module 2- biological molecules Flashcards
(273 cards)
1
Q
which 4 elements are the most important in living organisms ?
A
- hydrogen
- oxygen
- carbon
- nitrogen
2
Q
which 2 elements are also really important for living organisms ?
A
- phosphorous
- sulfur
3
Q
what is bonding determined by ?
A
- the number of unpaired electrons present in the outer orbitals of different elements
4
Q
how many bonds to carbon atoms from with other atoms ?
A
4
5
Q
how many bonds can nitrogen atoms form with other atoms ?
A
3
6
Q
how many bonds can oxygen atoms form with other atoms ?
A
2
7
Q
how many bonds can hydrogen atoms form with other atoms ?
A
1
8
Q
what is a covalent bond ?
A
a strong bond where 2 atoms share a pair of electrons
9
Q
what is an ionic bond ?
A
1 atom in a pair donates an electron and the other receives it forming 1 positive ion and 1 negative ion, held together by opposite charges
10
Q
what is an ion ?
A
an atom/molecule where the total number of electrons isn’t equal to the total number of protons
11
Q
what type of ion is positively charged and what type of atom is negatively charged ?
A
cation - positive
anion - negative
12
Q
what are hydrogen bonds ?
A
a slightly negatively charged atom binds to a slightly positively charged hydrogen atom
13
Q
what are molecules contained carbon described as ?
A
organic
14
Q
which elements are in water ?
A
hydrogen
oxygen
15
Q
what elements are in a carbohydrate ?
A
carbon
hydrogen
oxygen
16
Q
what elements are in a lipid ?
A
carbon
hydrogen
oxygen
17
Q
what elements are in a protein ?
A
carbon
nitrogen
hydrogen
sulfur
oxygen
18
Q
what elements are in nucleic acid ?
A
- carbon
- nitrogen
- oxygen
- hydrogen
- phosphorus
19
Q
what happens when mineral ions are dissolved in solution ?
A
they are electrolytes
20
Q
what are calcium ions used for ?
A
nerve impulse transmission
muscle contraction
21
Q
what are sodium ions used for ?
A
nerve impulse transmission
kidney function
22
Q
what are potassium ions used for ?
A
nerve impulse transmission
stomatal opening in leaves
23
Q
what are hydrogen ions used for ?
A
catalyzing many reactions
ph regulation
24
Q
what are ammonium ions used for ?
A
used by bacteria to make nitrate ions
used by plants to make up proteins
25
what are nitrate ions used for ?
the form plants take up nitrogen
used by plants to make proteins
26
what are hydrogen carbonate ions used for ?
to maintain blood plasma pH
27
what are chloride ions used for ?
to balance positive charges of sodium and potassium ions in cells
28
what are phosphate ions used for ?
- Phospholipid formation for cell membranes and nucleic acids
- ATP formation
29
what are hydroxide ions used for
- catalyzing reactions
- pH regulation
30
what is an anabolic reaction ?
where smaller molecules join to form larger ones
31
what is a catabolic reaction ?
where larger molecules are broken down into smaller ones
32
what is a monomer ?
a small single molecule which joins together to make a polymer
33
what is a polymer (macromolecule )
a large molecule made up of monomers
34
what is a condensation reaction ?
when 2 molecules join together involving the removal of water
35
what is a hydrolysis reaction ?
when a molecule is split apart involving the addition of water
36
what is a hydrolysis reaction ?
when a molecule is split apart involving the addition of water
37
what is starch used for ?
an energy store for plants
38
how is starch formed ?
alpha glucose molecules joined by glycosidic bonds to form 2 different polysaccharides
39
what are the 2 types of starch ?
amylopectin
amylose
40
what substance in plants is stored by starch
glucose
41
how is amylose formed ?
by alpha glucose molecules joined together by 1-4 glycosidic bonds
42
give properties of amylose
- helix shape ( formed by long chains of glucose which twist ) - these are stabalised by hydrogen bonds
43
how does the helix shape of amylose help with its function ?
it makes the polysaccharide more compact and less soluble than the glucose molecules used to make it
44
how is amylopectin formed ?
by 1-4 glycosidic bonds between alpha glucose molecules and glycosidic bonds between carbon 1-6 via condensation reaction
45
what type of shape / structure does amylopectin form ?
a branched structure
46
what is glycogen used for ?
in animals and fungi it is used as an energy storage molecule
47
glycogen forms more branches than amylopectin, how is this useful ?
it makes it more compact, needs less space to be stored
animals are more mobile so use more energy so need more energy storage space
48
how does branching help with glycogen ?
