Botany for CEE
CEE medical preparation lessons
1
Biomolecules
π
INTRODUCTION
β’ Biomolecules:
Molecules
o
r
g
a
n
i
c
/
i
n
o
r
g
a
n
i
c
present in living organisms
β’ Cellular Pool:
β Definition: Collection of biomolecules in cells
β Nature: Crystallocolloid
β Contents:
Table 1: Cellular pool components
Type | Examples |
Organic | Carbohydrate, lipid, protein |
Inorganic | Water, minerals, salts |
π
ORGANIC COMPOUNDS
π
Carbohydrate
β’ Introduction:
β’
C
,
H
,
O
compound β
C
n
(
H
2
O
)
n
β hydrate of carbon
β’
Ratio often β
C
:
H
:
O
=
1
:
2
:
1
β’
Natureβs most abundant organic substance
β’
Modern definition β optically active polyhydroxy aldehyde/ketone β monosaccharides on hydrolysis
β’
Major energy source β glucose, fructose
β’ Key Terms:
β table:
β’ Classification:
β Taste + Structure + Solubility:
β table:
β Reducing Nature:
β table:
β Hydrolysis:
β Monosaccharides / Simple Sugar:
β Carbonyl Group:
β table:
β Carbon Number:
β table:
β Oligosaccharides:
β Disaccharides:
Maltose
Sucrose
Lactose
β Other:
Trisaccharides
Tetrasaccharides
β Polysaccharides:
Starch
Glycogen
Cellulose
β’ Important Carbohydrates:
β table:
β’ Honey:
Mainly fructose
β
38
%
+ glucose
β
32
%
β’ Functions:
β’
Energy source
β’
Storage form β glycogen/starch
β’
Structural form β cellulose
π
Lipid
β’ Introduction:
β’
Biological molecules β water insoluble
β’
Soluble in non-polar organic solvents β chloroform, benzene
β’
Not polymers
β’
Heterogeneous group β
C
,
H
,
O
β’
Oxygen atoms << carbon atoms
β’
True lipids = esters of fatty acids + alcohol
β’ Ester Formation:
R
C
O
O
H
+
R
β²
O
H
β
R
C
O
O
R
β²
+
H
2
O
β’ Fatty Acids:
β Definition:
Large molecules with acidic group β
R
β
C
O
O
H
β 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
Palmitic acid
16
C
, stearic acid
18
C
Oleic acid β 1 double bond; linoleic acid β 2 double bonds; linolenic acid β 3 double bonds
Iodine value = degree of unsaturation of oils/fats
β 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 |
β’ Major Categories:
β Simple Lipids:
β Definition: Esters of fatty acids + alcohol
β Types:
β Fats:
β Definition: Fatty acids + glycerol; triglycerides
β Glycerides:
Table 1: Glycerides
Type
Composition
Water released
Monoglyceride
1 glycerol + 1 fatty acid
H
2
O
Diglyceride
1 glycerol + 2 fatty acids
2
H
2
O
Triglyceride
1 glycerol + 3 fatty acids
3
H
2
O
β General Reaction:
G
l
y
c
e
r
o
l
+
3
R
C
O
O
H
β
T
r
i
g
l
y
c
e
r
i
d
e
+
3
H
2
O
β Oils: Fats rich in unsaturated fatty acids
β Waxes:
β’
Long-chain fatty acids + long-chain alcohols other than glycerol
β’
Water insoluble; soluble in benzene/light petroleum
β’
Protective agent β moisture penetration β
β’
Candles β paraffin wax + higher fatty acids
β’
Moisture barrier + heat insulator
β 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 |
β Compound / Complex Lipids:
β 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 | |
β Derived Lipids:
β Definition: Lipid derivatives
β Important Example:
β Steroids:
β’
Fused hydrocarbon rings + long hydrocarbon chain
β’
Cholesterol β animal fat
β’
Phytosterol β plant fat
β’
Diosgenin β antifertility pills
β’
Steroid hormones β corticoids, testosterone, oestrogen, progesterone
β’ Special Points:
β’
Lipids β polymers
β’
All lipids β fats; e.g., steroids = lipid but not fat
β’
Superheated steam hydrolysis β glycerol + fatty acid
β’
Saponification = alkaline hydrolysis of fat
β’
F
a
t
+
N
a
O
H
β
S
o
a
p
+
G
l
y
c
e
r
o
l
β’
Soap = sodium/potassium salt of higher fatty acid
β’
Sodium soap β hard soap β washing/cleaning
β’
Potassium soap β bathing
