Exam 2 Flashcards - Set 12

Why can't bacteria grow in solutions with very high concentrations of sugar?
A) Sugar raises the solution's osmolarity.
B) Sugar lowers the solution's pH.
C) Bacteria cannot digest pure sugar.
D) Sugar raises the solution's pH.
E) Sugar lowers the solution's osmolarity.

You find that a microorganism has optimum growth at pH 9 and a temperature of 15°C, this organism is a(n):
A) alkalophilic mesophile
B) acidophilic thermophile
C) alkalophilic psychrophile
D) neutrophilic mesophile
E) neutrophilic psychrophile
g) acidophilic mesophile

Which of the following is/are true?
a) peripheral membrane proteins span through the membrane
b) integral membrane proteins sits on the surface of the membrane
c) the membrane is a very rigid monolayer structure that encapsulates the cell
d) LPS is found in Gram- inner and outer membranes
e) non of the above are correct

True/False: Microbial genomes consist of one (usually) or more DNA chromosomes.

Names the purines.

Name the pyrimidines.

Name the three parts that each nucleotide consists of.

Nucleotides are connected to each other by _____ _________ _____.

Hydrogen bonding allows complementary base interactions.
- A pairs with ___ (via ____ H bonds)
- G pairs with ___ (via ____ H bonds)

At high temperatures (___-___ °C), the hydrogen bonds in DNA break and the duplex falls apart, or _______, into two single strands

RNA differs from DNA:
- Usually ____ stranded
- Contains _______ sugar
- ______ replaces thymine

______ is a horizontal gene transfer mechanism requiring cell-to-cell contact, which could transfer large segments of some bacterial chromosomes.

Bacterial and archaeal chromosomes range in size from ____ to ______ kilobase pairs (kb).

Eukaryotic chromosomes range from _____ (Microsporidia) to over _____ million kb (flowering plants). The human genome is over __ million kb.

Eukaryotic genomes typically contain more than ____% noncoding DNA, while prokaryotic genomes typically contain less than ____%.

Name the type of gene transfer:
- from parent to child

Name the type of gene transfer:
- transfer of small piece of DNA from one cell to another

A ______ ____ produces a functional RNA, which usually encodes a protein.

A ____ _____ _____ regulates the expression of a structural gene.

A gene can operate independently of others, or it may exist in tandem with other genes in a unit called an _____.

______ is a group of genes/operons; usually in one pathway and regulted by a common regulator.

Bacteria pack their DNA into a series of loops of domains, collectively called the _____.
- loops are anchored by histone-like proteins

Name the type of supercoil:
- DNA is overwound

Name the type of supercoil:
- DNA is underwound

Eukarytoes, bacteria, and most archaea possess _______ supercoiled DNA.

Archaea living in acid at high temperatures possess _____ supercoiled DNA.

Enzymes that change DNA supercoiling are called ______.

Name the type of topoisomerase:
- usually single proteins
- cleave one strand of DNA
- releases supercoil

Name the type of topoisomerase:
- Have multiple subunits
- Cleave both strands of DNA
- introduces supercoil
- requires energy
- Example: DNA gyrase

Name the type of topoisomerase:

Name the type of topoisomerase:

Since their chromosomes are linear, eukaryotes require a reverse transcriptase called ______ to replicate their ends

Eukaryotic cells pack their DNA within the nucleus using proteins called ______.

A large portion of eukarytoic chromosomes are composed of noncoding DNA, including ____ and ______.

True/false: archaeal genomes combine features of bacteria and eukaryotes.

Like bacteria, archaea have:
- _____ operons
- _____ reproduction
- Cells _____ a nuclear membrane
- A single _____ chromosome

In most species of archaea, the process of DNA replication, transcription, and translation more closely resemble those of:
A) bacteria
B) eukaryotes
C) neither

Two kinsd of extragenomic DNA molecules can interact with bacterial genomes:
- _____ transferred plasmids
- genomes of _______ (viruses that infect bacterial cells)

Name the type of plasmid replication:
- starts at a single origin and occurs in two directions simultaneously

Name the type of plasmid replication:
- Starts at a single origin and moves in only one direction

Name the type of plasmid replication:

Plasmids have tricks to ensure their inheritance:
- Low-copy-number plasmids segregate ____ to daughter cells
- High-copy-number plasmids segregate ____ to daughter cells

The bacterial chromosome is packed in a series of protein-bound loops collectively called the _____.

Topoisomerases are enzymes that ____ DNA.