Biological Molecules Flashcards
(76 cards)
1
Q
Monomer Definition
A
- smaller units from which larger molecules are
made.
2
Q
Polymer definiton
A
- molecules made from a large number of monomers
joined together.
3
Q
3 examples of monomers
A
Monosaccharides, amino acids, nucleotides
4
Q
reaction that joins two molecules?
A
Condensation reaction
5
Q
a condensation reaction involves
A
- Formation of a bond
- Elimination of water molecule
6
Q
reaction that seperates two molecules?
A
- Hydrolysis
7
Q
a hydrolysis reaction involves
A
- Breaking chemical bond
- Uses molecule of water
8
Q
Monomer of carbohydrates
A
Monosaccharides
9
Q
what are the different monosaccharides
A
- Glucose
- Fructose
- Galactose
10
Q
monomers of lactose
A
- glucose
- galactose
11
Q
monomers of sucrose
A
- glucose
- fructose
12
Q
monomers of maltose
A
- glucose
- glucose
13
Q
what bond is formed between monosaccharides
A
glycosidic bond
14
Q
how is a glycosidic bond formed + what does it consist of
A
- Condensation reaction
- Formation of chemical bond
- Releases molecule of water
15
Q
isomers of glucose?
A
- alpha glucose
- beta glucose
16
Q
what’s the difference between the two isomers?
A
H and OH reversed
17
Q
test for reducing sugars
A
-add benedicts to sample
heat in water bath
18
Q
what does a positve test show
A
red/orange ppt
blue -> green -> yellow -> orange -> red
19
Q
test for non-reducing sugars
A
-HCL to sample boil - sodium hydrogencarbonate -benedicts to sample heat in water bath
20
Q
why is sodium hydrogencarbonate used
A
to neutralise the HCL
21
Q
what are polysaccharides
A
condensation of many glucose units
22
Q
3 examples of polysaccharides are?
A
- cellulose
- starch
- glycogen
23
Q
what isomer of glucose is used for each polysaccharide
A
cellulose - b glucose
starch - a glucose
glycogen - a glucose
24
Q
where is glycogen found
A
in animals
25
what are the 4 main properties of glycogen
- insoluble
- large
- lots of side branches
- compact
26
insoluble advantage
doesn't affect water potential
27
large advantage
doens't diffuse out
28
lots of side branches advantage
more active sites for enzymes to act on
| quicker hydrolysis + release of glucose
29
where is starch found
in plants
30
two components of starch are?
- amylose
| - amylopectin
31
two key properties of starch
- insoluble
| - large
32
structure of amylopectin
- a glucose
| - long branched
33
what are side branches useful for
more active sites for enzymes to act on
| quicker hydrolysis + release of glucose
34
structure of amylose
- a glucose
- long unbranched
- good for storage
35
why is amylose good for storage
- coiled
- compact
- so more can be stored in small space
36
test for starch
- iodine in iodide potassium solution
37
positive result for starch?
blue/black colour
38
where is cellulose found
in plants
39
what is the role of cellulose
structural ( cell walls)
40
what isomer is cellulose made of
b glucose
41
structure of cellulose
- straight cellulose chains
- held together by hydrogen bonds
- forming microfibrils
42
hydrogen bonds in large numbers=
more strength
43
microfibrils provide
structural strength
44
which polysaccharides have 1,4 links
cellulose
amylopectin
amylose
glycogen
45
which polysaccharides have 1,6 links
amylopectin
| glycogen
46
two groups of lipids
phospholipids
| triglycerides
47
structure of triglycerides
3 fatty acids
| 1 glycerol
48
bond between 1 fatty acid + glycerol
ester bond
49
what reaction joins the fatty acids + glycerol
condensation reaction
forms a bond
releases molecule of water per bond
50
structure of phospholipids
2 fatty acids
glycerol
phosphate molecule
51
a fatty acid is known as a
hydrocarbon 'tail'
52
test for lipids
sample + ethanol
shake
add water
53
positive result
milky emulsion
54
the R group of a fatty acid can be
variable
| saturated or unsaturated
55
what does it mean if the R group is unsaturated
has one or more double bond between the carbon-carbon
56
properties of phospholipid
forms a bilayer
due to hydrophobic head and hydrophilic tail
so is barrier to water-soluble substances in centre
57
properties of triglyceride
insoluble - doesn't affect water potential
| C-H bonds - store LOTS of energy
58
roles of lipids (5)
- energy reserve (C-H)
- insulator
- protection
- insoluble in water= reduces water loss/waterproofing
- source of water
59
what happens if lipids are hydrolysed
produces fatty acids
| lowers pH
60
similarities in phospholipids + triglycerides
- contain glycerol
- contain ester bonds
- contain C, H, O elements
- fatty acids in both = saturated/unsaturated
- both insoluble
61
differences in phospholipids + triglycerides
- phospholipids= 2 fatty acids, triglycerides= 3
- phospholipids = phosphate molecule
- phospholipids= hydrophilic head, hydrophobic tail
- phospholipids= form bilayers/micelles
62
monomer of proteins
amino acid
63
2 amino acids is called
a dipeptide
64
what bond is between amino acids
peptide bond
65
what reaction forms a peptide bond
- condensation reaction
- formation of a chemical bond
- releases molecule of water
66
the R group in an amino acid
variable
| allows for 20 different amino acids
67
test for proteins
sample + sodium hydroxide solution
| + copper II solution
68
positive result
purple
69
what is the primary structure
- order of amino acids
| - peptide bonds between amino acids
70
secondary structure
- folding of polypeptide chain
- due to hydrogen bonds
- forms a-helix structure or beta-pleated sheet
71
tertiary structure
- 3-D folding due to:
- ionic bonds
- disulphide bridges **(sulfur + sulfur)**
- hydrogen bonds
72
quaternary structure
2 or more polypeptide chains
| e.g collagen, insulin, haemoglobin
73
what shape are globular proteins
compact
| spherical
74
properties + roles of globular proteins
metabolic roles
water soluble
e.g haemoglobin
75
what shape are fibrous proteins
long
| thin
76
properties + roles of fibrous proteins
insoluble
composed of many polypeptide chains
structure roles
e.g keratin, collagen