β’
Chylomicrons = lipids
β’
Rancidification = spoilage of fats/oils on long storage
π
Protein
β’ Introduction:
β’
Complex natural compounds
β’
Many
Ξ±
-amino acids + peptide linkages
β’
Basis of structure + function of life
β’
Nitrogenous organic compounds of protoplasm
β’
Animals > plants in protein content
β’
Hydrophilic high-polymer colloids
β’
Optically active β chiral centers at
Ξ±
-position
β’ Amino Acids:
β Definition:
Amino-substituted acids β amino
(
β
N
H
2
)
+ carboxyl
(
β
C
O
O
H
)
groups
β Nature:
β’
Amphoteric
β’
Slightly acidic pH
β’
Building blocks of proteins
β General Structure:
Table 1:
Ξ±
-amino acid components
Central atom
Attached groups
Ξ±
-carbon
β
N
H
3
+
,
β
C
O
O
β
,
H
, variable side chain
(
β
R
)
β Zwitter Ion:
β Definition: Proton shift: carboxyl group β amino group β dipolar ion
β Charge: + and - charge together
β Isoelectric Point:
β’
pH where amino acid does not migrate in electric field
β’
Net charge = 0
β’
Constant for each amino acid
β’
Minimum solubility
β’
Dipolar ion concentration maximum
β 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 |
β 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
β’ Colour Reactions:
Table 1: Protein colour tests
Test
Reaction
Indicates / Note
Biuret test
Protein + 10% NaOH + few drops
C
u
S
O
4
β reddish violet
Peptide linkage; colour β peptide bonds
Millonβs reaction
Protein + Millonβs reagent β white ppt; heat β brick red
Phenol group; tyrosine-containing proteins
Ninhydrin reaction
Protein + pyridine solution of ninhydrin β deep blue to violet pink
Amino acids/proteins
Xanthoproteic test
Protein +
H
N
O
3
+ heat β yellow
Aromatic amino acids
β’ Denaturation:
β’
Agents β heat, UV radiation, solvents, reagents
β’
Change may be reversible/irreversible
β’
Most readily near isoelectric point
β’
Primary structure intact; 3D structure destroyed
β’
Reversal β renaturation / refolding
β’
Example β boiled egg = irreversible denaturation
β’
Globular protein β fibrous protein
β’ Classification:
β By Hydrolysis Product:
Table 1: Simple, conjugated and derived proteins
Type
Hydrolysis product
Examples
Simple proteins
Only
Ξ±
-amino acids
Albumins, albuminoids, globulins, glutelins
Conjugated proteins
Ξ±
-amino acids + non-protein substance
Nucleoproteins, glycoproteins, phosphoproteins, haemoglobins
Derived proteins
Intermediate hydrolysis products of proteins
Peptides, proteoses, peptones
β 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
Collagen,
Ξ±
-keratin, elastin, chondrin, ossein, fibroin
Protective proteins
Immunoglobulin, thrombin, fibrinogen
Transport proteins
Haemoglobin, myoglobin, albumin
Albumins bind ligands and transport them
β 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 |
β’ 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
Hydrogen bonds between
β
C
=
O
and
β
N
H
;
Ξ±
-helix +
Ξ²
-sheet
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
β Secondary Details:
β’
Ξ±
-helix β single amino acid chain coiled spirally; H-bond between 1st and 4th amino acids
β’
Ξ²
-pleated sheet β two/more polypeptide chains; parallel or antiparallel
β MCQ Point: Primary bonds for secondary + tertiary structure β H-bond
β’ Functions:
β’
Energy source
β’
Body defense β immunoglobulins
β’
Muscle contraction β actin + myosin
β’
Structural component β collagen, keratin; hair, nail, bone
β’
Catalysis β enzymes
β’
Chemical messengers β insulin, GH, oxytocin
β’
Transport β haemoglobin, myoglobin, albumin
π
Vitamins
Listed only
π
INORGANIC COMPOUNDS
π
Water
Listed only
π
Mineral
Listed only
π
Salts
Listed only
Q1.
