are the non-coding region and are removed
during splicing
Introns
The process of transcribing the single stranded RNA into a double – stranded DNA
Reverse Transcription
are sequences appearing in the mature mRNA
Exons
It contain RNA as genetic material
Retrovirus
A collection of codons that specify all the amino acids found in proteins
Genetic code
Characteristics:
• It is degenerate (Redundant; Many amino acids have numerous codons)
• It is non – overlapping
• The code is comma less (no markers to differentiate one codon from one another)
• The code is nearly universal
Genetic Code
A sequence of 3 bases in mRNA that specifies a particular Amino acid
Codons
• A base in the DNA is replaced by another which alters the codon in the MRNA
Point mutations
The codon containing the changed base codes for the same amino acid
Silent mutation
The codon containing the changed base codes for a different amino acid
Missense
The codon containing the changed base codes for a stop codon
Nonsense
Occurs when the number of bases added or deleted is not a multiple of 3 which shifts the reading frame to a completely different set of codons
Frameshift
• The most widespread compounds involved in the buildup functions of the cell
• Presence of a carbonyl (Aldo or Keto group) and at least two hydroxyl groups
Carbohydrates
Same chemical formula but differs in the
position of hydroxyl groups
Stereoisomers
Stereoisomers that are mirror images
Enantiomers
Stereoisomers that differ in the position of the hydroxyl group at only one asymmetric carbon.
Epimers
• These are simple carbohydrates that are named depending on the number of Carbon atoms and the specific carbonyl group present
• They can either be Dextrorotatory or Levorotatory
• Examples: D – Galactose, L - Fructose
Monosaccharides
Composed of 2 to 12 monosaccharide units linked by glycosidic bond
• Sucrose
• Table Sugar
• Glucose + Fructose
• Lactose
• Milk Sugar
• Galactose – linked β-1,4 to glucose
Oligosaccharides
• These are high – molecular carbohydrates with more than ten monosaccharide units linked by glycosidic bond
Polysaccharides
These acidic polysaccharides are found etracellularly
Chondroitin sulfate & Hyaluronic acid
• General test for Carbohydrates
• Monosaccharides give the most rapid result
• Uses α-naphthol and sulfuric acid
• (+) result: purple ring
Molisch Test
• Tests for the presence of reducing sugars
• All monosaccharides give a positive result
• Uses Copper (III) sulfate, Sodium citrate and Sodium carbonate in a mildly basic solution
• (+) result: red to orange precipitate
Benedict’s test
• Uses Copper (III) in a slightly acidic medium
• Used to differentiate a reducing monosaccharide from a reducing disaccharide
• (+) result: red ppt (within 3 minutes = Monosaccharide, longer than 3 minutes = disaccharide)
Barfoed’s Test
• Test for differentiating pentose and hexose monosaccharides
• Used concentration HCl and orcinol + ferric chloride
• (+) result: Pentoses = bluish to green, Hexoses + brownish to gray
Bial’s Test
