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RNA

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RNA Ribonucleic Acid Structure of RNA Single stranded Ribose Sugar 5 carbon sugar Phosphate group Adenine, Uracil, Cytosine, Guanine Types of RNA Three main types ... – PowerPoint PPT presentation

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Title: RNA


1
RNA
  • Ribonucleic Acid

2
Structure of RNA
  • Single stranded
  • Ribose Sugar
  • 5 carbon sugar
  • Phosphate group
  • Adenine, Uracil, Cytosine, Guanine

3
Types of RNA
  • Three main types
  • Messenger RNA (mRNA) transfers DNA code to
    ribosomes for translation.
  • Transfer RNA (tRNA) brings amino acids to
    ribosomes for protein synthesis.
  • Ribosomal RNA (rRNA) Ribosomes are made of rRNA
    and protein.

4
Transcription
  • RNA molecules are produced by copying part of the
    nucleotide sequence of DNA into complementary
    sequence in RNA, a process called transcription.
  • During transcription, RNA polymerase binds to DNA
    and separates the DNA strands. RNA polymerase
    then uses one strand of DNA as a template from
    which nucleotides are assembled into a strand of
    mRNA.

5
mRNA
6
How Does it Work?
  • RNA Polymerase looks for a region on the DNA
    known as a promoter, where it binds and begins
    transcription.
  • RNA strands are then edited. Some parts are
    removed (introns) - which are not expressed and
    other that are left are called exons or expressed
    genes.

7
The Genetic Code
  • This is the language of mRNA.
  • Based on the 4 bases of mRNA.
  • Words are 3 RNA sequences called codons.
  • The strand aaacguucgccc would be separated as
    aaa-cgu-ucg-ccc the amino acids would then be
    Lysine Arginine Serine - Proline

8
Genetic Codes
9
Translation
  • During translation, the cell uses information
    from messenger RNA to produce proteins.
  • A Transcription occurs in nucleus.
  • B mRNA moves to the cytoplasm then to the
    ribosomes. tRNA read the mRNA and obtain the
    amino acid coded for.
  • C Ribosomes attach amino acids together forming
    a polypeptide chain.
  • D Polypeptide chain keeps growing until a stop
    codon is reached.

10
Translation to Protein
11
Translation
12
Mutations
  • Gene mutations result from changes in a single
    gene. Chromosomal mutations involve changes
    whole chromosomes.

13
Gene Mutation
  • Point Mutation Affect one nucleotide thus
    occurring at a single point on the gene. Usually
    one nucleotide is substituted for another
    nucleotide.
  • Frameshift Mutation Inserting an extra
    nucleotide or deleting a nucleotide causes the
    entire code to shift.

14
Gene Mutation
15
Chromosomal Mutations
  • Deletion Part of a chromosome is deleted
  • Duplication part of a chromosome is duplicated
  • Inversion chromosome twists and inverts the
    code.
  • Translocation Genetic information is traded
    between nonhomologous chromosomes.

16
Chromosomal Mutations
17
Mutations
18
More Mutations
19
Gene Regulation
  • In simple cells (prokaryotic) lac genes which are
    controlled by stimuli, turn genes on and off.
  • In complex cells (eukaryotic) this process is not
    as simple. Promoter sequences regulate gene
    operation.

20
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