biomolecules Flashcards
(352 cards)
1
Q
biomolecules
A
they are molecules involved in the maintenance and metabolic reactions in a living organism
2
Q
elements of carbohydrates
A
C,H,O
3
Q
elements of proteins
A
C,H,O,N,S
4
Q
examples of proteins
A
methionine,cysteine
5
Q
elements of lipids
A
C,H,O
6
Q
Elements of nucleic acids
A
C,H,O,N.P
7
Q
are carbohydrates a polymer or macromolecule
A
they are both polymers and macromolecules
8
Q
are proteins polymers or macromolecules
A
macromolecule
9
Q
are lipids polymers or macromolecules
A
macromolecule
10
Q
are nucleic acids polymers or macromolecules
A
macromolecule
11
Q
carbohydrates building blocks
A
monosaccharide
12
Q
proteins building blocks
A
amino acids
13
Q
lipids building blocks
A
fatty acids and glycerol
14
Q
nucleic acid building blocks
A
nucleotide
15
Q
carbohydrate:
A
- hydrates of carbon
- ratio of H to O is 2:1( if its not 2:1 its a lipid)
16
Q
the general formula of carbohydrates are
A
Cn(H2O)n
17
Q
classification of biomolecules can be made based on
A
1)behavior during hydrolysis
2)based on functional groups
18
Q
what happens during hydrolysis
A
water is added, bond is broken
19
Q
monosaccharide:
A
carbohydrates that cannot be hydrolysed further into a simpler unit ( example: glucose)
20
Q
disaccharide:
A
gives 2 monosaccharide units on hydrolysis
21
Q
examples of disaccharide hydrolysis reactions
A
maltose-> glucose + glucose
lactose-> glucose + galactose
sucrose-> glucose + fructose
22
Q
polysaccharide
A
gives many monosaccharides unit on hydrolysis (example: starch and glycogen- functional) (example: cellulose- structural)
23
Q
ketose- ketone ( functional group)
A
24
Q
aldose- aldehyde( functional group)
A
25
triose (3 carbon atoms)
C3H6O3
- monosaccharide
26
tetrose( 4 carbon atoms)
C4H8O4
- monosaccharide
27
Pentose( 5 carbon atoms)
C5H10O5
- monosaccharide
28
Pentose sugar examples:
- ribose sugar (RNA)
- deoxyribose sugar (DNA)
29
hexose (6 carbon atoms)
C6H12O6
- monosaccharide
30
Hexose sugar examples
- glucose
- fructose
31
glucose formula
C6H12O6
32
glucose short
hexose, monosaccharide, aldose
33
role of glucose
release energy by breaking down of bonds, building blocks of polysaccharides like starch, cellulose and glycogen
34
glucose straight chain formula
35
alpha glucose
36
beta glucose
37
Ring structures of alpha and beta glucose
- ring structures are stable
-first carbon atoms double bond break and the 5th carbon atom sacrifices its OH group to the first carbon atom.
- ring is formed between 1st and 5th carbon atom
- alpha and beta glucose are isomers
- glucose has pyranose ring
38
pyranose
six corner ring
39
similarities between alpha and beta glucose
pyranose ring, same number of carbon , hydrogen and oxygen, both are isomers, same number of bonds.
40
beta glucose
-OH group of first atom is above the plane of the ring
- cellulose is made up of beta glucose and is more stable
- solidly packed molecules, cannot be broken down
41
alpha glucose
- OH group of the first carbon is below the plane of the ring
- starch and glycogen is made up of alpha glucose and is not very stable
-molecules are compressed but can be easily taken apart
42
fructose short
ketose, hexose, furanose ring
43
furanose
5 corner ring
44
fructose straight chain
45
alpha fructose
46
beta fructose
47
similarities between glucose and fructose
isomers, same number of Carbon, hydrogen and oxygen. same number of bonds, monosaccharides.
48
glucose long
pyranose ring, ring formed between between 1st and 5th carbon atom, aldose , energy source
49
fructose long
furanose ring, ring formed between 2nd and 5th carbon atom. not and energy source
50
properties of monosaccharides
- sweet in taste
- soluble in water
- reducing sugar (+ test with benedicts solution)
- building blocks of polysaccharides
51
disaccharides long
made up of 2 monosaccharides formed by the condensation reaction, 1 molecule of water released, glycosidic bond formed.
