History of Molecular Biology & Terminology
DNA is an acronym for
Deoxyribonucleic acid
What is the difference between transcription and translation?
Transcription is the process of copying the code in a section of DNA onto a strand of mRNA. Translation is the process of decoding the mRNA into a sequence of amino acids that becomes a protein.
A gene is
specific sequences of nucleotides called "open reading frames" (ORFs) which start with a "start codon" and end with a "stop codon"
What is the difference between animal and plant cytokinesis?
In plant cells, a cell wall forms instead of a cleavage furrow. Cell plate joins to the plasma membrane. When the cell plate is large enough, it separates into 2 daughter cells.
Checkpoints that must be passed before cell division can proceed
G1
DNA & RNA are N________ A__________
Nucleic acids
Write the corresponding mRNA transcript on the whiteboard: 3'-GCTACTGACTAT-5'
5'-CGAUGACUGAUA-3'
What phase is most of a cell's life spent?
Interphase
DOUBLE trouble!!
Choose Prophase, Metaphase, or Anaphase stage... Using two different pipe cleaners and pony beads each team will make 3 chromosomes and place them in the stage they were given.
The first team with the correct chromosomes and positions wins the points
The answer is on a Google slide
Cells that multiply out of control due to a safety check malfunction. p 159
Cancer
Constructed a 3-D model of DNA (pg 136)
Watson & Crick
If DNA is a giant library, its bookshelves are chromosomes, what are the books?
Genes
What does helicase do in DNA replication?
It breaks the hydrogen (H+) bonds ... splitting the DNA strand.
What direction is the leading strand and what direction is the lagging strand?
The leading strand is 3' - 5"
The lagging strand is 5' - 3'
Where does M checkpoint occur and what does it ensure? p 159
Metaphase during mitosis and ensures all chromosomes are attached to spindle fibers before the spindle fibers pull the sister chromatids apart.
Fredrick Griffith
Developed the Transforming principle and described the structure of DNA and that structure provided a mechanism for it to be replicated.
Decode the proteins from the following mRNA sequence.
5'-AUGGCUGAUGGUCAUUAUUGUUUUUAG-3'
AGU GCU GAU GGU CAU UAU UGU UUU UAG
Met-Ala-Asp-Gly-His-Tyr-Cys-Phe
The Central Dogma of Biology
Genetic information flows in one direction only, from DNA to RNA to protein
Name the phases of mitosis.
Interphase (G2), Prophase, Prometaphase, Metaphase, Anaphase, Telophase & Cytokinesis.
Human brain and muscle cells remain in this phase. Why?
G0 , Stem (satellite) cells wait for a need to transform like a muscle injury. They then transform into myoblasts that then go through mitosis.
Chargaff rules (pg 134)
in a sample of DNA, amounts of A and T are equal and amounts of C & G are equal
Where does the mRNA go after capping and splicing?
It exits the cell nucleus, enters the cytoplasm then joins with a ribosome.
DAILY DOUBLE
Original the DNA (coding) transcript was 5'-ATT-3' but mutated to 5'-ATC-3'
What effect would you expect on the organism?
They are different codons but they both map to the same amino acid.
What are telomeres? p157 & 160-161
The built-in checkpoints that must be met before cell division look for 3 main things.
Is it safe and appropriate for the cell to divide, are they needed now
Is there enough energy, chemical resources (nutrients)
Is DNA damaged & in need of repair p 156-157