Chapter 7 and 8: Microbial Metabolism and Genetics- Part 1

Question 1

Glycolysis…

Answer 1

Oxidizes glucose to pyruvate

Question 2

Pentose phosphate pathway

Answer 2

Less commonly used than glycolysis, initiates the oxidation of glucose

Question 3

TCA Cycle

Answer 3

Incorporates an acetyl group and releases CO2

Question 4

In prokaryotes, the membrane (where respiration occurs?) is the..

Answer 4

Cytoplasmic membrane surrounding the cell

Question 5

IN eukaryotes, the membrane (where respiration occurs?) is the…

Answer 5

Inner membrane of the mitochondrion

Question 6

The eukaryotic and prokaryotic systems of respiration are..

Answer 6

Nearly identical

Question 7

In respiration, a ________ _________ ________ is used to consume donated electrons

Answer 7

Terminal electron acceptor

Question 8

What is commonly used as the acceptor by aerobic microorganisms?

Answer 8

Oxygen!

Question 9

Fermentation is used by..

Answer 9

Organisms that cannot perform respiration to consume electrons

• Oxygen not available
• Obligate anaerobes

Question 10

Fermentation products are particularly useful for identifying ______ bacteria

Answer 10

Enteric (bacteria of the intestines

Question 11

E coli is a…

Answer 11

Facultative anaerobe

Question 12

An obligate anaerobe can either undergo ______ or _____ ______

Answer 12

Fermentation

Anaerobic photosynthesis

Question 13

Does the ETC or fermentation produce more energy?

Answer 13

ETC

Question 14

Saccaromyces is…

Answer 14

Yeast

produces ethyl alcohol

Question 15

Central dogma of molecular biology

Answer 15

DNA –> RNA–> Protein
(via transcription then translation)
&DNA replication to create duplicate of original molecule

Question 16

Differences between Eukaryotic and Prokaryotic Gene expression: Prokaryotic mRNA

Answer 16

mRNA is not processed

Question 17

Differences between Eukaryotic and Prokaryotic Gene expression: Eukaryotic mRNA

Answer 17

A cap is added to the 5’ end of mRNA and a poly A tail is added to the 3’ end

Question 18

Exons are..

Answer 18

Expressed and made into proteins

Question 19

Introns are…

Answer 19

Removed by chopping them out

Question 20

Differences between Eukaryotic and Prokaryotic Gene expression: Prokaryotic introns

Answer 20

mRNA does not contain introns

Question 21

Differences between Eukaryotic and Prokaryotic Gene expression: Eukaryotic introns

Answer 21

mRNA contains introns, which are removed by splicing

Question 22

Differences between Eukaryotic and Prokaryotic Gene expression: Prokaryotic translation

Answer 22

Translation of mRNA begins as it is being transcribed

Question 23

Differences between Eukaryotic and Prokaryotic Gene expression: Eukaryotic translation

Answer 23

The mRNA transcript is transported out of the nucleus so that it can be translated in the cytoplasm

Question 24

Monocistronic

Answer 24

One RNA molecule is for 1 protein

Question 25

Polycistronic

Answer 25

One RNA could make multiple proteins

Question 26

Differences between Eukaryotic and Prokaryotic Gene expression: Prokaryotic (polycistronic vs monocistronic)

Answer 26

mRNA is often polycistronic; translation usually begins at the first AUG that follows a ribosome binding site

Question 27

Differences between Eukaryotic and Prokaryotic Gene expression: Eukaryotic (polycistronic vs. monocistronic)

Answer 27

mRNA is monocistronic; translation begins at the first AUG

Question 28

In general, would the process of protein synthesis (transcription followed by translation) be faster for prokaryotes or eukaryotes?

Answer 28

Prokaryotes
(Do not have to remove introns, one RNA for multiple proteins, mRNA not processed and does not have to travel out of the nucleus)

Question 29

Prokaryotic Gene Regulation: Some genes are _________ expressed

Answer 29

Constitutively

Question 30

Two step process of prokaryotic gene regulation

Answer 30

Have to remove repressor and add activator

Question 31

Prokaryotic gene regulation: repressors

Answer 31

Bind to the DNA between the promoter and transcriptional start site, thus block RNA polymerase

Question 32

Prokaryotic gene regulation: activators

Answer 32

Interact with the promoter region to facilitate RNA pol binding

Question 33

The lac operon is a…

Answer 33

Sensing pathway for lactose

Question 34

What stimulates the expression of genes that metabolize lactose?

Answer 34

The presence of lactose and absence of glucose in culture media

Question 35

lac Operon process Step #1

Answer 35

As glucose levels drop, cAMP increases

Question 36

After cAMP increases, what happens in the presence of lactose?

Answer 36

cAMP binds to catabolite activating protein (CAP), allowing it to bind to the promoter

Question 37

After CAP binds to the promoter…

Answer 37

Allolactase, an isomer of lactose, binds to the lac represser, preventing it from binding to the DNA

Question 38

After allolactase binds, what happens?

Answer 38

RNA polymerase binds to the DNA and begins mRNA synthesis

Question 39

Why doesn’t lactose metabolism occur in the presence of glucose?

Answer 39

Because cAMP would not be present which prevents binding to activator site

Question 40

What is the purpose of allolactase?

Answer 40

To remove the repressor

Question 41

The lactose operon contains how many genes?

Answer 41

Three

Question 42

What does permeate do?

Answer 42

Affects permeability, helps bring lactose inside of cell