Biological molecules Flashcards
(95 cards)
1
Q
what is water made from and what bonds are there?
A
1x hydrogen
2x oxygen
covenant bonds, hydrogen between water
2
Q
Is water polar/non polar?
A
polar
3
Q
what type of charge does water have?
A
negative
4
Q
where are there hydrogen bonds in water?
A
between water molecules
5
Q
What is a metabolic reaction?
A
any reaction in a living organism that keeps them alive
6
Q
what is a metabolite?
A
a molecule that takes part in a metabolic reaction
7
Q
What is water used in commonly?
A
hydrolysis and condensation
8
Q
what is cohesion?
A
attraction between the same type of molecule
9
Q
what is specific heat capacity?
A
amount of thermal energy to raise 1kg of something by 1 kelvin (or degree)
10
Q
how is water a useful solvent?
A
- Water is a key solvent as lots of metabolic processes occur with water
11
Q
How is water used for thermoregulation?
A
water uses lots of thermal energy when it evaporates
12
Q
How does surface tension work?
A
water has strong cohesion, surface tension when it meets air
13
Q
Why does water have strong cohesion with itself?
A
hydrogen bonds
14
Q
How is the ocean a good habitat?
A
it is thermally stable (temp doesn’t change or fluctuate)
15
Q
what is a Polymer?
A
complex molecules made of lots of monomers joined together
16
Q
how are polymers made?
A
condensation reaction
17
Q
What is released in a condensation reaction?
A
water mol
18
Q
what is a polysaccharide?
A
three or more monosaccharides joined together
19
Q
what is a monomer?
A
Basic molecular units that could form polymers
20
Q
what are carbohydrates made from?
A
carbon, hydrogen oxygen
21
Q
what are three examples of a monosaccharide?
A
glucose, fructose and galactose
22
Q
What are three examples of a disaccharide?
A
sucrose, lactose and maltose
23
Q
What are three examples of a polysaccharide?
A
starch, glycogen and cellulose
24
Q
What is the general formula of polysaccharides?
A
(CH2O)n
25
What is a triose sugar?
what is an example of this?
3 carbon atoms, glyceraldehyde
26
What is a pentose sugar?
what is an example of this?
5 carbon atoms, ribose
27
What is a hexose sugar?
6 carbon atoms, glucose
28
What are properties of monosaccharides?
good source of energy, reducing sugars, cyclic/straight chains
29
are monosaccharides soluble in water?
yes, insoluble in non-polar substances
30
What is an isomer?
molecules with the same molecular formula as each other but are connected in different ways.
31
What are the two isomers of glucose?
Alpha
beta
32
What is the plane of a molecule?
midline of molecule
33
How do you distinguish between the isomers of glucose?
Alpha - H on top
Beta - OH on top
34
What are the two functional groups in glucose?
Aldehyde, Hydroxyl
35
What are the components of the aldehyde group?
hydrogen, carbon, oxygen
36
What are the components of the Hydroxyl group?
OH
37
How do you identify galactose?
H below plane
38
How do you identify glucose?
H above the plane
39
how do you identify fructose?
5 membered
40
What is a disaccharide?
formed when two monosaccharides are joined together
41
How are disaccharides formed?
condensation reactions
42
What bonds are formed between disaccharides?
glycosidic
43
What does glucose a + glucose an equal?
maltose
44
what does glucose a + fructose equal?
sucrose
45
what does glucose a + galactose equal?
lactose
46
What is the disaccharide molecular formula?
2x monosaccharide but remove 1x H2O
47
What are the disaccharide reducing sugar?
maltose and lactose
48
what is the disaccharide that is a non-reducing sugar?
sucrose
49
what is the name of the glycosidic bond that forms in disaccharide?
1-4 glycosidic bonds
50
how do glycosidic bonds form disaccharides?
Reaction occurs between the hydroxyl groups on C1 (carbon 1), left glucose and C4 (carbon 4), right glucose
51
What reaction breaks glycosidic bonds?
hydrolysis - using water to form the original hydroxyl groups
52
What is the Benedict's test for reducing sugars?
