Topic 1 Biological molecules Flashcards
(166 cards)
1
Q
what are three examples of monomers
A
amino acids, monosaccharides, nucleotides
1
Q
what are the two isomers of glucose
A
Alpha and Beta
2
Q
what happens during a condensation reaction
A
monomers are joined together to make polymers
3
Q
what happens during a hydrolysis reaction
A
polymers are broken down and turn back into monomers
4
Q
name three monosaccharides
A
glucose, fructose, galactose
5
Q
what are the three disaccharides
A
maltose sucrose lactose
6
Q
monosaccharides that make maltose
A
glucose + glucose
7
Q
monosaccharides that make sucrose
A
glucose + fructose
8
Q
monosaccharides that make lactose
A
glucose + galactose
9
Q
what are the bonds formed between monosaccharides
A
glycosidic bonds
10
Q
what does the condensation of amino acids form
A
proteins
11
Q
what does the condensation of two monosaccharides produce
A
disaccharides
12
Q
what do many disaccharides produce
A
polysaccharides
13
Q
what is hydrolysis
what does it require
what does it produce
A
- the reaction that breaks down large biological molecules
- the reaction requires water
-splits larger molecules into its smaller components
14
Q
what does the condensation of fatty acids and monoglycerides form
A
lipids
15
Q
what is a benefit of hydrolysis?
A
smaller molecules produced can easily diffuse into cells or be transported using protein channels
16
Q
what does the hydrolysis of proteins produce
A
amino acids
17
Q
hat does the hydrolysis of disaccharides produce
A
monosaccharides
18
Q
what does the hydrolysis of lipids produce
A
fatty acids and monoglycerides
19
Q
what differs phospholipids to other triglycerides
A
phospholipids consist of two fatty acids and a phosphate group instead of three fatty acids attached to glycerol
20
Q
what do phospholipids form when they submerged into water
A
micelles
21
Q
what are the two subtypes of fatty acids
A
saturated and unsaturated
22
Q
what structure would a saturated fatty acid have
A
only single car carbon bonds
23
Q
what is a physical property of saturated fatty acids
A
tend to be solid and room temp
24
trait of the structure of unsaturated fatty acid
have at least one double carbon bond
25
name given to a fatty acid with more than one double carbon bond
polyunsaturated acid
26
property of unsaturated fatty acids
tend to be liquid at room temp
27
what are some vague functions of lipids 4 points
protect vital organs
prevent evaporation of water in plant (waxy cuticle)
insulates the body
myelin sheath around some neurons
28
define non polar
has no overall charge
29
define hydrophobic
repels water therefor does not dissolve in it
30
what are the three main components of triglycerides
fatty acids
glycerol
ester bonds
31
why are lipids containing many unsaturated fatty acids liquid at room temperature
because the unsaturation causes kinks in the straight chains so that the fatty acid chains do not pack closely together
32
why do lipids have such a high energy content
high ratio of C-H bonds
33
what is esterification
the formation of a triglyceride from one glycerol and 3 fatty acids in 3 condensation reactions eliminating three molecules of water
34
what are triglycerides
a type of lipid
35
what is the structure and properties of triglycerides
non-polar
high ratio of CH bonds (lots of energy stored in them)
hydrophobic
low mass to energy ratio (therefor good for storage)
36
what are phospholipids
modified triglycerides that are important in the formation of cell membranes
37
what is the structure of phospholipids that allow them to form a phospholipid bilayer
the head/phosphate end is (hydrophilic) whereas the tail is hydrophobic is hydrophobic
when the molecule comes in contact with water the hydrophobic ends turn inwards in the membrane to form a phospholipid bilayer
38
term for having both hydrophobic and hydrophilic ends
amphipathic
39
relate the structure of phospholipids to their chemical properties and their functional role in cellular membranes
.they are amphipathic
.form a bilayer where the hydrophilic heads face outwards making soluble molecules unable to pass through a membrane
40
how does the cell membrane of an arctic fish differ from a tropical fish
.arctic fish will have an increased amount of unsaturated fatty acids to prevent the cell membrane from becoming too rigid
41
what type of proteins do all enzymes have and what does this mean
globular proteins
they are highly folded and soluble in water
42
what monomers are proteins made out of
amino acids
43
what are the 5 general structures present in proteins
A central carbon atom
An amino group (-NH2)
A carboxyl group (-COOH)
A hydrogen atom (-H)
An R group or a variable side group
44
what is the test for proteins and describe
.biuret test
.add equal volume of biuret solution
(sodium hydroxide and copper sulphate) to the sample solution
.colour change from blue to lilac indicates positive results
45
what happens during a hydrolysis reaction
