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AS Biology > Chapter 2: Biological molecules > Flashcards

Chapter 2: Biological molecules Flashcards

1
Q

what are the two types of chemical compounds

A

inorganic compounds and organic compounds

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2
Q

what are inorganic compounds

A
  • from rocks and mineral deposits

- e.g. Na+, K+, Mg2+

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3
Q

what are organic compounds

A
  • formed by organisms
  • C is the basic element
  • C, H, O, N, P, S
  • C atoms join by covalent bond to form chains or rings
  • chains and rings as the C-skeleton of organic molecules
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4
Q

what are monomers

A
  • relatively simple molecule
  • used as a basic building block for the synthesis of a polymer
  • n(monomer) joins up polymer usually by condensation reactions (H2O will come out)
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5
Q

what are polymers

A
  • a giant molecule
  • made from many similar repeating subunits (monomers)
  • joined together in a chain
  • macromolecule = a very large biological molecule such as polysaccharide, protein,nucleic acid
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6
Q

what is the basic unit/monomer of carbohydrate

A

monosaccharide

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7
Q

whatis the linkage of carbohydrates

A

glycosidic bond

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8
Q

what is the macromolecule of carbohydrate

A

polysaccharide

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9
Q

what is the basic unit/monomer of lipids

A

fatty acids and glycerol

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10
Q

what is the linkage of lipids

A

ester bond

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11
Q

what is the macromolecule/polymer of lipids

A

lipids do not reach this level

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12
Q

what is the basic unit (monomer) of proteins

A

amino acids

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13
Q

what is the linkage of proteins

A

peptide bonds

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14
Q

what is the macromolecule/polymer of proteins

A

polypeptides

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15
Q

what is the basic unit (monomer) of nucleic acid

A

nucleotide

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16
Q

what is the linkage of nucleic acid

A

phosphodiester bond

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17
Q

what is the macromolecule (polymer) of nucleotides

A

nucleic acids (DNA, RNA)

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18
Q

what are carbohydrates

A
  • made of C, H, O where H:O ratio 2:1, same as H20
  • general formula= Cx(H2O) y
  • hydrate of carbon
  • two forms:sugar and polysaccharide
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19
Q

what are sugars

A
  • in mono and disaccharide form
  • sweet and soluble
  • triose (made of 3 carbons)
  • tetrose (made of 4carbons)
  • pentose (made of 5 carbons)
  • hexose (made of 6 carbons)
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20
Q

what are polysaccharides

A
  • not sweet, insoluble

- e.g. starch, glycogen, cellulose

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21
Q

what is the structure of a glucose molecule

A
  • made up of 6 carbon atoms
  • each carbon (C2 to C6) has a -H and -OH attached to it
  • C1 is part of the functional group (carbonyl group)
  • the carbon atom is numbered starting from #1 for the ‘C’carbon nearest to the functional group
  • form2 rings : alpha and beta
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22
Q

what is a functional group

A

a specific group of atoms within an organic molecule that gives the molecule its specific property

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23
Q

what are the two forms that starch exist in

A
  • amylose

- amylopectin

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24
Q

what is the structure of amylose molecule

A
  • unbranched
  • glucose residues linked by a-1,4-glycosidic bond
  • amylose chains coil up in 3D form as the glycosidic bonds are not straight/180 deg to each other
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25
Q

what is the structure of amylopectin molecule

A
  • branched (branches to main chain glycogen)
  • in the main chain, residues are linked by a-1,4-glycosidic bond
  • in the branch chain (at the branching point between the branch chain and the main chain) they are linked by a-1,6-glycosidic bond
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26
Q

what are glucose residues

A

once glucose monomers are attached to form a polymer, its calleda glucose residue

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27
Q

what are the properties/characteristics of glycogen

A
  • similar to amylopectin but its highly branched
  • the chains and branches can fold into compact form (takes up less space)
  • glycogen molecules clump together to form granules (liver and muscle cells)
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28
Q

what is the function of starch and glycogen

A
  • food and energy storage compound
  • starch in plants and seeds
  • glycogen in animals and many fungi
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29
Q

why is starch and glycogen used for food and energy storage

A
  • they are insoluble in water (prevents lysis by osmosis)
  • does not easily react with water soluble compounds in the cell, while glucose is a reactive molecule
  • compact and occupies less space
  • easily converted back to glucose when needed (7 terminal glucose residues can be removed at a time, one per branch)
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30
Q

what is the terminal glucose residue

A

the last glucose in a chain (1st to be removed) is called the terminal glucose residue

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31
Q

what is the structure of cellulose molecules

A
  • made up of Beta glucose subunits
  • one beta molecule needs to be rotated 180 deg for the OH groups to line up alongside to form a glycosidic bond
  • B-1,4-glycosidic bond
  • 10000 glucose residues per chain
  • unbranched chain, can stack up parallel to each other bound by intramolecular and intermolecular hydrogen bonds
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32
Q

what are the properties/characteristics of cellulose?