1. Add benedict’s reagent (blue), and bring to boil
2. Positive – coloured precipitate
3. Green --> yellow --> orange --> brick red precipitate = reducing sugar present
53
What is a positive Benedict's result for reducing sugars?
blue to brick red
green --> Yellow --> orange --> brick red
54
How to tell if there is a high concentration of a reducing sugar present in a substance?
the benedicts test will go further along the colours, closer to brick red
55
What is an organic substance?
only contains hydrogen and carbon
56
What is electronegativity?
the attraction of an atom for electrons being shared
57
how are reducing sugars classified?
on their ability to donate electrons
58
What is a reducing sugar?
sugars that donate electrons
59
what are non reducing sugars?
sugars that do not donate electrons
60
what are examples of reducing sugars?
Glucose
Fructose
Galactose
61
how do you improve accuracy of a Benedict's test (reducing)?
1. Filter solution and weigh the precipitate
2. Remove precipitate and use colorimeter
62
What is the benedicts test for non reducing sugars?
1. add dilute hydrochloric acid and heat in water bath until it boils (monosaccharides)
2. neutralise the substance (sodium hydrogen carbonate)
3. add benedicts reagent
63
When might you use a benedicts test for non reducing sugars?
if the test for reducing sugars is negative
64
What is a non reducing sugar?
sucrose
65
What is used to break the polysaccharides into monosaccharides in a non reducing sugar benedicts test?
hydrochloric acid and heat in a water bath until boiling
66
What is used to neutralise the substance in the non reducing sugar Benedict's test?
sodium hydrogen carbonate
67
What is a polysaccharide?
formed when two or more monosaccharides are joined together by condensation reactions
68
What is amylose?
– lots of a-glucose molecules joined together by glycosidic bonds
69
how are polysaccharides formed?
Condensation reactions
70
How are polysaccharides broken?
hydrolysis reactions
71
what is the function of starch?
glucose storage molecule
72
What is the structure of starch and how does it relate to the function?
1. Insoluble --> doesn’t affect the water potential of a cell and cannot leave a cell through osmosis
2. Large molecule and cannot cross the cell membrane to leave the cell.
3. made from glucose a
73
What type of glucose is starch made from?
glucose a
74
What is amylose?
is an unbranched chain of a-glucose
75
What isomer of glucose is amylose?
glucose a
76
What is the function of amylose?
storage molecule
77
how is amylose good for storage?
- The angles of the glycosidic bonds give it a coiled structure, makes it compact
- Hydrogen bonds – stabilises the helix
- Insoluble (cannot be involved in osmosis, change the water potential)
78
What type of bonds stable the helix for amylose?
Hydrogen
79
how is amylopectin branched?
C1-6 Glycosidics
80
How does the structure of amylopectin help its function?
Branched shape - there are more ends available for enzyme hydrolysis in the same time so glucose released more rapidly
81
What is glycogen?
glucose storage molecule for animals and bacteria
82
what isomer is glycogen?
a glucose
83
What bonds does glycogen have?
C1-4 and C1-6
84
How is glycogen adapted for function?
- More 1-6 glycosidic bonds – chains are shorter and more branched (compact)
- Easy for hydrolysis as only need a water molecule (used as a respiratory substrate – molecule used in respiration)
85
What is cellulose?
in cell walls
86
what isomer is cellulose?
B glucose
87
What bonds are in cellulose?
C1-4
hydrogen
88
How is cellulose adapted for function?
- every second glucose molecule is inverted to form a straight chain
- Hydrogen bonds – weak but lots of them (crosslinked)
- Resists digestion by enzymes
- Reinforcement structure creates a semi rigid cells: allows plant to grow up without skeleton
89
What is a cellulose microfibril?
Microfibril – hydrogen bonds join to cellulose polymers to form a cellulose microfibrils
90
What is a cellulose macrofibril?
Macrofibrils – lots of microfibrils joined together to make the cell wall
91
What is cellulose's function?
provides support to the plant cell walls. Can resist turgor pressure.
92
What is the bonds for carbohydrates?
glycosidic
93
what are the bonds for lipids?
ester
94
what are the bonds for proteins?
peptide
95
what are the bonds for nucleic acids?
phosphodiester
