Qtr 3 Final Essays

Question 0

DNA fragments

Answer 0

Length determined using gel electrophoresis- measured in base pairs

Question 1

Restriction enzymes

Answer 1

Cut DNA with very precise recognition sequences-They are symmetrical or palindromic

Question 2

PCR

Answer 2

Polymerase chain reaction-replicates DNA so it can be analyzed further

Question 3

Specific disease in the lab

Answer 3

Cystic fibrosis-results from mutation of the cystic fibrosis transmembrane conductor gene which codes for a protein that regulates the flow of chlorine ions across membranes

Question 4

Agarose

Answer 4

Polysaccharide obtained from agar that is the most widely used medium for gel electrophoresis procedures

Question 5

Gene expression in prokaryotes

Answer 5

Inducible operon: gene is expressed when a molecule interacts with a regulatory protein otherwise it’s off
Repressive operon: usually expressed but can be turned off by molecule binding to a regulatory protein

Question 6

Gene expression in eukaryotes

Answer 6

Gene is expressed when an active activator protein binds to the regulatory gene allowing the RNA polymerase to bind to the promoter

Question 7

Lytic cycle

Answer 7

Virulent viruses (kill their infected host cell) are reproduced through the lyric cycle- they lyse their host cells

Question 8

Lysogenic cycle

Answer 8

Temperate viruses (reproduce without killing their host cell) reproduce through the lysogenic cycle-phases DNA recombined with the bacterial chromosome-once inserted=prophage

Question 9

Reproductive cycle of an HIV retrovirus

Answer 9

Retroviruses attack cells in the blood HIV like retroviruses attaches to a blood cell then injects it’s RNA causing the cell to creat more of the virus-can’t kill you but lowers immune system

Question 10

Processes that lead to the emergence of new diseases

Answer 10

Flu epidemics
Pandemics
When viruses spread from animals to humans

Question 11

Viroids

Answer 11

Infectious agents that are not living entities but can still transmit disease
Lack protein cost and are merely circular single stranded RNA fragments that replicate on their own inside plant cells

Question 12

Prions

Answer 12

Abnormal forms of the protein PrP

Transmit several diseases that affect neural tissues in animal and humans

Question 13

Vaccine creation

Answer 13

Preparation containing weakened or dead microbes of the kind that cause a disease
Administered to stimulate the immune system to produce antibodies against the disease

Question 14

Nuclear transplantation

Answer 14

Moving a cell nucleus and it’s emetic material from one cell to another
-way of cloning
Ex. Dolly the sheep

Question 15

Elements of transcription

Answer 15

Synthesis of RNA using DNA

Question 16

RNA polymerase in transcription

Answer 16

Starts transcription
Binds to the promoter where the RNA polymerase binds to the DNA sequence
Takes the DNA strands apart and connects RNA nucleotides

Question 17

End of transcription

Answer 17

Sequence signaling the end in bacteria is the terminator

Question 18

Three stages of transcription

Answer 18

Initiation
Elongation
Termination

Question 19

Initiation

Answer 19

At the promoter on the 5’ to 3’ template

Ends with a TATA box

Question 20

Transcription factors

Answer 20

Binds to the DNA before the polymerase so the transcription initiation complex is formed

Question 21

Elongation

Answer 21

Occurs after transcription initiation complex is formed

RNA polymerase untwists the DNA’s double helix

Question 22

Gene can be transcribed until

Answer 22

The termination sign stops it which is where the RNA polymerase detaches and the completed RNA transcript is left

Question 23

DNA to RNA to protein

Answer 23

transcription to make RNA then the RNA polymerase travels down following the helicase

Question 24

Helicase

Answer 24

Unwinds the DNA strands so RNA polymerase can read the gene and construct a pre-mRNA

Question 25

As pre-mRNA emerges

Answer 25

It is capped with a modified nucleotide that protects the RNA from degradation

Question 26

Pre-mRNA

Answer 26

Is spliced by proteins called spliceosomes which chips out non-coding regions of RNA called introns found between the coding regions called exons (exons are expressed)
RNA then has a 5’ cap, 3’ poly-a tails and no introns

Question 27

Translation occurs

Answer 27

And called mRNA
exported from the nucleus by means of large protein pores which allows the import and export of chemicals into the nucleus

Question 28

Once in the cytoplasm the mRNA

Answer 28

Must be translated

Question 29

Translation

Answer 29

Ribosomes bind to the mRNA with the help of proteins and scans the mRNA until it finds a start codon

Question 30

After finds a start codon

Answer 30

A tRNA binds to the A-site inside the ribosome

Question 31

tRNAs are

Answer 31

Small ribozymes that bind a specific amino acid then bring the amino acid to the ribosome when needed which are then slowly added to the growing protein chain

Question 32

As the protein emerges,

Answer 32

It passes trough a pore clef a translocon and passes into the endoplasmjc reticulum

Question 33

After passes into the ER

Answer 33

It finds it’s way to the Golgi apparatus which packages the protein in a vesicles which heads for the cell membrane and merges with it forcing the protein out of the cell