Biomolecules | CEE Academy

📚

INTRODUCTION

▢ Biomolecules: Molecules \(organic/inorganic\) present in living organisms

▢ Cellular Pool:

❖ Definition: Collection of biomolecules in cells

❖ Nature: Crystallocolloid

❖ Contents:

Table 1: Cellular pool components

Type	Examples
Organic	Carbohydrate, lipid, protein
Inorganic	Water, minerals, salts

📚

ORGANIC COMPOUNDS

📖

Carbohydrate

▢ Introduction:

•
•
Ratio often → \(C:H:O = 1:2:1\)
•
Nature’s most abundant organic substance
•
Modern definition → optically active polyhydroxy aldehyde/ketone → monosaccharides on hydrolysis
•
Major energy source → glucose, fructose

▢ Key Terms:

❖ table:

▢ Classification:

❖ Taste + Structure + Solubility:

◉ table:

❖ Reducing Nature:

◉ table:

❖ Hydrolysis:

◉ Monosaccharides / Simple Sugar:

◈ Carbonyl Group:

■ table:

◈ Carbon Number:

■ table:

◉ Oligosaccharides:

◈ Disaccharides:

Maltose
Sucrose
Lactose

◈ Other:

Trisaccharides
Tetrasaccharides

◉ Polysaccharides:

Starch
Glycogen
Cellulose

▢ Important Carbohydrates:

❖ table:

▢ Honey: Mainly fructose \(\approx 38\%\) + glucose \(\approx 32\%\)

▢ Functions:

•
Energy source
•
Storage form → glycogen/starch
•
Structural form → cellulose

📖

Lipid

▢ Introduction:

•
Biological molecules → water insoluble
•
Soluble in non-polar organic solvents → chloroform, benzene
•
Not polymers
•
Heterogeneous group → \(C,H,O\)
•
Oxygen atoms << carbon atoms
•
True lipids = esters of fatty acids + alcohol

▢ Ester Formation: \(RCOOH + R'OH \rightarrow RCOOR' + H_2O\)

▢ Fatty Acids:

❖ Definition: Large molecules with acidic group → \(R-COOH\)

❖ Saturation:

Table 1: Saturated vs Unsaturated fatty acids

Feature	Saturated fatty acids	Unsaturated fatty acids
Double bond	Absent	One/more present
Melting point	Higher	Lower
Health note		Healthy fats
Examples		Oleic acid → 1 double bond; linoleic acid → 2 double bonds; linolenic acid → 3 double bonds

Iodine value = degree of unsaturation of oils/fats

❖ Essentiality:

Table 1: Essential fatty acids

Type	Examples / Note
Essential fatty acids	Linoleic acid, linolenic acid, arachidonic acid
Deficiency	Toad skin / phrynoderma
Non-essential fatty acids	Synthesized in body

▢ Major Categories:

❖ Simple Lipids:

◉ Definition: Esters of fatty acids + alcohol

◉ Types:

◈ Fats:

■ Definition: Fatty acids + glycerol; triglycerides

■ Glycerides:

Table 1: Glycerides

Type	Composition	Water released
Monoglyceride	1 glycerol + 1 fatty acid	\(H_2O\)
Diglyceride	1 glycerol + 2 fatty acids	\(2H_2O\)
Triglyceride	1 glycerol + 3 fatty acids	\(3H_2O\)

■ General Reaction: \(Glycerol + 3RCOOH \rightarrow Triglyceride + 3H_2O\)

◈ Oils: Fats rich in unsaturated fatty acids

◈ Waxes:

•
Long-chain fatty acids + long-chain alcohols other than glycerol
•
Water insoluble; soluble in benzene/light petroleum
•
Protective agent → moisture penetration ↓
•
Candles → paraffin wax + higher fatty acids
•
Moisture barrier + heat insulator

◉ Fats vs Oils:

Table 1: Fats vs Oils

Feature	Fats	Oils
Fatty acid	Rich in saturated FA	Rich in unsaturated FA
Room temperature	Solid/semi-solid	Liquid
Source	Animals only	All plants + some animals
Examples	Vanaspati ghee, margarine	Sunflower oil, mustard oil

❖ Compound / Complex Lipids:

◉ Definition: Simple lipid + other compound

Table 1: Compound lipids

Type	Composition	Special point
Glycolipid	Carbohydrate + lipid
Phospholipid	Phosphoric acid + lipid	Cell membrane + intracellular membrane; lung surfactant prevents collapse
Lipoprotein	Protein + lipid

