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Biology MDCAT > Biological Molecules > Flashcards

Biological Molecules Flashcards

1
Q

what are bioelements

A

25 naturally occurring elements found in living beings

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2
Q

how many bioelements are found in human beings

A

16

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3
Q

what are major bioelements

A

the 6 most common bioelements that make up 99% of human protoplasm

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4
Q

what are minor bioelements

A

the bioelements that compose less than 1% of protoplasm

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5
Q

what are trace elements

A

the elements that composed less than 0.01% of protoplasm

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6
Q

what are proportions of biomolecules in bacterial cells

A 
water - 70
protein - 15
carbs- 3
lipids - 2 
DNA - 1 
RNA - 6 
Other organic(enzymes hormones metabollites) - 2
inorganic ions (Na, K, Ca, Mg, Cl, SO4) - 1
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7
Q

what are the proportions of biomolecules in mammalian cells

A 
water - 70
protein - 18
carbs- 4
lipids - 3 
DNA - 0.25
RNA - 1.1 
Other organic(enzymes hormones metabollites) - 2
inorganic ions (Na, K, Ca, Mg, Cl, SO4) - 1
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8
Q

what are macromolecule and polymers

A

high molecular weight compound formed from many repeating unit
formed by condensation reactions

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9
Q

what are micromolecules or monomers

A

individual units of polymers

formed by hydrolysis reaction

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10
Q

what is condensation reaction

A

when two monomers join

hydroxyl and hydrogen is removed to make water and a bond between monomers

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11
Q

when two monomers join it forms what

A

dimer

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12
Q

when more than two monomers join what is formed

A

polymer

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13
Q

condensation reaction is also called

A

dehydration synthesis

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14
Q

which conditions are required for condensation reaction

A

proper enzymes

monomers in an activated energy-rich form

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15
Q

what is hydrolysis reaction

A

breakdown of polymer into monomer with the addition of water molecules
an 0H group is attached to one monomer while one H is attached to another monomer

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16
Q

what is the lowest and highest amount of water present in any organism

A

20% in seeds and bones
85-90% in brain cells
99% in jelly fish

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17
Q

describe the high polarity of water

A

oxygen is highly electronegative is is partially negative
hydrogen is partially positive
this makes it a polar compound

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18
Q

what is the significance of high polarity in water

A

it is a universal solvent for polar substances as well as on-polar substances having charged groups in their molecules

this allows for chemical reactions to occur in aqueous medium

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19
Q

describe hydrogen bonding in water

A

partially positive hydrogen atoms of one molecules are attracted to the partially negative oxygen atom of atom molecule forming hydrogen bonds between two molecules of water

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20
Q

what is the significance of hydrogen bonding in water

A

water is liquid at high temperatures

high cohesion and adhesion

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21
Q

what is cohesion in water molecules and its significance

A

cohesion is attraction of water molecules with each other

it allows water to flow freely

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22
Q

what is adhesion in water and its significance

A

attraction of water to polar surfaces

useful in flow of water

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23
Q

what is the specific heat capacity of water and its significance

A

the number of calories required to raise the temperature of 1gm of water by 1 C (1 calorie/4.18 joules)

water has high specific heat capacity due to hydrogen bonds

its temp does not change easily so it works as a temperature stabilizer and protects living material from sudden temperature changes

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24
Q

what is high heat of vaporization of water and its significance

A

amount of heat required to convert a unit mass of liquid to gas

water has high heat of vaporization (574 colories per gram )

large amount of heat is required to remove small amount of water so it provides efficient way to remove heat from body through sweat