process where a water molecule is added to a dipeptide and the peptide bond is broken to release two amino acids
46
what is a dipeptide
a molecule formed from two amino acids that are joined by a peptide bond
47
what happens during a condensation reaction with two amino acids
the hydroxyl (OH) in the carboxyl group of one amino acid reacts with the hydrogen (H) in the amino group of another amino acid
to form a peptide bond between the carbon of one amino acid and the nitrogen of another
48
what is the name for the resulting chain of many hundreds of amino acids
polypeptide
49
what is the primary structure of any protein
the sequence of amino acids in a polypeptide chain formed via polymerisation
50
what does the primary structure of a protein determine
determines the its ultimate shape and hence its function
51
what is the secondary structure of a protein and why is this because of the hydrogen bonds shared
the shape that the chain of amino acids makes (either alpha or beta pleated sheet)
Hydrogen in the -NH has a slightly positive charge whereas oxygen in the -C=O bond has a slight negative
resulting in weak hydrogen bonds to form into either alpha or beta
52
what are the three main monomers learnt
amino acids
nucleotides
monosaccharides
53
what polymer do amino acids make
protein
54
what polymer do nucleotides make
DNA
55
what 3 polymers do monosaccharides make
starch
glucose
cellulose
56
benefit of hydrolysis
breaks larger molecules into smaller ones that can easily diffuse into cells or be transported using protein channel
57
what does hydrolysis of carbohydrate produce
disaccharides and monosaccharides
58
what does hydrolysis of lipids produce
fatty acids and monoglycerides
59
benedict's on non-reducing sugars
.non reducing sugars will show negative result (sucrose is non-reducing)
.boil and add HCL to hydrolyse the non-reducing sugar
.neutralise the solution with sodium hydrogen carbonate
.repeat benedict's
.colour change shows presence
60
what does ATP stand for
adenosine triphosphate
61
(brief) role of glucose during respiration
during cellular respiration energy released from glucose helps to make adenosine triphosphate
62
4 brief functions of starch
.main energy storage material in plants
.starch is stored in the seeds of plants
.broken down into glucose by plants when more energy is needed
.starch can act as a source of food for humans and animals
63
why is energy stored as starch and not glucose in plants
-it is insoluble in water and so does not effect the water potential in a cell
-is compact allowing for more energy to be stored
64
what is the test for starch and describe
the iodine test
.add few drops of iodine solution into sample and observe colour change
.change from orange to blue-black indicates starch presence
65
what two polysaccharides make starch
amylopectin and amylose
66
features of amylopectin
.has a long branched structure
.this makes it ideal for quick energy release
67
feature of amylose
.a long unbranched helical structure
.making it ideal for storage
68
how is glycogen formed
by the condensation reactions of alpha-glucose molecules
69
main function of glycogen and why is it suited for this
.main energy storage material in animals
.it is a compact and highly branched molecule (similar to amylopectin)
.when animals need to release its structure makes it easy for glucose to be quickly released
70
what is glycogenolysis
process of glycogen being broken down to release glucose when blood glucose levels decrease
71
3 points on cellulose structure
.is a long chain of beta-glucose
.beta-glucose molecules are linked by glycosidic bonds to form linear cellulose chains that are unbranched
.microfibrils are strong fibres that are made of many cellulose chains that are held together by hydrogen bonds
72
what is the function of cellulose and why are they best suited
.acts as a major component of cell walls that offer structural support (because of the strength of the microfibril fibres that they are made out of)
73
what are the two types of starch, their structure and therefore what they are good at
amylose-unbranched-good for energy storage
amylopectin-branched-good for quick energy release
74
what three elements form carbohydrates
hydrogen
carbon
oxygen
75
what are triglycerides
a type of lipid mainly used as energy storage molecules
76
how are triglycerides formed
condensation of 1 molecule of glycerol and 3 molecules of fatty acid
77
how does condensation reaction occur to form triglycerides
ester bonds form between the glycerol and fatty acid chains
one water molecule released per triglyceride formed
three molecules of water released per triglyceride formed
78
what are phospholipids
a type of lipid that forms a bilayer (they are the main component of cell membranes)
79
what is the main difference between saturated and unsaturated fatty acids
the hydrocarbon tail
80
describe test for lipids
Emulsion test
-add ethanol to sample
-shake solution
-mixture will form white milky layer in presence of lipid