- lots of free ends where glucose can be added or removed
- this speeds up the process
of storing or releasing glucose
49
what similar properties do amylopectin and glycogen have which makes them good for storage ?
insoluble branches and compact
50
why is starch a good energy store ?
it isn’t soluble so doesn’t affect the water potential of a cell
it is unreactive
it is compact and doesn’t take up much space to store
it releases energy quickly as there are lots of end points to release glucose from via hydrolysis using enzymes
51
why is glycogen a good energy store ?
-it is insoluble
-it has a branched structure = quick energy release
- doesn’t effect water potential of cell
- 1-4 glycosidic bonds = easy to make and break
- coiled up shape, easy to store
-
52
glucose is stored as starch or glycogen until it is needed for what process ?
respiration
53
to release glucose molecules from starch/glycogen, what reaction needs to occur ?
a hydrolysis reaction
54
what does a hydrolysis reaction do ?
addition of water molecules
this reverse the condensation reaction which forms the glycosidic bond
55
how is the hydrolysis reaction catalyzed ?
by enzymes
56
how is the hydrolysis reaction catalyzed ?
by enzymes
57
what is cellulose used for ?
in plant cell walls for structure and support
58
how is cellulose formed ?
by beta glucose which are joined together by every other molecule being flipped 180 degrees
in between each molecule a hydrogen bond links them
59
what type of chain molecule is formed in cellulose
a straight chain molecule
60
cellulose molecules are linked together by hydrogen bonds forming strong fibres
called what ?
microfibrils
61
microfibrils join to form what in cellulose ?
macrofibrils
62
what do macrofibrils join together to form what ?
fibres
63
how are macrofibrils strong ?
- they combine to produce fibres which are interwoven
- they are embedded in a gel like structure called pectin
64
why is cellulose ideal for the structure of cell walls ?
- microfibrils have high tensile strength due to glycosidic bonds betweeen individual glucose molecules and hydrogen bonds holding cellulose chains together
- macrofibrils are criss crossed ( in different directions )
- cellulose is embedded in pectin
65
why is cellulose hard to digest ?
most animals don’t contain enzyme cellulose
cellulose usually passes through digestive system and is used as a source of fibre
66
what are polysaccharides
large polymers made by joining lots of monosaccharides together by condensation reactions making long chains
67
how are monosaccharides joined (bonds)
glycosidic bonds
68
how do you test for simple sugars (all monosaccharides and most disaccharides )
benedict’s test
69
how do you test for non reducing sugars (sucrose)
modified benedict’s test
70
how do you test for starch ?
iodine test
71
what are lipids ?
molecules containing hydrogen carbon and oxygen
generally fats/oils
72
what state are fats at room temperature ?
solid
73
what state are oils at room temperature ?
liquid
74
what are the properties of lipids ?
- they are soluble in organic solvents
- they are NOT soluble in water
- they are non polar molecules
- hydrophobic
75
what does non polar mean ?
the electrons of the molecule in outer orbitals are evenly distributed so there are no positive or negative areas so don’t form hydrogen bonds
76
what does hydrophobic mean ?
repels water
77
what are simple lipids known as ?
triglycerides
78
how many glycerol molecules to fatty acids are there in a triglyceride ?