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25
describe hydrophobic exclusion of water and its significance
reduction of contact area between water and hydrophobic surface it helps maintain integrity of lipid bilayer membrane
26
describe ionization of water and its significance
dissociation molecules into its ions is called ionization water releases each number of hydroxy and hydrogen groups equilibrium is maintained at 25C and helps maintain the pH of the medium
27
what is the significance of low density of ice
in freezing ponds or lakes it forms an insulating layer above the water and provides allows some organisms to live under the ice
28
what are carbohydrates
polyhydroxy aldehydes or ketones
29
carbohydrates are classified into
monosaccharides, disaccharides, polysaccharides
30
what are the general characteristics of monosaccharides
``` consist of single saccharides unit they are simplest carbohydrates and cannot be hydrolyzed highly soluble in water they are the sweetest carbohydrates range of carboon atoms is 3-7 general formula is Cn H 2n On ```
31
what are the general characteristics of disaccharides
they are composed of 2-10 saccharides units they yield 2-10 monosaccharides on hydrolysis less soluble in water less sweet in taste
32
what are the general characteristics of polysaccharide
they are composed of more than 10 saccharides units they have highly complex structure they yield at least 11 monosaccharides on hydrolysis they are generally insoluble in water they are tasteless
33
monosaccharides are classified on the bases of what and their classification
on the bases of functional group aldoses ketoses ``` on the basis of carbon atoms C3 trioses C4 tetroses C5 pentoses C6 hexoses C7 heptoses ```
34
what are the aldose and ketoses of trioses and their function
glyceraldehyde dihydroxy acetone both are intermediates in photosynthesis and cellular respiration
35
what are the aldoses and ketoses of tetroses and their function
erythrose erthrulose both are intermediates in bacterial photosynthesis
36
what are the aldoses and ketoses of pentoses and their function
ribose / deoxyribose components of DNA and RNA ribulose intermediate in photosynthesis
37
what are the aldoses and ketoses of hexoses
glucose/galactose respiratory fuel/ component of milk sugar fructose intermediate in respiration
38
what are the aldoses and ketoses of heptoses and their function
glucoheptose sedoheptulose intermediates in photosynthesis
39
in ribose how is ring structure formed
when dissolved in water oxygen of aldehyde reacts with C4 and OH group of C4 IS SHIFTED TO C1
40
what is the difference betweeen alpha and beta glucose
OH group on C1 is alpha is downward | while in beta it is upward
41
what aare sterioisomers
molecules that have same molecular formula but iffeent arrangement in 3D space
42
what are enantiomers
type o of stereoisomers molecules are non-superimposable images of each other
43
what is an example of enantiomers
L and D-glucose
44
oligosaccharides are classified into
Disaccharides trisaccharide's tetrasaccharides
45
what are the examples and general formula of disaccharides
C12 H22 011 sucrose maltose lactose
46
what is the structure function and properties of sucrose
also called cane sugar used as a sweetener it is a transport sugar in plants it is soluble unreactive formed by condensation reaction of glucose (OH at C1) and fructose (H of OH at C2) has alpha 1-2 glycosidic bond
47
what is the structure, function and properties of maltose
called malt sugar intermediate disaccharide produced during breakdown of starch and glycogen found in germinating seeds of plants formed by condensation of alpha glucoses OH group at C1 and H of OH group at C4 forming alpha 1-4 glyosidic bond
48
what are the properties and how is lactose formed
commonly known as milk sugar formed by condensation of beta galactose (OH of C1) and beta glucose (H of OH at C4) form beta 1-4 Glyosidic bond
49
polysaccharides are classified into
homopolysaccharides | heteropolysaccharides
50
what are homopolysaccharides and their examples
``` polysaccharides formed by condensation of same monomers starch cellulose glycogen chitin ```
51
what are heteropolysaccharides and their examples
polysaccharides formed by condensation of different monomers agar pectin peptidoglycan
52
main sources of starch are
cereal grain and potato tubers
53
starch is stored in plants in with prts
roots stem and seeds
54
describe the digestion of starch in humans
it is digested in oral cavity and small intestine by amylase it yields maltose which is digested by maltase into glucose
55
what is the identification test for starch
iodine test gives blue color
56
what are the types of starches
amylose and amylopectin
57
describe the structure of amylose
unbranched linear chain of glucoses attached by alpha 1-4 glyosidic bonds
58
amylose is soluble in what
hot water
59
describe the structure and solubility of amylopectin
branched chain of glucoses with branches formed by alpha 1-6 Glyosidic bonds it is insoluble in water
60
what is the function and where is glycogen present in humans
