Biological Molecules Flashcards
1
Q
What is a monomer
A
The smallest unit from which larger molecules are made
2
Q
What is a polymer
A
Molecules made from a large number of monomers joined together
3
Q
What is hydrolysis reaction
A
When water is used to break bonds
4
Q
What is condensation reaction
A
Joins two molecules together with the formation of a chemical bond
- water is produced as a bi product
5
Q
What is polymerisation
A
Forming a polymer from a long chain or monomers
6
Q
What is an organic compound
A
Contains carbon
- found in living things
7
Q
Examples of organic compounds
A
- sugars
- fatty acids
- carbohydrates
8
Q
What elements are carbohydrates made from
A
- carbon
- oxygen
- hydrogen
9
Q
What elements are lipids made from
A
- carbon
- oxygen
- hydrogen
10
Q
What elements are proteins made from
A
- carbon
- hydrogen
- oxygen
- nitrogen
- (sulfur)
11
Q
What elements are nucleic acids made from
A
- phosphorus
- carbon
- oxygen
- hydrogen
- nitrogen
12
Q
What monomers are in carbohydrates
A
Monosaccharides
13
Q
What monomers are in lipids
A
Fatty acids and glycerol
14
Q
What monomers for proteins
A
Amino acids
15
Q
What monomers form nucleic acids
A
Nucleotides
16
Q
What polymers for carbohydrates
A
Polysaccharides
17
Q
What polymers form lipids
A
Triglycerides
18
Q
What polymers for proteins
A
Polypeptide
19
Q
What polymers for nucleic acids
A
Polynucleotides
20
Q
What are covalent bonds
A
- atoms share electrons
- are able to form polar molecules when the electrons are shared unequally
21
Q
What are ionic bonds
A
- atoms give a receive electrons
- charged particles called ions
22
Q
What is hydrogen bonding
A
- weak electrostatic intermolecular bonds formed between molecules containing hydrogen
- molecules with an uneven charge distribution is polarized
23
Q
What bonding takes place in water
A
Hydrogen bonding
- delta positive hydrogen bonds with delta negative oxygen from two different water molecules
24
Q
Properties of water
A
- high surface tension/cohesion
- adhesion
- high specific heat capacity
- high latent heat of vaporization
- solid, liquid and gas
- ice is less dense than water
- universal solvent
25
Biological importance of water having high surface tension
- columns of water in plant vascular tissue are pulled up the xylem tissue together from the roots
- insects like pond-skippers can walk on water
26
Biological importance of water being able to adhere to things
- Evapotranspiration
- tiny tubes in root hairs such water from the soil
- xylem and stomata
27
Biological importance of water having a high specific heat capacity
- living organisms need a stable temperature for enzyme-controlled reactions to happen properly
- aquatic organisms need a stable environment in which to live
- releases heat energy slowly to moderate the Earth’s climate
28
Biological importance of water having a high latent heat of vaporization
- help to cool living things are keep their temperature stable
- water evaporating
29
Biological importance of water being a liquid at room temperature
- provides habitats for living things in rivers, lakes and seas
- form a major component for the tissue in living organism
- provide a reaction medium for chemical reactions
- provide an effective transport system (in blood and vascular tissue)
30
Biological importance of waters density
Ice is less dense then water so :
- aquatic organisms have a stable environment to live in through the winter
- ponds and or their bodies of water are insulated against extreme cold. The layer of ice reduces the rate of heat loss
31
Biological importance of water being a universal solvent
- molecules and ions can more around and react together in water. Many reactions happen in the cytoplasm which is 70% water
- molecules and ions can be transported around living things whilst dissolved in water
32
What is specific heat capacity
The amount of energy required to raise the temperature of 1kg of water by 1C
33
What is latent heat of vaporization
The amount of energy required to change one mole of a liquid into a gas
34
Examples of monosaccharides
Pentose (5 carbons)
- deoxyribose
- ribose
Hexose (6 carbons)
- galactose
- glucose
- fructose
35
Examples of disaccharides
- sucrose
- maltose
- lactose
36
Examples of polysaccharides
- starch
- cellulose
- glycogen
37
What are carbohydrates broken down into
Sugars
- monosaccharide
- disaccharide
Non-sugars
- polysaccharides
38
What are fructose
- very soluble
- sweeter then glucose
- found in fruit and nectars
39
What are galactose
- not as soluble as fructose
- important role in producing glycolipids and glycoproteins
40
What are the two different types of glucose
- alpha glucose
- beta glucose
41
What is the difference between alpha and beta glucose