52
alpha glucose+ alpha glucose
53
maltose+ H2O - glycosidic bond formed
54
annotation of maltose
- condensation reaction
- 2 alpha glucose involved
- water removed, 1,4 glycosidic bond formed
55
alpha glucose + alpha glucose
maltose + H2O
56
alpha glucose + beta fructose
sucrose + H2O
57
sucrose formation
58
annotation of sucrose
- condensation reaction
- alpha glucose and beta fructose involved
- water is removed
- alpha -1 glucose and beta-2 fructose glycosidic bond
59
properties of disaccharides
- sweet in taste
- soluble in water when hydrolysed gives 2 monosaccharide units
60
condensation reaction definition
a reaction in which 2 molecules are linked together with the release of a water molecule, a new bond is formed (covalent),
61
hydrolysis reaction definition
a reaction in which water is added to provide H+ and OH- ions which break down the bond and split large molecules into small ones.
62
test for reducing sugar
take 2cm^3 of sample, add 2cm^3 of benedicts solution, heat at 90℃, observe the color change. ( blue-> green,yellow,orange, brick red)
63
reducing sugar
acts as a reducing agent, it reduces CuSO4 (Cu2+ into CuO(Cu2+))
64
test for non reducing sugar
take 2cm^3 of sample, to it add 2cm^3 of dilute HCl. ( to break glycosidic bond) heat it at 90℃. add excess sodium hydrogen carbonate. add 2cm^3 of benedicts solution, heat it at 90℃, observe the color change to brick red
65
why add excess sodium hydrogen carbonate?
to neutralize benedicts soliton
66
polysaccharide example
starch
67
general formula starch
(C6H10O5)n
68
starch
stored as grains, made up of 2 components: amylose - alpha glucose, unbranched, long straight chain made up of many alpha glucose, joined by alpha 1,4 glycosidic bond
69
amylose chain
spiral/helix/curved and coiled up structure. it results in starch to compact and occupy less space/ tightly packed. each turn contains 6 glucose molecules. helix is joined by hydrogen bond which provides stability and helix structure
70
amylose chain
71
amylose gives +ve test with iodine
which is trapped in helix and forms a poly iodide complex which turns the color of iodine from brown -> blue black. when heated at high temperature, hydrogen bond breaks, helix structure lost, iodine not trapped, color of solution remains brown
72
amylopectin
80% of starch, branches every 24-30 glucose molecule, bonds alpha 1,4 glycosidic bond and alpha 1,6 glycosidic bond
73
amylopectin
74
bonds in amylopectin
alpha 1,6
alpha 1,4
75
bond in amylose
alpha 1,4
76
branches in amylose
unbranched
77
amylopectin branches
branched
78
amylose size
small
79
amylopectin size
large
80
amylose shape
helical
81
amylopectin shape
not helical
82
amylose with iodine test
+ve
83
amylopectin with iodine test
-ve
84
compactness of amylose
less compact
85
compactness of amylopectin
more compact
86
cross link amylose
No
87
cross link in amylopectin
Yes
88
% in amylose
20
89
% in amylopectin
80
90
how is the structure of starch adapted for its function
many C-C and C-H bonds, breaking up of these bonds releases stored energy . insoluble, does not affect the osmotic balance inside of the cell, bulky in nature, cannot diffuse out, compact, occupies less space, stored as grains.
91
how is the structure of glycogen adapted for its function
many C-C and C-H bonds, breaking up of these bonds releases stored energy . insoluble, does not affect the osmotic balance inside of the cell, bulky in nature, cannot diffuse out, compact, occupies less space, stored as granules.
92
glycogen
93
glycogen
alpha glucose, bond 1,4 and alpha glucose 1,6 glycosidic bond branches every 8-10 glucose molecule ( more branches, short branched)
94
similarities between amylopectin and glycogen
alpha glucose 1,4 and alpha glucose 1,6 glycosidic bond, polysaccharide/polymer/insoluble, bulky
95
differences between amylopectin and and glycogen
amylopectin is stored as grains, and branches are less branched, long branches.
glycogen is stored as granules and branches are many short btanches
96
cellulose short
beta glucose beta 1,4 glycosidic bond, unbranched
97
cellulose
98
why each glucose molecule is rotated 180degrees in cellulose
to prevent helix
99
—-
hydrogen bond
100
fibers contain
hydrogen bonds and microfibres
101
microfibres contain
60-70 cellulose
102
in order to maintain beta 1,4 glycosidic bonds in cellulose
each succesive glucose molecule is rotated 180 degrees to prevent the formation of helix( cellulose is a part of cell wall so it cannot be in the form of a helix)
103
hydrogen bonds in cellulose
is formed between 2 cellulose chains, invidual hydrogen bond is weak but many hydrogen bonds together form high tensile strength about 60-70 cellulose molecule become tightly cross linked to form microfibrils are in turn held together in bundles called fibre. hydrogen bonds join 5 microfibrils together
104
importance of hydrogen bonds in cellulose
- provide high tensile strength
- holds the chains together
105
how is the structure of cellulose adapted for its function?