it is a storage carbohydrate | found in liver and muscles
61
what is the test for glycogen
iodine test | gives red color
62
describe the strucutre of glycogen
it is the same as amylopectin but more branched
63
what are pure forms of cellulose
cotton and paper
64
what is cellulose composed of
chains of beta glucose joined by beta 1-4 glyosidic bonds
65
what is the result of cellulose in iodine test
no color
66
proteins contain which elements other than C H O N
``` P S Fe I Mg ```
67
what are proteins
polymers of amino acids | polypeptide chains
68
how many amino acids are commonly found in proteins
20
69
what is the structure of an amino acid
``` an alpha carbon to which an Hydrogen is attached amino group NH2 carboxyl group COOH variable R group ```
70
which amino acids are the simplest and their R groups
glycine - H | alanine - CH3
71
how are dipeptides and polypeptides formed
by translation
72
what is translation
condensation of amino acids on ribosome under instructions of mRNA which takes these instructions from DNA OH from carboxylic group is removed and H from amine group is removed the bond formed is called peptide bond
73
wat is primary structure of proteins
specific sequence and number of amino acids at the time of translation
74
what are secondary structure and their types
alpha helical and beta pleated sheets established by hydrogen bonding between opposite charge bearing groups of amino acids
75
what is tertiary structure
structure formed by ionic bonds, disulfide bonds to fomr globule shape
76
what is quaternary structure
more than one globule is attached together by hydrophobic interaction
77
what is the significance of amino acid sequence
sickle cell anemia point mutation in DNA in beta globin chain glutamic acid is replaced by valine
78
describe the structure of hemoglobin
two alpha chains (141 each) | two beta chains (146 each )
79
what are the problems in sickle cell anemia
sickle or crescent shaped RBC are sticky and stiff and tend to thrombose causing pain and organ damage
80
what is the classification proteins on the basis of shape
fibrous and globular
81
what are the characteristics of fibrous proteins and examples
``` fibre/filament shaped exist in secondary structure insoluble in aquous medium elastic in nature cannot be crystallized ``` ``` collagen fibrinogen actin myosin keratin ```
82
describe the characteristics of globular proteins and their examples
``` spherical/globular shape exist in tertiary or quaternary structure soluble in aqueous medium inelastic in nature can be crystalized ``` enzymes hormones antibodies channel proteins
83
enlist structural proteins and their functions
collagen - establishes bone matrix and cartilage matrix elastin- provides support for connective tissues of tendons/ligaments keratin- strengthens protective covering of hair, nail, quills, feather , horns and beaks histone- arranges DNA into chromosomes
84
enlist functional proteins and their functions
enzymes - involved in metabolism; speed up metabolic reactions hormones- regulation of physiological activities; glucose, calcium, blood pressure antibodies - produced by WBC in response to antigen; immunity hemoglobin- transport of oxygen and carbon dioxide in RBC fibrinogen- involved in blood clotting process found in blood plasma ovalbumin- found in egg whites storage of amino acids casein - milk based protein involved in storage of amino acids
85
what are lipids
heterogenous group of organic compounds that are insoluble in water and soluble in organic solvents such as acetone, alcohol, eter
86
difference between carbs and lipids
lipids have less proportion of oxygen
87
what is the molecular formula of tristearin
C57 H110 O6
88
what is the most abundant lipid in living things
acylglcerol
89
what is acylglycerol
ester of glycerol and fatty acids
90
what is glycerol
it is a trihydroxy alcohol containing three carbon atoms each having an OH group
91
what is fatty acid
type of organic acid containing one carboxylic acid group attached to a hydrocarbon group number of carbons vary in even number from 2-30
92
what are monosaccharides, disaccharides, trisaccharides
glycerol attached to one fatty acid glycerol attached to two fatty acid glycerol attached to three fatty acid
93
how many fatty acids are found
30
94
which fatty acids are the simplest
``` acetic acid (2C) butyric acid (4C) ```
95
which fatty acids are the most common
``` palmitic acid (16C) stearic acid (18C) ```
96
which properties of fatty acids increase with increasing number of carbon atoms
melting point hydrophobic nature solubulity on organic sol
97
what are saturated fatty acids, their nature and source and example
they contain max number of hydrogen atoms tend to solid at RTP higher melting point animal fats palmitic acid
98
what are unsaturated fatty acids, their nature, source and example
fatty acids that have one or more than one pair of carbon atoms joined by a double bond they are liquid at RTP they have low melting point they are plant lipids(oils) oleic acid
99
