Test Review For Unit 1 Exam

Question 1

Central dogma of molecular biology

Answer 1

DNA -> RNA -> protein

Question 2

What goes against the central dogma of molecular biology?

Answer 2

Retroviruses

Protein -> RNA -> DNA

Question 3

Thermus aquaticus

Answer 3

• T. aquaticus was isolated from a hot spring
• the DNA polymerase from T. aquaticus is used in molecular biology for a procedure called polymerase chain reaction
• the DNA polymerase from T. aquaticus is able to withstand very high temperatures
• T. aquaticus can survive high temperature and low pH

Question 4

Escherichia coli

Answer 4

• E. coli is called “the workhorse of molecular biology”
• E. coli can grow in a simple solution of water, a carbon source, and minuses salts
• the chromosome of E. coli consists of one circular DNA molecular containing approximately 4000 genes

Question 5

Usefulness of fungi in biotechnology research

Answer 5

• fungi produce the blue veins in some types of cheeses
• yeast is responsible for the alcohol in beer and for bread rising
• the 2-micron circle is a useful extrachromosomal element from yeast that can be utilized in molecular biology research
• fungi produce many industrial chemicals and pharmaceuticals

Question 6

Differences in eukaryotic vs. prokaryotic translation

Answer 6

• in eukaryotes, mRNA is made in the nucleus but translated in the cytoplasm
• prokaryotes often couple transcription and translation, forming a polysome
• eukaryotic mRNA does not have a Shine-Dalgarno sequence, but prokaryotic mRNA does
• many eukaryotic proteins are chemically modified after translation, which is a much rarer penomenon in prokaryotes

Question 7

Why do mitochondria and chloroplasts contain their own genes

Answer 7

They are thought to have once been free-living organisms similar to bacteria that formed a symbiotic relationship with a unicellular eukaryote

Question 8

Methylation of DNA…

Answer 8

Results in the removal of histones from the methylated regions

Question 9

___ ___ ___ regulate gene expression.

Answer 9

Prokaryotic sigma factors

Question 10

Sigma subunit -

Answer 10

• Recognizes the promoter and binds catalytic portion of the enzyme
• transcription factors that associate with prokaryotic RNA polymerase and control which genes are transcribed

Question 11

The sigma70 subunit, RpoD -

Answer 11

The most commonly used form that recognized house keeping genes

Question 12

The sigma32, RpoH -

Answer 12

Activates genes needed during heat shock including chaperonins and proteases

Question 13

___ ___ ___ such as ___ can loosen nucleosomes, making them more accessible to various regulatory proteins.

Answer 13

Histone post-translation modification; acetylation

Question 14

The enzymes called ___ ___ ___ transfer acetyl groups to lysines within the tail, and structure loosens.

Answer 14

Histone acetyl transferases (HATs)

Question 15

To tighten the nucleosomes, ___ ___ remove the acetyl groups, and the histones re-aggregate

Answer 15

Histone deacetylases

Question 16

In ___, methylation distinguishes synthesized strand from the template.

In ___, methylation is used to silence various genes of DNA and prevent their expression.

Answer 16

Prokaryotes

Eukaryotes

Question 17

Lac operon

Answer 17

+ glucose + lactose -> lac operon off because has glucose

• glucose + lactose -> lac operon on
• glucose - lactose -> lac operon off

Question 18

Lactose acts as an ___.

Answer 18

Inducer