1) each succesive glucose molecule is rotated 180*, it keeps the molecule straight, prevents the formation of helix
2) cellulose is unbranched linear polymer allowing it to lie parallel to each other with many OH groups projecting in different direction to form hydrogen bond, it provides intensive strength to withstand turgor pressure and prevents the cell from bursting
3) arrangement of fibre around the cell help in maintaining the shape of the cell
106
similarities between starch, cellulose and glycogen
polysaccharide, polymer and insoluble
107
starch bond
alpha glucose 1,4 and alpha glucose 1,6
108
glycogen bond
alpha glucose 1,6 and alpha glucose 1,4
109
cellulose bond
beta glucose 1,4 glycosidic bond
110
starch function
storage
111
glycogen function
storage
112
cellulose function
structural
113
starch branch
only amylopectin branched
114
glycogen branches
branched
115
cellulose branches
unbranched
116
starch is present in
chlorophlast
117
glycogen is present in
muscle and liver
118
cellulose is present in
cell wall
119
starch is present as
grains
120
glycogen is present as
granules
121
cellulose is present as
fibre
122
starch orientation
same
123
glycogen orientation
same
124
cellulose orientation
each succesive glucose is rotated 180 degrees
125
importance of being branched
- compact
- occupy less space
- quickly hydrolysed
- insoluble- no osmotic change
126
starch monosaccharide
alpha glucose
127
glycogen monosaccharide
alpha glucose
128
cellulose monosaccharide
beta glucose
129
differences between the structure of deoxyribose and the ring structure of alpha glucose
alpha glucose is a pyranose ring and deoxyribose sugar has a furanose ring, alpha glucose has 6 carbons and deoxyribose has 5 carbons, 5 OH bonds in alpha glucose , bond formed between 1st and 5th carbon atoms in alpha glucose
130
advantages for a mammal having a storage molecule that is highly branched
many ends for attachement of glucose, can be stored quickly, makes it more compact, occupies less space
131
2 structural differences between fructose and sucrose
1) fructose is a monosaccharide and sucrose is a disaccharide
2) fructose has no glycosidic bonds and sucrose has glycosidic bonds
132
color of iodine solution in the presence of starch
blue-black
133
describe how a hydrogen bond is formed
hydrogen bond is formed between oxygen and hydrogen atom. oxygen has a slight negative charge and hydrogen has an electro positive charge.
134
what would happen to the iodine- amylose complex if the solution was heated at 60 degrees celsius
hydrogen bond breaks, colour remains orange brown, looses helix structure, iodine not trapped
135
number of different types of amino acids
20
136
every amino acid has
- 1 amine group
- R group
- carboxylic acid
- hydrogen
all attached to same carbon
137
amino acid
138
formation of peptide bond
139
number of peptide bonds
- number of peptide bond is = n-1, when n is the number of amino acids
- peptide bond is not broken by adding water at room temperature
140
zwitter ions
amino acid when dissolved in water form zwitter ions ( have positively and negatively charged groups or amphoteric)
141
zwitter ions
142
Examples of proteins
- all enzymes are proteins
- some hormones, for example: insulin, glycine
- protection, examples: antibodies, fibrinogen, thrombin and fibrin
- contractile ( present in muscle ) example: myocin and actin
143
structural proteins
collagen and keratin
144
transport proteins
hemoglobin, myoglobin, and carrier proteins
145
homeostasis
some proteins act as a buffer to maintain the PH
146
properties determined by R group
- physical and chemical properties of an amino acid
- bonds can be formed between amino acids which help in folding, solubility, and polarity (charge).
- if an amino acid contains a polar R group, it can form a hydrogen bond, and the amino acid is considered to be soluble.