The disaccharide present in milk isΒ [IOM 2008]
π
IOM 2008
A
Sucrose
B
Maltose
C
Lactose
D
Cellobiose
Show Solution
Q2.
The enzyme used during fermentation carbohydrate to CO2, and alcohol is [IOM 2003, MOE 2064]
π
IOM 2003, MOE 2064
A
Zymase
B
Diastase
C
Invertase
D
Maltase
Show Solution
Q3.
Which is not a carbohydrate? [BPKIHS ]
π
BPKIHS
A
Starch
B
Cellulose
C
Glycogen
D
Haemoglobin
Show Solution
Q4.
Which of the following is not a polysaccharide [BPKIHS]
π
BPKIHS
A
Starch
B
Cellulose
C
Glycogen
D
Maltose
Show Solution
Q5.
Which of the following is a polysaccharide [I.E.]
π
I.E.
A
Isomaltose
B
Cellobiose
C
Lactose
D
Inulin
Show Solution
Q6.
Hydrolysis of table sugar produces [MOE - Curriculum]
π
MOE - Curriculum
A
Two molecules of glucose
B
Glucose and fructose
C
Glucose and galactose
D
Glucose and lactose
Show Solution
Q7.
Which of the following base is purine [MOE 2065]
π
MOE 2065
A
Thymine
B
Uracil
C
Cytosine
D
Adenine
Show Solution
Q8.
Which of the following is an aldohexose? [I.E.]
π
I.E.
A
Cellulose
B
Sucrose
C
Galactose
D
Raffinose
Show Solution
Q9.
Molisch test is given byΒ [I.E.]
π
I.E.
A
Glucose
B
Sucrose
C
Fructose
D
All of these
Show Solution
Q10.
Maltose on hydrolysis produces [BPKIHS]
π
BPKIHS
A
Glucose
B
Maltose
C
Fructose
D
Mannose
Show Solution
Q11.
Which of the following cannot form peptide bond on polypeptide chain? [IOM]
π
IOM
A
Aspartic acid
B
Alanine
C
Glutamic acid
D
Acetic acid
Show Solution
Q12.
Amino acids usually exist in the form of zwitter ions. This means that they consist of [IOM 1999]
π
IOM 1999
A
The basic NH2 group and acidic COOH group
B
The basic NH3 group and acidic COO- group
C
The basic COO- group and the acidic NH3+, group
D
Positive ammonium [NH_4^+] group and negative chloride [CI-] group
Show Solution
Q13.
Isoelectric point is the pH at which [BPKIHS 2000]
π
BPKIHS 2000
A
Amino acid becomes acidic
B
An amino acid becomes basis
C
Zwitter ion has +ve charge
D
Zwitter iron has zero charge
Show Solution
Q14.
The enzyme pepsin hydrolyses [BPKIΞΞ]
π
BPKIΞΞ
A
Proteins to amino acids
B
Fats to fatty acids
C
Starch to glucose
D
Nucleotide to nitrogen base
Show Solution
Q15.
Presence of peptide bond is the characteristic features of [MOE 2065)
π
MOE 2065)
A
Carbohydrates
B
Lipids
C
Nucleic acid
D
Proteins
Show Solution
Q16.
Lipids consist up ofΒ Β [KU 2008]
π
KU 2008
A
Fat, oil and its derivatives
B
Amino acid derivatives
C
Polysterene
D
Carbohydrates
Show Solution
Q17.
Enzyme is a [I.E. 2003]
π
I.E. 2003
A
Hormone
B
Protein
C
Fatty acid
D
Steroid
Show Solution
Q18.
DNA multiplication is called [MOE]
π
MOE
A
Translation
B
Transduction
C
Transcription
D
Replication
Show Solution
Q19.
The purine base present in RNA is
A
Uracil
B
Cytosin
C
Thymine
D
Guanine
Show Solution
Q20.