81
what do amino acids form
proteins/polypeptides
82
what are dipeptides
formed from condensation of two amino acids
83
what is the structure of amino acids
.each has a central (alpha) carbon atom
.central carbon atom has four atoms bonded to it
-NH2 (amine group)
-COOH (carboxyl group)
-H (hydrogen group)
-R (a side group)
84
5 aspects of basic amino acid structures
central (alpha) carbon
amine group
carboxyl group
hydrogen atom
R group
85
what does R group determine
how the amino acid interacts and bonds with other amino acids in a polypeptide
86
what is the only amino acid without a carbon atom in its R group
glycine
87
how many different amino acids are there
20
88
what two end terminals of two amino acids and joined during condensation reaction
amine terminal and carboxyl terminal
89
what are the four main functions of proteins
transport proteins
structural proteins
antibodies
enzymes
90
what is the role of channel proteins
transport molecules across the cell membrane that are too large to diffuse freely or molecules that carry a charge
91
role of structural proteins
.are long, strong polypeptide chains
.they are connected by cross-links that hold the chains parallel to each other
92
role of antibodies
(made up of polypeptide chains)
.are used in the immune response
.antibodies are diverse proteins each with a different sequence of amino acids
93
role of enzyme and brief structure
.biological catalysts
.increase the rate of a reaction without being used up
.they are tightly folded, complex proteins that are soluble
94
describe the test for proteins
Biuret test
.add sample to distilled water and biuret solution
.shake well
.test changes from blue to violet in presence of proteins
95
when will a biuret test be negative
if it only contains free amino acids as it tests for peptide bonds
96
what are 3 examples of proteins with quaternary structure
collagen
haemoglobin
insulin
97
when can quaternary structure take place
when there are multiple polypeptides
98
describe the lock and key model
enzyme and substrate fit together perfectly
the substrate is a key fitting into a lock
99
describe induced fit model
.enzyme and substrate come together and their interaction causes a small shift in the enzymes structure
.shift means enzyme and substrate can bind to form complex and catalyse reaction
100
what determines the shape of the enzyme active site and what else can change its shape
.the 3D tertiary structure
.environmental factors can change tertiary structure of the active site (and denature it)
101
how does PH affect enzyme controlled reactions
. Change PH changes number of OH and H ions surrounding the enzyme
.these interact with the charges on the enzyme's amino acids
.resulting in a change in tertiary structure
102
how does increasing temperature effect enzyme controlled reactions
.increasing temperature will increase kinetic energy
.this increases chance of collision between enzyme and substrate, making them more likely in a set period of time
.increasing rate of reaction
.extreme temperature increase will change enzyme structure and denature it
103
explain increasing substrate concentration on rate of reaction 4 points
.increases the number of substrate molecules that can form enzyme-substrate complexes at any one time
.this increases initial rate of reaction
.but when all enzyme molecules are engaged in complexes rate cannot increase further
.rate will then plateau because enzyme is said to be saturated
104
what do competitive inhibitors do and what are they
.Competitive inhibitors have a similar shape to usual substrate and affect the active site directly
.the bind to the active site blocking access for the formation of ES complexes
.they are chemicals that slow down rate or stop reaction altogether
105
what is the function of non competitive inhibitors and structure 4 step explination
.are not shaped complementary to the active site
.they bind to the allosteric site of an enzyme
.changing the shape of the enzyme/active site
.causing it to no longer be complementary to the substrate molecules
106
two ways to calculate rate of reaction
-decrease in reactants/time
-increase in products/time
107
three main uses of water
reactant in cells (photosynthesis, hydrolysis)
provides structural support in cells
keeps organisms cool to maintain optimum body temperature
108
how is water polar
oxygen atoms are slightly negatively charged
hydrogen atoms are slightly positively charged
109
what are the five useful properties of water
.cohesive
.good solvent
.good metabolite
.high heat of vaporisation
.high heat capacity
110
why does water have cohesive properties and why is that useful
. cohesion is the strong attraction between water molecules due to hydrogen bonds
.cohesion produces surface tension
111
why is water a good solvent
.water is a polar molecule (positive end attracts negative ions negative end attracts positive ions )
..ions and polar molecules can easily dissolve in it
112