147
types of structures of proteins
primary structure, secondary structure, tertiary structure and quaternary structure
148
primary structure
linear sequence of amino acids joined by peptide bonds to form a polypeptide. change in the primary structure changes the property of protein, change in primary structure affects all levels of proteins
149
primary structure
the line is a peptide bond and the ends have NH2 and COOH
150
secondary structure : α helix
undergoes folding to give a secondary structure which is maintained by hydrogen bond. hydrogen bond formed between the first and 4th oxygen in the carboxyl group, C=O of the first amino acid, and hydrogen in the NH group of amino acids four down the chain, pattern of bonding pulls the polypeptide chain into a helical structure, each helix contains 3.6 amino acids R group of amino acid projects outward where they are free to interact
151
alpha helix diagram
152
secondary structure : β pleated sheet
2 or more segment of the same poly-peptide chain lined up next to each other, form a sheet-like structure held by a hydrogen bond, R group extend above or below the plane of a sheet.
153
beta pleated sheet diagram
154
beta pleated sheet structural chain
155
in secondary structure R group
projects out
156
tertiary structure
formed due to interaction of R groups, 3D in nature, allow distant amino acid to be closer to each other, due to folding and interaction between R group,
157
hydrogen bond
formed between electropositive and electronegative atoms, weak bonds can be broken by increasing temperature and change in PH
158
bond formed that common for tertiary and quaternary structure
hydorgen and ionic and disulphide
159
hydrogen bond
160
ionic bond
formed between oppositely charged ions at a particular PH. change in the PH breaks ionic bond
161
ionic bond
162
disulfide bond
formed between 2 cysteine, covalent bond, strongest bond, last bond to break, can be broken by increasing the temperature
163
disulphide bond
164
strength of bond ( decreasing strength)
1) disulphide
2) ionic
3) hydrogen
165
hydrophobic interaction
interaction between 2 nonpolar R groups. wander waals force: non specific attractive force between 2 groups that are very close to each other
166
hydrophobic interaction
167
quaternary structure is made up of more than
one poly-peptide chain
168
primary -> secondary
folding/ coiling
169
primary features
1 poly peptide , peptide bond
170
secondary features
1 polypeptide and hydrogen bond
171
tertiary features
1 polypeptide, interaction of R groups, 3D, hydrogen and ionic and disulphide bond, hydrophobic interaction
172
quarternary features
more than 1 polypeptide, hydrogen, ionic, disulfide, hydrophobic
173
shapes of globular
spherical
174
shapes of fibrous
long narrow fibre
175
solubility of globular
soluble in H2O
176
solubility of fibrous
insoluble in H2O
177
stability of globular
unstable
178
stability of fibrous
stable
179
durability of globular
sensitive to change
180
durability of fibrous
less sensitive
181
sequence of amino acids in globular
regular in temperature and PH
182
sequence of amino acids in fibrous
irregular in temperature and PH
183
Purpose of globular
functional
184
Purpose of fibrous
structural
185
example of globular
enzymes, hemoglobin, antibodies
186
example of fibrous
collagen
187
globular
proteins which are spherical, soluble in water, hydrophilic R group outside, and hydrophobic R group inside
188
hemoglobin
quarternary, 4 polypeptide chains ( 2 alpha and 2 beta-globin ), globular, each polypeptide chain contains 1 haem/Fe2+/prosthetic group (non-protein component) 2 genes required to make hemoglobin, each polypeptide chain contains 1 haem so 4 haem group in hemoglobin
189
1 Fe2+ carries 1 molecule of oxygen =
4 molecules of O2, 8 atoms of O2 carried by hemoglobin molecule. chains are arranged in a way that the hydrophobic R group is facing inside and the hydrophilic R group pointing outside ( towards cytoplasm) this makes the hemoglobin soluble
190
hemoglobin is arranged towards the cell membrane so that it decreases diffusion distance
191
loading of O2 in
alveoli
192
unloading of O2 in
tissue
193
CO + hemoglobin ->
carboxyhemoglobin (the most stable, permanent, binding, irreversible)
194
O2+ hemoglobin ->
oxyhemoglobin ( reversible)
195
CO2 + hemoglobin ->
carbaminohemoglobin ( reversible)
196
CO and O2 share
the same binding site ( heam)
197
CO2 binds to the
polypeptide chain
198
affinity
CO, O2, CO2 ( decreasing order of affinity)
199
collagen
fibrous, quarternary , 3 polypeptide
200
collagen is present in
skin, walls of blood vessels, ligament, tendon
201
3 poly peptides coil together to a
triple helix which is a collagen molecule
202
triple helix which is a collagen molecule has
hydrogen bonds
203
triple helix has
staggered and has covalent bonds
204
order of amino acids
glycine, proline, arginine/hydroxyproline
205
glycine formula
206
why is glycine present in every 3rd position?