Glycolipids and Phospholipids areΒ [BPKIHS/ KU/ MOE]
π
BPKIHS/ KU/ MOE
A
Simple lipids
B
Complex lipids
C
Derived lipids
D
Lipoproteins
Show Solution
Q21.
Milk sugar is [MOE/IOM/KU]
π
MOE/IOM/KU
A
Maltose
B
Fructose
C
Sucrose
D
Lactose
Show Solution
Q22.
Starch is hydrolyzed to maltose by an enzyme [MOE)
π
MOE)
A
Lipase
B
Diastase
C
Zymase
D
Invertase
Show Solution
Q23.
Which of the following is the sweetest sugar?[BPKIHS
π
BPKIHS
A
Sucrose
B
Glucose
C
Fructose
D
Maltose
Show Solution
Q24.
Hydrolysis of sucrose is calledΒ [MOE]
π
MOE
A
Inhibition
B
Saponification
C
Inversion
D
Hydration
Show Solution
Q25.
Alkaline hydrolysis of esters is known as [MOE, IOM, BPKIHS 2005]
π
MOE, IOM, BPKIHS 2005
A
Esterification
B
Saponification
C
Dehydration
D
Alkalination
Show Solution
Q26.
Which of the following enzymes hydrolyses triglycerides to fatty acid and glycerol? [KU]
π
KU
A
Amylase
B
Maltase
C
Lipase
D
Pepsin
Show Solution
Q27.
Fat is a [K.0.]
π
K.0.
A
Lipid
B
Protein
C
Carbohydrate
D
Amino acids
Show Solution
Q28.
Two complementary strands of DNA in a double helix are joined to each other by [IOM]
π
IOM
A
Glycosidic bond
B
Phosphodiester bond
C
Hydrogen bond
D
Peptide bond
Show Solution
Q29.
The main function of RNA in the body is [IOM]
π
IOM
A
Transmission of hereditary characters
B
Protein synthesis
C
Acts as second messenger
D
Maintenance
Show Solution
Q30.
Upon hydrolysis protein give [BPKIHS]
π
BPKIHS
A
Fatty acids
B
Amino acids
C
Hydroxyacids
D
Alcohols
Show Solution
Q31.
Liquid fats are converted into solid fats by [BPKIHS]
π
BPKIHS
A
Hydrogenation
B
Saponification
C
Hydrolysis
D
Oxidation of double bond
Show Solution
Q32.
Synthetic detergents can be represented by the general formula [BPKIHS/IE]
π
BPKIHS/IE
A
RONa
B
ROSO3Na
C
RCOONa
D
RCOOH
Show Solution
Q33.
The degree of unsaturation of fat can be determined by means of [BPKIHS]
π
BPKIHS
A
lodine number
B
Octane number
C
Saponification number
D
Melting point
Show Solution
Q34.
Fats and oil are [BPKIHS]
π
BPKIHS
A
Monoesters of glycerol
B
Diesters of glycerol
C
Triesters of glycerol
D
Diesters of glycol
Show Solution
Q35.
Magnesium is present inΒ [BPKIHS]
π
BPKIHS
A
Vitamin C
B
Haemoglobin
C
Vitamin B
D
Chlorophyll
Show Solution
Q36.
Which of the following metal ion play an important role in muscle contraction? [IOM]
π
IOM
A
K+
B
Na+
C
Mg++
D
Ca++
Show Solution
Q37.
Antimony compounds are used in the treatment of [IOM]
π
IOM
A
Kala-azar
B
Filaria
C
Sleeping sickness
D
Chagas disease
Show Solution
Q38.
The cation necessary for coagulation of blood is [I.E. 2003]
π
I.E. 2003
A
Na
B
Ca
C
K
D
Cl
Show Solution
Q39.
Yeast is an important source of [BPKIHS]
π
BPKIHS
A
Sugar
B
Protein
C
Riboflavin
D
Haemoglobin
Show Solution
Q40.
Fatty acids which must be obtained from diet are [BPKIHS 2005]
π
BPKIHS 2005
A
Essential fatty acids
B
Non essential fats
C
Saturated fatty acids
D
Unsaturated fatty acids
Show Solution
Q41.
