biological molecules Flashcards
1
Q
What is a monomer
A
smaller units which can create larger molecules
2
Q
what is a polymer
A
molecules made from a large number of repeated monomers joined together
3
Q
what is a saccharide
A
sugar
4
Q
3 examples of monomers
A
nucleotide, amino acid and monosaccharides
5
Q
3 examples of polymers
A
dna, protein and starch
6
Q
what is condensation
A
a reaction that joins two molecules together with a chemical bond involving the elimination of a molecule of water
7
Q
what is hydrolysis
A
a reaction that breaks down a chemical bond between two molecules and involves the use of water molecules
8
Q
how are biological polymers formed
A
from their monomers by condensation
9
Q
how are biological monomers formed
A
broken down from their polymers by hydrolysis
10
Q
what is a unit of carbohydrates called
A
saccharides
11
Q
what is a monosaccharide
A
monomers from which larger
carbohydrates are made
12
Q
what group is sugar a part of
A
carbohydrates (containing C, H, O)
13
Q
3 examples of monosaccharides
A
glucose, fructose and galactose
14
Q
3 examples of disaccharides
A
sucrose, maltose and lactose
15
Q
3 examples of polysaccharides
A
starch, cellulose and glycogen
16
Q
how is a glycosidic bond formed
A
a condensation reaction between two monosaccharides
17
Q
how are disaccharides formed
A
condensation of two monosaccharides
18
Q
formula for alpha glucose
A
C6H12O6
19
Q
draw alpha glucose
A
search on google
20
Q
draw beta glucose
A
search on google
21
Q
what is an isomer
A
same molecular formula, different structure
22
Q
what are the two isomers for glucose
A
a- glucose and b-glucose
23
Q
what is the disaccharide maltose formed by
A
a- glucose + a- glucose
24
Q
what is the disaccharide sucrose formed by
A
glucose + fructose
25
what is the disaccharide lactose formed by
glucose + galactose
26
how are polysaccharides formed
condensation reaction between many glucose monomers
27
notes on glycogen
found in animals, made from a- glucose, highly branched and store of glucose
28
notes on starch
found in plants, made from a- glucose, highly branched and store of glucose
29
notes on cellulose
found in plants, made form b- glucose, parallel long single chains, hydrogen bond cross linkages, used for cell wall strength
30
what bond do carbohydrates form
glycosidic
31
what bond do proteins form
peptide
32
what bond do lipids form
ester
33
what bond do nucleic acids form
phosphodiester
34
what makes a sugar 'reducing'
can donate electrons
35
what makes a sugar 'non reducing'
gains electrons (cannot donate electrons, therefore cannot be oxidised)
36
how do you find out the chemical formula of a disaccharide
add all the carbons, hydrogens and
oxygens in both monomers then subtract 2 H and 1 O (for the water molecule lost)
37
why does the liver and muscle cells have a high number of glycogen
higher cellular respiration rate in these cells
38
bond between glycogen monomers
1-4 and 1-6 glycosidic bonds
39
properties of glycogen
helical shape
highly branched
made up of lots of glucose
large molecules
40
how does glycogen's helical shape adapt it for it's function
compact so lots of energy can be stored in small areas
41
how does glycogen being highly branched adapt it for it's function
increases surface area for enzymes to act on making hydrolysis faster
42
how does glycogen being made up of lots of glucose adapt it for it's function
glucose molecules can be obtained through hydrolysis and can be used in respiration
43
how does glycogen being made of large molecules help adapt it for its functions
its insoluable & unable to leave cell freely, this means they won't be lost from the cell & also won't effect water potential
44
is starch less dense and more soluble than glycogen, what does it mean
glycogen is less dense, more soluble, broken down rapidly, indicating higher metabolic requirements of animals compared with plants
45
bond between starch monomers
1-4 glycosidic bond in amylose, 1-4 and 1-6 in amylopectin
46
properties of starch
helical shape
can be branched or unbranched
insoluble
made of lots of glucose
large molecues
47
how does starch's helical shape adapt it for its function
compact, lots of glucose can be stored in a small space
