Biomolecules Flashcards
1
Q
What is the biological test for starch?
A
- Add a few drops of iodine solution
2. Record any colour change
2
Q
What is the colour change for the biological starch test?
A
Yellow to Dark Blue/ Black (for a positive result)
3
Q
What is the biological test for reducing sugars?
A
- Add 2cm’ of Benedict’s reagent to the solution
- Place in a 90° - 100° water bath for 5 mins.
- Record any colour change
4
Q
What is the colour change for the biological test for reducing sugar?
A
Blue to Red (for a positive result)
5
Q
What is the biological test for non-reducing sugars?
A
- Add 1cm’ of 1M of hydrochloric acid to solution
- Place in a 90°-100° water bath for 2 mins
- Neutralise with sodium hydrogen carbonate
- Add 2cm’ of Benedict’s reagent
- Place in a 90°- 100° water bath for 5 mins
- Record any colour change
6
Q
What is the colour change for the biological test for non-reducing sugar?
A
Blue to Red (for a positive result)
7
Q
What is the biological test for a protein?
A
- Add 2cm’ of 0.4M sodium hydroxide to solution
- Add 0.4M copper (II) sulphate drop by drop
- Shake gently and record results
8
Q
What is the colour change for the biological for a protein?
A
Blue to Purple (for a positive result)
9
Q
What is the biological test for a lipid?
A
- Shake solution with absolute ethanol for 1 min
- Add 2cm’ of water and shake well
- Record observations
10
Q
What is the colour change for the biological for a lipid?
A
Clear to a milky solution (for a positive result)
11
Q
What are the three types of carbohydrates?
A
- Monosaccharides
- Disaccharides
- Polysaccharides
12
Q
Which two carbohydrates for crystals, are soluble, and ?
A
Monosaccharides and Disaccharides
13
Q
What are the 4 functions of carbohydrates? (In humans and plants)
A
- Instant energy source
- Transportable form of energy
- Stored as glucose
- Structural material ( in plants)
14
Q
What is the formula for Glucose?
A
C6H12O6
15
Q
What is the definition of a disaccharide?
A
Two monomers joined together by a condensation reaction
16
Q
What is the definition of a condensation reaction?
A
A reaction between two hydroxyl groups where water is lost and a glycosidic bond is formed.
17
Q
What type of bond is C-O-C?
A
A glycosidic bond
18
Q
What is made from Glucose + Glucose?
A
Maltose
19
Q
What is made from Glucose + Galactose?
A
Lactose
20
Q
What is made from Glucose + Fructose?
A
Sucrose
21
Q
What is the definition of a hydrolysis reaction?
A
Splitting a glycosidic bond using a molecule of water
22
Q
What is the general formula of a monosaccharide?
A
C(H2O)n
23
Q
What is a ring with 6 carbon atoms called?
A
A Hexose
24
Q
Why is glucose a suitable sugar? (4 reasons)
A
- Its very soluble so its easily transported in plasma
- A polar molecule (uneven charge within the molecule)
- Small so easily crosses membranes
- Major respiratory substrate is readily broken down in respiration and energy release to make ATP
25
Why is chitin good for animal/insects' exoskeleten?
1. Its waterproof which prevents water loss
2. Its strong for support
3. Its light weight for flight
26
What is the structure of Glycogen? (3 points)
.Alpha glucose
.More Branched
.1-4 and 1-6 glycosidic bonds
27
What is the function of starch?
Storage in plants
28
What are the two types of starch?
Amylose and Amylopectin
29
What is the structure of amylose?
Straight chain
30
What is the structure of amylopectin?
Curved/ Coiled chain
31
What is the structure of starch?
.Alpha molecules joined in a straight chain with similar bonds
. 1-4 glycosidic bonds
. Either amylose or amylopectin
32
Why does amylopectin form a coil?
Amylopectin forms a coil structure for a more stable structure of molecules, iodine molecules slot between the coil to cause the colour change in the iodine test.
33
What is the function of cellulose?
Used for structure in plants
34
What bonds join the linear chains in cellulose?
Hydrogen bonds
35
In cellulose 60-70 chains make what?
Microfibril
36
In cellulose several microfibrils make what?