The placement of the -OH group
- if hydroxyl group is above it is a beta glucose
- if hydroxyl group is below it is an alpha glucose
42
How are disaccharides formed
Hydrogen from one monosaccharide and OH from other monosaccharide attach through condensation reaction
- the covalent bond formed is called a 1-4 carbon glycosidic bond
43
What type of sugar are maltose and lactose
Reducing sugar
44
What type of sugar is sucrose
Non-reducing sugar
45
What monosaccharides make maltose
Glucose + glucose
46
What monosaccharides make lactose
Glucose + galactose
47
What monosaccharide makes sucrose
Glucose + fructose
48
Where are maltose commonly found
The mouth
49
Where is lactose normally found
Milk
50
Where is sucrose normal found
Sugar beet and sugar cane
51
What are the main differences between monosaccharides and polysaccharides
- not sweet, insoluble, not crystalline, compact and dense granules
- large monomers made from monosaccharides joined by glycosidic bonds
- branched chains
- energy storage molecule within cells
- glucose is released for respiration
52
What is the role of alpha-glucose in the body
- energy source
- component of starch and glycogen
53
What is the role of beta-glucose in the body
- energy source
- component of cellulose which provide structural support in plant cell walls
54
What is the role of ribose in the body
- component of ribonucleic acid (RNA), ATP and NAD
55
What is the role of deoxyribose in the body
- component of deoxyribonucleic acid (DNA)
56
What are the two substances in starch
Amylose - 20%
Amylopectin - 80%
57
What is amylose
- component part of starch
- glucose/energy storage in plants found particularly in chloroplasts
- few branches
- highly compact
58
What type of bonds does amylose have
1-4 glycosidic bonds
59
What is amylopectin
- highly branched molecules
- more branches = more energy released
- can be hydrolyzed by amylase quicker then amylose
- more glucose available for respiration
- humans have a higher metabolic demand to plants
60
What type of bonds does amylopectin have
1-6 glycosidic bonds
61
What colour does amylose turn when mixed with iodine
Blue/black
62
What colour does amylopectin turn when mixed with iodine
Stays orange/brown
63
Why is starch such a good storage molecule
- has a high osmotic potential (wont be dissolved in water)
- high number of glucose available at one time
- more glucose are available for respiration
64
Where is glycogen found
Animals
- human liver and muscles
65
What is glycogen
Storage carbohydrate in animals
66
What is the structure of glycogen
- highly branched
- 1-6 glycosidic bond every 20-30 monomers
- contains some hydrogen bonds
- spiraling
- not enough to hold iodine
67
Why is glycogen a good storage molecule
- insoluble = osmotic potential
- highly branched
- large/compact
68
What is the structure of cellulose like
- alternate glucose are inverted
- straight chain
- hydrogen bonds between the -OH groups (intermolecular)
- form bundles called microfibrils
Microfibril -> macrofibril -> fibre
- gives structural support to cellulose cell walls
69
How has cellulose adapted
- insoluble
- large molecule
- many hydrogen bonds
- glycosidic bonds
- criss-cross arrangement of microfibrils
- humans don’t have the enzymes to break them down
- cellulose give us fibre
70
What is the structure of lactose like
- beta glucose
- one glucose monomer and one galactose monomer
- beta glycosidic bonds
- sugars in opposing orientations
71
What is the structure of maltose like
- alpha glucose
- both monomers are glucose
- alpha glycosidic bonds
- both monomers in the same direction
72
What is the structure of amylose like
- coiled
- no glucose are inverted
- granular
- alpha 1-4 glycosidic bonds
73
What is the structure of cellulose like
- no coiling
- alternate glucose is inverted
- beta 1-4 glycosidic bonds
- fibrous
74
What bond do dipeptide have
Peptide bond
75
What type of reaction forms a dipeptide
Condensation reaction
76
What is an amino acid
- monomers of all proteins
- all amino acids have the same basic structures
77
What is a peptide bond
A bond formed when two amino acids are joined by a condensation reaction
78
What is the general structure of an amino acid
H R O
| | ||
N — C — C
| | |
H H OH
79
What is the general formula for a dipeptide
H R O R O
| | || | ||
N — C — C — N — C — C
| | | | |
H H H H OH
80
How many different amino acids are there
20
81
What does glycine have in the R group of the amino acid
Hydrogen
82
What does alanine have in the R group of the amino acid
CH3
83
What does the R group in an amino acid change about the amino acids function
The R group determines how the protein will bond
84
What does amphoteric mean
Attracted to both water and fats