48
how does starch being insoluble adapt it for its function
doesn't affect water potential, so water isn't drawn in by osmosis, also can't leave cell
49
how does starch being made of lots of glucose adapt it for its function
glucose molecules can be obtained through hydrolysis and can be used in respiration
50
how does starch having large molecules adapt it for its function
insoluble, and unable to leave the cell freely, can't be lost from cell
51
properties of cellulose
straight chains and microfibrils
52
how does cellulose having straight chains adapt it for its function
chains are close together allowing hydrogen bonds to form between the -OH groups resulting in collective strength
53
how does cellulose having microfibrils adapt for its function
chains of cellulose are grouped into microfibrils and fibres for more strength
54
how do cellulose molecules have to be arranged in order to join eachother
alternate molecules need to be inverted due to beta glucose having opposite hydroxyl groups
55
what bond is found between chains in cellulose
hydrogen
56
how to test for starch
add food sample in test tube with iodine, if present it goes from orange/yellow to blue black
57
how to test for a reducing sugar
equal volumes of food sample and benedicts reagent and heat, if a reducing sugar is present it will go from blue to orange/red (it can go from blue, green, yellow, orange or red depending on how much is present)
58
how to test for non reducing sugars
do benedicts test, if no colour change, get new sample of non reducing sugar, add HCL then heat, then neutralise with alkali sodium hydrogencarbonate, repeat benedicts when neutral, if present will turn red/brown
59
what function do lipids serve
storage of energy
60
why are lipids insoluble in water
b/c they're non polar so don't attract water molecules but dissolve in alcohol
61
what is a polar molecule
slight positive at one end, slight negative at the other end
62
draw glycerol
.
H
|
H - C - OH
|
H - C - OH
|
H - C - OH
|
H
63
draw a fatty acid
.
O
||
HO - C - R
64
what are triglycerides
condensation w/ 1 glycerol molecule and 3 fatty acids
3 water molecules eliminted in the process
fatty acids have general formula RCOOH
ester bonds between fatty acid & glycerol
65
what is esterfication
the forming of an ester bond, between O&C
66
draw the ester bond in triglycerides
O
||
O - C
67
what is a saturated fatty acid
all carbon atoms are joined by single bonds
68
what is an unsaturated acid
atleast one double bond between carbon atoms
69
what does hydrophilic mean
interacts with water
70
what are phospholipids made of
glycerol, 2 fatty acid chains, phosphate (the head is hydrophilic while the tail is hydrophobic)
71
what's are the properties of triglycerides
lots of carbon hydrogen bonds
low mass to energy ratio
large non polar molecules
high ratio of hydrogen to oxygen atoms
72
explain why triglycerides have lots of carbon hydrogen bonds
these bonds have high ratio of energy storing bonds so lots of energy is released when broken down
73
why do triglycerides have low mass to energy ratio
lots of energy can be stored in a small molecule
74
why are triglycerides large non polar molecules
so they're insoluble in water & does not affect water potential of cells
also can't escape cell
75
explain why triglycerides have a high ratio of hydrogen oxygen atoms
release water when oxidised so provides water
76
how is the structure of phospholipids related to it's properties
polar molecules
in aqueous environment they form bilayer --> water soluble substances can't easily pass membrane
hydrophilic heads attracted to water inside & outside of cell so point outwards
hydrophobic tails point away from water
77
how do you test for lipids
add ethanol and water to food sample
then shake
if lipid is present it will turn cloudy white emulsion
78
how does an unsaturated fatty acid affect its hydrocarbon tail
it makes it kink (bend slightly) they can't pack together tightly
so they're not as straight as saturated fatty acids
79
why are lipids not considered polymers
they are formed from fatty acids and a glycerol molecule not repeating units of a single monomer
80
draw an amino acid
.