A macrofibre
37
What is the structure of cellulose?
. Beta glucose
. B-Glycosidic bonds
. Every other B-Glucose is flipped 180°
38
Chitin is a polysaccharide made of what?
Beta Glucose
39
Why do polysaccharides store glucose in its insoluble form?
To prevent an osmotic effect
40
What is the structure of chitin?
Same structure as cellulose but has nitrogen, creating a Acetyl amide side groups.
41
What elements do lipids contain?
Carbon, Hydrogen, and oxygen. (Phosphate lipids also contain phosphate)
42
Are lipids polar or non-polar ? Do they dissolve?
Non-polar so do not dissolve (but do dissolve in non-polar substances like organic solvents)
43
What are the 5 functions of lipids?
1. Energy source and storage: 1g of lipid= X2 of carbs
2. Protection: protecting organs from physical damage
3. Thermal insulation
4. Oxidation: of triglycerides to produce metabolic water
5. Phospholipids: are a component of cell membranes and electrical insulation of nerves.
6. Waxes and Oils: waterproofing
44
What are three types lipid chains?
1. Unsaturated
2. Saturated
3. Polyunsaturated
45
What is the definition for a saturated chain?
A chain where all the carbon atoms are joined by single hydrogen bonds.
46
What is the definition for a unsaturated chain?
A chain with carbon to carbon bonds
47
What is the structure of a saturated chain?
Straight chain
48
What is the melting point of a saturated chain?
High melting point
49
What is the structure of a unsaturated chain?
Bents chain
50
What is the melting point of a unsaturated chain?
Lower melting point
51
What is the definition of a polyunsaturated chain?
A chain with more than one carbon to carbon bond
52
Are triglycerides polymers?
No, they are three fatty acids and a glycerol
53
What bond is found in a triglyceride?
Ester bond
54
What is the definition of a fatty acid?
A long molecule with a polar hydrophilic end
55
How are triglycerides and phospholipids created?
During a condensation reaction
56
How are triglycerides and phospholipids broken down?
During a hydrolysis reaction
57
What do phospholipids have instead of a third fatty acid?
A phosphoric group
58
What do phosphoric groups create in a phospholipid?
A hydrophilic head and hydrophobic tail
59
What is the biomolecule test for lipids?
1. Add ethanol which dissolves any lipids present
2. Add water
3. A positive result forms a milky solution
60
What do fatty deposits cause?
Obstructions in the blood vessels
61
What does high blood pressure cause?
Hypertension
62
What 4 factors contribute to heart disease?
1. Diet high in saturated fats
2. Smoking
3. Lack of exercise
4. Alcohol
63
What do low density lipoproteins cause?
Atheroma to form which blocks blood vessels
64
How do high density lipoproteins effect the body?
These are good for the body
65
What elements are found in proteins ?
Carbon, Hydrogen, Oxygen, Nitrogen, some contain sulphur and others contain phosphorus.
66
What is the monomer that mades up a polypeptide chain?
Amino Acid
67
What is the polymer called that consists of amino acids?
Polypeptide chain
68
What is the N-terminal and where is it found on an amino acid?
- NH2, at one end of the molecule called the N- terminal
69
What is the -COOH group on a amino acid called and where is it found?
A Carboxyl group, at the other end of the molecule called the C-terminal
70
Which element of an amino acid is different in each one?
The R-Group
71
What is the bond found between amino acids in a polypeptide chain?
Peptide Bond
72
What reaction takes place during the formation of a polypeptide chain?
Condensation Reaction
73
What reaction takes place during the breaking down of a polypeptide chain?
Hydrolysis Reaction
74
What is the structure of a primary protein structure?
A linear chain of amino acids
75
What bond is made between adjacent amino acids in the primary structure?
Covalent bonds
76
What bonds are between amino acids in a primary structure protein? How are they formed?
Peptide bonds made in a condensation reaction
77
When does hydrolysis occur in the human body?
During digestion
78
What is the structure of a secondary protein?
A polypeptide chain which may take on a regular arrangement. Ones with small R-groups will form a Alpha helix and those with large R-groups create and Beta pleated sheet.
79
What bonds hold the structure of secondary proteins together?
Hydrogen bonds
80
What secondary structure do proteins with small R-groups form?