A
  • the most abundant organic molecule because presence in cell wall
  • has a slow breakdown rate
  • has a high tensile strength = difficult to break by pulling on each end
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33
Q

what is delta charge of atoms

A

slightly charged (+/-) attraction due to uneven electron distribution

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34
Q

what are hydrogen bonds

A

-a relatively weak bond, formed between the delta +H of with any one of the three types of delta - atoms -O, -N, -F

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35
Q

what is a dipole?

A

-the unequal sharing of electrons/distribution of charge between two atoms in a molecule is called a dipole

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36
Q

what are the properties o polar molecules

A

-molecules with dipole are polar
-polar molecules are hydrophillic (water loving) because they attract H2O
molecules to form hydrogen bonds with them

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37
Q

why do cellulose fibres have high tensile strength

A
  • because glucose molecules have many intermolecular and intramolecular hydrogen bonds due to the many -OH groups and 1 -O-
  • because of the building up/structure of cellulose fibres (specify)
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38
Q

what is the building up/structure of cellulose fibres

A

60-70 cellulose molecules-> join to form microfibril-> join to form cellulose fibre-> join to form cell wall

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39
Q

why is the cell wall strong

A

cellulose fibres are arranged in different orientation in primary wall and secondary wall layers
-this gives the cell wall its rigid property that contributes to its function

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40
Q

what are the properties/characteristics of lipids

A
  • a diverse class of organic compounds
  • insoluble in H2O but soluble in organic solvents (e.g. chloroform,acetone, ether)
  • consists of C, H, O where the ratio of H:O is never 2:1 (never has water molecule)
  • includes tryglycerides, phospholipids, steroids etc.
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41
Q

what are tryglycerides

A
  • a type of lipid formed when 3 fatty acids combine with a glycerol with an ester bond (-COO-)
  • it is produced by a condensation reaction, releasing 3H20 in the process
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42
Q

what are fatty acids made up of

A

fatty acids = acid head +hydrocarbon tail

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43
Q

what are the acid heads that fatty acids are made up of

A
  • (-COOH)
  • carbonyl group
  • acidic group
  • hydrophillic
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44
Q

what are the hydrocarbon tails fatty acids are made up of

A
  • formula CnH2n+1 (represented by letter ‘r’)
  • fatty acid tail
  • variable in length (number of C) but usually 15-17C atoms
  • if more than 4C atoms, the tail is hydrophobic
  • can be saturated (singlebonds) or unsaturated (double bonds) (see diagram)
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45
Q

what is the difference in structure (chains) between saturated fat and unsaturated fat

A
  • saturated fats are straight chains

- unsaturated fats have a kink/backwards twist at each double bond

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46
Q

what are the two types of double bonds

A

-cis form (hydrogen atom on same side of chain)
-trans form (hydrogen atoms on opposite sides of chain)
(see diagram)

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47
Q

what are the properties/characteristics of saturated fatty acid chains

A
  • straight chains

- highly ordered parallel packing

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48
Q

what are the properties/characteristics of unsaturated ftty acid chains

A
  • are between saturated fatty acid chains
  • double bonds disrupt the close packing of fatty acids
  • this is because of the kinks
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49
Q

what are the properties/characteristics of tryglycerides

A
  • come in two forms: oils and fats
  • both are non polar (water insouble)
  • both float in water as they are less dense than the water
  • rich energy source
  • lighter storage compound than carbohydrates and proteins for the same amount of energy released on oxidation
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50
Q

what is the difference between the two forms of tryglyceride

A

Oils:

  • liquid at rtp
  • more unsaturated bonds
  • lower melting point

Fats:

