Biochemistry Flashcards
(112 cards)
1
Q
What is the difference between macronutrients and micronutrients?
A
Macronutrients needed in small concentrations; Micronutrients needed in trace concentration.
2
Q
What is an inorganic ion?
A
An atom or molecule with no more than one carbon atom where the number of electrons does not equal the number of protons, giving it a negative or positive charge.
3
Q
What is magnesium (Mg2+) used for in living organisms?
A
Used to make chlorophyll for photosynthesis; necessary for bone development in mammals.
4
Q
What happens to plants without magnesium?
A
They develop chlorosis, leading to stunted growth and yellow leaves.
5
Q
What is iron (Fe2+) used for in living organisms?
A
Used to make haemoglobin, which is needed for oxygen transport.
6
Q
What condition results from a lack of iron?
A
Anaemia.
7
Q
What are phosphate ions (PO4^3-) used for in living organisms?
A
Used to make nucleotides, ATP, and phospholipids in cell membranes.
8
Q
What is calcium (Ca2+) used for in living organisms?
A
Used in bones and teeth in mammals; provides strength to plant cell walls.
9
Q
What percentage of the mass of many living things is water?
A
65-95%.
10
Q
What is a dipole?
A
A molecule with a negative and positive charged end, but no overall charge.
11
Q
What does polar mean in the context of water molecules?
A
A molecule with separated charges.
12
Q
Water is able to form _______.
A
[hydrogen bonds].
13
Q
What is a hydrogen bond?
A
A weak attractive force between the partial positive charge of a hydrogen atom of one molecule and the partial negative charge on another atom (usually oxygen or nitrogen).
Hydrogen bonds are significant in water’s unique properties due to their abundance.
14
Q
What is hydrolysis?
A
Breaking down molecules with the addition of a water molecule.
Hydrolysis is a key reaction in many biological processes.
15
Q
What is condensation?
A
The release of a water molecule as two other molecules are combined into a more complex molecule.
Condensation reactions are essential in forming larger biological macromolecules.
16
Q
List some key properties of water.
A
- Polarity
- High surface tension
- Works as a solvent
- Thermal properties (high specific heat capacity and high latent heat of vaporisation)
- Key metabolite (reactant in photosynthesis and hydrolysis, product of aerobic respiration and condensation)
- Provides support and buoyancy to certain organisms
These properties make water essential for life.
17
Q
What does high specific heat capacity mean?
A
The amount of heat, measured in joules, required to raise 1 kg of water by 1°C.
It takes a lot of energy to change the temperature of water, which helps maintain stable temperatures in aquatic environments.
18
Q
What is high latent heat of vaporisation?
A
The amount of heat needed to turn a substance into a gas.
This property allows water to effectively regulate temperature through evaporation.
19
Q
Why are the properties of water important to living things?
A
They help maintain a constant temperature in cells and tissues, acting as a temperature buffer and stabilizing aquatic habitats.
The high water content in organisms is crucial for their physiological processes.
20
Q
Why is the latent heat of vaporisation important ?
A
Allows mammals to evaporate sweat to cool down.
21
Q
Put these carbohydrate terms in order of size: disaccharide, monosaccharide, polysaccharide
A
- monosaccharide, 2. disaccharide, 3. polysaccharide
22
Q
Put these monosaccharide terms in order of size: triose, pentose, hexose
A
- triose, 2. pentose, 3. hexose
23
Q
What is polymerisation?
A
The process of bonding monomers together to form polymers.
24
Q
Define monomer.
A
Building block/small subunit that can be linked into a chain.
25
Define polymer.
Chain of monomers.
26
What are the common polymers and monomers in biology?
* Polysaccharides (complex carbohydrates) - monosaccharide monomers
* Polypeptides - amino acid monomers
* Polynucleotides (nucleic acids) - mononucleotide monomers
27
Give an example of a triose.
Glyceraldehyde
28
Give examples of pentose sugars.
* Ribose
* Deoxyribose
29
What are the main monosaccharides?
* Glucose
* Fructose
* Galactose
30
What type of sugar is glucose?
Hexose
31
What is the general formula of a monosaccharide?
(CH2O)n
32
What is the formula of all hexose sugars?
C6H12O6
33
What is an isomer?
Molecules with the same chemical formula but different arrangements of atoms.
34
What are the two isomers of glucose?
Alpha and beta
## Footnote
Isomers are compounds with the same formula but different structures or arrangements.
35
Identify the structural formula of a triose sugar.
C3H6O3
## Footnote
A triose sugar has three carbon atoms.
36
Identify the structural formula of a pentose sugar.
C5H10O5
## Footnote
A pentose sugar has five carbon atoms.
37
Identify the structural formula of a hexose sugar.
C6H12O6
## Footnote
A hexose sugar has six carbon atoms.
38
What is the difference between alpha and beta glucose regarding the hydroxyl group?
Hydroxyl group points up on carbon 1 in beta, down in alpha
## Footnote
This difference affects the properties and reactions of the two isomers.
39
List the key functions of monosaccharides.