- simplest amino acid with a small R group when compared with other amino acids, it allows the 3 polypeptide chain to lie closer to each other and form a triple helix
- triple helix is arranged in parallel rows and have stagered ends
- in between the collagen molecule, covalent bonds are present, collagen bonds join to form fibrils which in turn form fibre
207
how is the structure of collagen adapted for its function?
presence of hydrogen bonds and covalent bonds between collagen molecule form high tensile strength. it helps to withstand high pressure/pulling forces
208
differences between hemoglobin and collagen
hemoglobin is globular whereas collagen is fibrous
hemoglobin has 4 polypeptide and collagen has 3 polypeptide
hemoglobin function is carries O2 and collagen function is high tensile strength
209
biuret test
takes 2cm3 of sample, to it add KOH ( changes PH, ionic and hydrogen bond breaks) add 2cm3 of CuSO4, blue -> lilac
210
adaptations of cellulose
Presence of gaps between microfibrils allows solute to reach cell membrane and makes cell wall fully permeable.
211
lipids
- less oxygen when compared to carbohydrates
- releases more energy, ( has many C-C and C-H breaking in which releases a lot of energy )
- insoluble in water but soluble in organic solvent ( alcohol)
212
triglyceride
glycerol + 3 fatty acids
213
glycerol structure
214
glycerol
- polar
- water soluble
- triol -3OH-
- hydrophillic
215
saturated fatty acid
C-C single bond
solid at room temperature
animal source
it shows the tendency to stick to each other and to the walls of arteries
216
unsaturated fatty acid
- C=C or C≡C
- liquid at room temperature
- plant source
- hydrogenation - excess of converting unsaturated fatty acids to a saturated fatty acid by the addition of H2
217
formation of triglyceride
218
glycerol is linked to fatty acids by
ester bond
219
as the polar group of glycerol and fatty acids are lost during
condensation , triglyceride produced is non polar and its insoluble in H2O
220
examples of lipids
- fats and oils
- phospholipid
- wax
- steroid
221
fats and oils functions
energy reserve
222
phospholipid function
cell membrane
223
wax function
waterproofing surface of plant leaf
224
steroids function
horomones
225
how is triglycerides adapted for its function
- has many C-C and C-H bonds breaking up of these bonds releases energy
- fats stored under the slom of adipose tissue acts as an insulator
- blubber: present in sea mammals helps in bouncy acts as an insulating layer
- metabolic source of water in animals living in desert, triglyceride is oxidised to release water
226
phospholipid
227
phospholipid head is
hydrophilic
228
phospholipid tail is
hydrophobic
229
one fatty acid chain is replaced with
phosphate group in phospholipids
230
phospholipid contains
charge/ polar so its soluble/hydrophillic
231
head of phospholipid is made up of
glycerol + phosphate group
232
tail is
nonpolar/ hydrophobic ( made up of 2 fatty acid chains)
233
phospholipid is present as a bilayer in the cell membrane with
hydrophillic head pointing outward and hydrophobic tail inside
234
the hydrophobic chain makes the cell membrane
selectively permeable allows only fat soluble materials to pass through it
235
water
hydrogen bond is present between 2 water molecules
236
properties of water
1) polarity
2) high surface tension and cohesion
3) density and freezing points
4) neutral
5) high water capacity
237
polarity description
uneven distribution of chargers over a molecule
238
importance of water being polar
1) allows water to be a solvent
2) water as a transport medium
239
how does polarity allow water to be a solvent
molecules that have groups with dipoles are said to be polar, they are attracted to water molecules, because the water molecules also have dipoles, such molecules are said to be hydrophilic (water-loving), and they tend to be soluble in water. molecules that do not have dipoles are said to be non-polar, example: lipids, are not attracted to water and they are hydrophobic (water-hating). such properties make possible the formation of plasma membranes
240
how does polarity help water as a transport medium
water is the transport medium in blood, in the lymphatic excretory and digestive systems of animals, and in the vascular tissues of plants, here again its solvent properties are essential
241
high surface tension and cohesion description
- water molecules have very high cohesion, in other words, they tend to stick to each other
- high surface tension: at the surface of a liquid a force called surface tension exists between molecules as a result of cohesive forces between molecules. this force makes the surface occupies the least possible surface area
242
importance of high surface tension and cohesion
1) this is the reason for the way water moves in long, unbroken columns through the vascular tissue in plants and is an important property in cells