what does water being a good metabolite mean
.is used or formed in many metabolic reactions such as condensation or hydrolysis
113
what is waters high heat capacity caused by
hydrogen bonding between water molecules
114
what are the three components of ATP
adenine
ribose
3 phosphate groups
115
what simply is the function of ATP
used to power most energy-requiring cellular reactions
116
what is formed when ATP is hydrolysed
ADP
117
what does ADP stand for
adenosine diphosphate
118
what enzyme catalyses ATP hydrolysis
ATP hydrolase
119
what does DNA stand for
deoxyribonucleic acid
120
What isomer of glucose is cellulose made of
Beta glucose
121
what does RNA stand for
ribonucleic acid
122
what are the two polymers made from the monomer nucleotide
DNA
RNA
123
what are the three components of a nucleotide
phosphate group
pentose sugar
nitrogenous base
124
what are the four bases in DNA
thymine
guanine
cytosine
adenine
125
what is the sugar in DNA called
deoxyribose sugar
126
what is the sugar in RNA called
ribose
127
what are the four bases in RNA
adenine
guanine
cytosine
uracil
128
how do nucleotides join to form polynucleotides
nucleotides join via condensation reactions between the phosphate group of one nucleotide and the sugar of another forming a phosphodiester bond
129
how many hydrogen bonds form between adenine and thymine
2
130
how many hydrogen bonds form between cytosine and guanine
3
131
what word is used to describe the positioning of the polynucleotide strands in the double helix when they run in opposite directions
antiparallel
132
what two nitrogenous bases are purine
adenine and guanine
133
what two (technically 3) nitrogenous bases are pyrimidines
thymine
uracil
cytosine
134
136
Contents of ATP
Ribose molecule
Adenine molecule
Three phosphate groups
137
ATP stands for…
Adenosine diphosphate
138
2 general uses of ATP hydrolysis in cells
Hydrolysed to aid energy requiring reactions in cells
Release inorganic phosphate to phosphorylate other compounds making them more reactive
139
simple stages of DNA replication
DNA helix are unwinds DNA and breaks hydrogen bond between bases
Double helix unwinds
New DNA nucleotides attracted to exposed bases on template strands and base pairing
DNA polymerase joins adjacent nucleotides through condensation
140
141
How are triglycerides formed
Condensation of one molecule of glycerol and three molecules of fatty acid
142
what bond is between glycerol and fatty acid
Ester
143
How are phospholipids different to triglycerides
one fatty acid is substituted by a phosphate containing group
144
What are phospholipids made from
One glycerol
Two fatty acids
One phosphate containing group
145
What 2 things are added in an emulsion test
Alcohol
Water
146
4 parts of general protein structure
Central carbon C
Amine group NH2
Carboxyl group COOH
R group Side chain R
147
Bond between amino acids ?
Peptide
148
149
What are the 5 properties of water
Metabolite
Solvent allowing for transportation
High specific heat capacity so buffers temp change
Large latent heat of evaporation cooling effect
Cohesion
150
What property of water helps to prevent temp increase in a cell
High specific heat capacity so buffers changes in temperature
151
152
The two ways in which hydrolysis of ATP is used in cells
Providing energy for other reactions
Phosphorlate others substances to make them more reactive
153
Describe how an ATP molecule is formed from its component molecules
3 phosphate
1 adenine group
-ribose group
Formed through condensation of ADP + Pi by ATP synthase
154
equation for the reaction catalysed by ATP synthase
ADP + Pi = ATP + H2O
155
Suggest why human ATP synthase is not inhibited and bacterial synthase is by a specific inhibiting enzyme
Enzyme active site shape is too specific
Enzyme cannot bind to human cells to form a complex
Due to different tertiary structure
156
Two ways in which ATP is a suitable energy source for cells to use
Releases energy instantaneously/ readily available
Can be rapidly resynthesised
157
How is ATP resynthesised in cells
From ADP and Pu
By ATP synthase
During respiration
158
How to test for presence of lipids
Add ethanol
Add water
Shake
Should turn white/milky
159
How is an ester bond formed in a phospholipid molecule
Condensations between glycerol and fatty acid
160
what is a single repeating unit form which larger molecules are made
A monomer
161
Describe structure of Dana
5 marks
Double helix structure
Sugar phosphate backbone joined by phosphodiester bonds
Complementary base pair
joint together by hydrogen bonds
Nucleotides join together by peptide bonds
Polymer of nucleotides
162
What is the role of single stranded DNA fragments in replication
A template that determines the order of bases to form complementary base pairs
163
2 differences between ATP and DNA
ATP had 3 phosphate groups
ATP does not have a deoxyribose sugar but a ribose sugar
164
What end does DNA helix ask attached at
3’
165
What side does dna polymerase attach at
5’
166