  • solid at rtp
  • more saturated bonds
  • higher melting point
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51
Q

why are tryglycerides a rich energy source

A
  • higher calorific value than carbohydrates and CHONs (proteins)
  • energy of lipids is 2x the energy of carbohydrates per unit mass
  • this is because of more C-H bonds/more H:O ratio in the lipids
  • -H can be further oxidised to release energy
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52
Q

what are the functions of tryglycerides in plants

A
  • energy storage compounds
  • found in seed, fruits and chloroplasts (as lipid droplets)
  • e.g. olive oil, peanut oil, corn oil
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53
Q

where are tryglycerides found in animals

A
  • found in adipose tissue
  • made of fat cells
  • cels are filled up until nucleus is pushed to the side against the cell membrane
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54
Q

what are the functions of tryglycerides in animals

A
  • energy storage for hibernation
  • thermal and electrical insulation
  • blubber
  • H2O source
  • protection of internal organs
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55
Q

what is the function of blubber

A

help sea mammals to float (buoyancy)and provide thermal insulation

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56
Q

how does H2O source help animals

A

fat stored in desert kangaroo rat and humps of camel an be oxidised in respiration to form H2O

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57
Q

what is the benedict’s test

A

the test for reducing sugars (eg. glucose, maltose, fructose)

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58
Q

why/how does benedicts solution indicate the presence of reducing sugars

A

the functional group Aldehyde (RCOH) can reduce Cu2+ to Cu+

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59
Q

what is the procedure of the benedict’s test

A
  1. solution starts out blue as sample is added
  2. volume of sample must be equal to volume of benedicts solution
  3. heated in a water bath, water level just above solution level (submerged)
  4. heat for 2-5 mins, make sure water bath is boiling before placing test tube in
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60
Q

what color and opacity solutions may benedict’s test produce

A
  • green opaque
  • orange opaque
  • brick red opaque
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61
Q

why doesnt benedicts test work for non reducing sugars (i.e. sucrose)

A
  • functional groups of both glucose residue and fructose residue are attached to each other by glycosidic bond (A-1,2-glycosidic bond)
  • cannot reduce Cu2+ to Cu+
  • must hydrolyse first
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62
Q

what is protection (provided by tryglycerides) in animals

A

fats around internal organs protect them from damage caused by impact

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63
Q

what are phospholipids

A
  • lipid containing a phosphate group

- main molecule that forms plasma membrane

64
Q

what do phospholipids consist of

A

glycerol and phosphoric acid (fatty acid tails)

65
Q

how are phospholipids formed

A

glycerol joins up with fatty acid tails via condensation (remove H2O)

66
Q

which part of the phospholipid molecule is polar/hydrophillic

A

phosphate head

67
Q

which part of the phospholipid molecule is nonpolar/hydrophobic

A

the fatty acid tails

68
Q

which part of the phospholipid molecule is the ester bon

69
Q

which part of the phospholipid molecule is the phosphoester bond

70
Q

what are amino acids

A
  • the monomer for protein

- there are 20 different types of amino acids

71
Q

what determines a protein’s shape and function

A

The sequence, type and number of the amino acids within a protein determines its shape and therefore its function

72
Q

what are the functions of proteins

A 
Enzymes
Cell membrane proteins (eg. carrier)
Hormones
Immunoproteins (eg. immunoglobulins)
Transport proteins (eg. haemoglobin)
Structural proteins (eg. keratin, collagen)
Contractile proteins (eg. myosin)
73
Q

what is the general structure of all amino acids

A

The general structure of all amino acids is a central carbon atom bonded to:
An amine group -NH2
A carboxylic acid group -COOH
A hydrogen atom
An R group (which is how each amino acid differs and why amino acid properties differ e.g. whether they are acidic or basic or whether they are polar or non-polar)

74
Q

what is a zwitterion (properties)

A
  • electrically neutral
  • but carries + and - charges on different atoms
  • dipolar and soluble in water
75
Q

how is a zwitterion formed

A
  • acid (+H^+) is added to amino acid so H2N forms H3N^+

- base (-OH) is added to amino acid so (-COOH +OH- -> -COO^- + H2O)

76
Q

what can amino acids be

A
  • a buffer

- an ion

77
Q

what is a buffer

A

a solution that resists the change of pH upon the addition of small amounts of acid or base, upon dilution

