Questions
What is a gene and how does the enzyme that catalyzes transcription find the start of...

What is a gene and how does the enzyme that catalyzes transcription find the start of the gene?

What is the DNA chain/thread read in the transcript?

Do the eukaryotes also have only one enzyme that catalyzes the transcription of RNA?

How are the eukaryotic primary mRNA transcripts processed before they can be transported from the cell nucleus to the ribosomes in the cytosol?

In: Biology

Describe the clinical consequences of a genetic or nutritional deficiency in the enzyme or cofactor listed...

Describe the clinical consequences of a genetic or nutritional deficiency in the enzyme or cofactor listed below. Describe the cause of this disease (lack of type of food or genetic inheritance pattern) and its prevalence. Include any theory that describes the molecular mechanisms that connect the lack of enzyme activity to the disease symptoms.

a) hexokinase
b) phosphofructokinase
c) glyceraldehyde 3-phosphate kinase

In: Biology

What are the two general strategies for maintaining the very high degree of fidelity of DNA...

What are the two general strategies for maintaining the very high degree of fidelity of DNA replication during replication itself?

Following the discovery of DNA polymerase I, what experimental evidence suggested that another enzyme is the primary enzyme of replication?

What are the features of DNA polymerase that ensure the right nucleotides are inserted?

Describe the mechanism of polymerization used by polymerases.

In: Biology

RECOMBINANT DNA REVIEW 1. How are genes cut into pieces, in preparation for recombinant DNA cloning?...

RECOMBINANT DNA REVIEW

1. How are genes cut into pieces, in preparation for recombinant DNA cloning?

2. What enzyme is used to securely paste a new piece of DNA into a recombinant DNA molecue? What other process is this enzyme used in?

3. How does recombinant DNA get into bacteria? Name the process and how it works.

In: Biology

say you have deduced that a particular genetic disorder is caused when the body cannot produce...

say you have deduced that a particular genetic disorder is caused when the body cannot produce a particular enzyme, encoded by gene ABC. Therefore you compare gene ABC’s nucleotide sequence between healthy people and people who have the disorder (because they do not produce the enzyme). But the DNA nucleotide sequence from the start site of transcription to the termination point of transcription is always exactly the same for people in both groups. If this genetic disorder is caused by a mutation in the DNA, where is the mutation likely to be, and how is the mutation acting to result in these observations? Apart from the enzyme itself, what molecule’s absence from the cells of an affected person would verify this?

In: Biology

8. A circular plasmid of 6200 base pairs (bp) with three restriction enzyme sites at 900,...

8. A circular plasmid of 6200 base pairs (bp) with three restriction enzyme sites at 900, 1300, and 4000 bp. You digest this plasmid, then run the digest on a gel. What are the expected DNA fragment sizes?

9. A linear plasmid of 6200 base pairs (bp) with three restriction enzyme sites at 900, 1300, and 4000 bp. You digest this plasmid, then run the digest on a gel. What are the expected DNA fragment sizes?

10. In a random sequence consisting of equal proportions of all four nucleotides, what is the average distance between restriction enzymes for a restriction enzyme with a 4-base cleavage site (hint- look for a similar problem in your book).

In: Biology

DNA replication requires many enzymes to accomplish the process successfully. This results in a replication process...

DNA replication requires many enzymes to accomplish the process successfully. This results in a replication process that is known to be bi-directional, semi-conservative and semi-discontinuous. You discover a new prokaryotic organism that lacks the gene coding for an DNA polymerase I enzyme, and therefore this enzyme is not made in this species. Additionally, the DNA polymerase III enzyme from this organism lacks any 3’ to 5’ nuclease activity but has 5’ to 3’ nuclease activity. Based on what you know about DNA replication and the functions of DNA polymerase I and DNA polymerase III, discuss the effect of these changes on DNA replication in this organism. Please explain your answer in full.

In: Biology

DNA replication requires many enzymes to accomplish the process successfully. This results in a replication process...

DNA replication requires many enzymes to accomplish the process successfully. This results in a replication process that is known to be bi-directional, semi-conservative and semi-discontinuous. You discover a new prokaryotic organism that lacks the gene coding for an RNA polymerase I enzyme, and therefore this enzyme is not made in this species. Additionally, the DNA polymerase III enzyme from this organism lacks any 3’ to 5’ nuclease activity but has 5’ to 3’ nuclease activity. Based on what you know about DNA replication and the functions of DNA polymerase I and DNA polymerase III, discuss the effect of these changes on DNA replication in this organism. Please explain your answer in full.

In: Biology

In the lab, you measure the initial rate of an enzyme reactionas a function of...

In the lab, you measure the initial rate of an enzyme reaction as a function of substrate concentration in the presence and absence of an unknown inhibitor (0.05 mM). The following data are obtained when the total enzyme concentration is 1 x 10-6mM:


[S] mM

0.0001

0.0002

0.0005

0.001

0.002

0.005

0.01

0.02

0.05

0.1

0.2

No

Inhibitor

V0 (mM/min)

33

50

71

83

91

96

98

99

100

100

100

With

Inhibitor

V0 (mM/min)

17

29

50

67

80

91

95

98

99

100

100

A) What are Vmax and Km in the absence of inhibitor? (2 marks)

B) What kind of inhibitor is it likely to be and why? (1 mark)

C) Calculate the inhibition constant for this inhibitor with the enzyme. (3 marks)

D) Calculate the turnover number and specificity constant for this enzyme. (2 marks)

E) When [S] = 0.0004, what will V0 be in the i) absence ii) presence of inhibitor? (2 marks)

In: Chemistry

1. Once glucose enters a cell, it it ‘phosphorylated' in order to Select one: a. trap...

1. Once glucose enters a cell, it it ‘phosphorylated' in order to

Select one:

a. trap it inside the cell

b. raise its free energy (G)

c. tag it for entry into mitochondria

d. remove protons (H+)

e. A and B

2. Energy transfers always make heat energy and more disorder. This tendancy toward more disorder refers to

Select one:

a. entropy

b. a heat sink

c. the big bang

d. e=mc squared

e. heat equilibrium

3. According to the current model, an enzyme binding to its target molecule is most like

Select one:

a. a square peg in a round hole, because the enzyme can bind to a variety of target molecules

b. a lock fitting a key, because the pocket where the enzyme fits its specific target molecule is precise, and rigid

c. a hand fitting a doorknob, because the enzyme folds around its target molecule, squeezing it

d. an electric pencil sharpener, because inserting the target molecule into the enzyme causes the enzyme to cut it

4. Which cell structure is INCORRECTLY matched with its function?

Select one:

a. Rough ER: Synthesis of membrane proteins

b. Smooth ER : Assembly of new membranes

c. Lysosome : Digestion of ‘food' substances taken into cell

d. Golgi body : Receives, modifies, and exports

e. Central vacuole : Physical support

5. Which of these are NOT features of microtubules?

Select one:

a. Assists in cell support and movement

b. Controls cell locomotion by cilia and flagella

c. Made of tubulin proteins

d. Are the thickest cytoskeletal fiber

e. Needed to form durable structures like hair and fingernails

In: Biology