency of cell
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28. Nucleic acids exhibit a wide variety of

secondary structures. 31. These biomolecules are in a metabolic flux.
Secondary structures exhibited by DNA is the 32. Any chemical or physical process moves
famous Watson-Crick model. spontaneously to equilibrium.
DNA is a double helix. 33. The steady state is a non-equilibrium state.
The two strands are antiparallel i.e., run in the 34. The living state is a non-equilibrium steady-
opposite direction. state to be able to perform work
The backbone is formed by the sugar 35. Living process is a constant effort to prevent
phosphate-sugar chain. falling into equilibrium. This is achieved by
A and G of one strand pairs with T and C, on the energy input.
other strand. 36. Metabolism provides a mechanism for the
production of energy. Hence the living state
and metabolism are synonymous.
37. ENZYMES o high temperature destroys enzymatic
o Almost all enzymes are proteins. activity because proteins are denatured
o Ribozymes à catalytic RNA. by heat.
o An active site of an enzyme is a crevice or 45. Concentration of Substrate à
pocket into which the substrate fits. At fixed enzyme concentration with the
o Enzymes get damaged at high increase in substrate concentration à the
temperatures (say above 40°C). velocity of the enzymatic reaction rises at first.
o Thermal stability seen in enzymes à reaches a maximum velocity (Vmax) à not
isolated from thermophilic organisms. exceeded by any further rise in concentration of
38. Rate of a physical or chemical process refers to the substrate. à This is because no free
the amount of product formed per unit time. enzyme molecules to bind with the additional

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39. There are thousands of types of enzymes each substrate molecules @ SATURATION EFFECT
catalysing a unique chemical or metabolic 46. The Michaelis constant (KM) is defined as the

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reaction. substrate concentration at which the reaction
40. Enzymes eventually bring down activation rate is half of its maximal value (or in other

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energy barrier making the transition of ‘S’ to ‘P’ words it defines the substrate concentration at

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more easy. which half of the active sites are occupied).

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41. Each enzyme (E) has a substrate (S) binding site 47. An enzyme with a high Km has a low affinity for
in its molecule so that a highly reactive its substrate, and requires a greater
enzyme-substrate complex (ES) is produced. concentration of substrate to achieve Vmax
42. ES complex is short-lived and dissociates into
its product(s) P and the unchanged enzyme @
48. The activity of an enzyme is also sensitive to the
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presence of specific chemicals that bind to the
with an intermediate formation of the enzyme- enzyme. When the binding of the chemical
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product complex (EP). shuts off enzyme activity, the process is called
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43. The catalytic cycle of an enzyme action has inhibition and the chemical is called an
following steps: inhibitor.
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o Active site of Enzyme + Substrate à 49. When the inhibitor closely resembles the
Enzyme substrate complex formation substrate in its molecular structure and inhibits
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o In ES complex the substrate ffitted more the activity of the enzyme, it is known as
tightly competitive inhibitor.
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o Enzyme- product complex is formed e.g., inhibition of succinic dehydrogenase by

through catalysis (Bond reorganisation) malonate which closely resembles the
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o Dissociation of Enzyme Product complex substrate succinate in structure. Such

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into enzyme & product competitive inhibitors are often used in the
44. Factors Affecting Enzyme Activity control of bacterial pathogens.
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o The activity of an enzyme can be affected 50. CLASSIFICATION & NOMENCLATURE OF ENZYMES
by a change in the conditions which can On the basis of the type of reactions à 6
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alter the tertiary structure of the protein. classes each with 4-13 subclasses
o Temperature, pH, change in substrate Named accordingly by a four-digit number.
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concentration or binding of specific OXIDOREDUCTASES/DEHYDROGENASES:

chemicals that regulate its activity. Enzymes which catalyse oxidation-reduction
o Enzymes generally function in a narrow between two substrates
range of temperature and pH TRANSFERASES:
o Each enzyme shows its highest activity at Enzymes catalysing a transfer of a group
a particular temperature & pH called the HYDROLASES:
optimum temperature & optimum pH. Enzymes catalysing hydrolysis of ester, ether,
o Activity declines both below and above peptide, glycosidic, C-C, C-halide or P-N bonds.
the optimum value. LYASES:
o Low temperature preserves the enzyme Enzymes that catalyse removal of groups from
in a temporarily inactive state substrates by mechanisms other than
hydrolysis leaving double bonds.
 ISOMERASES: 5. Fructose have the same number of carbon as present
Includes all enzymes catalysing inter- in glucose
conversion of optical, geometric or positional 6. An acid soluble compound formed by phosphorylation
isomers. of nucleoside is called à Nucleotide
LIGASES: 7. When we homogenise any tissue in an acid the acid
Enzymes catalysing the linking together of 2 soluble pool represents Cytoplasm
compounds, e.g., enzymes which catalyse 8. The most abundant chemical in living organisms à
joining of C-O, C-S, C-N, P-O etc. bonds. Water
51. CO-FACTORS à 9. Proteins are heteropolymers usually made of à20
o Non-protein constituents types of monomers
o bound to the enzyme to make the 10. Proteins perform many physiological functions. For

