DNA - Transcription, Translation, and Mutations - PowerPoint PPT Presentation

Loading...

PPT – DNA - Transcription, Translation, and Mutations PowerPoint presentation | free to download - id: 6c75c5-YThmZ



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

DNA - Transcription, Translation, and Mutations

Description:

DNA - Transcription, Translation, and Mutations Central Dogma DNA is copied as RNA Transcription RNA uses U instead of T RNA is read to make proteins ... – PowerPoint PPT presentation

Number of Views:38
Avg rating:3.0/5.0
Date added: 12 December 2019
Slides: 19
Provided by: zcoh
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: DNA - Transcription, Translation, and Mutations


1
DNA - Transcription, Translation, and Mutations
2
DNA
  • Two strands coiled called a double helix
  • Sides made of a pentose sugar Deoxyribose bonded
    to phosphate (PO4) groups by phosphodiester bonds
  • Center made of nitrogen bases bonded together by
    weak hydrogen bonds

3
DNA Double Helix

3
4
Antiparallel Strands
  • One strand of DNA goes from 5 to 3 (sugars)
  • The other strand is opposite in direction going
    3 to 5 (sugars)

5
DNA

5
6
Synthesis Phase (S phase)
  • S phase during interphase of the cell cycle
  • Nucleus of eukaryotes

7
DNA Replication
  • Begins at Origins of Replication
  • Two strands open forming Replication Forks
    (Y-shaped region)
  • New strands grow at the forks

7
8
Proofreading New DNA
  • DNA polymerase initially makes about 1 in 10,000
    base pairing errors
  • Enzymes proofread and correct these mistakes
  • The new error rate for DNA that has been
    proofread is 1 in 1 billion base pairing errors

9
DNA Damage Repair
  • Chemicals ultraviolet radiation damage the DNA
    in our body cells
  • Cells must continuously repair DAMAGED DNA
  • Excision repair occurs when any of over 50 repair
    enzymes remove damaged parts of DNA
  • DNA polymerase and DNA ligase replace and bond
    the new nucleotides together

10
DNA, RNA, and Protein
The Code
  • Experiments during the 1960s demonstrated that
    the DNA code was a three-base code.
  • The three-base code in DNA or mRNA is called a
    codon.

11
Central Dogma
  • DNA is copied as RNA Transcription
  • RNA uses U instead of T
  • RNA is read to make proteins Translation
  • Read by using the reverse of RNA, similar to
    DNAs 2nd strand

12
DNA, RNA, and Protein
Translation
  • In translation, tRNA molecules act as the
    interpreters of the mRNA codon sequence.
  • At the middle of the folded strand, there is a
    three-base coding sequence called the anticodon.
  • Each anticodon is complementary to a codon on the
    mRNA.

13
Activity
  • The first number tells you where the mutation
    starts, followed by the number or what is deleted
  • Ex 487del7 means starting at base 487 7 bases
    are deleted.

14
What Are Mutations?
  • Changes in the nucleotide sequence of DNA
  • May occur in somatic cells (arent passed to
    offspring)
  • May occur in gametes (eggs sperm) and be passed
    to offspring

15
Chromosome Mutations
  • Five types exist
  • Deletion
  • Inversion
  • Translocation (dont worry)
  • Nondisjunction (dont worry)
  • Duplication

16
Deletion
  • Due to breakage
  • A piece of a chromosome is lost

17
Inversion
  • Chromosome segment breaks off
  • Segment flips around backwards
  • Segment reattaches

18
Duplication
  • Occurs when a gene sequence is repeated
About PowerShow.com