Biological molecules Flashcards
(110 cards)
1
Q
What are monomers?
A
Small units which are components of larger molecules
2
Q
What are polymers?
A
Molecules made from monomers joined together
3
Q
What is a condensation reaction?
A
Joins monomers together by chemical bonds. Eliminates a water molecule
4
Q
What is a hydrolysis reaction?
A
Water is added to break a chemical bond between two molecules. (Opposite of condensation)
5
Q
Chemical elements that make up carbohydrates
A
C,H,O
6
Q
Chemical elements that make up lipids
A
C,H,O
7
Q
Chemical elements that make up proteins
A
C,H,O,N,S
8
Q
Chemical elements that make up nucleic acids
A
C,H,O,N,P
9
Q
Which way is the OH group facing on carbon 1 in alpha glucose?
A
Downwards
10
Q
Which way is the OH group facing on carbon 1 in beta glucose?
A
Upwards
11
Q
Glucose properties
A
Water soluble (as the molecule is polar and forms hydrogen bonds)
Provides energy for ATP production
12
Q
What is a monosaccharide?
A
A single sugar molecule
13
Q
What is a disaccharide?
A
A molecule comprising of two monosaccharides joined by a glycosidic bond
14
Q
What is a polysaccharide?
A
A polymer made of many sugar monomers
15
Q
What is a hexose sugar?
A
Monosaccharide with 6 carbons
16
Q
What is a pentose sugar?
A
A monosaccharide with 5 carbons
17
Q
Ribose properties
A
Water soluble
Component of RNA nucleotides
18
Q
Two monosaccharides that make up maltose
A
two alpha glucose molecules
19
Q
Where is maltose found?
A
In germinating seeds
20
Q
Where is glucose found?
A
Fruit
21
Q
Two monosaccharides that make up sucrose
A
alpha? glucose and fructose
22
Q
Where is sucrose found?
A
In phloem tissue and fruit
23
Q
Where is fructose found?
A
Fruit and nectar
24
Q
Two monosaccharides that make up lactose
A
alpha? glucose and galactose
25
Where is lactose found?
In milk/ milk products
26
Where is galactose found?
In milk
27
Which are the most and least sweet out of glucose, fructose and sucrose?
Fructose is the most sweet
Galactose is the least sweet
28
What is the bond formed between to alpha glucose molecules after a condensation reaction?
1,4 glycosidic bond (or 1,6)
29
What is starch?
Many alpha glucose molecules
Glucose is stored as starch.
Two forms
30
What are the two forms of starch?
Amylose
Amylopectin
31
Shape of amylose
Coils into helix (due to hydrogen bonding)
32
Amylose properties
Long chain
Unbranched
alpha glucose
1,4 glycosidic bonds
Compact
Less soluble
(Plants)
33
Amylopectin properties
Long chain
Branched
alpha glucose
1,4 and 1,6 glycosidic bonds
Insoluble
(Plants)
34
Glycogen properties
Chain
Branched - more than amylopectin
alpha glucose
1,4 and 1,6 glycosidic bonds
Compact
Insoluble
(Animals)
35
Why is the breakdown of glycogen faster than amylose?
It has more free ends where glucose molecules can be added or removed. Speeds up the storing/releasing of glucose molecules. Therefore suited to storage role.
36
Cellulose properties
straight - chain molecule
Unbranched
Beta glucose (each alternative one is rotated 180)
1,4 glycosidic bond
Strong
Insoluble (makes cell walls)
37
Formation of fibres from cellulose
Many chains are cross linked by hydrogen bonds to form microfibrils.
Many microfibrils are cross linked to form macrofibrils.
Combine to form cellulose fibres.
38
Why is cellulose important for a healthy digestive system?
It's hard to break down. Forms fibre and roughage.
39
How do the properties of glucose relate to its function?
Polar - soluble in water (dissolve in cytosol of cell)
Small - can travel through the bloodstream and into/out of cells
40
How do the properties of amylose relate to its function?