how many carbons are there in palmitic acid long with its formula and melting point and typical source
16 CH3 (CH2)14 COOH 63 most fats and oils
100
how many carbons are there in stearic acid long with its formula and melting point and typical source
18 CH3 (CH2)16 COOH 70 most oils and fats
101
how many carbons are there in oleic acid long with its formula and melting point and typical source
18 CH3 (CH2)7 CH=CH (CH2) 7 COOH 4 olive oil
102
how many carbons are there in linoleic acid long with its formula and melting point and typical source
18 CH3(CH2)4 CH=CHCH2CH=CH(CH2)7COOH -5 Vegetable oils
103
waxes are ------------ compounds
highly hydrophobic
104
two types of waxes are
natural waxes | synthetic waxes
105
what are the properties of waxes
chemically inert resistant to atmospheric oxidation protective function in animals and plants
106
what are natural waxes and their types and locations
they are typically long chain fatty acids and long acohols beeswax (in honey comb) cutin (on leaf surface of plants)
107
what are synthetic waxes and give an example and function
derived from petroleum and polyethylene | paraffin wax is used to make candles
108
phospholipids are derived from
phosphatidic acid
109
what is the structure of phospholipid
it is similar to a diacylglyceride attached to a phosphate group
110
how are phospholipids formed
phosphatidic acid combines with one of choline-nitrogenous base ethanolamine- amino alcohol inositol- amino acid serine - amino acid
111
most common phospholipid is
phosphatidylcholine or lecithin
112
all terpenes are synthesized from
isoprene unit
113
two, four and six isoprene unit form what and give their examples
monoterpene menthol diterpene vitamin A / phytol (chlorophyll tail) triterpene ambrein
114
what is natural rubber
polyterpene
115
what are steroids
lipids of high molecular weight which can be crystalline
116
describe the composition of steroid nucleus
consists of 17 carbons in four attcahed rings three rings contain 6 carbon atoms while the fourth contains five
117
how are steroids' synthesized and what differentiates different steroids
by isoprene units they side chains
118
what is the significance of cholesterol
structural component of membrane | precursor of bile acids, testosterone, progesterone and estrogen
119
what is the function and nature of bile salts
they emulsify fats and vitamin D | it is steroid
120
prostaglandins are derived from and where are they present
arachidonic acid | every mammalian tissue
121
what is the significance of prostaglandins
reduce blood pressure in some areas and raise it in other help induce fever and inflammation intensify sense of pain help in platelet aggregation during blood clotting
122
how does aspirin reduce fever and pain
inhibits prostaglandin synthesis
123
nucleic acid was reported by who and when
Friedrich Miescher in 1869
124
whe was the basic structure and chemical nature of nuclein determined
1920
125
two types of nucleic acids are called
DNA | RNA
126
nucleotides of DNA and RNA are called
deoxyribonucleotides and ribonucleotides
127
each nucleotides is composed of
pentose sugar phosphate nitrogenous base
128
which component of nucleic acid provides it is acidic property
phosphoric acid
129
two major classes of nitrogenous bases are--------- and what are their examples
purine (double ring) adenine guanine pyrimidine (single ring) thymine cytosine uracil
130
enlist the nucleosides
``` adenosine guanosine cytidine thymidine uridine ```
131
nitrogenous base and phosphoric acid is linked with which carbon of pentose sugar
1 | 5
132
describe polymerization of nucleotides
they are joined by condensation reaction molecule released is pyrophosphate cleavage of pyrophosphate by addition of water releases alot of energy which drives the process phosphodiester bonds form between fifth and third carbon atom
133
describe the end structure of polynucleotide chain
they have free phosphate at 5'end | they have free hydroxyl group at 3' end
134
describe the structure of ATP
adenine ribose three phosphate groups
135
what are high energy bonds in ATP
bonds joining three phosphate groups
136
describe the structure of NAD
two nucleotides one containing nicotinamide sugar and phosphate other containing adenine sugar and phosphate joined together by their phosphate group
137
NAD is what
coenzyme
138
the ratio of purines to pyrimidines is
1:1
139
what is chargaffs rule
ratio of purines to pyramidines is 1:1
140
who claimed first that DNA is a double helix
mourice wilkins and rosalind franklin by diffraction analysis
141
when and who found nitrogenous bases in DNA show specific ratios
1951 | erwin chargaff
142
when and who presented the first model of DNA
in 1953 james watson and francis crick
143
what is the lengthof each turn and width of DNA
3.4nm and 2nm legth
144
two strands of DNA are -------------- to each other
antiparrallell
145
which nucleotides pair with each other and why
adenosine and thymidine due to two hydrogen bonds | cytosine and guanosine due to three hydrogen bonds

Biology MDCAT (4 decks)

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