BIOCHEM QUIZ
Non-reducing
sucrose and trehalose
1. most commonly used precipitant for the salting out of proteins 2. Protects proteins from denaturation at saturation 3. Proteins proteins from bacterial growth at saturation
Ammonium sulfate
Similar Similibus Solvuntur
LIke Dissolves Like
Methyl amine test
Many disaccharides will test change due to a yellow color but lactose will give red color.
The aim of all extraction procedures is to separate cellular or fluid lipids from the other constitutents, proteins, polysaccharides, small molecules (amino acids, sugars) but also to preserve these lipids for further analyses.
The aim of all extraction procedures
Bligh and Dyer Method
This technique is similar to Folch -higher yield of lipids -more complex -Not very good method for specific lipids and preserving them—solid phase extraction is
Affinity Chromatography
This type of purification is very specific to a single protein
TRUE
Total lipid content determined using one solvent may be different from that determined using another solvent.
Molisch Test
Which test is (+) for carbohydrates?
Iodine Test
Which test is + for starch?
Molisch Test
Which test will a positive test result give a red-violet layer at the interface between the acid bottom and the aqueous solution top
• There is a great diversity of methods b/c biological tissues are not similar when considering their structure, texture, sensitivies, and lipid contents.
Why are there hundreds of techniques to extract and purify lipids?
Red Tetrazolium Test
positive for reducing sugars
Barten's Test
positive result is a red precipitate
• It is very important that the proportions of chloroform, methanol, and water in the combined phases should be as close as possible to 8:4:3 (by volume)
• It is very important that the proportions of chloroform, methanol, and water in the combined phases should be as close as possible to
Folch Method
• One of the most common methods for extracting lipids
• Polar lipids (such as glycolipids or phospholipids) are more soluble in polar solvents (such as alcohols), than in non-polar solvents (such as hexane).
• Polar lipids (such as ) are more soluble in polar solvents (s), than in non-polar solvents ().
Centrifugation
• The precipitated nucleic acids are removed by -------------
• Used hexane and isopropyl alcohol for experiment.
• Used --------- for experiment.
• Ethyl ether and petroleum ether are the most commonly used solvents, but pentane and hexane are also used for some foods.
• _____ are the most commonly used solvents, but _______ are also used for some foods.
• Tolerable Upper Intake Levels
• help understand toxicity of micronutrients—vitamins, minerals. Most can have.
extraction
•Efficient ____ from the starting material is vital for success of any purification procedure.
Bial Test
Get range of colors. Yellow, red, purple
Energy Content of Food
Calculated by calorimetry
Seliwanoff Test
(+ ketohexoses and - aldohexoses)
Bial Test
(+ pentoses and - for hexoses)
Barten's Test
(monosaccharides (+ in 1-3 mins.) vs. disaccharides (+ in 8-10 mins.)
Methyl Amine Test
+ for lactose
Bial Test
+ result is a green blue
Solid Phase Extractions
- Ideally will isolate a component of interest from a more complex sample in pure concentrated state. - Many lipids are rather similar in their physical properties—it may only be practical to isolate groups of lipid classes of related polarity
Iodine Test
This test may go to a brownish color
Reducing disaccharides
lactose and maltose
Ammonium Sulfate
---------- is the (1) most commonly used precipitant for salting out of proteins.
Seliwanoff Test
A positive result is developed when deep red precipitate develops.
Iodine Test
A positive result is obtained when a deep blue color appears (it looks almost black)
Red Tetrazolium Test
A positive test is obtained when a deep red color develops.
Methyl amine test
A yellow color will appear first. Then select the FIRST tube that develops a red color.
Ethanol
How did we precipitate the nucleic acids?
Spectrometry
How do you quantify the amount of protein?
on the polarity of the lipids present compared to that of the solvent.
In practice, the efficiency of solvent extraction depends on
Protamine Sulfate
Nucleic acids can be removed from the extract by addition of --------------
• Ion-exchange chromatography • Separation by hydrophobic interaction • Affinity chromatography—Very specific to single protein
Purification
TRUE
Since different lipids have different polarities, it is impossible to select a single organic solvent to extract them all.
1. Preparation of Crude Extract 2. Extraction of Nucleic Acids 3. Removal of Nucleic acids from extract 4. Precipitation 5. Purification 6. Quantification
Steps in Protein
Reducing monosaccharides
glucose, glyceraldehyde, galactose
Methyl amine test
This is a very RAPID test
**Lower layer mostly chloroform and contains virtually all of the lipids
WHat is the lower layer made of?
Bligh and Dyer Method Solid Phase Extractions Thin Layer Chromatography
What are the other techniques?
• Uses chloroform-methanol (2:1 by volume)
What does the Folch Method use?
Preparation of Crude Extract
What is the first step of protein?
• Lower layer is composed of chloroform-methanol-water in the proportions 86:14:1 (by volume). **Lower layer mostly chloroform and contains virtually all of the lipids
What is the lower layer composed of?
Complete disruption of cells
What is the most important step of the process of preparation of crude extract?
2. Extraction of Nucleic Acids
What is the second step of protein?
• Upper phase consists of the same solvents in the proportions 3:48:47 contains contaminants.
What is the upper phase consist of?
Soap and salt solution
What type of solution was used to break down the cell walls?
egg yoke and avocado
What types of lipids did we use in lab?
EAR
average macronutrient for 50% of population.
Bial Test
contains concentrated HCl
Barten's Test
expose to a high amount of heat--boiling
Protein
most temperature labile
• Extract is shaken and equilibrated with one fourth its volume of a saline solution
• Extract is shaken and equilibrated how?