Alpha Helix
81
What secondary structure do proteins with large R-groups form?
Beta Pleated Sheet
82
Can the shape of a tertiary structure protein change?
Yes, globular proteins are susceptible to change
83
What is the structure of a tertiary protein?
The peptide structure folds in a 3D shape, creating a globular protein
84
What bonds are present in a tertiary structure protein?
Ionic bonds, Hydrogen bonds, Disulphide bonds, and Hydrophobic bonds
85
What is the structure of a quaternary protein?
Several tertiary-structure peptide chains fitted together
86
What bonds hold the quaternary structure of a protein together?
Weak interactions between R-groups
87
What is the special feature of a quaternary protein?
It can carry a prosthetic group eg. haem in haemaglobin
88
What is haemoglobin?
A globular protein involved in metabolism
89
When is oxyhemoglobin formed?
It is created when it bond with oxygen
90
What is the structure of haemoglobin?
FOUR folded polypeptide chains and FOUR iron containing haem groups
91
What is the shape of haemoglobin?
Compact and spherical
92
Is haemoglobin soluble?
Yes
93
How are haemoglobin proteins arranged?
Hydrophobic ends point in, Hydrophilic ends point out
94
What is meant by the term conjugated protein?
A protein and non-protein prosthetic group
95
What is the function of haemoglobin?
To carry oxygen from the lungs to tissue and CO2 from the tissue to the lungs in the blood
96
What are two properties of haemoglobin?
3D shape
| Soluble in water
97
What is the structure of collagen?
Three identical left handed helix peptide chains wound around each other to form a triple helix
98
What is the function of glycine in collagen?
Its small so allows the chains to pack closely together
99
What is every third amino acid in each peptide chain in collagen?
Glycine
100
What bonds hold the three strands in collagen together?
Hydrogen bonds
101
What gives collagen its strength?
Collagen molecules cross-link through covalent bonds to form fibres.
102
What is the function of collagen? (2)
1. Gives strength to bones, muscles, skin, and tendons
| 2. Provides strength and structure
103
What are the two properties of collagen?
1. Insoluble in water
| 2. Strong and tough
104
Why is it important in animals that water works as a universal solvent?
Allows molecules such as glucose to dissolve, to be transported around the body. Its polar charge means it can dissolve molecules which allows for oxygen to be transported to fish in water.
105
What is meant by 'universal solvent'?
Both polar and non-polar molecules can dissolve in it
106
Why is it important in plants that water works as a universal solvent?
Allows gases like oxygen and CO2 to diffuse in and out of the water being transported around the plant.
107
Why can gases dissolve in water?
They molecules are attracted to the polarity of the water
108
Why is it significant to animals that water is a reactant in hydrolysis?
Aids the breakdown of polymers
109
Why is it significant to plants that water is a reactant in hydrolysis?
Used in the synthesis of ATP during photosynthesis
110
What is cohesion between water molecules? Why does it occur?
Hydrogen bonds between water molecules means water has high levels of cohesion. This means the water "sticks" together. In large amounts the hydrogen bonds are quite strong and cause a high surface tension.
111
Why is cohesion of water important for animals?
Provides a stable surface for insects to 'skate' across in their environment.
112
Why is cohesion of water important for plants?
Means streams of cohesion water can be "pulled" up the xylem tissue
113
What is meant by high latent heat of vaporisation?
When changing state heat energy is taken in or expelled. This is latent heat. This means that water requires large amounts of energy to change state
114
Why is high latent heat of vaporisation important for animals?
Prevents easy loos of water which would lead to dehydration
115
Why is high latent heat of vaporisation important for plants?
Provided structure as water is retained in the plant
116
Why is it important in animals that water has a high specific heat capacity?
Means the temperature of the body wont vastly increase which prevents the denaturing of enzymes
117
Why is it important in plants that water has a high specific heat capacity?
Ensure water stays in cohesion for transpiration
118
Why is it significant that water is less dense as ice than water as a liquid?
It allows ice to form an insulating layer on the top of ponds/ lakes when frozen to maintain an environment for biodiversity.
119
Why is it important that water is transparent?
Allows sunlight to pass through for photosynthesis in aquatic plants.