❖ Derived Lipids:

◉ Definition: Lipid derivatives

◉ Important Example:

◈ Steroids:

•
Fused hydrocarbon rings + long hydrocarbon chain
•
Cholesterol → animal fat
•
Phytosterol → plant fat
•
Diosgenin → antifertility pills
•
Steroid hormones → corticoids, testosterone, oestrogen, progesterone

▢ Special Points:

•
Lipids ≠ polymers
•
All lipids ≠ fats; e.g., steroids = lipid but not fat
•
Superheated steam hydrolysis → glycerol + fatty acid
•
Saponification = alkaline hydrolysis of fat
•
•
Soap = sodium/potassium salt of higher fatty acid
•
Sodium soap → hard soap → washing/cleaning
•
Potassium soap → bathing
•
Chylomicrons = lipids
•
Rancidification = spoilage of fats/oils on long storage

📖

Protein

▢ Introduction:

•
Complex natural compounds
•
•
Basis of structure + function of life
•
Nitrogenous organic compounds of protoplasm
•
Animals > plants in protein content
•
Hydrophilic high-polymer colloids
•

▢ Amino Acids:

❖ Definition: Amino-substituted acids → amino \((-NH_2)\) + carboxyl \((-COOH)\) groups

❖ Nature:

•
Amphoteric
•
Slightly acidic pH
•
Building blocks of proteins

❖ General Structure:

Table 1: \(\alpha\)-amino acid components

Central atom	Attached groups
\(\alpha\)-carbon

❖ Zwitter Ion:

◉ Definition: Proton shift: carboxyl group → amino group → dipolar ion

◉ Charge: + and - charge together

❖ Isoelectric Point:

•
pH where amino acid does not migrate in electric field
•
Net charge = 0
•
Constant for each amino acid
•
Minimum solubility
•
Dipolar ion concentration maximum

❖ 20 Amino Acids:

Table 1: Amino acids + one-letter symbols

Amino acid	Symbol	Special point
Alanine	A
Arginine	R	Semi-indispensable
Asparagine	N
Aspartic acid	D
Cysteine	C	Sulphur-containing; deficient in pulses
Glutamine	Q
Glutamic acid	E
Glycine	G	Simplest; lowest molecular weight; no asymmetric carbon; no optical isomerism
Histidine	H	Blood buffer in haemoglobin; semi-indispensable
Isoleucine	I	Essential
Leucine	L	Essential
Lysine	K	Essential; deficient in cereals
Methionine	M	Sulphur-containing; deficient in pulses
Phenylalanine	F	Essential
Proline	P	Cyclic; imino acid; no free amino + carboxyl group
Serine	S
Threonine	T	Essential; deficient in cereals
Tryptophan	W	Most complex; indole ring; deficient in maize
Tyrosine	Y	Precursor: dopamine, melanin, thyroxine, adrenaline, noradrenaline
Valine	V	Essential

❖ Essentiality:

Table 1: Essential vs Non-essential amino acids

Non-essential	Essential
Alanine	Arginine
Asparagine	Histidine
Aspartic acid	Isoleucine
Cysteine	Leucine
Glutamine	Lysine
Glutamic acid	Methionine
Glycine	Phenylalanine
Proline	Threonine
Serine	Tryptophan
Tyrosine	Valine

Arginine + histidine = semi-indispensable; not essential in adult organisms

▢ Colour Reactions:

Table 1: Protein colour tests

Test	Reaction	Indicates / Note
Biuret test		Peptide linkage; colour ∝ peptide bonds
Millon’s reaction	Protein + Millon’s reagent → white ppt; heat → brick red	Phenol group; tyrosine-containing proteins
Ninhydrin reaction	Protein + pyridine solution of ninhydrin → deep blue to violet pink	Amino acids/proteins
Xanthoproteic test	Protein + \(HNO_3\) + heat → yellow	Aromatic amino acids

▢ Denaturation:

•
Agents → heat, UV radiation, solvents, reagents
•
Change may be reversible/irreversible
•
Most readily near isoelectric point
•
Primary structure intact; 3D structure destroyed
•
Reversal → renaturation / refolding
•
Example → boiled egg = irreversible denaturation
•
Globular protein → fibrous protein

▢ Classification:

❖ By Hydrolysis Product:

Table 1: Simple, conjugated and derived proteins

Type	Hydrolysis product	Examples
Simple proteins	Only \(\alpha\)-amino acids	Albumins, albuminoids, globulins, glutelins
Conjugated proteins		Nucleoproteins, glycoproteins, phosphoproteins, haemoglobins
Derived proteins	Intermediate hydrolysis products of proteins	Peptides, proteoses, peptones

❖ By Function:

Table 1: Functional classification of proteins

Class	Examples
Enzymes	Ribonuclease, amylase, trypsin, catalase
Regulatory proteins	Insulin, growth hormone, parathormone
Storage proteins	Ovalbumin, casein, ferritin, glutelins, globulins
Contractile + motile	Actin, myosin, tubulin, kinesin
Structural proteins
Protective proteins	Immunoglobulin, thrombin, fibrinogen
Transport proteins	Haemoglobin, myoglobin, albumin

Albumins bind ligands and transport them

❖ By Shape:

Table 1: Fibrous vs Globular proteins

Feature	Fibrous proteins	Globular proteins
Shape	Thread-like; side-by-side fibres	Folded compact units; often spheroidal
Stabilizing force	Hydrogen bonds	Various intramolecular interactions
Solubility	Insoluble in water; soluble in concentrated acids/alkalies	Soluble in water, dilute acids/alkalies
Examples	Collagen, keratin of hair/nails, myosin of muscles	Insulin, haemoglobin, myoglobin, albumin, actin, troponin

▢ Structure:

Table 1: Levels of protein structure

Level	Meaning	Bonds / Key points
Primary	Linear amino acid sequence	Determines protein function
Secondary	Shape of individual polypeptide chain
Tertiary	3D compact folding of polypeptide chain	H-bonds, Van der Waals interactions, disulphide bonds, electrostatic bonds, hydrophobic effect
Quaternary	Inter-relation between >2 polypeptide chains	Subunit arrangement

❖ Secondary Details:

❖ MCQ Point: Primary bonds for secondary + tertiary structure → H-bond

▢ Functions:

•
Energy source
•
Body defense → immunoglobulins
•
Muscle contraction → actin + myosin
•
Structural component → collagen, keratin; hair, nail, bone
•
Catalysis → enzymes
•
Chemical messengers → insulin, GH, oxytocin
•
Transport → haemoglobin, myoglobin, albumin

📖

Vitamins

Listed only

📚

INORGANIC COMPOUNDS

📖

Water

Listed only

📖

Mineral

Listed only

📖

Salts

Listed only

Q1.

The disaccharide present in milk is [IOM 2008]

📅IOM 2008

Q2.

The enzyme used during fermentation carbohydrate to CO2, and alcohol is [IOM 2003, MOE 2064]

📅IOM 2003, MOE 2064

Q3.

Which is not a carbohydrate? [BPKIHS ]

📅BPKIHS

Q4.

Which of the following is not a polysaccharide [BPKIHS]

📅BPKIHS

Q5.

Which of the following is a polysaccharide [I.E.]

📅I.E.

Q6.

Hydrolysis of table sugar produces [MOE - Curriculum]

📅MOE - Curriculum

Q7.

Which of the following base is purine [MOE 2065]

📅MOE 2065

Q8.

Which of the following is an aldohexose? [I.E.]

📅I.E.

Q9.

Molisch test is given by [I.E.]

📅I.E.

Q10.

Maltose on hydrolysis produces [BPKIHS]

📅BPKIHS

Q11.

Which of the following cannot form peptide bond on polypeptide chain? [IOM]

📅IOM

Q12.

Amino acids usually exist in the form of zwitter ions. This means that they consist of [IOM 1999]

📅IOM 1999

Q13.

Isoelectric point is the pH at which [BPKIHS 2000]

📅BPKIHS 2000

Q14.

The enzyme pepsin hydrolyses [BPKIΗΑ]

📅BPKIΗΑ

Q15.

Presence of peptide bond is the characteristic features of [MOE 2065)

📅MOE 2065)

Q16.

Lipids consist up of [KU 2008]

📅KU 2008

Q17.

Enzyme is a [I.E. 2003]

📅I.E. 2003

Q18.

DNA multiplication is called [MOE]

📅MOE

Q19.

The purine base present in RNA is

Q20.

Glycolipids and Phospholipids are [BPKIHS/ KU/ MOE]

📅BPKIHS/ KU/ MOE

Q21.

