1.1 Chemical elements joined together to form biological compounds Flashcards
1
Q
Definition of Molecules
A
A group of atoms bonded together
C6H12O6
2
Q
Definition of Ions
A
Atom or molecules with a net electric charge (+ or -) due to the loss or gain of electron
3
Q
Compounds
A
Formed from 2 or more elements H2O
4
Q
Function of magnesium
A
Constituent of chlorophyll needed for photosynthesis
5
Q
Function of Iron
A
Constituent of hemoglobin
6
Q
Function of Phosphate
A
Making nucleotides e.g ATP, DNA, RNA. Constituent of phospholipids
7
Q
Function of Calcium
A
Structural component of bones and teeth, component of cell walls
8
Q
Structure of water
A
Covalent bonds
Polar
Molecule
9
Q
Polar - water
A
Oxygen is slightly negatively charged
Hydrogen atoms are slightly positively charged
10
Q
Hydrogen bonding
A
Hydrogen bonds exist between water molecules.
The slightly negative oxygen of one water molecule attracts the slightly positive hydrogen atoms of other water molecules
11
Q
High specific heat capacity
A
is the measure of the amount of energy needed to raise the temperature of a fixed amount of that substance by 1ᵒC
A large amount of energy is needed to cause a small rise in the temperature of water - aquatic environments stay stable
12
Q
Universal solvent
A
- unequal distribution electrical charge makes water a good solvent
- polar molecules e.g amino acid, sugar readily dissolve in water
- non polar molecules such as lipids will not dissolve in water
13
Q
Ice is less dense than water
A
- forms an insulating when frozen
- ponds and aquatic habitats do not freeze solid so animals can still swim
-Water expands when frozen
-Ice floats on water
14
Q
High latent heat of vaporisation
A
A lot of energy is needed to evaporate water so organisms use water to cool down (e.g Sweating) and aquatic habitats don’t disappear easily by evaporation
- Transpiration in plants also has a cooling effect on leaves
15
Q
Water is transparent
A
Light can pass through aquatic plants to photosynthesise
Light can pass through the cytoplasm of plant cells to reach the chloroplast
16
Q
High surface tension
A
Cohesion is the tendency of molecules of a substance to attract one another
Cohesion between the water molecules on the surface of the water forms a skin that covers the water
17
Q
Cohesion
A
Water to water
18
Q
Adhesion
A
Water to object
19
Q
Water is a metabolite
A
Water is used in many biochemical reaction e.g as a reactant in photosynthesis
20
Q
Water is a liquid at most temperatures
A
can be used as a transport medium e.g in blood, xylem in plants
21
Q
What compounds are in carbohydrates?
A
Carbon, Hydrogen, Oxygen
22
Q
Functions of carbohydrates
A
- Source of energy
- Store of energy
- Structural support
23
Q
3 main types of carbohydrates
A
- Monosaccharides
- Disaccharides
- Polysaccharides
24
Q
General formula of carbohydrates
A
n(CnH2nOn)
25
Name the 2 glucose monomers
Alpha glucose
Beta glucose
ABBA
26
Definition of isomer
They have the same chemical formula but different structural formulas
27
Functions of monosaccharides
Sweet, soluble
- When C-H and C-C bond are broken - energy released - transferred to make ATP
- As building blocks to make larger molecules
- Intermediates in reactions e.g triose intermediates in respiration and photosynthesis reactions
28
Hydrolysis
Chemical addition of water to break a bond
29
How are disaccharide formed
Formed when 2 monosaccharides join together
30
What is released during a condensation reaction?
Water
31
What's the name of the reaction when 2 monosaccharides join together?
Condensation reaction
32
What's the name of the bond when 2 monosaccharides bond together?
Glycosidic bond
33
What 2 monosaccharides form Sucrose?
glucose and fructose
34
What is the name of the disaccharide formed from glucose and fructose?
Sucrose
35
What's the source of sucrose?
Stored in plants such as sugar beet and sugar canes
36
What is the name of the disaccharide formed from glucose and galactose?
Lactose
37
What 2 monosaccharides form Lactose?
Glucose and galactose
38
What is the source of Lactose?
Milk sugar - main carbohydrate found in milk
39
What 2 monosaccharides form Maltose?
glucose and glucose
40
What is the source of Maltose?
Malt sugar found in seeds such as barley
41
What is the name of the disaccharide formed from glucose and glucose?
Maltose
42
What test detects sugars in solutions?
Benedict's test
43
Benedict's test
Need to heat solution
- Colour changes from blue, green, yellow to a brick read if sugar is present
44
Polymer
A large molecule comprising of repeated monomers, bonded together
45
Monomer
are the individual monosaccharides which join to form the polysaccharide
46
Polymerisation
The process of bonding many monomers by condensation reactions to form one large molecules
47
2 examples of alpha glucose polysaccharides
Starch
Glycogen
48
2 examples of beta glucose polysaccharides
Cellulose
Chitin
49
Polymer made up of alpha glucose molecules bonded together in 2 different ways, forming what 2 polymers?
amylose and amylopectin
50
Startch facts
it is a polysaccharide
insoluble
store of glucose in plants
51
How to test for starch?
Iodine test
52
What colour does iodine change if starch is present?
