Molecular Genetics

Front 1

Activators

Back 1

Opposite to repressor proteins, activators must be present to allow the transcription of a gene to occur.

Hint 1

It's a type of Gene Regulation (in eukaryotes). It's the opposite of a repressor.

Front 2

DNA Packaging

Back 2

DNA must be unwound locally before it is transcribed.ge

Front 3

Genome Scattering

Back 3

Related genes are often spread apart on a eukaryotic chromosome. Each may have the same "control site" (activator sequence) so that only one activator is requires to initiate transcription.

Front 4

Introns/Exons

Back 4

A transcribed gene may have "useless" intruder segments known as introns that have to be separated from the "useful" expressed segments known as exons. The mRNA has to be modified before it can be translated.

Hint 4

It's an example of post-transcriptional regulation.

Front 5

Restriction Enzymes

Back 5

Also known as nucleolases, restriction enzymes cut DNA at specific places.

Hint 5

You can find these enzymes in viruses, meiosis and digestive processes.

Front 6

Blunt Ends vs Sticky Ends

Back 6

Blunt Ends occur when the nitrogenous bases are paired with a complementary base at the cleavage point. Where as Sticky Ends occur when nitrogenous bases are cleaved and are left unpaired - they are ready to bond.

Hint 6

Geneticists like sticky ends more than blunt ends.

Front 7

DNA Ligase (Genetic Engineering Tool)

Back 7

Fuses two "sticky ends" ends together (splicing).

Front 8

Plasmids (Genetic Engineering)

Back 8

Plasmids are small circular pieces of DNA that can enter and exit bacterial cells, they contain few genes and are structured as rings.

Front 9

What do you call a Plasmid that has had specific DNA inserted into its ring?

Back 9

It's called recombinant DNA

Front 10

Name two reasons why plasmids would be used.

Back 10

Gene Therapy; trying to insert good DNA into a parent with defector gene.
Treatments; like insulin injection.

Front 11

PCR

Back 11

This tool essentially makes photocopies of DNA to get many identical copies.

Hint 11

The polymerase chain reaction

Front 12

Give an example of when we would use a PCR ?

Back 12

Well, if you only had a small sample of blood (which has very little DNA in it) you could make photocopies of the DNA to properly analyze it for diseases etc.

Front 13

A.G.E

Back 13

Separates molecules based on their size (number of base pairs) and their molecular charge using an electric current.

Hint 13

Agarose Gel Electrophoresis

Front 14

In Electrophoresis, the smaller the fragment the (...) the migration distance. Explain your reasoning.

Back 14

The smaller the fragment, the larger the migration distance. This is because the pores in the agarose gel will only allow a specific size fragment through. The more concentrated the gel, the smaller the pores, the shorter the distance the fragments will travel.

Front 15

Name 3 differences between Prokaryotes and Eukaryotes

Back 15

In prokaryotes, translation and transcription can happen simultaneously (1) because they don't have a nuclear membrane (2) and since they are single celled transcription happens much faster than in Eukaryotes.

Front 16

Nucleosomes

Back 16

8 histone proteins with DNA wrapped around it twice.

Hint 16

Hockey puck

Front 17

Translocation

Back 17

Two or more chunks of DNA exchange places, this may disrupt an existing gene or 2. Transaction may produce a fusion protein.

Front 18

Lac Operon

Back 18

An active repressor protein sits on the DNA, inhibiting the production of proteins to be synthesized. When the inducer is introduced, in this case lactose, the repressor is turned off, allowing the production of 3 proteins that can break down lactose

Front 19

Function of rRNA

Back 19

rRNA binds with proteins to form ribosomes.

Front 20

Initiation (DNA replication)

Back 20

DNA helicase disconnects the hydrogen bonds, separating the nitrogenous bases.
DNA gyrase relives the tension by rotating the strands away from eachother.
SSBP's bond with the free bases to prevent them from rebounding.
RNA primers take away the SSBP's and hold the place for DNA later.

Front 21

Elongation (DNA replication)

Back 21

DNA polymerase III adds the new DNA nucleotides to replace the RNA primers.
DNA polymerase I removes primers and assists.
DNA polymerase III only works in the 3' to 5' direction of the parent strand.
The leading strand is assembled continuously, and the lagging strand is formed did continuously in what are called Okazaki Fragments.