Milk sugar is [MOE/IOM/KU]

📅MOE/IOM/KU

Q22.

Starch is hydrolyzed to maltose by an enzyme [MOE)

📅MOE)

Q23.

Which of the following is the sweetest sugar?[BPKIHS

📅BPKIHS

Q24.

Hydrolysis of sucrose is called [MOE]

📅MOE

Q25.

Alkaline hydrolysis of esters is known as [MOE, IOM, BPKIHS 2005]

📅MOE, IOM, BPKIHS 2005

Q26.

Which of the following enzymes hydrolyses triglycerides to fatty acid and glycerol? [KU]

📅KU

Q27.

Fat is a [K.0.]

📅K.0.

Q28.

Two complementary strands of DNA in a double helix are joined to each other by [IOM]

📅IOM

Q29.

The main function of RNA in the body is [IOM]

📅IOM

Q30.

Upon hydrolysis protein give [BPKIHS]

📅BPKIHS

Q31.

Liquid fats are converted into solid fats by [BPKIHS]

📅BPKIHS

Q32.

Synthetic detergents can be represented by the general formula [BPKIHS/IE]

📅BPKIHS/IE

Q33.

The degree of unsaturation of fat can be determined by means of [BPKIHS]

📅BPKIHS

Q34.

Fats and oil are [BPKIHS]

📅BPKIHS

Q35.

Magnesium is present in [BPKIHS]

📅BPKIHS

Q36.

Which of the following metal ion play an important role in muscle contraction? [IOM]

📅IOM

Q37.

Antimony compounds are used in the treatment of [IOM]

📅IOM

Q38.

The cation necessary for coagulation of blood is [I.E. 2003]

📅I.E. 2003

Q39.

Yeast is an important source of [BPKIHS]

📅BPKIHS

Q40.

Fatty acids which must be obtained from diet are [BPKIHS 2005]

📅BPKIHS 2005

Q41.

The component of blood which maintain osmotic pressure is [BPKIHS 2005]

📅BPKIHS 2005

Q42.

The enzyme pepsin hydrolyses [BPKIHS 2005]

📅BPKIHS 2005

Q43.

DNA has which sugar in it [BPKIHS 2004]

📅BPKIHS 2004

Q44.

Maximum energy is produced by the oxidation of [BPKIHS 2005

📅BPKIHS 2005

Q45.

Nucleic acids are polymers of [IOM 2011]

📅IOM 2011

Q46.

Every carbohydrate is [IOM 2010]

📅IOM 2010

Q47.

Almost all pharmaceutical products produced by DNA technology [MOE 2013 Magh - 6]

📅MOE 2013 Magh - 6

Q48.

Simplest amino acid [BPKIHS - 2016]

📅BPKIHS - 2016

Q49.

The common point among enzymes, hormone and vitamin in our body is [BPKIHS - 2016]

📅BPKIHS - 2016

Q50.

The building block of protein is [BPKIHS - 2016)

📅BPKIHS - 2016)

Q51.

α-helical structure of protein is stabilized by [BPKIHS - 2014]

📅BPKIHS - 2014

Q52.

Which of the following is present in least proportion in cell membrane? [BPKIHS - 2011]

📅BPKIHS - 2011

Q53.

Corn is immersed in boiling water. It is then cooled and solution becomes sweet. It is due to [BPKIHS - 2011]

📅BPKIHS - 2011

Q54.

Which of the following is a co enzymes? [BPKIHS - 2010]

📅BPKIHS - 2010

Q55.

Starch is polymer of BPKIHS - 2010

📅BPKIHS - 2010

Q56.

All are essential amino acids except [BPKIHS - 2010]

📅BPKIHS - 2010

Q57.

Cane sugar on hydrolysis gives [IOM-2014]

📅IOM-2014

Q58.

Which component is most dispersed in a cell? [IOM-2012)

📅IOM-2012)

4Biomolecules

Table 1: Cellular pool components

Table 1: Saturated vs Unsaturated fatty acids

Table 1: Essential fatty acids

Table 1: Glycerides

Table 1: Fats vs Oils

Table 1: Compound lipids

Table 1: \(\alpha\)-amino acid components

Table 1: Amino acids + one-letter symbols

Table 1: Essential vs Non-essential amino acids

Table 1: Protein colour tests

Table 1: Simple, conjugated and derived proteins

Table 1: Functional classification of proteins

Table 1: Fibrous vs Globular proteins

Table 1: Levels of protein structure

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