78
Q

what are R groups

A
  • variable groups
  • determines the identity of an amino acid
  • has 4 major groups
79
Q

what are the 4 major R groups

A
  • neutral and nonpolar (hydrophobic)
  • neutral and polar (hydrophillic) (not charged but unequal distribution of charge)
  • basic/can be charged (hydrophillic)
  • acidic/can be charged (hydrophillic)
80
Q

which neutral and nonpolar r group molecule is the smallest r group

A

Glycine (one H)

-short form Gly

81
Q

which neutral nonpolar r group molecule has SH

A

cysteine

short form Cys

82
Q

what is the base of the basic positive r group molecules

83
Q

what is the base of the acidic negative charge r group molecules

A

COOH (H released)

84
Q

how is a peptide bond formed

A

In order to form a peptide bond a hydroxyl (-OH) is lost from a carboxylic group of one amino acid and a hydrogen atom is lost from an amine group of another amino acid
The remaining carbon atom (with the double-bonded oxygen) from the first amino acid bonds to the nitrogen atom of the second amino acid
This is a condensation reaction so water is released. The resulting molecule is a dipeptide

85
Q

what is a polypeptide

A

When many amino acids are bonded together by peptide bonds the molecule formed is called a polypeptide. A protein may have only one polypeptide chain or it may have multiple chains interacting with each other

86
Q

what is hydrolysis of polypeptides

A

During hydrolysis reactions polypeptides are broken down to amino acids when the addition of water breaks the peptide bonds

87
Q

which part of a dipeptide/polypeptide is a peptide bond

88
Q

what is a n terminus/n terminal

A

the NH end of a polpeptide chain

89
Q

what is the C terminus/C terminal

A

the C=O end of a polypeptide chain

90
Q

how many amino acid residues can a polypeptide have

A

100-1000 amino acid residues

91
Q

how many polypeptide chains make up a protein

A

1 or more polypeptide chains can make up 1 protein

92
Q

what does conformation mean

A

a 3D structure or shape

93
Q

what are the 4 levels of protein structure

A
  • primary
  • secondary
  • tertiary
  • quaternary
94
Q

what is the primary structure of a protein

A

the sequence of amino acids from the N terminal to the C terminal in a polypeptide chain

95
Q

what is the secondary structure of a protein

A

the spatial arrangement of a polypeptide chain due to its regular coiling (a-helix) or regular folding (b-pleated sheet)

96
Q

what are the 2 types of secondary protein structures

A

alpha helix and beta pleated sheet

97
Q

how is a alpha helix formed

A
  • the electronegative O of the carbonyl group (C=O group) of each amino acid residue forms a hydrogen bond with the electropositive H of the amino group (-NH group) located 4 amino acid residues ahead in the linear sequence
  • both C=O group and -NH group are part of peptide bond
98
Q

what are the properties and characteristics of alphahelix

A
  • due to the extensive hydrogen bonds, alpha helix is very stable, rigid and rod like
  • has a small R group
  • 1 turn/singular coil has 36 aa residues
  • insoluble in water
  • makes up keratin
99
Q

why do alpha helixes have a small R group

A

-if the R group is big, it may interfere with the Hydrogen bonds and the alpha helix cant be formed

100
Q

how are Beta pleated sheets formed

A
  • adjacent polypeptide chains arrange parallel in the same or opposite direction (which causes folding)
  • chains are held by H bonds between the electronegative O of the carbonyl group (C=O group) of an amino acid residue with the electropositive H of the amino group (-NH group) of an a residue in the adjacent chain
101
Q

what are the properties/characteristics of beta pleated sheets

A
  • double folded on itself

- due to extensive Hydrogen bonding, Beta pleated sheet is very stable and rigid (strong)

102
Q

what is the tertiary structure of proteins

A

myoglobin - consists entirely of 8 a-helix which form a pocket that encloses a haem group

103
Q

what are the properties and characteristics of the tertiary protein structure

A
  • a precise and compact ‘globular’ chape formed from extensive bending and folding/coiling of a polypeptide chain
  • water soluble
104
Q

how are myoglobins water soluble

A
  • hydrophillic R group will face the aqueous surrounding
  • hydrophobic R group will form R group interactions among themselves in the internal surface to be shield away from the aqueous surrounding
105
Q

why do polypeptide chains bend and fold into tertiary structure

A
  • either bondswill form between molecules in the chain that have NH3+ and COO- which folds toward each other
  • or the polypeptide chains bend because the hydrophobic R group will bend away from the water (point inwards) while the hydrophobic R group points outwards to bend with water
106
Q