1 glycerol molecule : 3
fatty acids
79
what chemical group is glycerol in ?
alcohols
80
what chemical group are fatty acids in ?
carboxylic acids (-COOH)
81
what type of bonds form between glycerol and fatty acids ?
ester bonds
known as esterification
82
forming a triglyceride is a condensation reaction, how are 3
water molecules formed ?
- both glycerol and fatty acids have hydroxyl groups
- this forms 3 water molecules and bonds between glycerol and fatty acids
83
what is needed for a triglyceride to break down ?
3 water molecules
then hydrolysis can take place
84
what does a saturated lipid mean ?
there are no double bonds between carbon atoms in fatty acid chains
85
what does an unsaturated lipid mean ?
there is 1 double bond between carbon atoms in a fatty acid
86
what does a polyunsaturated lipid mean ?
there is more than 1 double bond between carbon atoms
87
how are double bonds less compact ? if
double bonds cause the molecule to kink
88
why are unsaturated fats often liquid at room temp ?
there is a kink at double bonds which makes them less compact in arrangement
89
what can lead to obesity ?
excess fat
90
what are phospholipids ?
- modified triglycerides
- contain phosphorus carbon oxygen and hydrogen
91
where are phosphate ions (PO43-) found ?
cytoplasm of cells
92
how are phosphate ions soluble in water ?
they have extra electrons which caused them to be negatively charged
93
what is replaced with a phosphate group to form a phospholipid ?
1 fatty acid
94
the phosphate end of the phospholipid is charged and can therefore dissolve in water, how could we describe this as ?
it is hydrophilic
95
the fatty acid end of a phospholipid is non polar and a long chain of hydrocarbons, what could we call this ?
the hydrophobic end
96
the phospholipid had two ends, what are these 2 ends ?
the tail which is non polar, repelling water and called hydrophobic
the head which is charged, attracting water, and called hydrophilic
97
what does hydrophobic mean ?
repels water
98
what does hydrophilic mean ?
attracts water
99
how to phospholipids work with water ?
they form a layer on the surface of water
phosphate heads are in the water with the fatty acid tails sticking out
100
what are surface active agents/surfactants ?
phospholipids in water
101
describe how phospholipids form a bilayer in water
phospholipids form a 2 layered sheet arrangement with the hydrophobic tails pointing inwards with the hydrophilic heads protecting them from water ?
102
how does the bilayer phospholipids form help with cells ?
- they help to form cell membranes
- they are able to separate the aqueous environment in which cells usually exist from the aqueous cystol within cells
103
how does the bilayer phospholipids form help with cells ?
- they help to form cell membranes
- they are able to separate the aqueous environment in which cells usually exist from the aqueous cystol within cells
104
what are sterols ?
a type of lipid known as steroid alcohols
found in cells
105
how are sterols structured ?
- complex alcohol molecules based on a 4 ring carbon structure with a hydroxyl group at one end
- have hydrophilic and hydrophobic characteristics
106
how are sterols structured ?
- complex alcohol molecules based on a 4 ring carbon structure with a hydroxyl group at one end
- have hydrophilic and hydrophobic characteristics
107
what part of sterols is hydrophobic and what part is hydrophilic ?
hydroxyl group = hydrophilic
rest of molecule = hydrophobic
108
give an example of a sterol ?
cholesterol
109
where is cholesterol made ?
liver
intestines
110
what does cholesterol do ?
plays a role in the formation of cell membranes
111
what does cholesterol do ?
plays a role in the formation of cell membranes
adds stability and regulates fluidity of cell membranes
112
where is cholesterol positioned ?
between phospholipids with a hydroxyl group at the periphery of the cell membrane
113
how does cholesterol regulate the fluidity of cell membranes !
it keeps them at low temperatures and stops them being too fluid at high temperatures
114
give examples of what cholesterol manufactures
vitamin d
steroid hormones
bile
115
give the roles of lipids ?
- membrane formation and creation of hydrophobic barriers
- hormone production
- electrical insulation needed for impulse transmission
- waterproofing
- long term energy storage
116
how are lipids used as a long term energy storage ?
