Biochemistry & Molecular Biology
NOTE: THE NUMBER OF PURINES = THE NUMBER OF PYRMIDINES
Purines→ have two rings→ ADENINE & GUANINE
Pyrimidines→ have 1 ring→ Cytosine, Thymine, Uracil
Lecture 1
• Remember genetic information flows from DNA to RNA and finally to a protein
• Protein can’t be directly created from DNA.
• DNA must make RNA for the RNA to finally make the protein
• Nothing can go backwards, except RNA going back to DNA this is called reverse
transcription
• The genome (the DNA)
• The transcriptome (the RNA)
• The proteome (the protein)
• Make RNA from DNA→ Transcription
• Make Proteins from RNA→ Translation
• Copy of DNA→ Replication
• Once RNA is formed from DNA, the RNA then makes a Messenger RNA
• The Messenger RNA helps produce the Proteome→
•
, • Now the Protein made from the Messenger RNA is folded in different ways in order to make
ion channels, receptors, antibodies, enzymes, transcription factors→ Transcription Factors
bind to DNA
Chargaff’s Rule:
• Chargaff’s rules
o A=T
o C =G
o A+G = C+T
o PURINES = PYRMIDINES
• NOTE: Phosphates carry negative charge
• 5’ phosphate: The start of the polymer
• 3’ hydroxyl (-OH): The end of the polymer
• 5’ to 3’ always
• The phosphodiester bond: links subunits
• N-Glycosidic bond links the base and sugars
•
•
G&C increase the temp of DNA. The more G&C bonds
the higher the temp, because they have 3 Hydrogen Bonds
• A&T has 2 Hydrogen Bonds
RNA
• In RNA it is slightly different to DNA
o DNA is double stranded, whilst RNA is single stranded
o DNA has A&T, & G&C, whilst RNA has A&U, & G&C
o RNA has an extra -OH group. On the 3’ carbon
, Lecture 2
Remember Chargaff’s Rule:
• A=T, G=C
• A+G=C+T
• The amount of purine = pyrimidine
• The number of sugars (deoxyribose) = the number of phosphates = the number of bases
The bases are not directly covalently bound to each other. They are bound covalently to
the sugar. This is called the N-Glycosidic bone. The sugar phosphate is the backbone for
where all the bases come off.
• Remember the phosphates are the ones connecting the sugars!
RNA- Ribose structure
• N-Glyosidic Bond goes from nitrogen from the base into the sugar.
NOTE: THE NUMBER OF PURINES = THE NUMBER OF PYRMIDINES
Purines→ have two rings→ ADENINE & GUANINE
Pyrimidines→ have 1 ring→ Cytosine, Thymine, Uracil
Lecture 1
• Remember genetic information flows from DNA to RNA and finally to a protein
• Protein can’t be directly created from DNA.
• DNA must make RNA for the RNA to finally make the protein
• Nothing can go backwards, except RNA going back to DNA this is called reverse
transcription
• The genome (the DNA)
• The transcriptome (the RNA)
• The proteome (the protein)
• Make RNA from DNA→ Transcription
• Make Proteins from RNA→ Translation
• Copy of DNA→ Replication
• Once RNA is formed from DNA, the RNA then makes a Messenger RNA
• The Messenger RNA helps produce the Proteome→
•
, • Now the Protein made from the Messenger RNA is folded in different ways in order to make
ion channels, receptors, antibodies, enzymes, transcription factors→ Transcription Factors
bind to DNA
Chargaff’s Rule:
• Chargaff’s rules
o A=T
o C =G
o A+G = C+T
o PURINES = PYRMIDINES
• NOTE: Phosphates carry negative charge
• 5’ phosphate: The start of the polymer
• 3’ hydroxyl (-OH): The end of the polymer
• 5’ to 3’ always
• The phosphodiester bond: links subunits
• N-Glycosidic bond links the base and sugars
•
•
G&C increase the temp of DNA. The more G&C bonds
the higher the temp, because they have 3 Hydrogen Bonds
• A&T has 2 Hydrogen Bonds
RNA
• In RNA it is slightly different to DNA
o DNA is double stranded, whilst RNA is single stranded
o DNA has A&T, & G&C, whilst RNA has A&U, & G&C
o RNA has an extra -OH group. On the 3’ carbon
, Lecture 2
Remember Chargaff’s Rule:
• A=T, G=C
• A+G=C+T
• The amount of purine = pyrimidine
• The number of sugars (deoxyribose) = the number of phosphates = the number of bases
The bases are not directly covalently bound to each other. They are bound covalently to
the sugar. This is called the N-Glycosidic bone. The sugar phosphate is the backbone for
where all the bases come off.
• Remember the phosphates are the ones connecting the sugars!
RNA- Ribose structure
• N-Glyosidic Bond goes from nitrogen from the base into the sugar.