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enzyme catalytically active. example some proteins function as enzymes & some
o In these instances, the protein portion of proteins performs as à Hormones

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the enzymes is called the APOENZYME.
11. Glycogen is a homopolymer made up of Glucose units
o Three kinds of cofactors may be

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12. The number of ‘ends’ in a glycogen molecule would be
identified:

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à Equal to the number of branches plus one
§ prosthetic groups,
13. The primary structure of a protein molecule has àTwo

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§ co-enzymes and
ends
§ metal ions.
14. Dissolving CO2 in water reactions is also enzyme-
o Prosthetic groups are organic

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mediated in biological system
compounds à tightly bound to the
15. 80% of cytoplasm in plant cells is Water
apoenzyme.
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16. Two groups of involved in peptide linkage between
o Co-enzymes are also organic compounds
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à their association with the apoenzyme different amino acids are NH2 & COOH
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is only transient, usually occurring

during the course of catalysis.
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o The essential chemical components of

many coenzymes are vitamins, e.g.,
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coenzyme nicotinamide adenine 17. Role of enzyme in reactions is to àDecrease activation

dinucleotide (NAD) and NADP contain energy
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the vitamin niacin. 18. End product is responsible for inhibition of enzymatic
o A number of enzymes require metal ions process during feed back.
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for their activity 19. Enzymes are not found in à Viruses (except Retro
virus family)
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e.g., zinc is a cofactor for the proteolytic

enzyme carboxypeptidase. 20. ATP is a nucleotide
21. Glycoproteins have carbohydrate as prosthetic group.
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o Catalytic activity is lost when the co-

22. Km value of enzyme is substrate conc. at 1/2 V max
factor is removed from the enzyme
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23. Nitroginase Enzyme first used for nitrogen fixation

which testifies that they play a crucial 24. Most of the water in the young plant cell à in
role in the catalytic activity of the
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cytoplasm; Mature plant cell à in Central vacuole

enzyme. 25. Osmotically inactive chief stored material in animal
GOLDEN POINTS by BIOMENTORS body is Glycogen
26. Lipids are insoluble in water because lipid molecules
1. Living organisms have more carbon, oxygen and
are à Hydrophobic
hydrogen per unit mass than inanimate objects
27. Galactose is a reducing sugar
2. Silicon is not found in living organisms 28. Sucrose not give positive Fehling’s test (non reducing
3. Amino acids have both an amino group and a carboxyl sugar)
group in their structure. 29. Mathematical explanation for enzyme action on
4. An amino acid under certain condition have both substrate was provided byà Michaelis and Menten
positive and negative charges simultaneously in the 30. Km value is dependent upon Substrate concentration
31. The major role of minor elements inside living
same molecule. Such a form of amino acid is calledà
organisms is to act as à Co-factors of enzymes
Zwitter ionic form 32. Tyrosinase needs copper as an activator
33. The catalytic efficiency of two different enzymes can be 55. In a disaccharide two monosaccharides are linked by a
compared by the Km value glycosidic bond.
34. Competitive inhibition is seen when the substrate and 56. Excess carbohydrates and proteins are stores in the
the inhibitor compete for the active site on the body as Fats
enzyme 57. Cellulose is a homopolymer
35. Enzymes, vitamins and hormones can be classified 58. Enzymes require optimum temperature & pH for
into a single category of biological chemicals, because maximal activity
all of these help in regulating metabolism 59. Enzymes are denatured at high temperature but in
36. Nucleotides are building blocks of nucleic acids. certain exceptional organisms they are effective even
37. Each nucleotide is a composite molecule formed by at temperatures 80°-90℃
Base-sugar-phosphate 60. Enzymes are highly specific
38. Carbohydrates, the most abundant biomolecule on 61. Remember the figure give below
earth, are produced by Some bacteria, algae and

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green plant cells

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39. The simplest amino acid is àGlycine
40. Richest source of protein is à Soyabean

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41. This curves shows à

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A B C D
Transition Potential Activation Activation

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state energy energy energy with
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without enzyme
enzyme
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62. A disaccharide that gives two molecules of glucose on

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A = Normal enzyme action, hydrolysis isà Maltose

B = Competitive inhibition, 63. The given curve shows enzymatic activity in relation to
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C = Non-competitive inhibition temperature

42. An organic substrate bound to an enzyme and
essential for its activity is calledà Coenzyme
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43. About 98 per cent of the mass of every living organism

is composed of just six elements including carbon,
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hydrogen, nitrogen, oxygen and Phosphorus and

sulphur
X axis Y axis
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44. Boron element is very essential for uptake and

Temperature Enzyme activity
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utilization of Ca2+ and membrane function.