- contains both a hydrophilic and a hydrophobic part
85
What does protein being amphoteric allow it to do
Allows it to act as a buffer
86
How is protein able to act as a buffer
- can ionize as both an acid and a base
- can donate ions to ionize
- if the solution is acidic it accepts H+ ions (amino group)
- if the solution is alkaline it donates H+ ions (carboxyl group)
87
Why can a large variety of polypeptides be formed
100 amino acids in a polypeptide chain
20 different amino acids
20^100 different polypeptide chains
88
What are the different shapes of protein conformations
- primary structure
- secondary structure
- tertiary structure
- quaternary structure
89
What is primary structure
The sequence of amino acids found in protein molecules
90
With is secondary structure
- the coiling and folding of an amino acid chain
- often happens as a result of hydrogen bonds forming between different part of the chain
- alpha helix and beta pleated sheets
91
What is tertiary structure
- the overall three-dimensional shape of a protein molecule
- forms due to interactions including hydrogen bonds, disulphide bridges, ionic bonds and hydrophobic interactions
92
What is quaternary structure
Protein structure when a protein consists of more than one polypeptide chain
- insulin
93
What is a disulphide bond
Strong covalent bond formed by the oxidization of -SH groups of two cysteine side chains
94
What happens when something is hydrophilic
Polar R groups attract other polar molecules like water
95
What happens when something is hydrophobic
Non polar R groups face the inside of the protein
96
What is the function of a globular protien
- compact spherical shape
- soluble in water (hydrophilic side chain)
- metabolic function
- specific 3D shape
97
What is the function of a fibrous protein
- long, parallel chains
- insoluble in water
- peptide chains cross link for strength
- structural molecule
- repeated amino acid sequence
98
Example of a globular protein
- haemoglobin
- enzymes
- transport proteins
- antibodies
99
Example of a fibrous protein
- collagen
- keratin
100
What is the function of haemobglobin
- transports oxygen around the body
101
What is the function of collagen
Provides mechanical strength in blood vessel walls, tendons, bones, cartilage and connective tissue
102
What test is used for protein
Biuret test
- turns purple if protein is present
103
What monosaccharide does amylose contain
Alpha glucose
104
What monosaccharide does cellulose contain
Beta glucose
105
What monosaccharide does glycogen contain
Alpha glucose
106
What type of glycosidic bond does amylose have
1-4
107
What type of glycosidic bond does cellulose have
1-4
108
What type of glycosidic bond does glycogen have
1-4 and 1-6
109
What shape is amylose
Helical structure
110
What shape is cellulose
- straight chain
- unbranched
111
What shape is glycogen
- circular/spherical
- branched
112
Where is the hydrogen bonding in amylose
Within
113
Where is the hydrogen bonding in cellulose
Within and between
114
Are amylose, cellulose and glycogen soluble in water
No
115
What is the structure of triglycerides
Glycerol molecules bonded to three fatty acids
116
What is the structure of phospholipids
Glycerol molecule bonded to two fatty acids and a phosphate group
117
What is the structure of cholesterol
Four carbon based rings
118
What is the role of triglyceride in living organisms
- energy source
- energy store
- buoyancy
- insulation
- protection
119
What role does phospholipids have in living organisms
- membranes
120
What role does cholesterol play in living organisms
- membrane fluidity
- regulation
121
How does the structure of triglycerides help it perform its roles
- high proportion of hydrogen atoms
- low density
122
How does the structure of phospholipids allow it to perform its role
- pelar head attracted to water on outside of membrane
- non polar train on inside of membrane
- provides stability
- controls entry of molecules to cell
123
How does the structure of cholesterol help it perform its role
Small size enables molecule to sit in hydrophobic part of membrane and regulate fluidity
124
How much energy is released on complete breakdown between lipids and carbohydrates
Lipids - 37
Carbohydrates - 17
125
How easy can lipids and carbohydrates be broken down
Lipids - not easily hydrolised, energy is released slowly
Carbohydrates - more easily hydrolised, energy released quickly
126
How soluble are lipids and carbohydrates
Lipids- insoluble in water
Carbohydrates - sugars = highly soluble in water
- polysaccharides = low solubility in water
127
Production of metabolic water in lipids and carbohydrates
Lipids - lots of water produced by oxidation
Carbohydrates - less water produced by oxidation
128
