Nucleic Acids:RNA
By:Lily Rosemary L.
Masilang
Overview:
Structure of Nucleic Acids Five Common BasesRNA: DefinitionComposition of Ribonucleic acidComponents of Nucleic AcidsStructure of Ribonucleic acidTypes of RNAFunctions of RNAProtein Synthesis
The Structure of Nucleic Acids
The Structure of Nucleic Acids
The Structure of Nucleic Acids
Five Common BasesAbbr. Base Nucleoside Nucleic
Acid
A Adeninedeoxyadenos
ine DNA
adenosine RNA
G Guaninedeoxyguanos
ine DNA
guanosine RNA
C Cytosinedeoxycytidin
e DNA
cytidine RNA
T Thyminedeoxythymid
ine (thymidine)
DNA
U Uracil uridine RNA
RNA: DefinitionShort for Ribonucleic acid
A substance in the cells of plants and animals that helps make proteins.
is a polymeric molecule implicated in various biological roles in coding, decoding, regulation, and expression of genes.
Composition of RNA
Components of Nucleic Acids
Food with rich and low purines
• Similar to DNA but with some important differences:– Single strand – The sugar is Ribose– Uracil matches Adenine– Shorter than DNA
Structure of RNA
• RNA does not form an analogous double helical structure.
• RNA form a heteromeric double helix.
Structure of RNA
Structure of RNA
• Many RNA molecules have secondary structure in which intermolecular loops formed by complementary pairing.
Types of RNA• Messenger RNA (mRNA)• Ribosmal RNA (rRNA)• Transfer RNA (tRNA)
Other types of RNAo Small nuclear RNA (SnRNA),o Micro RNA(miRNA) ando Small interfering RNA(SiRNA) ando Small Nucleolar RNAs (snoRNA)o Riboswitches
Messenger RNA• Used as template to make
proteins• Carries instructions for
polypeptide synthesis from nucleus to ribosomes in the cytoplasm.
• The 5’ terminal end is capped by 7- methyl guanosine triphosphate cap.
Ribosomal RNA• Makes up the ribosomes.• Forms an important part of both
subunits of the ribosomes.• Component performs the
peptidyl transferase activity and thus is an enzyme (a ribozyme).
Transfer RNAThey transfer the amino acids from
cytoplasm to the protein synthesizing machinery, hence the name tRNA.
Matches amino acids to mRNA to help make proteins.
Key to the translation process of mRNA sequence into the amino acids sequence of proteins.
Structure of tRNA
• Primary structure- The nucleotide sequence of all the tRNA molecules allows extensive intrastand complimentarity that generates a secondary structure.
• Secondary structure- Each single tRNA shows extensive internal base pairing and acquires a clover leaf like structure. The structure is stabilized by hydrogen bonding between the bases and is a consistent feature.
Tertiary structure-The L shaped tertiary structure is formed by further folding of the clover leaf due to hydrogen bonds between T and D arms.
The base paired double helical stems get arranged in to two double helical columns, continuous and perpendicular to one another.
Structure of tRNA
Other types of RNA• Small Nuclear RNAs- play a critical role in gene
regulation by way of RNA splicing.– The splicing of pre-mRNA give rise to mature
mRNA.• MicroRNAs- have been shown to inhibit gene
expression by repressing translation– also play significant roles in cancer and other
diseases• Small Interfering RNAs- they also work to inhibit
gene expression– They may have evolved as a defense mechanism
against double-stranded RNA viruses.
• Small Nucleolar RNAs- These molecules function to process rRNA molecules, often resulting in the methylation and pseudouridylation of specific nucleosides
• Riboswitches- are RNA sensors that detect and respond to environmental or metabolic cues and affect gene expression accordingly
Other types of RNA
Functions of RNA
• Its principal role is to act as a messenger carrying instructions from DNA for controlling the synthesis of proteins,
• In some viruses RNA rather than DNA carries the genetic information.
Protein synthesis
the process by which individual amino acids are connected to each other in a specific order dictated by the nucleotide sequence in DNA.
process by which the genetic code puts
together proteins in the cell.
Protein Synthesis
• The production of proteins by an individual cell.
• The genetic information stored in DNA is used as a blueprint for making proteins.
• Why Proteins?
The Process of Protein Synthesis
TranscriptionInitiation
RNA polymerase
Elongation Transcription
Termination Transcription
References• http
://www.vivo.colostate.edu/hbooks/genetics/biotech/basics/nastruct.html
• http://www.whatislife.com/reader/dna-rna/dna-rna.html
• https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/nucacids.htm
• http://www.nature.com/scitable/definition/ribonucleic-acid-rna-45
• http://www.nature.com/scitable/definition/ribonucleic-acid-rna-45
• http://www.slideshare.net/namarta28/rna• http://chemistry.tutorvista.com/biochemist
ry/nucleic-acid-function.html• http://slideplayer.com/slide/4640877/• http://www.nature.com/scitable/topicpage/
rna-functions-352• http://chemistry.elmhurst.edu/vchembook/
584proteinsyn.html• www.phschool.com/science/biology_place/
biocoach/translation/init.html
References
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