LECTURE 4 - Central dogma of molecular biology

Question 1

key components of molecular biology

Answer 1

• The genome (the DNA)
• The transcriptome (the RNA)
• The proteome (the protein)
  The key components
• Genome – the complete genetic composition of a cell or species
• Transcriptome – the set of all RNA molecules in one cell or a population of cells.
• Proteome - the complete set of proteins expressed by an organism, cell or tissue type.

Question 2

what can transcriptome make

Answer 2

mRNA, microRNA, small nuclear RNA, rRNA, tRNA

RNA as the messenger/some functional properties
* mRNA is the message for making
proteins
* MicroRNA and snRNA have regulatory
roles (there are lots of other RNAs that
we don’t cover in this course)
* Ribosomal RNA and transfer RNA
important for protein synthesis (Protein
synthesis/translation lecture later)

Question 3

spontaneous deamination in RNA

Answer 3

Deamination of Cytosine (C): Under certain conditions, cytosine (C) in RNA can spontaneously lose its amino group, C –> U

C-G to A-U Transition: When deamination occurs, it can lead to a change in the base-pairing properties of RNA. Cytosine (C) normally pairs with guanine (G) in RNA. However, after deamination, the converted uracil (U) can now base pair with adenine (A) in RNA. This transition changes the RNA sequence and can affect the information it carries.

This process is one of the reasons why RNA is generally considered less stable than DNA. DNA has thymine (T) instead of uracil (U), and thymine is less prone to spontaneous deamination.