- for thermal insulation to reduce heat loss
- cushioning to protect
vital organs
- adds buyancy for aquatic animals e.g whales
117
how do you test for lipids ?
emulsion test
118
describe how to carry out the emulsion test
- mix sample with ethanol
- mix solution with water
- shake
- if white emulsion forms at the top a lipid is present
119
what is food synergy ?
where nutrients don’t work in isolation, they work as part of the combined effect of a whole range of nutrients
120
which type of fat is healthier and why ?
unsaturated
121
which type of fats do plants generally contain ?
- unsaturated triglycerides, normally as oils
122
what type of fats do animals generally contain ?
saturated triglycerides normally as solids
123
why would people want to find a substitute for butter ?
it his high in saturation as it is made from cows milk
124
how have scientists tried to make butte healthier in the past ?
using vegetable oils and using hydrogen to remove double bonds to make it a solid = MARGARINE
125
why did the initial method of making margarine / healthier butter not work ?
when breaking the double bonds a by product called trans fat was produced
126
what is an advantage of trans fat ?
it increases shelf life
127
what is a disadvantage of trans fat ?
it is linked to corornary heart disease
128
what do scientists now use when making a substitute for butter ?
they use mono/poly saturated plant oils
129
what is an advantage of using mono/polysaturated plant oils in butter substitutes ?
it reduces high cholesterol levels which reduce the development of coronary heart disease
130
what are carbohydrates ?
molecules which contain hydrogen carbon and oxygen
131
what is the formula for carbohydrates ?
(CH2O)n
132
what are carbohydrates also known as ?
saccharides/sugars
133
what are carbohydrates also known as ?
saccharides/sugars
134
what are monosaccharides ?
single, simple sugars
135
give an example of monosaccharides ?
glucose
136
i
137
what are disaccharides ?
complex sugars, 2 monosaccharides joined together
138
give an example of a disaccharide ?
maltose
139
what is a polysaccharide ?
NOT a sugar
2+ monosaccharides joined together
140
give an example of a polysaccharide
glycogen
141
what is the formula of glucose ?
C6H12O6
142
describe the structure of glucose ?
- it is a monosaccharide composed of 6 carbons
- contains 5 OH groups
- has a C:O ratio of 1:1
143
what is a hexose monosaccharide ?
a monosaccharide composed of 6 carbons
144
what are the 2 variations of glucose ?
alpha
beta
145
what are the 2 variations of glucose ?
alpha
beta
146
what is the difference between alpha and beta glucose ?
the OH groups are switched
147
what is the difference between alpha and beta glucose ?
the OH groups are switched
148
glucose molecules are polar, what does this mean ?
they are soluble in water and have hydrogen bonds which from between the hydroxyl groups and water molecules
149
how does glucose being polar a good thing ?
it allows glucose to be dissolved in the cytosal of a cell
150
describe a condensation reaction between 2 glucose molecules ?
2 alpha molecules are side by side and the 2 hydroxyl groups react so the bonds are broken and new bonds are reformed in different places forming new molecules
151
what type of bond is formed between the 2 OH molecules when glucose reacts in a condensation reaction ?
glycosidic bond
152
why is the glycosidic bond in aloha glucose molecules known as a 1,4 glycosidic bond ?
the bond happens between carbon 1 and 4
153
describe the formation of maltose ?
2 hydrogen and 1
oxygen atom are removed form the glucose monomers and join to form water
a bond forms between C1 & C4 forming maltose
154
what is a product of a condensation reaction ?
water
155
what do fructose + glucose make ?
sucrose
156
what type of sugar is sucrose ?
a non reducing sugar
157
what does galactose + glucose make ?
lactose
158
what are pentose monosaccharides ?
sugars which contain 5 carbon atoms
159
give 2 examples of a pentose monosaccharide ?
ribose
deoxyribose
160
where is ribose present ?
RNA nucleotides
161
where is deoxyribose found ?