2) high cohesion also results in high surface tension at the surface of the water, this allows certain small organisms, such as the pond skater, to exploit the surface of the water as a habitat. allowing them to settle on or skate over its surface
243
density and freezing properties description
water is an unsual chemical because the solid form, ice is less dense that its liquid form . below 4°C the density of water starts to decrease, ice therefore floats on liquid water and insulates water under it
244
density and freezing properties importance
this reduces the tendency for large bodies of water to freeze completely, and increases the chances of life surviving in cold condition
changes in the density of water with temperature cause currents to help to maintain the circulation of nutrients in the ocean
245
neutral description
PH=7
246
nuetral importance
suitable PH for living cells
247
high water capacity description
it is the amount of heat required to raise the temperature of 1Kg of water by 1°C
as hydrogen bonding restricts the movement of water molecules, a relatively large amount of energy is needed to raise the temperature of water
248
high water capacity importance
this means that large bodies of water such as oceand and lakes are slow to change temperature as environmental temperature changes, as a result they are more stable habitats
due to the high proportionation of water in the body internal changes in the temperature are also minimized , making it easier to achieve stable body temperature
249
the high heat of vaporization description
it is the amount of heat needed to vaporize a liquid
250
high heat of vaporization importance
since a relatively large amount of energy is needed to convert water to gas, the process of evaporation transfers a correspondingly larger amount of energy and can be an effective means of cooling the blood, as in sweating and panting conversely, a relatively large amount of energy must be transferred from water before it is converted from a liquid to solid ( ice), this makes it less likely that water will freeze an advantage both for the bodies of living organisms and for organisms which live in water, i.e. large amount of heat can be lost with minimal loss of water from the body(cooling effect)
251
biological functions of water in all organisms
structure- high water content of cells( 70-95% )
solvent and medium for diffusion
reagent in hydrolysis
252
biological functions of water in plants
osmosis and turgidity ( important in many ways, such as growth, cell enlargement, support, guard cell mechanism)
reagent in photosynthesis
translocation of inorganic ions and organic compounds
253
biological functions of water in animals
transport in the blood vascular system, lymphatic system, excretory system
osmoregulation
cooling by evaporation, such as sweating
254
what will break an ionic bond between amino acids?
ph change, not high temperature
255
how many dipeptides can be assembeld from 12 amino acids?
12^2 = 144
256
function of iron in hb
binds oxygen to hb molecuke
257
min no of c atoms in an amino acid?
two
258
which have properties dependent on hydrogen bonds?
cellulose, hb and water
259
which features result in collagen having high tensile strength?
1. covalent bonds between adjacent molecules
bio post pp notes 6
2. each 3 stranded molcule is held together by hydrogen bonds
3. r group of every 3rd amino acid is small insoluble nature is irrelevant!
260
when ph is low, some enzymes don’t function properly as their 3d shape
gets changed. what explains the change in 3d shape?
h+ ions attach themselves to negatively charged r groups
261
peptide bond is a
covalent bond
262
disulphide bond is the
the strongest/ last to break
263
carboxyl group is
COOH
264
n is the number of amino acids, number of peptide bonds would be
n-1
265
in the formation of a peptide bond
one amino acid loses oh group from
cooh
266
both hydrogen and ionic bonds are
weak bonds
267
when primary structure changes
all subsequent structures change as
well
268
glucose has c
=o
269
antibodies are made of
two polypeptides
270
glycine has a small
r group
271
hb changes shape as
oxygen loads
272
collagen is insoluble in
water
273
collagen is a repeat sequence of
3 amino acids
274
there is no branching in
proteins
275
hb and collagen always contain atleast
4 double bonds even
276
during protein denaturation,
tertiary structure of enzyme is lost / affected
(happens when extreme ph yk)
277
ionic bond in secondary >
peptide bond in secondary (in those venn
diagram qs)
278
large increases in temp dont increase
hydrophobic interactions
279
disulphide maintains both
tertiary and quarternary structure
280
peptide bond can’t be broken down by hydrolysis at
room temperature
281
any side chain binding at the site of the R group needs to have
a carbon atom which can form a bond
282
if different regions form a 3d shape
it is tertiary!!