* Respiratory substrates (break C-C and C-H bonds, transfer energy to ATP)
* Building blocks for larger molecules (i.e. polysaccharides)
* Reaction intermediates (i.e. in respiration and photosynthesis)
* Make up nucleotides in RNA and DNA, ATP and ADP
## Footnote
Monosaccharides are essential in various biological processes.
40
What is Benedict's test used for?
To test for the presence of reducing sugars
## Footnote
Reducing sugars can donate an electron, and Benedict's test identifies them through a color change.
41
What is the role of copper (II) ions in Benedict's test?
They are reduced to copper (I) ions in copper (I) oxide when exposed to reducing sugars
## Footnote
This reduction indicates the presence of reducing sugars.
42
At what temperature should the Benedict's test be heated?
70-80 degrees
## Footnote
This heating is necessary to facilitate the reaction in the test.
43
What color indicates a negative test in Benedict's test?
Blue
44
What color indicates a small amount of sugar in Benedict's test?
Green/yellow
45
What color indicates a larger amount of sugar in Benedict's test?
Red/orange
46
Why is Benedict's test considered a semi-quantitative test?
Only indicates sugar content, doesn't tell you actual amount.
47
What is the monomer unit of carbohydrates?
Monosaccharide
48
What is formed when two monosaccharides are joined together?
Disaccharide
49
Fill in the blank: When biological monomers are joined together to form polymers, a molecule of water is lost. This is known as a _______.
condensation reaction
50
What happens during a hydrolysis reaction?
A molecule of water is added to break the bonds that link the monomers.
51
What special name is given to the bond formed by condensation between two monosaccharides?
Glycosidic bond
52
Sucrose is made from which monosaccharide subunits?
Fructose and glucose
53
Maltose is made from which monosaccharide subunits?
Glucose and glucose
54
Lactose is made from which monosaccharide subunits?
Glucose and galactose
55
What is the chemical group involved in the condensation reaction represented by СН2ОН?
Hydroxyl group
## Footnote
Hydroxyl groups are typically involved in condensation reactions, leading to the formation of glycosidic bonds.
56
What type of bond is formed between glucose and fructose?
1, 2 Glycosidic bond
## Footnote
This bond connects the anomeric carbon of one sugar to the hydroxyl group of another.
57
What is the hydrolysis equation for maltose?
C12H22O11 + H2O → C6H12O6 + C6H12O6
## Footnote
Maltose is hydrolyzed into two glucose molecules.
58
True or False: Sucrose is a reducing sugar.
False
## Footnote
Sucrose is a non-reducing sugar and must be hydrolyzed to detect its monosaccharides.
59
What is the first step in testing for non-reducing sugars?
Carry out Benedict's test on all three liquids
## Footnote
This step helps identify which sample contains glucose.
60
Fill in the blank: To hydrolyze sucrose, add a small amount of _______ to the solution.
HCl
## Footnote
Hydrochloric acid is used to hydrolyze non-reducing sugars.
61
What is the purpose of neutralizing the acid with NaOH in the non-reducing sugar test?
To enable Benedict's solution to work
## Footnote
Neutralization is necessary for the test to accurately detect reducing sugars.
62
What color indicates the presence of a reducing sugar in the Benedict's test?
Orange
## Footnote
The blue color indicates no reducing sugar present.
63
What is the significance of the carbon 1 in the glycosidic bond formation?
It is the anomeric carbon of glucose
## Footnote
The anomeric carbon is crucial for the formation of glycosidic linkages.
64
How else could we hydrolyse sucrose?
Sucrase enzyme
## Footnote
Sucrase is an enzyme that breaks down sucrose into glucose and fructose.
65
What is a method to obtain a quantitative measure of sugar in a sample?
Biosensor
## Footnote
A biosensor uses enzymes or biomolecules with a transducer to provide an electrical signal for measuring blood sugar.
66
What are the monomers involved in starch?
Alpha glucose
## Footnote
Starch is composed of alpha glucose monomers.
67
What type of bonds hold the monomers in starch together?
1,4 alpha glycosidic bond (and 1,6 alpha glycosidic bonds for amylopectin)
## Footnote
These bonds are essential for the structure of starch.
68
Describe the overall shape of amylose.
Helix
## Footnote
Amylose has a helical structure which is stabilized by hydrogen bonds.
69
Describe the overall shape of amylopectin.
Branching chains
## Footnote
Amylopectin has a branched structure due to its 1,6 alpha glycosidic bonds.
70
What bonds are involved in holding the overall structure of amylose together?
Hydrogen bonds
## Footnote
Hydrogen bonds provide stability to the helical structure of amylose.
71
What are the four main polysaccharides that need to be described?
Starch, Glycogen, Cellulose, Chitin
## Footnote
Each polysaccharide has unique structures and functions in biological systems.
72
Fill in the blank: Polymers can be described using the following steps: Name the monomers involved, name the bonds holding the monomers together, describe the overall shape of the molecule, and describe any ______ involved in holding the overall structure together.
bonds
## Footnote
This emphasizes the importance of understanding the structural components of polymers.
73
What are the two structures that make up starch?