Helix shape - compact so its energy dense a good storage molecule
Insoluble - doesn't affect water potential
41
How do the properties of amylopectin relate to its function?
Branched - increase surface area for enzyme so can be hydrolysed quickly
Insoluble - good storage molecule
42
How do the properties of glycogen relate to its function?
More branched - compact and energy dense - used for storage
Hydrolysed quickly than starch - animals need glucose faster due to higher metabolic rate
43
How do the properties of cellulose relate to its function?
Mechanical strength - strong fibres due to hydrogen bonding
Insoluble - difficult to break down
Gaps between fibres - permeable cell walls
44
State of lipids at room temperature
Liquid = oils
Solid = fats
45
What is a triglyceride made up of?
Glycerol and 3 fatty acids
46
What bond is there in a trigylceride?
Ester bond
47
Why are lipids non-polar?
Outer electrons form evenly distributed bonds, so there are no +ve or -ve areas
48
What is a macromolecule?
A large complex molecules with a larger molecular weight - containing a lot of atoms
49
What types of reaction is esterification?
Condensation
50
What is saturated?
No double bonds in the fatty acid chain
51
What is monounsaturated?
One double bond
52
What is polyunsaturated?
Two or more double bonds
53
How saturation affects room temperature state?
A molecule with more double bonds cannot pack as closely together - as double bonds make the molecule bend. Therefore they are liquid at room temperature = oils
54
Which is healthier, saturated or unsaturated?
Unsaturated (more double bonds = oils = healthier)
55
What is a phospholipid?
Has a phosphate ion (PO43-) and only two fatty acids.
56
Why is the head of a phospholipid hydrophobic?
Th phosphate ion has extra electrons which are negatively charged, so is hydrophobic (soluble in water).
57
Why are the tails of a phospholipid hydrophilic?
They are non-polar
58
How do phospholipids interact with water?
Form a layer on the surface of the water - they are therefore surfactants
Form cell membranes - bilayer which separates the outside aqueous environment from the cytosol inside the cell. (hydrophobic tails on inside and hydrophilic heads on outside)
59
Where are ester bonds when a trugylcerde/phosphpolipid is formed?
Hydroxyl from COOH on the fatty acid and a H from the hydroxyl group on the glycerol
60
Hydrolysis of triglycerides
3 molecules of water supplied and ester bonds are broken
61
How do the properties of triglycerides relate to their function?
Long term energy storage
Thermal insulation
Cushioning - protect vital organs
Buoyancy for aquatic animals
Electrical insulation around nerves
62
How do the properties of cholesterol relate to their function?
Have a hydrophilic OH group (the rest is hydrophobic).
Regulates fluidity of membranes
Hormone production
63
What are sterols?
Complex alcohol molecules
64
How do the properties of phospholipids relate to their function?
Membrane bilayers
Creating of hydrophobic barriers
65
The general structure of the amino acid
Amine group = basic
R group = variable side chain
Carboxyl group = acidic
66
How many different amino acids are there?
20
67
What bonds are formed between amino acids?
Peptide (covalent)
68
What is a dipeptide?
Two amino acids
69
What is a polypeptide?
Three or more amino acids
70
How is a peptide bond formed?
OH from carboxylic group and H from amine group
71
What is the condensation reaction of amino acids catalysed by?
Peptidyl transferase
72
How do proteins have specificity?
Different amino acid sequence = different bonds/interactions between r groups = folds into different structures with different shapes = specific
73
What is the primary structure of proteins?
Sequence of amino acids
74
Bonds in primary structure
peptide bonds
75
What are the two secondary structures of proteins?
alpha helix
b pleated sheets
76
What happens in secondary structure?
Negatively (weak) charged N an O interact with weakly positive H atoms
77
Bonds in secondary structure
Peptide bonds
Hydrogen bonds
78
What happens in tertiary structure?