283
which property of water allows insects to stand on the surface of ponds?
cohesion between water molecules
ability to form hydrogen bonds with other molciles
*other properties are honestly irrelevant
284
which property of water minimises temperature changes in cells &
organisms?
specific heat capacity only
^preference over lov ig
285
as a frozen lake warms after a cold winter, mineral nutrients are brought
to surface. whyyyyy
1. water’s greatest density is at 4 C
2. water is a solvent
high shc and hydrogen bonds are *irrelevant
286
why may fish living in ponds survive temperatures below 0 C in winter?
ice on pond surface insulates the water in the pond
properties of water needed for fish to survive: high thermal capacity, max
density at 4 C
287
which feature of water is least likely to affect the life of an animal in a
tropical rain forest?
maximum density at 4 C
^water won’t freeze in a tropical rain forest so this property is irrelevant
as a whole
288
which property of water is important in transpiring plants to prevent
enzymes in leaves from being denatured?
t retains a lot of heat to evaporate = high lov [due to presence of h
bonds]
[amount of energy to make liq to gas is high]
[IRRELEVANT] it retains a lot of heat (does not mean shc, shc is when it
requires a high amount of heat for a change in temperature)
289
what processes in plants is hydrogen bonding important on hot sunny
days?
anything that prevents water loss
allowing leaves to cool down at night = more water loss (?) - so its wrong
290
processes based on h bonding
everythign except solvent i think
1. temp control due to evaporation
2. provides constant env for aquatic organisms
291
in unsaturated lipid molecules, where are double bonds located?
within fatty acids only
292
the beetroot qs (red pigment cannot pass out of cells)
in ethanol, phospholipids dissolve so pigment passes out
in dilute hcl, protein denatures so pigment passes out
293
unsaturated —> saturated fats / what property of fats has changed?
their hydrocarbon chain will fit together more closely
extra: uns are liquids at room temp and s are solids!
294
trigylcerides have a LOWER ratio of oxygen to carbon than
carbohydrates (this is also the reason they release greater amounts of
energy!)
295
trigylcerides are
hydrophobic
296
non-polar fatty acid chains can be attracted to
each other by
hydrophobic interactions
297
function of triglycerides is like
energy storage mainly
298
which juice contains the greatest mass of non-reducing sugars?
mass of ppt before hydrolysis is due to reducing sugars! so substract the
mass before and after to get mass of non-reducing sugars
mass of ppt directly proportional to mass of reducing sugar
299
when its just reducing sugars, you can use either the reducing or non
reducing test cuz it doesnt make a diff
add hydrolytic enzyme and heat w benedicts
boil w hcl, neutralize and then heat w benedistcs
NOT - dissolve in water, neut and then heat LMAOO
300
which may contain non reducing sugars?
when there’s a diff in intensity of color in the reducing and non-reducing
sugar tests ykwim
301
[cellulose related] what is the significance of the fact that the oh groups
on carbon 2 in adjacent glucose molecules are on opposite sides of the
molecule?
they can form hydrogen bonds with adjacent oh and ch2oh groups
of other cellulose molecules
302
semi-quantitative test
provides indication of relative concentrations
color of solution approximately tells u conc of rs (benedicts is a sq test)
303
the working of a colorimeter
colored solution = less light transmitted when compared to colorless
solution
less light transmitted = more light absorbed
as intensity of color increases, absorbance increases!
y axis will be absorbance
304
serial dilution =
solution reduces by a percentage of the previous
solution
305
when an enzyme is present
biuret test will give a purple color
306
only reactions where there is an obvious color change can be
investigated using a
colorimeter
307
no solid particls formed during
benedict’s test
308
triglycerides are not suited for cell surface membrane cuz
no phosphate
polar group; cant form hydrogen bonds with water; cant form bilayer
309
triglycerides > carbs cuz
less mass needed to provide same energy /
low(er) mass to energy ratio
310
mention that water is
dipolar
311
mportancd of water as a solvent in plants
1. dissolves ions and minerals and named polar substances
2. transport of solutes through xylen
3. storage of solutes in vacuole
4. metabolic reactions occur in water
312
peptide bond is stronger than any
tertiary structure bond
313
unless specific amino acid chain given
primary structure can’t be seen
314
secondary
areas of random arrangements are shown
315
tertiary:
3d / globular / interaction of r groups / folding of polypeptide
chain or secondary structure
316
globular proteins can have
quarternary structure also
317
triglycerides have a large
mass per unit volume (more energy released)
318
if a specific protein is mentioned
go over its functions and type first (for
example, if collagen is mentioned, say fibrous / structural function
319
fats over carbs?
lower mass to energy ratio
higher carbon to hydrogen ratio (more ch bonds)
320
polysac over glucose?