45. In a protein the amino acids are linked by Peptide 64. The enzymes carries out the initial step in the
digestion of milk in humans is Pepsin
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bonds
46. Three most abundant elements in protoplasm are 65. In humans, milk protein-digesting enzyme is
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Carbon, hydrogen, oxygen the stomach is pepsin. In calves it is rennin. Rennin is

47. Chitin is present in the cell wall of fungi also present in small amounts in human infants but
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48. Carbohydrates are commonly found as starch in plant

not adults.
storage organs.
66. Pepsin acts on water insoluble caseinogen (milk
49. A competitive inhibitor of succinic dehydrogenase is
àMalonate protein) to form soluble 'casein'.
50. Inulin, a low molecular weight polysaccharide is 67. Lecithin is a component of cell membrane
obtained from roots of à Dahlia ; polymer of D-
fructose in which monomer units are linked together
by beta (1->2) glycosidic linkage.
51. Collagen is à Fibrous protein
52. Spirulina BGA is the rich source of à Protein
53. In human per cent of body weight of carbohydrates,
lipids and proteins respectively is à1, 15, 17
54. Table sugar is Sucrose 68. Glycerol is a trihydroxy propane
69. In a normal adult, ascending order of concentration of metabolism, blood clotting and permeability of cell
following molecules is: K > Na > Fe > Cu membrane. e.g., Lecithin, cephalin
70. A phosphoglyceride is always made up of saturated or 93. Biomarker of human faeces à Coprosterol ; It is
unsaturated fatty acids esterified to a glycerol formed as a result of the reduction by bacteria in
molecule to which a phosphate group is also attached intestine from the double bond of cholesterol between
71. Macromolecule chitin is nitrogen containing C5 and C6.
polysaccharide 94. Terpenes : found in essential oils and present mostly in
72. Transition state structure of the substrate formed oils of camphor, eucalyptus, lemon and mint. Phytol is
during an enzymatic reaction is à Transient and
a terpenoid alcohol present in Vitamin A, K, E and in
unstable
pigments like chlorophyll carotenoid.
73. The essential chemical components of many
95. Total known amino acid are more than 200 out of these

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coenzymes are Vitamins of B complex mainly
only 20 amino acid takes part in protein synthesis
74. Enzymes are denatured at high temperatures

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called protein amino acid.
75. Substrate binds with enzyme at its active site
96. Glycine is a simplest amino acid.

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76. A non-competitive inhibitor binds the enzyme at a site
97. Sulphur containing amino acids : They have sulphur

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distinct from that which binds the substrate
atom in side chain. e.g., methionine, cysteine.
77. Malonate is a competitive inhibitor of succinic

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dehydrogenase 98. Proline and hydroxyproline have, NH (imino group)

78. Sucrose is a non-reducing carbohydrate. instead of NH 2 hence are called imino acids.

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79. The presence of competitive inhibitor increases the Km 99. Purines : Purines are 9 membered double ringed
of the enzyme for the substrate nitrogenous bases which possess nitrogen at 1' ,3' ,7'
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80. A competitive inhibitor reacts reversibly with the and 9' positions. They are adenine (A) and guanine (G).
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enzyme to form an enzyme –inhibitor complex 100. Pyrimidines : They are smaller molecule than purines.
81. In competitive inhibition, the inhibitor molecule is not
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These are 6 membered single ringed nitrogenous

chemically changed by the enzyme bases that contain nitrogen at 1' and 3' positions like
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82. The competitive inhibitor does not effect the rate of cytosine (C), thymine (T) and uracil (U).
breakdown of the enzyme substrate complex 101. ATP was discovered by Karl Lohmann (1929).
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83. An allosteric inhibitor of the enzyme acts by binding to 102. Formation of ATP is endergonic reaction.
the non-catalytic site of the enzyme (allosteric site)
103. Glycogen : It is a branched polymer of glucose and
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84. The two polypeptide of human insulin are linked

contain 30,000 glucose units. It is also called animal
together by à Disulphide bridges
starch. It is also found as storage product in blue green
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85. Holoenzyme = Apoenzyme + Cofactor

algae, slime moulds, fungi and bacteria. It is a non-
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86. Cofactor à may be Prosthetic group, Co-enzymes or

reducing sugar and gives red colour with iodine. In
Metal activator
glycogen, glucose molecule are linked by 1 – 4
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87. The two functional groups characteristic of sugars are

glycosidic linkage in straight part and 1 – 6 linkage in
Carbonyl and hydroxyl
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the branching part glycogen has branch points about

88. Term lipid was coined by Bloor (1943). These are esters
every 8-10 glucose units.
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of fatty acids and alcohol.