what are crosslinks

A
  • the precise and exact shape of the tertiary structure is maintained by 4 types of bonds between R groups
  • the folding is very precise to the location of attracted molecule
107
Q

what are the 4 types of crosslinks in R groups

A
  • Disulphide bridges
  • Hydrophobic interactions
  • Ionic bonds
  • Hydrogen bonds
108
Q

what is the disulphide bridges crosslink

A

covalent bond between R groups of cysteine amino acids

109
Q

what are hydrophobic interactions crosslink

A

between non-polar R groups such as those on the amino acids tyrosine and valine

110
Q

what are ionic bonds crosslinks

A

between NH+and COO- ions on basic amino acids such as asparagine and acid ones such as aspartic acid

111
Q

what are hydrogen bonds crosslinks

A

between electronegative oxygen atoms on CO groups and electropositive H atoms on NH groups

112
Q

what is the order in strength of crosslinks bonds

A

disulfide>ionic>hydrogen>hydrophobic interactions

113
Q

what is the tertiary structure of the protein maintained by

A

it is maintained by the 4 types of bonds between R groups

114
Q

what is denaturation

A

the process where CHONs (proteins) loses their specific 3D shape (proteins function is based on their complementary shape) so the protein cannot form its normal biological function
-the change may be temporary or permanent

115
Q

what may denaturation be caused by

A
  • heat
  • acid/base/pH change and high salts
  • heavy metals (cations)
  • organic solvents and detergents
  • reducing agents
116
Q

why does heat cause denaturation

A

atoms gain kinetic energy and vibrate violently, breaking hydrogen bonds and then ionic bonds

117
Q

why does pH change cause denaturation

A

break ionic bonds (and then hydrogen bonds)

118
Q

why do heavy metals/cations cause denaturation

A

break ionic bonds

119
Q

why do organic solvents and detergents cause denaturation

A

disrupts hydrophobic interactions, form bonds with hydrophobic R groups

120
Q

why do reducing agents cause denaturation

A

break disulphide bridges

121
Q

what is renaturation

A

a process whereby a denatured protein spontaneously (by chance) refold into its original specific 3D shape after denaturation, when there is a suitable condition

122
Q

what is the quaternary structure

A

The 3D arrangement of a complex CHON structure made up of 1 polypeptide chain that are held together by disulphide bridges, ionic bonds, H bonds and hydrophobic interactions or sometimes including a non-CHON component (prosthethic group) (which sits in the pockets of subunits) to form a specific configuration/3D-shape
-each polypeptide chain has its own tertiary structure

123
Q

what are simple proteins

A

proteins purely made up of amino acids

124
Q

what are conjugated proteins

A
  • globular protein contains non protein components (prosthetic group) permanently in it
  • eg. carbo - carboprotein, lipid - lipoprotein, pigment - chromoprotein, nucleic acid - nucleoprotein
125
Q

what are fibrous proteins

A
  • long parallel chains
  • physically tough
  • insoluble in H2O (fibrous)
  • structural CHON
  • metabolically inactive
  • e.g. collagen, keratin, silk
126
Q

what are globular proteins

A
  • ball shape
  • compact
  • easily soluble
  • functional CHON
  • e.g. enzymes
127
Q

what are intermediate proteins

A

-fibrous but soluble

128
Q

what is an example of a globular protein

A

haemoglobin

  • the red pigment in red blood cells
  • transports O2
129
Q

what is an example of fibrous proteins

A

collagen

  • the most abundant protein in our body (1/3 of all proteins)
  • the main structural CHON of animals
  • holds the body together
  • found in skin, tendons, ligaments, cartilage, bones, teeth, walls of blood vessels, organs and connective tissue
  • flexible with high tensile strength
130
Q

why is collagen a triple helix

A
  • triple= 3 polypeptide chains twisted around each other in a rope-like formation
  • helix= each polypeptide chain is a helix (not as tightly wound as alpha helix)
  • strong with high tensile strength
131
Q

what is the primary structure of collagen polypeptide chain and molecule

A
  • every 3rd a.a. is glysine (allows tight coil)
  • covalent bonds between collagen molecules
  • H bonds and covalent bonds between polypeptide chains (hold chains together)
  • staggered ends of molecules overlap
  • molecules arrange parallel to form a fibril
  • bigger than cellulose molecule
132
Q