DNA nucleotides
162
water is a polar molecule, what does this mean ?
it has regions of positivity and negativity
163
where are the regions of positivity in a water molecule ?
the hydrogen atoms with a + charge
164
where are the regions of negativity in a water molecule ?
the oxygen atom
165
why do polar molecules interact with each other ?
the positive and negative regions attract each other
166
how to hydrogen bonds form between water molecules ?
the water molecules attract each other forming hydrogen bonds
167
what are hydrogen bonds ?
bonds which form between molecules
they are weak but occur in high numbers
168
why does water have a high boiling point and is liquid at room temperature ?
- they move around so constantly make and break hydrogen bonds
- it takes a lot of energy to increase the temperature and turn water to gas because of this
169
why is water less dense when solid ?
- it turns to ice when frozen
- the polar nature of water molecules means water makes 4 hydrogen bonds to other molecules forming a spaced out lattice structure which is rigid and open
170
why is water being less dense when solid a good thing ?
it creates a good habitat
it insulated water below
171
what is cohesion ?
when molecules are attracted to each other
172
how are water molecules cohesive ?
their polar nature
173
how is water being cohesive a good thing ?
- it makes it easy to flow
- it helps plants draw water up their roots
- helps when drinking up a straw
174
how does water get a skin of surface tension ?
- the molecules are more cohesive to each other than air
- the surface of water molecules contract resisting the force
175
what does adhesion mean ?
molecules are attracted to other materials
176
water molecules are attracted to other materials, how is this helpful ?
water is attracted to the sides of xylem vessels
177
water can act as a solvent, how is this helpful ?
many solutes in an organism can be dissolved, e.g proteins/amino acids
molecules in blood plasma can be dissolved
helps to transport dissolved compounds in and out of cells
178
water is a solvent and a polar molecule, what does this mean ?
anything polar can dissolve in it
179
anything polar can dissolve in water, why is this helpful ?
cellular reactions can take place in a solution
180
how can water help dissolve things (biological ionic reactions) ?
it is polar so the slight + end attracts the - ion and the slight - end attracts the + ion so ions can fully dissolve in water
181
water has a high specific heat capacity, what does this mean ?
it takes a lot of energy to raise 1 gram of it by 1 degree celsius
182
how is water having a high specific heat capacity helpful ?
- if doesn’t change state or temperature
- it provides a stable environment and a good habitat
- it acts as a coolant as it helps to buffer temperature changes during reactions in cells
- it provides a stable temperature for enzyme controlled reactions
183
water has a high latent heat of vaporization what does this mean ?
it takes a lot of energy to break all the hydrogen bonds between the molecules for it to go from a liquid to a gas (takes lots of energy)
184
why is water having a high latent heat of vaporization helpful ?
it can be used as a cooling mechanism , e.g sweating
185
why is water having a high latent heat of vaporization helpful ?
it can be used as a cooling mechanism , e.g sweating
186
what are peptides
polymers made up of amino acid molecule s
187
what are proteins
consist of one or more polypeptides arranged as macromolecules with specific biological functions
188
what elements to proteins have ?
carbon
hydrogen
oxygen
nitrogen
189
what are amino acids structure ?
basic structure - have an amine group
r group
carboxylic acid group
190
how many amino acids are found in cells ?
20
191
how many non essential amino acids are there ?
5
192
how many essential amino acids are there ?
9
193
how many conditionally essential amino acids are there ?
6
194
what is the synthesis of peptides ?
amino acids join when amine and carboxylic acid groups connect to the central carbon atom
195
what is the synthesis of peptides ?
amino acids join when amine and carboxylic acid groups connect to the central carbon atom
196
how exactly are proteins synthesized
hydroxyl in carboxylic acid group of one amino acid reacts with a hydrogen in the amine group of another amino acid
197
what bonds form between amino acids ?
peptide bonds
198
what kind of reaction happens between amino acids ?
condensation reaction
199
what is produced as a result of amino acids joining together ?
water
200
what kind of compound is 2 amino acids joined together called ?
dipeptic compound
201
what forms when many amino acids are joined together by peptide bonds ?