The component of blood which maintain osmotic pressure is [BPKIHS 2005]
π
BPKIHS 2005
A
Mineral salt
B
RBCs
C
Blood platelets
D
Albumin
Show Solution
Q42.
The enzyme pepsin hydrolyses [BPKIHS 2005]
π
BPKIHS 2005
A
Proteins to amino acids
B
Fats to fatty acids
C
Starch to glucose
D
Nucleotides to nitrogen bases
Show Solution
Q43.
DNA has which sugar in it [BPKIHS 2004]
π
BPKIHS 2004
A
Hexose
B
Ribose
C
Deoxyribose
D
Glucose
Show Solution
Q44.
Maximum energy is produced by the oxidation of [BPKIHS 2005
π
BPKIHS 2005
A
Carbohydrates
B
Minerals
C
Fats
D
Proteins
Show Solution
Q45.
Nucleic acids are polymers ofΒ Β [IOM 2011]
π
IOM 2011
A
Nucleoproteins
B
Globulins
C
Nucleosides
D
Nucleotide
Show Solution
Q46.
Every carbohydrate isΒ Β [IOM 2010]
π
IOM 2010
A
Ribose & deoxyribose
B
Triose and tetrose
C
Pentose and hexose
D
Aldose and ketose
Show Solution
Q47.
Almost all pharmaceutical products produced by DNA technology [MOE 2013 Magh - 6]
π
MOE 2013 Magh - 6
A
Proteins
B
Hormones
C
Antibiotics
D
Alcohol
Show Solution
Q48.
Simplest amino acidΒ [BPKIHS - 2016]
π
BPKIHS - 2016
A
Aspartic acid
B
Glycine
C
Tryptophan
D
Glutamic acid
Show Solution
Q49.
The common point among enzymes, hormone and vitamin in our body is [BPKIHS - 2016]
π
BPKIHS - 2016
A
They promote catalytic oxidation
B
They all are proteinaceous in nature
C
They are synthesized in our body
D
They aid in metabolism of our body
Show Solution
Q50.
The building block of protein isΒ [BPKIHS - 2016)
π
BPKIHS - 2016)
A
Fatty acid
B
Deoxyribose
C
Ribose
D
Amino acid
Show Solution
Q51.
Ξ±-helical structure of protein is stabilized byΒ [BPKIHS - 2014]
π
BPKIHS - 2014
A
Inter molecular H - bond
B
Intra molecular H - bond
C
Ξ±- 1, 3 - Glycosidic bond
D
Phosphodiester bond
Show Solution
Q52.
Which of the following is present in least proportion in cell membrane? [BPKIHS - 2011]
π
BPKIHS - 2011
A
Protein
B
Carbohydrate
C
Lipid
D
All equally present
Show Solution
Q53.
Corn is immersed in boiling water. It is then cooled and solution becomes sweet. It is due to [BPKIHS - 2011]
π
BPKIHS - 2011
A
Inactivation of enzymes
B
Conversion of disaccharides to monosaccharides
C
Conversion of starch into sugar
D
None of the above
Show Solution
Q54.
Which of the following is a co enzymes? [BPKIHS - 2010]
π
BPKIHS - 2010
A
Protein
B
Vitamin
C
Hormone
D
Mineral
Show Solution
Q55.
Starch is polymer ofΒ Β BPKIHS - 2010
π
BPKIHS - 2010
A
Glucose
B
Sucrose
C
Fructose
D
Maltose
Show Solution
Q56.
All are essential amino acids except [BPKIHS - 2010]
π
BPKIHS - 2010
A
Phenylalanine
B
Methionine
C
Tryptophan
D
Tyrosine
Show Solution
Q57.
Cane sugar on hydrolysis givesΒ [IOM-2014]
π
IOM-2014
A
Glucose and fructose
B
Glucose and galactose
C
Glucose and maltose
D
Glucose and sucrose
Show Solution
Q58.
Which component is most dispersed in a cell? [IOM-2012)
π
IOM-2012)
A
Carbohydrate
B
Lipid
C
Protein
D
Nucleic acid
Show Solution
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