Experiment#4: Isolation of Caffeine from Dried Tea Leaves Flashcards
A basic alkaloid from the Methylxanthine family. [1,3,7 - trimethylxanthine]
Caffeine
In this compund’s pure form, it is odorless, white and fleecy.
Caffeine
CAFFEINE
Caffeine is an alkaloid from what family exactly?
Methylxanthine
CAFFEINE
Caffeine has the _____ ___ system, a framework that plays an important role in living systems.
Purine Ring System
CAFFEINE
Caffeine is odorless, has a bitter taste and is ___ ____ in water.
highly soluble
CAFFEINE
Medications designed to increase the amount of water and salt expelled from the body as urine. Caffeine acts as one of these.
Diuretics
CAFFEINE
The stimulation of the heart resulting in a relaxation of the blood vessels.
Vasodilation
CAFFEINE
A) Small doses of Caffeine (50-200 mg) and b) high doses of Caffeine (over 200 mg) result in what sort of effects on the human body?
A) Small doses can increase alertness and reduce drowsiness and fatigue.
B) Large doses can result in ”coffee nerves” (insomnia, restlesness, headaches and muscle tremors)
COMPOSITION OF TEA LEAVES
The principal structural material of all plant cells. Tea leaves are primarily made up of this.
Cellulose
COMPOSITION OF TEA LEAVES
Cellulose is insoluble in water, and thus can be separated from caffeine by…?
Hot Water Extraction
TYPES OF TEA
This type of tea is produced through complete fermentation.
Black Tea
TYPES OF TEA
Catechins, which make up 20% of black tea’s dry weight, is oxidized during fermentation to form _________ and ___________.
Theaflavins and Thearubigins
TYPES OF TEA
These contribute to the sensory characteristic bright orange-red color of black tea.
Theaflavins
COMPOSITION OF TEA LEAVES
Basic nitrogen containing compounds found in plants.
Alkaloids
TYPES OF TEA
These leaves for this tea are heated immediately after harvesting, mechanically wound and compressed, and then dried to ensure the preservation of color.
Green Tea
COMPOSITION OF TEA LEAVES
Astringent, bitter plant polyphenols that either bind and precipitate or shrink proteins that have acidic behavior.
Tannins
COMPOSITION OF TEA LEAVES
Colored polyphenolic compounds of high molecular weight that thave acidic behavior and are water-soluble complex substances.
Tannins
COMPOSITION OF TEA LEAVES
As much as __% by weight of the leaf material in tea plants consists of caffeine.
5%
TYPES OF TEA
Also known as silver needle tea, this type of tea is a slightly-fermented type of tea.
White Tea
TRUE or FALSE | COMPOSITION OF TEA LEAVES
Chlorogenic Acids are water soluble and have acidic properties.
TRUE
TRUE or FALSE | COMPOSITION OF TEA LEAVES
Plant fats are soluble due to them having large hydrophilic groups present in their molecular structure.
FALSE. Plant fats are insoluble because they have large hydrophobic groups.
The body’s secondary source of energy (the first being glucose). This contains a high percentage of saturated fatty acids.
Triacylglycerol [TAGS]
COMPOSITION OF TEA LEAVES
Any type of colored substance produced by a plant.
Plant Pigments
COMPOSITION OF TEA LEAVES
Based on the Schematic Procedure during the post-lab discussion, provide the 4 possible Insoluble Cellular Materials present in tea leaves.
- Cellulose
- Fats
- Plant Pigments
- Proteins
COMPOSITION OF TEA LEAVES
These are esters formed between caffeic and quinic acids, representing an abundant group of plant polyphenols in the human diet.
Chlorogenic Acids
COMPOSITION OF TEA LEAVES
A group of phenolic secondary metabolites produced by certain plant species and an important component of coffee.
Chlorogenic Acids
COMPOSITION OF TEA LEAVES
Biochemical substances that are insoluble in water and are soluble in nonpolar solvents.
Plant Fats (Lipids)
Used to refer to lipids that are solid at room temperature.
Fats
COMPOSITION OF TEA LEAVES
Chlorophylls, carotenoids and flavonoids are examples of what?
Plant Pigments
PROCESS OF EXTRACTION
Provide the 7 characteristics of a Good Solvent for Liquid-Liquid Extraction.
- Low Boiling Point
- Does not react with solute or other solvent
- Not toxic
- Not highly flammable
- Immiscible with water
- Inexpensive
- Readily dissolves caffeine at room temperature
PROCESS OF EXTRACTION
This extraction process allows soluble components to be removed from solids using a solvent.
Solid-Liquid Extraction
PROCESS OF EXTRACTION
Based on the pdf lecture, what are the 2 possible applications of Solid-Liquid Extraction?
- Obtaining oil from oil seeds
- Leeching of metal salts from ores
PROCESS OF EXTRACTION
What are the 2 components of tea leaves that are readily soluble in hot water and are separated from the tea leaves themselves during Solid-Liquid Extraction?
Caffeine and Tannins
PROCESS OF EXTRACTION
An extraction that used a liquid solvent to remove a liquid component from a liquid mixture.
Liquid-liquid Extraction
PROCESS OF EXTRACTION
This extraction is also known as partitioning.
Liquid-liquid Extraction
PROCESS OF EXTRACTION
Provide at least 2 applications of Liquid-Liquid extraction out of the 4 provided in the lecture.
- Removal of vitamins from aqueous solutions
- Removal of aromatic compounds from crude oil fractions
- In the chemical and mining industries
- Downstream recovery of fermentation products
TRUE or FALSE | PROCESS OF EXTRACTION
In Liquid-Liquid Extraction, the aqueous layer will always be at the top and the organic layer will always be at the bottom.
FALSE. The determination of which solvent is at the top or bottom depends on the respective liquids’ densities.
TRUE or FALSE | PROCESS OF EXTRACTION
Dichloromethane is denser than water, meaning this organic layer will be found at the top.
FALSE. Denser liquids will always be found at the bottom.
PROCESS OF EXTRACTION
The ratio of the concentration of a compound in the two phases of a mixture of two immiscible solvents at equilibrium; dependent on temperature.
Distribution Coefficient
PROCESS OF EXTRACTION
______ ______ is a drying agent, and will remove any water that may still be present in the mixture.
Sodium Sulfate
PROCESS OF EXTRACTION
Sodium sulfate, calcium chloride and magnesium sulfate are all examples of…?
Anhydrous Salts
PROCESS OF EXTRACTION
These have a high affinity for water and reverses back to its hydrous form after it has absorbed water.
Anhydrous Salts
PROCESS OF EXTRACTION
Crude caffeine can be purified by _________.
Sublimation
PROCESS OF EXTRACTION
Liquid-liquid Extraction is comprised of 2 steps, namely?
- Mixing Phase
- Phase Separation
A procedure by which two liquids with different boiling points can be separated.
Distillation
PROCESS OF DISTILLATION
Distillation is a powerful technique for separating the component substance from a miscible fluid mixture by means of selective ________ and ________.
Selective Evaporation and Condensation