104. Starch : Starch is formed in photosynthesis and function
89. Linoleic acid, linolenic acid, arachidonic acid are
as energy storing substance. It is found abundantly in
essential fatty acid (Evans and Burr 1928).
rice, wheat, legumes, potato (oval and ecentric
90. Deficiency of essential fatty acid may cause follicular
shaped), banana, etc. Starch is of two types. Straight
hyper keratosis disease.
chain polysaccharides known as amylose and branched
91. Bees wax is a common example of wax. It is a
chain as amylopectin. Both composed of D – glucose
combination of palmitic acid and mericyl alcohol
units jointed by a - 1 - 4 linkage and a - 1 - 6
(C 30 H 61 OH ) .
linkage. It is insoluble in water and gives blue colour
92. Phospholipids : It is amphipathic molecule. These
when treated with iodine.
contain phosphoric acid. It helps in transport,
105. Cellulose : An important constituent of cell wall, made
up of unbranched chain of 6000 b–D glucose units
 linked by 1 – 4 glycosidic linkage. It is fibrous, rigid and synthesis. The sequence of nitrogenous bases is
insoluble in water. It doesn’t give any colour when repeated several times.
treated with iodine. It is a most abundant 121. Chargaff’s rule : Quantitatively the ratio of adenine (A) to
polysaccharide. thymine (T) and guanine (G) to cytosine (C) is equal. i.e.,
106. Chitin : It is a polyglycol consisting of N-acetyl–D– “Purines are always equal to pyrimidine”.
glucosamine units connected with b - 1, 4 glycosidic 122. C value : It is the total amount of DNA in a genome or
linkage. Mostly it is found in hard exoskeleton of insects haploid set of chromosomes.
and crustaceans and some times in fungal cell wall. 123. X-Ray crystallography study of DNA : It was done by
Second most abundant carbohydrate. Wilkins. It shows that the two polynucleotide chains of
107. Agar-Agar : It is a galactan, consisting of both D and L DNA show helical configuration.
124. RNA is second type of nucleic acid which is found in

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galactose and it is used to prepare bacterial cultures. It
is obtained from cell wall of red algae e.g., Gracilaria, nucleus as well as in cytoplasm i.e., mitochondria,

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Gelidium etc. plastids, ribosomes etc. They carry the genetic
108. The common sugars in hemicellulose are D-xylose, L– information in some viruses. They are widely

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arabinose, D-galactose, D-mannose and D-glucusonic distributed in the cell. Genomic RNA was discovered by

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acid. e.g., hemicellulose. Franklin and Conrat (1957).

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109. Gum : It secreted by higher plants after injury or
pathogenic attacks. It is viscous and seals the wound. It
NCERT IMAGES
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involves sugars like L-arabinose, D-galactose, D-
glucusonic acid. e.g., gum arabic.
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110. Mucopolysaccharides : These are gelatinous substance,
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containing amino sugars, uronic acid, etc. All slimy

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substances of plant are mucopolysaccharide. e.g.,

hyaluronic acid, vitreous humour, chondridine
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sulphate, heparin, husk of isabgol and mucilage also.

111. Protein : Word protein was coined by Berzelius (1838)
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and was used by G. J. Mulder first time 1840.

112. 15% - 30% of protoplasm is made up of protein.
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Average proteins contain 16% nitrogen, 50–55%

carbon, oxygen 20–24%, hydrogen 7% and sulphur 0.3
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– 0.5%.
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113. Phosphoprotein : They composed of protein and

phosphate e.g., casein (milk) and vitellin (egg).
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114. Proteins are the most diverse molecule on the earth.

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115. Monelin protein is the sweetest substance obtained

from African berry (2000 time sweeter than sucrose).
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116. Most abundant protein on earth is RuBisCo

117. Myosin is structural as well as enzymatic protein (ATPase).
118. Nucleic acids were first reported by Friedrich Miescher
(1871) from the nucleus of pus cell. Altmann called it
first time as nucleic acid. Nuclein was renamed nucleic
acid by Altman in (1889). They are found in nucleus.
They help in transfer of genetic information.
119. Term DNA was given by Zacharis.
120. Repetitive DNA : This type of arrangement is found near
centromere of chromosome and is inert in RNA
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KEY IMAGES FOR QUICK REVISION
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NUCLEOTIDE

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