Mastering for exam 3 brinninstool

Insertion sequences target which areas on a target DNA sequence?

A sequence of nucleotides identical to the inverted repeat sequence found on the insertion sequence itself

Why is reduction the term used to describe the gain of an electron?

The electron acceptor's net charge decreases.

The reactions involved in producing larger compounds from smaller compounds is called

anabolism

According to the animation, what is the net total (gain or loss) of ATP after one cycle?

loss of nine

glycolysis literally means

sugar splitting

Where does the energy to excite the electrons in photosystem I come from?

sunlight

How many molecules of ATP can be generated from one molecule of NADH?

3

According to the animation, ribosomes move along the mRNA in which direction?

5' to 3'

What drives the production of ATP in cyclic photophosphorylation?

Proton gradient

How does the proton gradient help ATP synthase to make ATP?

Protons move from outside the membrane to inside the membrane.

Which of the following statements regarding redox reactions is true?

Redox reactions involve an oxidation reaction coupled with a reduction reaction.

What is the fate of electrons in noncyclic photophosphorylation?

Reduce NADP+ to NADPH

How does replicative transposition differ from cut-and-paste transposition?

Replicative transposition results in the transposon being copied to a new location; in cut-and-paste transposition, the entire transposon moves to the new location.

Some organisms are capable of using aerobic respiration or anaerobic respiration but use aerobic respiration preferentially. Why is aerobic respiration favored?

Respiration with oxygen as a terminal electron acceptor generates more energy than respiration with other terminal electron acceptors.

Where does the energy come from to power the formation of GTP?

Succinyl CoA

According to the animation, what does the electron transport chain do to the concentration of hydrogen ions (protons)?

The concentration of protons is higher outside the membrane than inside.

In which organism would you likely find a chlorosome?

green sulfur bacteria

Organic micronutrients are commonly called __________.

growth factors

The use of amino acids to make proteins

is an example of anabolism.

In metabolism, energy that is not used

is given off as heat.

What is the fate of the NAD+ newly regenerated by fermentation?

it returns to glycolysis to pick up more electrons

Which of the following is an acid produced by fermentation?

lactic acid and propionic acid

The Tat system is involved in

protein secretion

Which of the following types of organisms uses hydrogen sulfide for reducing power?

purple sulfur bacteria

What carbon molecules remain at the end of glycolysis?

pyruvic acid

A reaction that involves the transfer of electrons from one molecule to another is referred to as

redox reaction

How many net ATPs can be made from one molecule of glucose in glycolysis?

2

Which energy-rich molecule directly powers cell work?

ATP

Why is ATP required for glycolysis?

ATP makes it easier to break apart glucose into two three-carbon molecules.

What is the intermediate product formed by pyruvic acid during alcoholic fermentation?

Acetaldehyde

Where would you expect to find electron transport chains in a prokaryote?

Along the plasma membrane

The term "respiration" is often used more broadly than is strictly accurate. The term "anaerobic respiration" may sound counterintuitive, but many different molecules can serve as electron donors or electron acceptors for prokaryotes. Which of the examples below is the best example of anaerobic respiration?

An organism uses an electron transport chain with sulfur as the terminal electron acceptor.

How is bacterial translation different from eukaryotic translation?

Bacteria can begin translation before transcription has terminated.

Noncyclic photophosphorylation employs which photosystem(s)?

Both photosystem I and photosystem II

Why does FADH2 yield less ATP than NADH?

FADH2 electrons enter the electron transport chain at a lower energy level.

Distinguish how fermentation and respiration differ.

Fermentation forms organic acids and takes place in the absence of oxygen, while respiration forms water and carbon dioxide in the presence of oxygen.

What is the key product formed by the Calvin-Benson cycle?

G3P

Which of the following statements about glycolysis is true?

Glycolysis is also called the Embden-Meyerhof pathway.

According to the animation, where would you find the lowest pH?

In the thylakoid space

Which of the following statements about fermentation is true?

It is an alternative way to return electron carriers to their oxidized state.

The Ames test is commonly used to test whether a particular chemical is mutagenic. When you conduct an Ames test, you need two groups of plates. One group of plates contains bacteria that are exposed to the chemical of interest, while the other plates contain bacteria that are not exposed to the chemical. Why is the latter group needed if you are just interested in the rate of mutation caused by the chemical?

It is important to compare the rate of mutations with the chemical to the normal background mutation rate. Mutations occur spontaneously even without the presence of a mutagen.

What is the role of water in cyclic photophosphorylation?

It provides electrons and protons.

What is the role of pyruvic acid in fermentation?

It takes the electrons from NADH, oxidizing it back into NAD+.

Iron is considered an essential element for many bacteria. Based on the animation, how would lack of iron affect energy production of a bacterium?

Lack of iron would mean lack of heme, and thus lower amounts of functioning cytochrome proteins. This would mean lower energy yields.

According to the animation, which compounds provide electrons to the system?

NADH and FADH2

What is the source of the electrons that reduce 1,3-bisphosphoglyceric acid?

NADPH

The most common pathway for carbon fixation for biosynthesis is the Calvin Cycle. This process requires 18 ATP and 12 NADPH in addition to 6 CO2 to form one 6-carbon molecule. The energy is supplied by ATP. What is the role of the NADPH?