Bonds form between R groups
79
Bonds in tertiary structure
Peptide
Hydrogen (weakest but most common)
Disulphide bonds - covalent/ strongest
Ionic - Between oppositely charged r groups (stronger than H bonds but no common)
Hydrophobic/hydrophilic interaction - form between non-polar r groups within interior of protein
80
What is quaternary structure?
2 or more subunits (polypeptides)
Interactions are the same as tertiary but are between protein molecules rather than with one.
81
What is the hydrolysis of polypeptides catalysed by?
Proteases enzymes
82
Structure of globular proteins
Roughly spherical (teritary)
Soluble (hydrophilic r groups on outside, hydrophobic on inside)
Compact
Have a very specific shape
Physiological. functional functions
83
What is insulin?
A globular protein
Hormone secreted by the pancreas that regulates blood glucose concentration
84
Structure of insulin
alpha helix and beta pleated sheet (two polypeptide chains) held by disulphide bridges
85
Why insulin being a globular protein in useful for its function?
Hormones travel in blood so need to be soluble
Need to fit into specific receptors so need specific shapes
86
What are conjugated proteins?
Globular proteins that contain a prosthetic group
87
What is a prosthetic group?
A non-protein component
88
What are proteins without a prosthetic group called?
Simple proteins
89
Examples of prosthetic groups
Lipids - Lipoproteins
Carbohydrates - Glycoproteins
Metal ions
Molecules derived from vitamins
90
What is a haem group?
Contain an iron ion (Fe2+).
91
Structure of haemoglobin
Globular
Conjugated
Quaternary
4 polypeptides (2 alpha and 2 beta)
4 prosthetic haem groups
Iron ion combines with O2 molecules to allow it to carry oxygen around the body
92
Structure of catalase
Enzyme
Quaternary
4 haem prosthetic groups
93
How the structure of catalase relates to its function?
Iron ion allows it to interact with hydrogen peroxide (H2O2) and speed up its breakdown.
H2O2 is a common by-product of metabolism but is damaging to cell/cell components
Catalase ensures it doesn't accumulate - converts H2O2 into H2O and O2
94
Structure of fibrous proteins
Long strands of polypeptide chains - have cross-linkages due to H bonds
Insoluble
Highly repetitive sequence = strong organised structure
High proportion of hydrophobic r groups in primary structure
95
What is collagen?
Connective tissue found in the skin, tendons, ligaments and nervous system.
Forms strong fibres and is used to provide strength
96
Structure of collagen
3 polypeptide chains wound together in a long, rope-like structure
Therefore strong and flexible
97
What is keratin?
Used for hard body parts - fingernails, skin, hair, horns, hooves
98
Structure of keratin
Lots of cysteine (sulphur-containing) = lots of disulphide bonds which are strong
Strong, inflexible and insoluble
The fewer the disulphide bonds, the more flexible.
99
What is elastin?
Found in elastic fibres (in blood vessels and alveoli) - can stretch and recoil due to coiling of elastin molecules and cross-linkages that keep the molecule together
Also found in lungs and bladder
100
Structure of elastin
Quaternary - made from stretchy molecules (tropoelastin)
101
Biological process that Ca2+ ions are involved in
nerve impulse transmission and muscle contraction
102
Na+ ions involved in
nerve impulse transmission and kidney function
103
K+ ions involved in
nerve impulse transmission and stomatal opening
104
H+ ions involved in
pH determination and catalysis of reaction
105
NH4+ ions involved in
production of nitrate ions by bacteria
106
OH- ions involved in
Catalysis of reaction
Bonding between biochemical molecules
Ph determination
107
NO3- ions involved in
present in soil and taken up by plants for amino acid and protein formation
108
HCO3- ions involved in
Maintainence of blood pH
Works with H+ in transport of CO2 in blood
109
Cl- ions involved in
Transport of CO2 in the blood
Moves in and out of red blood cells and maintains PH balance
110
PO43- ions involved in
cell membrane formation and nucleic acid and ATP formation