what is the order of formation in collagen

A

a helical polypeptide -> a collagen triple helix -> a fibril

133
Q

why does collagen have high tensile strength

A
  • staggered gaps between molecules (seen in dark lines)
  • fibres orientated to the forces they must withstand
  • tendons are parallel
  • skin placed in different directions in different layers to resist pulling forces from many directions
134
Q

what are examples of structural proteins function

A

tendons, cartilage, hair, nails

135
Q

what is an example of contractile proteins function

136
Q

what is an example of transport proteins function

A

haemoglobin

137
Q

what is an example of storage of energy proteins function

138
Q

what are examples of hormonal proteins function

A

insulin, growth hormone

139
Q

what are enzyme proteins for

A

catalyzing reactions in cells

140
Q

how do proteins aid in protection

A

immune response

141
Q

what are the properties of water

A
  • solvent
  • small molecule
  • high specific heat capacity
  • high latent heat of vaporization
  • molecular mobility
  • cohesion and surface tension
  • density and freezing
  • colloid formation
142
Q

which properties of water are due to hydrogen bonds

A
  • high specific heat capacity
  • high latent heat of vaporisation
  • molecular mobility
  • cohesion and surface tension
  • density and freezing
  • colloid formation
143
Q

why does water have solvent properties

A

-water is polar because it has a dipole between delta+ H and delta- O

144
Q

how does salt (polar. uncharged) dissolve in water

A
  • electronegative oxygen of water molecules are attracted to cations (+)
  • electropositive hydrogen of water molecules are attracted to anions (-)
  • a few water molecules surround the cations and anions to form hydration shell
  • therefore cations and anions are seperated by water molecules and become hydrated (surrounded by water molecules) in aqueous solution
  • as water moves, these ions will be transported together (e.g. mineral ions)
145
Q

how does glucose (polar, uncharged) dissolve in water

A
  • due to formation of H bonds between electropositive H of -OH group of glucose molecule with electronegative O of water molecule
  • glucose is a polyol = many alcohol = many
  • OH groups (therefore can form H bonds with many water molecules)
  • as water moves, these molecules will be transported together (e.g. sucrose in plants//glucose in animals)
146
Q

what happens when lipids (nonpolar) are added to water

A
  • lipid molecules are nonpolar/hydrophobic
  • it cannot form H bonds with water molecules
  • the water molecules form H bonds with each other, but not with the nonpolar molecule, therefore lipid does not dissolve in water
  • lipid molecules will clump together and become spherical-shaped to minimize surface area being exposed to water
147
Q

why is water a small molecule (function)

A
  • less than 1 nanometer

- so that it can diffuse across the partially permeable cell membrane freely

148
Q

why do water molecules have the ability to form hydrogen bonds with each other (function)

A
  • called cohesion
  • results in high specific heat capacity, high latent heat of vaporisation, molecular mobility, cohesion and surface tension, density and freezing properties, colloid formation
149
Q

what is a hydrogen bond

A

a bond formed between the H of -OH, -NH and -FH with either one of the delta negative atoms of -O, -N or -F

150
Q

what does heat do to water

A
  • breaks the hydrogen bonds between water molecules to set them free to move
  • raises the kinetic energy of the water molecules (move further apart and faster)
151
Q

what is specific heat capacity

A

the amount of heat (J) required to raise 1kg of water through 1C

152
Q

how does water have a high specific heat capacity

A

H2O molecules will absorb a lot of heat to break the H bonds between them and gain kinetic energy to move faster, leading to a raise in temperature

153
Q

why is the specific heat capacity of water important for the survival of organisms

A
  • maintain body temperature (because 70%-90% of body is made up of water)
  • maintain temperature of water body (e.g. lake, sea) to minimize temperature fluctuation
154
Q

what is latent heat of vaporisation

A

the amount of heat needed to break the H bonds between water molecules and set them free to move and raise the kinetic energy of the water molecules so they move faster and further away and vaporise

155
Q

why is water’s high latent heat of vaporisation important for the survival of organisms

A
  • when H2O evaporates, it absorbs lots of heat and cools down the body
  • water body will not dry out easily on a hot day so aquatic organisms can survive
156
Q

what is molecular mobility

A
  • individual H bonds are weak bonds
  • they can be easily broken and be formed again, allowing the water molecules to move
  • hence water is in liquid state

AS Biology (11 decks)

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