1a Biological Molecules Flashcards
1
Q
What are monomers?
A
Smaller units from which larger molecules are made
2
Q
What are polymers?
A
Molecules made from a large number of joined monomers
3
Q
Give examples of monomers
A
Amino acids
Nucleotides
Monosaccharides
4
Q
What’s a condensation reaction?
A
Joins two molecules together with the formation of a chemical bond and involves the elimination of a molecule of water
5
Q
What’s hydrolysis
A
A reaction that breaks a chemical bond between two molecules and involves the use of a water molecule
6
Q
What are monosaccharides
A
The monomers that carbs are made from
7
Q
What are common monosaccharides?
A
Glucose
Galactose
Fructose
8
Q
What bond forms during a condensation reaction in a carb
A
Glycosidic bonds
9
Q
What are disaccharides?
A
Formed by the condensation reaction of two monosaccharides
10
Q
What is maltose made of
A
Glucose and glucose
11
Q
What is sucrose made of
A
Glucose and fructose
12
Q
What is lactose
A
Glucose and galactose
13
Q
How could you separate a mixture of monosaccharides
A
Chromatography
14
Q
What are glucoses isomers
A
Alpha
Beta
15
Q
What are polysaccharides
A
Formed by the condensation reaction between many glucose units
16
Q
Which structures are made of alpha glucose?
A
Glycogen
Starch
17
Q
Which structure is made of beta glucose
A
Cellulose
18
Q
What’s the biochemical test for reducing sugars
A
Benedict’s solution heated
19
Q
What’s the biochemical test for starch
A
Iodine/potassium iodide
20
Q
What are the two groups of lipids
A
Triglycerides
Phospholipids
21
Q
How are triglycerides formed
A
Condensation
Glycerol and three fatty acids
22
Q
What bonds are formed between a glycerol and a fatty acid?
A
Ester bond
23
Q
What is a phospholipid
A
When one of the fatty acids is replaced with a phosphate group
24
Q
How do you test for lipids
A
Emulsion test
“White milky emulsion forms”
25
What can be saturated or unsaturated
The R group of a fatty acid
26
What’s the monomer of proteins
Amino acids
27
What’s the structure of an amino acid
R
H2N C. COOH
H
28
What’s an amine group?
NH2
29
What is different between the 20 different amino acids?
The R group
30
What bond forms during a condensation reaction of amino acids
Peptide bonds
31
What does a functional protein usually contain
One or more polypeptides
32
What test is used for proteins
Biuret test
33
What’s a reducing sugar
Sugar that serves as a reducing agent
All monosaccharides and some disaccharides
34
What’s a hexose sugar
Sugared made of 6 carbons
35
What’s the formula of glucose
C6h1206
36
What’s the structure of starch
2 polysaccharides- amylopectin (branched chain due to 1-6 glycosidic bonds) and amylose (straight chain that forms coils)
37
What’s the properties of amylose
Coiling makes it compact and more can store in a smaller place
38
Properties of amylopectin
Branches increase surface area for enzymes to hydrolyse glycosidic bonds allowing glucose to be released quickly
39
What are the uses of starch
Storing excess glucose in plants as it is too large to leave cells and is insoluble- doesn’t dissolve and doesn’t affect water potential
Can be hydrolysed to release glucose for respiration
40
What’s the structure of glycogen
Long branched chain with lots of side branches
The glycosidic bonds are 1-6
41
What are the properties of glycogen
Branches increase surface area for enzymes to hydrolyse glycosidic bonds allowing glucose to be released quickly
It’s a good compact molecule for storage
42
What are the uses of glycogen
Animals store excess glucose as glycogen in the liver then its used as an energy store as it is hydrolysed easily for respiration
43
What’s the structure of cellulose
Long unbranched straight chains
The glycosidic bonds are 1-4
Cellulose chains are then linked by hydrogen bonds between the glucose molecules to form thicker fibres called micro fibrils
44
What are the properties of cellulose
H-bonds between cellulose chains make microfibrils very strong but still flexible- support
45
What are the uses of cellulose
Provides support in plant cell wall and allows cells to become turgid
46
What’s hydrophilic
Section of molecule attracted to water
Phosphate group
47
What’s hydrophobic
Section of molecule repulsed by water
Fatty acids
48
49
What isn’t a polymer
Lipids
50
What are the bonds in triglycerides
Ester bond between each oh on the glycerol and the oh group on each fatty acid chain
They are non polar
51
What are the properties of triglycerides
Fatty acids are hydrophobic so they are insoluble in water
They bundle together as droplets bc the tails face inwards and glycerol heads shield from water
The hydrocarbon fatty acid chains can be saturated or unsaturated.