What happens when triglycerides are oxidised during respiration
Energy is releases
129
What are the roles of lipids
- long term energy store
- waterproofing
- insulation
- protection
- cell membranes
130
How are lipids able to help with waterproofing
Lipids are hydrophobic so they repel water
131
How is waterproofing by lipids used by living organisms
- outer layer of leaves to stop water from entering
- causes water droplets to form
- can’t be dissolved in water
- oil se creation from sebaceous gland
- birds have a preen gland to waterproof their feathers
132
Why is fat a good insulator
- stops energy from escaping (thermal/electrical)
- poor conductor of heat and hydrophilic ions
- triglycerides are stored in tissue under the skin
- myelin sheath covers nerve cells
133
What do fats protect
Delicate organs
134
What do phospholipids look like in a cell membrane
O O O O O O O
|| || || || || || ||
|| || || || || || ||
O O O O O O O
135
What is the formation of the phospholipid bilayer
- hydrophilic phosphate group on the outside
- hydrophobic fatty acid on inside
- form a bilayer
136
What is the structure of a triglyceride
O
||
CH20 — C ^^^^^^^^^^
| O
| ||
CH2O — C ^^^^^^^^^^
| O
| ||
CH20 — C ^^^^^^^^^^
^ester bond
137
What is an unsaturated fat
- molecules more spread out (kink)
- liquid at room temperature
- C=C double bond
- vegetable products
- weaker intermolecular bonds
138
What is a saturated fat
- no double bond (C=C)
- molecules compact
- solid at room temperature
- animal products
- max number of hydrogen atoms
- hydrogen chain is long and straight
139
How does the structure of the phospholipid bilayer make the membrane selectively permeable
- hydrophobic/small molecules can pass through
- channel proteins
- pump proteins
140
What is an example of cholesterol
Steroid
141
Examples of cations - inorganic ions
- hydrogen ions (H+)
- sodium ions (Na+)
- calcium ions (Ca^2+)
- potassium ions (K+)
- ammonium ions (NH4+)
142
Examples of anions - inorganic ions
- phosphate ions (PO4^3-)
- nitrate ions (NO3-)
- hydroxide ions (OH-)
- hydrogencarbonate ions (HCO3-)
- chloride ions (Cl-)
143
What is the function of calcium
- increases rigidity of bone, teeth and cartilage and is a component of the exoskeleton
- important in blood clotting and muscle contraction
- activator for several enzymes: lipase, ATPase, cholinesterase
- stimulates muscle contraction and regulates transmission of nerve impulses
- regulates membrane permeability
- important in cell wall development in plants
144
What is the function of sodium
- involved in regulation of osmotic pressure, control of water levels in body fluid and maintenance of pH
- affects absorption of carbohydrate in the intestine and water in the kidneys
- contributes to nervous transmission and muscle contraction
- constituent of vacuole in plants which helps maintain turgidity
145
What is the function of potassium
- involved in controle of water levels and maintenance of pH
- assists active transport of materials across the cell membrane
- involved in synthesis of glycogen and protein and breakdown of glucose
- generates healthy leaves and flowers in flowering plants
- contributes to nervous transmission and muscle contraction
- component of vacuoles in plants helping maintain turgidity
146
What is the function of hydrogen
- involved in photosynthesis and respiration
- involved in transport of oxygen and carbon dioxide in the blood
- involved in regulation of blood pH
147
What is the function of ammonium
- a component of amino acids, protein, vitamins and chlorophyll
- some hormones are made of proteins
- an essential component of nucleic acids
- involved in maintenance of pH in the human body
- a component of the nitrogen cycle
148
What is the function of nitrogen
- a component in amino acids, proteins, vitamins and chlorophyll
- an essential component of nucleon acids
- some hormones are made of protein which contain nitrogen
- a component of the nitrogen cycle
149
What is the function of hydrogen carbonates
- involved in regulation bloods pH
- involved in transport of carbon dioxide into and out of the blood
150
What charge are cations
Positive
151
What charge are anions
Negative
152
What is the test for sugars
Benedicts test
- reducing sugars just place in hot water
- non reducing sugars add hydrochloric acid to hydrolyze
- then add sodium hydrogencarbonate solution to neutralize
- then test for reducing sugars again
Both turn from blue to orange/red if sugars present
153
What test can be used for just reducing sugars
Reagent test strips
- blue to orange/red
154
What test is used for starch
Iodine
- from orange to blue/black
155
What test is for lipids
Emulsion test
- mix with ethanol then add to water
- cloudy means there are lipids present