polypeptide
202
how is the reaction of amino acid joining together (peptide bonds) catalysed ?
enzyme peptidyl transferase which is present in ribosomes
203
how do different proteins differ from each other ?
different r groups of amino acids which make up a protein interact, forming different types of bonds which fold polypeptides into proteins
different sequence of amino acids = different structures = different shapes
204
why are proteins specific shapes ?
they carry out specific functions in living organisms
205
what are the different levels of protein. structures ?
primary
secondary
tertiary
quaternary
206
what is the primary structure in proteins ?
it is the sequence in which amino acids are joined
only peptide bonds involved
directed by information carried in dna
particular amino acids in a sequence influences how the polypeptides told to give the protein it’s final shape = determines function
207
what is the secondary protein structure ?
oxygen, hydrogen, nitrogen atoms of basic structure interact forming hydrogen bonds which pull the amino acid unto different shapes
208
what 2 different shapes do the polypeptides make in secondary structure ?
alpha helix
beta pleated sheet
209
what is the tertiary structure ?
- folding of a protein into its final shape
- coiling/folding of sections of proteins in their secondary structure brings r groups of different amino acids closer together to interact and fold more
210
what interactions /bonds are involved in the tertiary structure ?
- hydrophobic / hydrophilic interactions
- hydrogen bonds
- ionic bonds
- disulfide bonds
211
what is the quaternary protein structure ?
- results from the association of 2 or more proteins called subunits
- interactions between subunits are the same as the territory structure except they are between individual molecules
212
give examples of proteins which are in the quaternary structure ?
hormones
enzymes
213
how do hydrophobic and hydrophilic interactions in the quaternary structure occur ?
- proteins are assembled in an aqueous environment
- the way a protein fold depends on whether the r groups are hydrophilic or hydrophobic
- hydrophilic groups are on the outside
- hydrophobic groups are on the inside
214
how are peptides broken down ?
- protease enzymes reverse the reaction - turning peptides back into their amino acids
215
what type of reaction breaks proteins down ?
- hydrolysis reaction -
water added
216
what are globular proteins ?
- compact, soluble in water usually spherical
217
how do globular proteins form ?
when proteins fold into their tertiary structures
hydrophobic r groups are kept away from aqueous environment
hydrophilic r groups are on outside as they are soluble in water
218
what are globular proteins used for ?
regulating processes needed for life such as chemical reactions
219
give 3 examples of globular proteins ?
- insulin
- haemoglobin
- protease
220
what is the function of insulin ?
regulates blood concentration
hormone that fits into specific receptors in cell surface membrane
221
what is the function of insulin ?
regulates blood concentration
hormone that fits into specific receptors in cell surface membrane
222
what are features of insulin
soluble
precise shape
223
what are conjugated proteins ?
globular proteins which constrain a non protein prosthetic group
224
what are proteins without a prosthetic group known as ?
simple proteins
225
give examples of a conjugated protein ?
haemoglobin
lipoprotein
glycoprotein
226
lipid + protein
lipoprotein
227
carbohydrate + protein
glycoprotein
228
what is the structure of haemoglobin ?
quaternary protein made from 4 polypeptides - 2 alpha + 2 beta subunits
- each subunit has prosthetic haem group
229
how is haemoglobin structured to help it carry oxygen around the body ?
the iron ion in the haem group can combine reversibly with oxygen
230
what is the structure of catalase ?
quaternary protein containing 4 haem prosthetic groups
presence of iron II ions in prosthetic groups allow catalase to interact with hydrogen peroxide + speed up its breakdown
231
what does catalase do in terms of hydrogen peroxide ?
hydrogen peroxide is damaging to cells and a common byproduct of metabolism - catalase helps to break this down to make sure cell damage doesn’t occur
232
what is a fibrous protein ?
organized strong long molecules which aren’t folded into complex 3-D shapes
233
how are fibrous proteins formed ?
from long insoluble molecules due to presence of high proportion of amino acids with hydrophobic r groups
234
what is the structure of fibrous proteins like ?