Amylopectin and amylose
## Footnote
Amylopectin consists of occasionally branched chains, while amylose consists of unbranched chains.
74
What is the main function of starch in plants?
Main store of glucose and chemical energy
## Footnote
Starch serves as a reserve of energy for plants.
75
Where is starch located in plant cells?
In starch grains, mainly in seeds and storage organs like potato tubers
## Footnote
Starch granules are found in various parts of a plant.
76
What is one adaptation of starch that prevents osmotic damage?
It is insoluble
## Footnote
Insolubility helps maintain water potential in cells.
77
Why is starch considered a compact molecule?
It allows a large amount of glucose and chemical energy to be stored in one place
## Footnote
Compactness is essential for efficient energy storage.
78
What type of bonds does starch contain that allows it to store energy?
C-C and C-H bonds
## Footnote
These bonds hold significant amounts of energy.
79
What can starch be hydrolyzed to, and why is this important?
Alpha-glucose, which is a source of energy for respiration
## Footnote
Hydrolysis is crucial for energy release during cellular respiration.
80
What are the monomers involved in glycogen?
Alpha glucose
## Footnote
Glycogen is composed solely of alpha glucose monomers.
81
What type of bonds hold the monomers together in glycogen?
1,4 and 1,6 alpha glycosidic bonds
## Footnote
These bonds determine the structure and properties of glycogen.
82
Describe the overall shape of the glycogen molecule.
Highly branching structure
## Footnote
The branching allows for rapid release of glucose when needed.
83
What is the function of glycogen?
Energy storage in animals; store of glucose.
84
Where is glycogen primarily located in the body?
In animal cells, especially liver and muscle cells.
85
What is one adaptation of glycogen that prevents osmotic damage?
It is insoluble, therefore it does not affect water potential of the cell.
86
Why is glycogen's large size important?
It is a large molecule and insoluble, therefore it does not diffuse out of the cell.
87
What allows glycogen to store a large amount of glucose?
It is compact, therefore a large amount of glucose can be stored in one place.
88
How does glycogen's branching affect its function?
It is more highly branched than starch, allowing for quicker and easier hydrolysis.
89
What are the monomers involved in cellulose?
Beta glucose, each monomer rotated 180° to its neighbour.
90
What type of bonds hold the monomers of cellulose together?
Beta 1,4 glycosidic bonds.
91
What is the overall shape of cellulose?
Straight chains.
92
What type of bonds hold the overall structure of cellulose together?
Hydrogen bond cross links between microfibrils.
93
What are cellulose fibrils?
Cellulose fibrils are structural components of plant cell walls formed from cellulose microfibrils.
## Footnote
They provide high tensile strength to cell walls.
94
What is the primary function of cellulose?
Provides high tensile strength to cell walls.
## Footnote
This prevents cell walls from bursting under osmotic pressure.
95
Where is cellulose found?
In the cell walls of plant cells, in the form of cellulose microfibrils.
## Footnote
This structure supports the plant.
96
What adaptation allows cellulose to function effectively?
Cellulose is a long straight chained molecule that can form cross-links with other chains to create microfibrils.
## Footnote
This structural property enhances its tensile strength.
97
How do hydrogen bonds contribute to the properties of microfibrils?
Many cross-linked hydrogen bonds provide high tensile strength to microfibrils.
## Footnote
This prevents cell walls from bursting and maintains turgor in plant cells.
98
What does it mean for cellulose fibers to be freely permeable?
There are spaces between the fibers, allowing water and its solutes to pass through the spaces of the cell wall.
## Footnote
This permeability is crucial for water transport.
99
What are the monomers involved in chitin?
Beta glucose with amino acid derivatives (acetyl amine groups).
## Footnote
Each monomer is rotated 180° to its neighbor.
100
What type of bonds hold the monomers in chitin together?
1.4 beta glycosidic bonds.
## Footnote
These bonds link the monomers in the chitin structure.
101
Describe the overall shape of chitin molecules.
Straight chains.
## Footnote
This configuration contributes to the structural integrity of chitin.
102
What bonds are involved in holding the overall structure of chitin together?
Hydrogen bond cross links between microfibrils.
## Footnote
These cross-links enhance the strength and stability of chitin.
103
What is the function of chitin?
Structural polysaccharide making up exoskeleton of insects and fungal cell walls
## Footnote
Chitin is strong, lightweight, and waterproof.
104
Where is chitin located?
Exoskeleton of insects, cell walls of fungi
105
What structural feature of chitin contributes to its high tensile strength?
Cross linked parallel chains
106
What are the adaptations of chitin that make it suitable for exoskeletons?
* Strong
* Lightweight
* Waterproof
107
What is the method for testing starch?
Grind up sample, add drops of iodine solution
108
What is the color change observed when starch is present in the iodine test?
Orange to black
109
Why might the starch food test be described as semi-quantitative?
Depth of blue-black colour indicates relative concentration of starch
110
What happens to the color intensity of the starch test at high temperatures?
Color intensity decreases
111
Why does low pH render the starch test unusable?
Hydrolyses starch
112
What color might the test result show at low concentrations of starch?
More violet