52
Eg of triglyceride
Used as an energy store as a lot of energy is released when fatty acid chains are broken down
53
What are the bonds in a phospholipid
Ester bond between 2 oh groups on the glycerol and the oh group on each fatty acid chain
54
What are the properties of a phospholipid
Phosphate group is hydrophilic and fatty acid chains are hydrophobic so they form bilayers that make up cell membranes
55
What’s a disulphide bridge (proteins)
Bond formed between sulphur atoms in R groups of amino acids
56
What’s the primary structure of a protein
The sequence of amino acids that make up the polypeptide of a protien
Can determine 3d shape and therefore affect active site in enzymes
57
What’s the secondary structure
The way in which the chain of amino acids of the polypeptides of a protein is folded
H bonds form between amino acids in the chain making it stable
This causes it to coil into an alpha helix or a beta pleated sheet
Most channel proteins are made of alpha helices
58
What’s the tertiary protein structure
The folding of a whole polypeptide chain in a precise way as determined by the amino acids its composed of
The 3d structure
Can involve H bonds, ionic bonds and disulfide bridges between R groups
A change to the sequence of amino acids would affect the secondary and tertiary structure as these bonds form in different places
All enzymes, antibodies and some hormones have tertiary structure
59
What’s the quaternary structure of a protein
A number of polypeptide chains linked together
Sometimes associated with non protein groups to form a protein
Antibodies and haemoglobin are examples
60
What do proteins contain
Carbon hydrogen nitrogen and oxygen
61
What are enzymes
Catalyse specific metabolic reactions at a cellular level
Proteins with a 3d structure
62
What is it called when a substrate is attached to an enzyme
Enzyme substrate complex (they are complementary)
63
How do enzymes speed up reactions
They lower the Ea by allowing reactions to happen at a lower temp
This is bc they hold them close together reducing repulsion so they can bond more easily or put more strains on the bonds so they break more easily
64
What’s the lock and key model
The shape of an active site is exactly complimentary to the specific substrate molecule and it fits in exactly when they collide to form an es complex
65
What’s the induced fit model
New evidence shows the active site is not exactly complimentary to the substrate. When the substrate collides with the enzyme, the active site can change shape to fit around the substrate and form an es complex
66
What’s the effect of increasing enzyme concentration on the rate of reaction
Increases no of active sites available to collide with the substrate
More es complexes can form
RoR increases until the amount of substrate becomes the limiting factor
Graph- steady increase then sudden plateau
67
What’s the effect on the RoR when increasing the substrate concentration
Increase RoR
More collisions so more complexes form
The RoR will slow as the enzyme concentration becomes the limiting factor
When all active sites are full=saturation point
Graph- increase then starting to stop (curve)
68
What effect does increasing the temp have
More Ek so molecules move faster so more collisions so more complexes form
Each enzyme has an optimum temp where increasing the temp decreases the rate.
This is bc the enzyme molecules vibrate too much so bonds break so tertiary structure breaks.
The active sites changes shape and no more complexes can form-enzyme is denatured permanently
69
What effect does increasing the pH
All enzymes have an optimum temp and pH either 2 or 7
Above and below this the H+ ions and OH- ions distrust the ionic and hydrogen bonds holding the tertiary structure together
At extremes, the enzyme is permanently denatured
70
What’s an enzyme inhibitor
When enzyme activity is prevented or slowed by molecules (an inhibitor)
71
What’s competitive inhibition
They have a similar shape to that of the substrate
Compete w/ the substrate to bind to the active sites
They block the active site so the substrate can’t bind so no complexes are formed.
72
What will increasing the conc of the substrate do to the rate of reaction of a competitive inhibitor
Increases
Will reverse the effects of the inhibitor as the substrate will outcompete for the active sites
73
What’s a non competitive inhibitor
Do not bind to the active site
Have a diff shape to the substrate
Bind to a site away from the active site- the allosteric site
Causes the active site to change shape so it is no longer complimentary to the substrate so no es complex is formed
74
What will increasing the conc of the substrate do to the rate of reaction of a non competitive inhibitor
Not affected
They can’t bind to the active site
75
What elements are common to all molecules of life
C
O
H
76
What are the four main groups of carbon based molecules common to all life forms
Carbs
Lipids
Proteins
Nucleic acids
77
Which molecule forms part of the plasma membrane
Phospholipids
78
Which two biological molecules are the main respiratory substances
Lipids
Carbs
79
What type of bond is formed between monomers
Covalent
80
Why are enzymes catalysts
Thy aren’t used up in the reaction
81
Why is the benedicts test known as a semi-
quantitive test
Bc it tells you how much sugar there is but not exactly how much
82