R
|
H(little 2)N -- C -- COOH
|
H
81
what varies the 20 different amino acids
the R chain
82
when do peptides form
when the carboxyl group on one amino acid reacts w/ the amine group on another
this forms peptide & water due to condensation
83
how do amino acids form peptides
carboxyl group reacts w/ amine group
one free amine group at one end and a free carboxyl at the other
84
how do you test for proteins
equal volume of food sample & biuret solution
shake gently
if protein present, goes from blue to lilac
85
what is the primary structure of proteins
sequence of amino acids that are joined w/ a peptide bond
sequence determines overall shape of protein
if the sequence is different, overall shape and function is change
86
what is the secondary structure of proteins
a - helix or b - pleated sheet can be formed
hydrogen bonds between amino group and carboxyl group of two different amino acids
87
what is the tertiary structure of proteins
3d arrangement
formed by disulfide bridges, ionic and hydrogen bonds
this allows it to be recognised by other molecules
88
what is the quaternary structure of proteins
contains more than one polypeptide chain
formed by interaction between different polypeptides & is held together by disulfide bonds
89
description of hydrogen bond in proteins
form secondary structure
between NH groups of one amino acid & C=O group of other
lots in a protein but easily broken
90
description of disulfide bridge in proteins
bond different polypeptide chains together forming quaternary structure
very strong, not easily broken
91
description of ionic bond in proteins
formed between carboxyl & amino groups that aren't involved in forming peptide bonds
weaker than disulfide bonds
easily broken by change in ph
92
description of peptide bond in proteins
bond between amino acids in a chain formed by condensation reaction, when amine group reacts w/ carboxyl group
water is eliminated during reaction
93
what is formed when enzymes and substrates bind together
enzyme substrate complex, which turns into an enzyme product complex
94
how does the induced fit model work
when a substrate binds to active site, the active site changes shape slightly
95
why can different catalysts be used for the same reaction
shape of active site is the same or different active sites that attach to different parts of a substrate
96
what is it called when the active site has the same shape as the substrate
the active site is complimentary to the substrate
97
what is the effect of ph on enzymes if too high or low
the ionic bonds holding the
enzymes, tertiary structure
together break
98
draw a peptide bond
.
O
||
C -- N
|
H
99
what is an inhibitor
substance that slows down the activity of an
enzyme
some are reversible others are non-reversible.
100
how do competitive inhibitors work
has a similar shape to substrate
this means it can fit into the active site of an enzyme
prevents substrate from binding to active site
so enzyme-substrate complexes are unable to form
101
how do non competitive inhibitors work
non-competitive inhibitor binds to a different part of the enzyme and changes its shape
substrate can't bind
102
non competitive inhibitors never allow enzyme substrate complex to do what
reach it's max
103
what bond does reversible inhibitation form with enzymes
weak hydrogen bonds
104
what bond does non reversible inhibitation form with enzymes
strong covalent bonds
105
what site do non competitive inhibitors bind to
allosteric site
106
what is dna
polymer
deoxyribonucleic acid
holds genetic information
107
what is rna
polymer
ribonucleic acid
transfers genetic information from DNA to the ribosomes
108
what is the structure of a nucleotide
phosphate (circle), pentose (pentagon), nitogen containing organic base (rectangle)
109
what are ribosomes formed by
rna and protein
110
what sugar does dna contain
deoxyribose
111
what sugar does rna contain
ribose
112
what are dna's bases
adenine & thymine
guanine & cytosine
113
what are rna's bases
adenine & uracil
guanine & cytosine
114
what element do all bases in dna and rna contain
nitrogen
115
what sugar do dna & rna both contain
pentose
116
how is a phosphodiester bond formed between two nucleotides
condensation reaction, between phosphate and deoxyribose
117
what is the structure of dna
sugar phosphate backbone
long
helical shape
specific sequence of bases
double helix
hydrogen bonds at bases
118
how does the sugar phosphate backbone support dna's function
provides strength and stability
119
how does being long and having a helical shape support dna's function
compact
stores lot of info in a small space
120
how does having specific sequence of bases support dna's function
allows info to be stored
121
how does having a double helix support dna's function
strands can act as templates
122
how does hydrogen bonds between bases support dna's function
double strands can be easily separaed for replication
123
what are pyrimidines
smaller bases containing single carbon ring structures
124
example of pyrimidines
thymine, uracil, cytosine
125
what are purines
larger bases containing double carbon ring structures
126
examples of purines
adenine, guanine
127
how to calculate percentage of bases in dna
complimentary bases have same %
subtract their total from 100
divide this by 2
this is percentage for other 2 bases
128
differences between dna and rna
dna:
long, double strand helix, thymine
rna:
short single chain, uracil
129
what bond is between complimentary dna bases
hydrogen
130