contains limited range of amino acids with small r groups
amino acid sequence is in primary structure and repetitive
235
give 3 examples of fibrous proteins ?
keratin
elastin
collagen
236
where is keratin found ?
in nails skin and hair
237
describe the structure of keratin ?
has a large proportion of sulfur containing amino acid cysteine - strong disulfide bones
238
what determines keratins flexibility ?
the number of disulfide bonds present
239
where is elastin found ?
elastic fibres present in :
blood vessels
alveoli in lungs
240
what does elastin do ?
gives structures flexibility but so they can return to their normal size
241
describe the structure of elastin ?
- quaternary protein made from stretchy molecules called topoelastin
242
what stretchy molecules are elastin made from ?
tropoelastin
243
what is collagen ?
connective tissue found in skin tendons ligaments and the nervous system
244
how is collagen formed ?
made up of 3 polypeptides wound together
245
describe the structure of collagen !
rope like structure
flexible
246
when is elastin formed ?
when multiple tropoelastin molecules aggregate via interactions between hydrophobic areas
247
why can elastin stretch and recoil ?
tropoelastin molecules contain hydrophobic and lysine rich areas
248
how is the structure of elastin stabilized ?
by cross linking covalent bonds involving lysine
249
what shape does collagen make
triple helix
250
what shape does collagen make
triple helix
251
how does tropocollagen form ?
many hydrogen bonds form between polypeptide chains forming long quaternary proteins with staggered ends
these proteins join end to end
252
how is collagen strong ?
tropocollagen cross links
253
what elements are found in cholesterol ?
H, C, O, N
254
what elements are found in ATP
H C O N P
255
how is water a good solvent ?
- medium for metabolic reactions
- transport
- organisms can take in nitrate ions to help them build proteins
256
which processes involve ester bonds ?
synthesis of triglycerides and polynucleotides
257
what bond holds alpha glucose and fructose together
1-6 glycosidic bond
258
state a physical property of glucose that allows it to be easily physically transported in the bloodstream
- it’s soluble in water
259
how are glucose and cholesterol structurally similar
- both contain carbon
- both have OH groups /hydroxyl groups
260
state similarities between lactose and maltose
- both contain 1-4 glycosidic bonds
- both have 2 6 membered rings
261
give differences between lactose and maltose
- lactose has b glucose
- lactose forms b glucose glycosidic bonds
- sugars in lactose are flipped
- maltose contains a glucose
- both monomers in maltose are the same direction
262
263
why do mammals store glycogen instead of glucose
- glycogen is insoluble = doesn’t effect water potential
- glycogen is metabolically inactive
- glycogen stores lots of energy
264
265
how do lipids suit their role as energy storage molecules in plants and animals
- fats have more c-c bonds / c-h bonds
- fats are energy rich
- more energy stored in less space
- don’t affect water potential of cell
- fatty acids are long carbon chains that can be broken down to release acetyl groups
- animal fats are saturated /harder = role in protection and insulation
266
267
why are triglycerides with less hydrogen atoms have higher melting points ?
- more double bonds
- less saturated
- so lower melting point
268
why do lipids provide buoyancy
less dense than protein
269
270
describe how the structure of llama haemoglobin is different from that of a camel haemoglobin *refer to 4 levels of protein structure
Primary structure =
- different amino acid sequence
- 1 amino acid changed
Secondary structure =
- amino acid could cause change to secondary structure
- initial coiling/folding of polypeptide chain (a helix / beta pleated sheet, h bonding)
Tertiary structure
- amino acid could change this
- further coiling of secondary structure
- (ionic bonding, disulphide bonds, hydrophilic/hydrophobic bonds )
- 3-D
Quaternary structure
- not changed by amino acid
- alpha and beta sub-units are still able to form haemoglobin in camel and llama
271
272
what are polymers composed of
several monomers that are similar in structure
273
if a molecule is more soluble in water what does this suggest about its amino acid r group structure
it has higher polarity