glucose is a reactive molecule
glucose would lower water potential
compact and insoluble points (give preference to these 2)
321
description of bonds
h bonds bwtween polar groups (co and nh)
ionic bonds between ionised amine and carboxylic acid groups
hydrophobic interactions between non polar side chains
disulphide between cysteine (s-h) groups
*when they ask to explain tertiary mention folding/coiling
322
state why tri and phospholipids cannot be described as polymers
not composed of monomers / repeating subunits
323
define polymer
macromolecule made up of many repeated subunits called monomers
324
h bonds dont stabilise mrna cuz
mrna is single stranded (no helix)
325
hb contains
nitrogen it seems
326
dna contains
phosphate it seems
327
phospholipids and antibodies contain
nitrogen
328
high lov
water is liquid over a wide range of temperatures
329
dna has a loose helix
/ collagen has a tightly coiled helix
330
secondary structure has a regular order/pattern based
on h bonds
between co group of one amino acid and nh group of another
331
proteins / amylose can form
helical structures (glycogen cannot form
helical structure)
332
hydrophilic means it can form h bonds with
water
333
for ser, its fluid filled channels or sacs NOT
flattened
334
phospholipids may have nitrogen / or an additional group like
choline
335
globular proteins are water soluble
can form h bonds w water
336
enzymes are
macromolecules
337
If glucose is hydrolysed and boiled with Benedict's solution
it tests negative
338
: Enzymes do NOT have
quaternary structure
339
Peptide bond is the last to break as temperature of enzyme is increased
Next is disulphide.
340
Tertiary structure maintain globular shapes of
enzyme
341
When 2 cysteine amino acids join
they are held together by peptide bonds only
342
Find out the wrong statement. What occurs during protein denatured by pH change
Breaking of peptide bonds leads to loss of active site - incorrect
Disruption of ionic bond b/w amino R groups - correct
Loss of alpha helix b/w amino acid - correct
Loss of tertiary structure which causes loss of function - correct.
343
What level of protein structures are always involved when competitive and noncompetitive inhibitors bind to enzymes?
Competitive and noncompetitive: tertiary structure
344
Explain how amino acids can be close together in an active site by explaining structure of protein.
Further coiling and folding of polypeptide chain
Giving tertiary structure
Held in position by R group interaction
Brings distant amino acid close
344
Globular proteins always have
hydrophilic amino acids to towards the outside and hydrophobic amino acids towards the inside
345
Explain role of H bonds in maintaining secondary structure:
H bonds maintain the alpha helix and beta pleated sheet
346
Describe the hydrogen bonding that occurs between water molecules
Hydrogen bond is a weak bond between oxygen atom of 1 H2O molecule and the hydrogen atom of another H2O molecule
Oxygen is highly electronegative more than H
Oxygen has two lone pairs so it can form 2 hydrogen bonds
Asymmetrical electron distribution
Oxygen has delta - and hydrogen has delta + charge
347
What is the effect of replacing glutamine (polar) with valine (non-polar) in alpha/beta globin?
Glutamine is polar and valine is non-polar
Change in tertiary shape
Change in quaternary structure of haemoglobin
Haemoglobin less soluble
Haemoglobin is less efficient at
transporting oxygen
348
Explain role of H bonds in maintaining tertiary structure:
H bonds stabilise further folding of polypeptide
Between R groups with amine and carboxyl groups
Helps maintain globular shape, 3D shape
349
Function of collagen in the wall of arteries:
1. withstands pressure ;
2. prevents, overstretching / AW ;
3. prevents, bursting
350
Structure of collagen vs. Haemoglobin:
1. 1 polypeptides are not identical (v. 2 identical, α / β, polypeptides) ;
2. triple helix or three, polypeptides / helices (v. 4 polypeptides) ;
3. only composed of amino acids or no, prosthetic group / haem / iron ;
4. (fibrous so) not globular ;
5. no complex folding / AW (v. complex folding) ; A no tertiary structure
6. glycine is repeated every 3rd position / more glycine ;
7. repeating triplets of amino acids / large number repeating amino acid sequences (v. greater variety) ;
8. AVP ; e.g. different primary structure / AW
9. variation in amino acid sequences (v specific sequences)
10. all polypeptides, helical / AW (v. α different to β, polypeptides)
11. hydrogen bonds tussen polypeptides (v. Van der Waals)
12. covalent bonds between molecules (to form fibrils) (v. none)
13. 300 nm long polypeptides (v 5–10nm)
14. each polypeptide over 1000 amino acids (each 141 / 146 amino acids)
351
