Genetics

Front 1

Purines

Back 1

A & G - larger

Front 2

Pyrimidines

Back 2

C & T - smaller

Front 3

Replication

Back 3

1. DNA unwinds

2. Leading strand is continuously synthesized 5' --> 3'

3. Lagging strand is synthesized discontinuously in 5' --> 3' direction. The short segments formed are Okazaki fragments.

4. DNA polymerase synthesizes the strands.

Front 4

Transcription

Back 4

DNA is translated into mRNA. It leaves the nucleaus to the cytoplams.

Front 5

Translation

Back 5

mRNA codons are translated into a sequence of amino acids which form proteins.

tRNA brings the amino acid to the ribosomes in the correct sequence.

Ribosomes are made up of two subunits, a small and a large. There are three binding sites: P, A, and E.

A - incoming amino acid
P - growing peptide chain
E - tRNA is released

Front 6

Nondisjunction

Back 6

Failure of homologous chrom to seperate during meiosis I or the failure of sister chromatids to seperate during meiosis II.

Causes 3 copies of a chromosome (trisomy) or 1 copy (monosomy).

Front 7

Down's syndrome

Back 7

Trisomy on chrom. 21

Front 8

Transformation

Back 8

(bacterial genetic variance)

Plasmid is incorporated into the chrom. through recombination.

Front 9

Conjugation

Back 9

(bacterial genetic variance)

The transfer of genetic material between two bacteria.

F+ cells join with F- cells to make them F+ as well. They trnasfer the F factor to the F- cells.

Hfr cells are those cells where the sex factor has become integrated into the genome.

Front 10

Transduction

Back 10

Parts of bacterial chrom. are packaged into a phage, and when they infect other bacteria, they introduce the new genetic information.

Front 11

Gene regulation

Back 11

-lets proks control their metabolism

-Includes structural genes, operator gene, and promoter gene.

Front 12

Operator gene

Back 12

this is the repressor binding site

Front 13

Promoter gene

Back 13

this is the binding site for RNA polymerase

Front 14

Regulator gene

Back 14

codes for the repressor molecule, which binds to the operator and blocks RNA polymerase from transcribing

Front 15

Inducible systems

Back 15

-require the presence of a substance (the inducer) for transcription to occur.

-repressor binds to operator when there is no INDUCER around.

-inducer binds to the repressor, and thus it cannot bind to operon and transcription occurs.

-When substrate is present, enzymes are transcribed.

Front 16

Repressible systems

Back 16

-Repressor is inactive until it combines with corepressor.

-Then, it binds to operator and transcription does not occur.

-Corepressors are often the end products.