Brown- orange to blue-black
53
Amylose
-unbranched polymer
-α glucose
-C1-C4 glycosidic bonds
-twists on it's self
54
Amylopectin
-chains of glucose monomers joined with
-C1-C4 glycosidic bonds crosslinked with C1-C6 glycosidic bonds
-α glucose
55
Glycogen
-Main storage product in animals in muscle and liver
-Similar to amylopectin but glycogens C1-C4 bond is shorter than amylopectin so its more branched
-C1-C4 and C1-C6 glycosidic bonds
-α glucose
56
Cellulose
-a structural polysaccharide - cell wall of plants
-β glucose
-C1-C4 glycosidic bonds
-unbranched
-Hydrogen crosslinked bonds
-adjacent glucose molecules rotated 180*
57
Chitin
-a structural polysaccharide
-β glucose
-C1-C4
-Amino acid side chains
-Rotated 180*
-cross linked by hydrogen bonds
*Strong
*Waterproof
*Lightweight
58
What are the compounds of lipids?
Carbon, oxygen, hydrogen
59
Examples of lipids
1. Triglycerides
2. Phospholipids
3. Waxes
4. Steroids
60
Lipids are ......
Non-polar
Insoluble in water
Fats and oils
61
Triglycerides consists of......
One molecule of glycerol
Three molecules of fatty acids
62
What group joined to the long hydrocarbon chain at the end of the fatty acid?
Carboxyl group (-COOH)
63
Saturated fatty acid contains
only C-C single bonds
64
Unsaturated fatty acid contains
at least one C=C double bond
65
Triglycerides are formed as a result of what reaction and which groups of the fatty acid are involved?
condensation reaction
-OH of the glycerol and the -COOH of each fatty acid
66
How many water molecules are removed in the formation of triglycerides?
3
3 condensation reactions
67
For each condensation reaction in a triglyceride what bond is formed?
Ester bond
68
Triglycerides contain
Glycerol
3 fatty acids
NO phosphate
69
Phospholipids contain
Glycerol
2 fatty acids
Phosphate
70
Phosphate head is .....
water loving
polar
hydrophilic
soluble in water
lots of oxygen
71
Fatty acid tail is.....
water hating
non polar
hydrophobic
insoluble in water
no oxygen
72
Waxes are....
Long-chained fatty acids are linked to a long-chained alcohol
Insoluble waxy cuticle
73
Roles of lipids - triglycerides
Energy reserves - Plant (seed), animal (adipose tissue)
Thermal insulation -stored under the skin - insulate against heat loss or heat gain
Protection - stored around delicate organs - kidney
Metabolic water - released during chemical reactions in the body
74
Roles of lipids - phospholipids
Biological - cell membrane
Electrical insulation - myelin sheath surrounding axons of nerve cells
75
Cause of heart disease
-fatty deposit sin the coronary arteries
- high blood pressure
76
High density lipoproteins
when food has been absorbed at the small intestine
-Diet in high saturated fats
-Increase in low density lipoproteins
-Atheroma deposited in coronary
-Angina, myocardial infarction
77
What 2 compounds combine to make lipoprotein?
Protein and lipids
78
The higher the ratio of high density lipoproteins : low density lipoproteins in a persons blood, the lower the risk of.......
cardio-vascular and coronary heart disease
79
What compounds are in proteins?
Carbon, Hydrogen, Oxygen and NITROGEN
some sulphur contains phosphorus
80
What is a monomer of protein called?
Amino acid
81
What is a polymer of protein called?
Polypeptide
(chain of amino acids)
82
What 3 groups form amino acid?
1. Variable R group
2. Carboxyl group (-COOH)
3. Amino acid (-NH2)
83
What's the name of the bond that joins 2 amino acids (dipeptide) And what's the reaction?
Peptide bond
Condensation reaction
84
Primary structure of a protein
Simple
-20 different amino acids
-Peptide bonds join the amino acids
85
Secondary structure of a protein
Hydrogen bonds
-long polypeptide chain twists into a 3D shape
1. Alpha helix
2. Beta pleated sheet
86
Tertiary structure of a protein
alpha helix of a secondary protein can be folded and twisted to give a MORE complex 3D structure
-Hydrogen bonds
-Ionic bonds
-Disulphide bonds
-Peptide bonds
Hydrophobic interaction
87
Quaternary structure of a protein
2 or more tertiary bonded together
-Hydrogen bonds
-Ionic bonds
-Disulphide bonds
-Peptide bonds
Hydrophobic interaction
e.g red blood cells
88
Globular proteins - hemoglobin
-hemoglobin consists of 4 polypeptide chains
-spherical
-own specific shape
-soluble
-easily changed chemically- unstable
-Metabolic functions
89
Fibrous proteins - collagen
-consists of polypeptides laid down in parallel chains
-very stable, insoluble, strong
- a single collagen fiber consists of 3 polypeptide chains that's twisted in a alpha helix form
-Hydrogen bonds
-similar shapes
-Structural functions
90
What iron containing group is in a globular protein? And what does it do?
- center of each polypeptide chain is an iron-containing group called haem
-Heam contains an iron ion - each iron ion can bond with one molecule of oxygen
- each hemoglobin can pick up four oxygen molecules
91
What's the food test of proteins?
Biuret changes from blue to purple
92
Qualitative
result indicates whether food group is present or not
don't know how much is present
93
Semi-quantitative
different colour changes can indicate different concentration
94
Quantitative
actual value for the concentration of food group present
colorimeter