NADPH is a source of electrons for reduction of the carbon compounds (reducing power).

Which of the following is needed as a reactant for the first step of the citric acid cycle?

Oxaloacetic acid

Since glucose, a hexose, is the major source of energy for most prokaryotes, why would they need to have pentose sugars available?

Pentose sugars are needed for nucleic acid synthesis.

What is the key difference between photoheterotrophs and photoautotrophs?

Photoheterotrophs use organic compounds as their carbon source; photoautotrophs use carbon dioxide as their carbon source. Submit

Why is the Calvin-Benson cycle also termed the "light independent reactions" of photosynthesis?

Sunlight is not directly needed to carry out this process.

If an organism used glycolysis (Embden-Meyerhof-Parnas pathway) to break down glucose and produce ATP but was unable to subsequently use fermentation or an electron transport chain (respiration), what problem would develop?

The available NAD+ would be converted to NADH and glycolysis would eventually stop due to the lack of NAD+.

How do polysomes illustrate the energy efficiency of a cell?

The cell can synthesize multiple copies of a protein from a single piece of mRNA.

If the gene that codes for transposase is mutated so that it no longer produces the fully functional enzyme, how will the insertion sequence be affected?

The insertion sequence would lose its ability to effect its own movement. Submit

A single base substitution happens to cause a nonsense mutation early in the gene for a protein. What will be the result?

The protein will be truncated so much that it is unlikely to function normally.

Which statement illustrates how prokaryotes determine where to begin translation so the correct protein is synthesized?

The rRNA recognizes the correct start codon with the aid of an upstream Shine-Dalgarno sequence.

Which step(s) of the Krebs cycle does (do) not produce any usable energy?

The second and seventh steps

How is anaerobic respiration different from aerobic respiration?

The terminal electron acceptor in anaerobic respiration is not oxygen.

Which step involves the release of carbon dioxide?

The third and fourth steps

What makes an insertion sequence different from other DNA sequences found in a cell?

They are capable of effecting their own movement from one location to another on DNA.

What is the fate of the NADPH molecules created during noncyclic photophosphorylation?

They are used in the Calvin-Benson cycle.

Where do the electrons from photosystem I ultimately go after they are passed through the electron transport proteins?

They return to photosystem I.

What is the role of light energy in photosynthesis?

To produce a proton gradient to make ATP

What is one difference between ubiquinones and cytochromes?

Ubiquinones are not made of protein; cytochromes are.

Frameshift mutations can be very severe. What is one reason why they are often so serious?

When a frameshift mutation occurs, it causes changes in many bases downstream and can affect many of the amino acids in the protein. Submit

What results from the process of translation?

a polypeptide

A mutant that has a nutritional requirement for growth is an example of a(n)

auxotroph

Where does the energy required for anabolic reactions come from?

catabolic reactions

The process of generating ATP using a proton gradient is referred to as

chemiosmosis

A defined culture medium is designed to meet the needs of a particular type of organism, suppling all of the nutrients the organism needs, including essential biochemicals that the cell cannot synthesize. Based on the following recipe, this defined medium would best support the growth of certain members of what group? Recipe: 7 g of K2HPO4; 2 g of KH2PO4; 1g of (NH4)2SO4; 0.1g of MgSO4; 0.02g of CaCl2; 10g of glucose; trace elements mix; 1000 mL of distilled water; adjust to pH 7.

chemoorganotroph

What molecule is used to capture light energy?

chlorophyll

Which of the following is a bacterium that performs oxygenic photosynthesis?

cyanobacteria

Transcription of chaperones is greatly accelerated when a cell is stressed by

excessive heat

Proteins known as chaperones are found only in Bacteria.

false

Trace elements are found in bacterial cells in very small amounts because they __________.

function only in a limited set of enzymes and cofactors

Which of the following molecules is broken down in cellular respiration, providing fuel for the cell?

glucose

Which of the following would NOT be required to grow an autotroph?

glucose

Gluconeogenesis is the process of synthesizing __________.

glucose from other compounds

Which of the following can be used as a final electron acceptor for aerobic respiration?

molecular oxygen

The addition of two bases to the genome of a prokaryote would be most damaging if located __________.

near the beginning of the coding region of a protein

How many of the six G3P's produced in one cycle are used to make one molecule of glucose?

one

The appearance of an abundance of colonies close to the test disk after an Ames test would suggest __________.

the chemical tested is a mutagen

During an oxidation reaction,

the donor molecule loses an electron and becomes oxidized.

Which of the following is a trait unique to photosynthetic eukaryotes?

the presence of chloroplasts

The first step of translation begins when __________.

the ribosome binding site (RBS) on the mRNA binds to the 16S rRNA to begin the formation of the initiation complex

What is the function of the Calvin cycle in purple bacteria?

to incorporate inorganic carbon into an organic compound

Applying your knowledge of metabolism, glycolysis starts with one molecule of glucose (6C) and produces a net total of __________.

two pyruvates; 2 NADH; 2 ATP

According to the animation, what does oxygen get reduced to at the end of the electron transport chain?

water

Which of the following is used in photosynthesis by both plants and cyanobacteria?

water, sunlight, and carbon dioxide