what carbons are the phosphodiester bonds between
3rd carbon and 5th carbon
131
what is the process of dna replication/ semi conservative replication
enzyme dna helicase unwinds double helix, breaks down hydrogen bonds
both strands act as templates
nucleotides line up in complimentary pairs
dna polymerase joins nucleotides together forming phosphodiester bonds
hydrogen bonds between bases reform
each new dna molecule has one original strand and one new strand
132
what is semi conservative replication and what does it ensure
one strand from template molecule
one strand newly synthesised
ensures new dna is accurate and there is genetic continuity between generations of cells
133
what direction can polymerase add bases from
5' (5 prime end) to 3' (3 prime end)
134
what is the name of the fragment that polymerase makes on the lagging strand
okazaki fragment
135
what is the role of dna helicase
breaks weak hydrogen bonds and unwinds dna
136
what is the role of dna polymerase
catalyses the condensation reaction inwhich nucleotides bond together forming phosphodiester bonds
137
what scientists supported the semi conservative dna replication
watson and crick
138
what experiment proved semi conservative replication
scientists grew bacteria in N15 (dense isotope)
bases contain nitrogen so it becomes incorporated in dna
dna strand is dense and towards bottom
then it's moved to N14 (less dense isotope)
dna copies, 1 strand is N14, other is N15
due to being a mix its in the middle of tube
bacteria divides again in N14
so N14&15 dna stays in middle but N14 dna is near the top in same test tube
139
draw out the semi conservative dna experiment
test tube 1: gen 0 N15 dna near bottom
test tube 2: gen 1 N15&14 dna in middle
test tube 3: gen 2 N15&14 dna in middle, N14 dna at top
140
what is atp
nucleotide derivative
adenosine triphosphate
provides an immediate energy source for cells
141
what is atp formed with
adenine, ribose and 3 phosphate groups
142
draw atp
phosphate (3 circles), ribose (pentagon), adenine (rectangle)
143
what happens when atp is broken down
broken down by hydrolysis
into adp and a phosphate group
catalysed by enzyme atp hydrolase
144
atp being broken down, word equation
atp + h2o --> adp + Pi + energy
145
what does Pi mean
inorganic phosphate
146
when is atp resynthesised
during photosynthesis and respiration
147
how is atp resynthesised
condensation reaction catalysed by atp synthase
adp and phosphate group join to form atp and water
148
atp resynthesised word equation
adp + Pi --> atp + h2o
149
what are the products of hydrolysis of atp used for
Pi made in this reaction can phosphorylate other compounds
this makes compounds more reactive
energy is released
this can be used for essential processes in the organism
150
why is atp useful as an immediate energy source
releases smal manageable amounts of energy so little is lost as heat
energy released instantaneously
can be rapidly synthesised
unable to leave cells
151
why do organisms need to make lots of atp
b/c can't be stored, only lasts a couple of seconds
only small amounts of energy is released at a time
152
where do inorganic ions occur
solution of cytoplasm or body fluids of organisms
some in high concentration, others in very low
153
how are inorganic ions specific
each type of ion has a specific role, depending on its properties
154
examples of inorganic ions
hydrogen ion, sodium ion, iron ion and phosphate ion
155
what is the role of the inorganic hydrogen ion
determines ph of a substance
156
explain how the hydrogen ion works
presence of hydrogen ions lower ph
can affect enzyme function as it can change tertiary structure of enzyme and denature it
157
what is the role of the inorganic iron ion
component of haemoglobin
158
explain how the iron ion works
charged so binds w/ oxygen forming oxyhaemoglobin
oxygen is then transported
159
what is the role of the inorganic sodium ions
co transport of glucose and amino acids
160
explain how the sodium ion works
sodium ion moved out of cell by active transport which creates sodium concentration gradient
this affects water potential
161
what is the role of the inorganic phosphate ion
component of dna and atp
162
explain how the phosphate ion works
component of nucleotides
in dna found as backbone
used to make atp in condensation of adp
163
what bond does water have
covalent bond
164
what does specific heat capacity mean
amount of energy required to raise the temperature of 1kg of a substance by 1*c
165
what are the properties of water
its a metabolite
has high specific heat capacity
dipolar
large latent heat of vaporisation
strong cohesion between water molecules
its a solvent
density
166
what does water being a metabolite mean
involved w/ condensation & hydrolysis reactions like photosynthesis and respiration
167
what does ice act as
an insulator
168
what does water having a high heat capacity mean
buffers changes in temperature
can gain lots of energy without changing temperature
169
what does it mean if water is dipolar
acts as good solvent
170
what does it mean if water have a large latent heat of vaporisation
cooling effect with little evaporative loss
171
what does it mean if water has strong cohesion
cohesion between molecules
water can be drawn up vessel in narrow columns e.g transport in plants
produces surface tension
172
suggest a method other than a colorimeter used to measure the quantity of reducing sugar in a solution with precipitate
filter and dry the precipitate
find mass/weight
