Bio 2120 Exam 2

ISU

Of the four processes in cellular respiration: glycolysis, pyruvate processing, citric acid cycle, electron transport and oxidative phosphorylation, which does not occur within the mitochondria?

Glycolysis

Which process of respiration in eukaryotic cells will proceed normally both in presence or absence of oxygen?

Glycolysis

In eukaryotes, the citric acid cycle occurs in the_____

matrix of mitochondria

The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is_____

Oxygen

Carbon dioxide (CO2) is released during which of the following stages of cellular respiration?

Oxidation of pyruvate to acetyl CoA and the citric acid cycle

In cellular respiration, oxygen serves as an electron acceptor. What serves as an electron acceptor in fermentation?

Pyruvate

Proton pumps in the inner mitochondrial membrane help maintain an electrochemical gradient across the membrane. This gradient is used to help drive ATP synthesis via.....

Oxidative phosphorylation 

Over Spring Break, you gained 7 pounds! You resolve to exercise more to lose weight. Your hours on the treadmill pay off, and you lose 5 pounds. The mass that you lost during exercise included sugars, lipids, and proteins. Where did those molecules go?

Much of the mass that you lost was consumed in respiration, exhaled as carbon dioxide and water.

Which of the following is not a high energy intermediate?

Pyruvate

Which of the following descriptions best fits the class of molecules known as nucleotides?

A nitrogenous base, a phosphate group, and a sugar

Which statement accurately summarizes a difference between ribonucleotides and deoxyribonucleotides? 

Ribonucleotides have a hydroxyl group bonded to their 2' carbon; deoxyribonucleotides have an H at the same location.

The Hershey-Chase experiment aimed to determine whether genes are made of proteins or DNA. In the experiment, the researchers grew a bacteriophage in either the presence of radioactive sulfur (35S) or radioactive phosphorus (32P).

They then allowed the virus to infect a host cell (E. coli). Which of the following was NOT an observation of the Hershey-Chase experiment?

radioactive 32P was found in the viral capsids at the end of the experiment

In a DNA double helix, what kind of chemical bonds are formed between the complementary nitrogenous bases (in other words bonds that join nitrogenous bases?

hydrogen bonds

A double-stranded DNA molecule contains a total of 120 purines and 120 pyrimidines. This DNA molecule could be composed of:

120 thymine and 120 adenine molecules

Nucleotides are linked together to form a nucleic acid chain when the hydroxyl group of the [ Select ] ["3'", "2'", "5'"] carbon of one nucleotide is linked to the phosphate group on the [ Select ] ["3'", "2'", "5'"] carbon of the next nucleotide via a [ Select ] ["dehydration synthesis", "hydrolysis"] reaction. This forms a [ Select ] ["hydrogen", "phosphodiester", "peptide"] bond.

Answer 1:

3'

Answer 2:

5'

Answer 3:

dehydration synthesis

Answer 4:

phosphodiester

What is the structural feature that allows DNA to replicate and pass on hereditary information to the daughter cell?

Complementary pairing of the nitrogenous bases

How are the structures of RNA and DNA similar?

Their sugar-phosphate backbones are formed by phosphodiester linkages.

Meselson-Stahl Experiment: Which hypothesis on DNA replication can be eliminated by data from the first generation of E.coli?

conservative

How does semiconservative DNA replication differ from conservative replication?

In semiconservative DNA replication, the DNA strands are separated and each strand is copied.

If one strand of a DNA molecule has the sequence of bases 5'ATTGCA3', the other complementary strand would have the sequence ________.

5'TGCAAT3'

In DNA replication, the double helix overwinds and develops tension ahead of the replication force. This could fracture and break the DNA.

To mitigate this from happening, the enzyme Topoisomerase .....

breaks and rejoins DNA

How are Okazaki fragments synthesized? They are synthesized using the
template and are synthesized in the [ Select ] ["5' → 3'", "3' → 5'"] direction.

["lagging", "leading"] strand as a

Answer 1:

lagging

Answer 2:

5' → 3'

In DNA synthesis, synthesis of the leading strand is ..........................., while synthesis of the lagging strand is ............................ (Fill in the blanks)

Continuous, discontinuous

A mutation completely inhibits telomerase. What is the result?

Ends of replicated RNA are left single-stranded

A mutation is known to affect the cell's ability to open the double helix during DNA replication. Which of the following proteins is likely affected?

Helicase

Two scientists, Beadle and Tatum developed a “one gene, one enzyme” hypothesis from an experiment with the model organism, Neurospora crassa. They were studying the pathway of metabolic events that lead to the production of arginine, an essential amino acid for growth of this organism. The pathway is as follows:

They identified a single mutation that disabled enzyme 2. What would be the characteristics of the Neurospora that bears that mutatio

It would grow on medium containing Citrulline, but not on Ornithine

In the process of transcription, ________.

RNA is synthesized

The statement "DNA → RNA → Proteins" ________.

is known as the central dogma

Which of the following processes is central to the initiation of transcription in bacteria?

Binding of sigma to the promoter region

The core promoter in prokaryotes is usually composed of which two features?

The TATA box and -35 box

Transcription in a bacterial cell begins at the +1 site of a gene. Translation begins at the Start codon of mRNA.

Answer 1:

+1 site

Answer 2:

Start codon

What RNA sequence will be transcribed from the DNA sequence shown below? 

5’ – ACTCGCATCGGCA – 3’ (TEMPLATE STRAND)

3’ – TGAGCGTAGCCGT – 5’ (CODING STRAND)

5’ | UGCCGAUGCGAGU | 3’

Termination of transcription in bacteria occurs when ________.

a hairpin secondary structure forms in the RNA transcript, and it separates from the RNA polymerase

The mature mRNA shown in this figure is smaller than the length of the primary mRNA transcribed directly from DNA because.. ________.

post transcriptional modification removes the introns and makes a shorter spliced mRNA transcript

One of the primary functions of mRNA molecules is to ________.

make a copy of DNA and function in the synthesis of proteins

Genotype is to ________ as phenotype is to ________.

DNA base sequence; physical traits that are products of the proteins produced

T/F?

In the genetic code, there is only a single codon for each amino acid.

False

Which one of the following is true? A codon..............

is the basic unit of the genetic code made of three bases

An organism acquires a point mutation in a protein coding region that changes the mRNA codon CCC to CCA. Which of the following statements is TRUE following this mutation?

 The organism’s genotype has been changed, but not its phenotype

In the figure, what is the function of the AGU or anticodon on the loop of the tRNA?

It base pairs with a codon of mRNA

What does it mean when we say the genetic code is redundant?

More than one codon can specify the addition of the same amino acid.

A mutation that results in premature termination of translation is known as________.

is a nonsense mutation

A frameshift mutation in a gene could result from ________.

either an insertion or a deletion of a base

The segment of mRNA shown below is translated into a protein. Note that the beginning of the segment is a start codon and the end is a stop codon. How many amino acids will this protein contain and why?

5’- AUGAAGUCUCCUCGUUAG-3’

Five, because the ribosome will add on an amino acid for the start codon, but will not add one for the stop codon

A tRNA with the anticodon of 3’-GUA-5’ enters the ribosome and adds on an amino acid to the growing polypeptide chain. Which amino acid has been added?

Histidine

Sigma is a factor in prokaryotes that .........

All of the above