Questions
Describe how you could separate a mixture of cytochrome C, ferritin and an enzyme X (MW...

Describe how you could separate a mixture of cytochrome C, ferritin and an enzyme X (MW 450 kDa and pI 8.4) using only one chromatography column. Be sure to include the type of column, the type of gel or resin, and the conditions to ensure elution ( and separation) of the proteins.

In: Biology

In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate. Which of the following reasons provides the...

In glycolysis, a glucose-phosphate is transformed into a fructose-phosphate. Which of the following reasons provides the best chemical rationale for this transformation? Choose the best answer.

A.

It is not possible to break a molecule of glucose into two pieces but it is possible to break a molecule of fructose into two pieces.
B.

Glucose is not a high phosphotransfer potential molecule but fructose is a high phosphotransfer potential molecule.
C.

There are no enzymes to add phosphate groups to glucose but there are enzymes to add phosphate groups to fructose.
D.

If glucose were broken into two pieces the molecules would have unequal length but if fructose is broken into two pieces the molecules will have the same length.

In: Biology

During periods of intense activity, when glycolysis is used in the generation of ATP, the reaction...

During periods of intense activity, when glycolysis is used in the generation of ATP, the reaction lies to the right, decreasing [ADP], generating ATP, and accumulating AMP. However, [ATP] is usually much greater than [ADP], and [ADP] is greater than [AMP]. Determine [AMP] when 7% of the ATP in a hypothetical cell is hydrolyzed to ADP. In this cell, the initial concentration of ATP is 267 μM, and the total adenine nucleotide concentration (the concentration of ATP, ADP, and AMP) is 3.90 × 102 μM. The equilibrium constant K is 0.82 What is the concentration of AMP after 7% of the ATP is hydrolyzed to ADP?

In: Chemistry

The addition of phosphate groups to intermediate molecules in glycolysis results in: a. Increased potential energy...

The addition of phosphate groups to intermediate molecules in glycolysis results in:

a.

Increased potential energy of that intermediate molecule
b.

Use of ATP
c.

Subsequent generation of ATP via substrate-level phosphorylation
d.

Direct generation of ATP via oxidative phosphorylation
e.

A, B, and C are correct

Which of the following statements regarding electron excitation in photosynthesis is correct?

a.

All forms of electromagnetic radiation are equally capable of generating free radicals
b.

All wavelengths of light induce equal degrees of electron excitation
c.

Electron excitation within photosynthetic pigments can result in fluorescence, heat, and reduction/oxidation reactions
d.

Following electron excitation, the degree of resonance-energy transfer would be increased if carotenoids were absent from the antenna complex
e.

All of the above are correct

  1. Heavy rains can cause leaching of ions from soil. The ion that is most likely to be lost is __________, which is absorbed via ___________.

    a.

    Potassium (K+); membrane channels
    b.

    Chloride (Cl-); membrane channels
    c.

    Nitrate (NO3-); membrane cotransporters
    d.

    Magnesium (Mg2+); membrane antiporters
    e.

    Calcium (Ca2+); membrane cotransporters

In: Biology

A 200 kg sled that is 40m long is sliding eastward at a speed of 5...

A 200 kg sled that is 40m long is sliding eastward at a speed of 5 m/s relative to the icy ground below. A 60 kg human is standing at the eastern edge of the sled and suddenly begins running westward at a constant speed of 10 m/s relative to the center of mass of the system that consists of the sled and the human.

1) Explain why the sled speed increase after the human starts to run.

2) Determine the sled speed relative to the ground while the human is running

The human now instantly comes to rest relative to the sled when he reaches the sled’s western edge

3) Determine time it takes for human to reach western edge of sled from east side

4) Determine ratio of the distance the sled has moved relative to the icy ground, to the distance the sled would have moved if the human had just remained at rest on the east side

In: Physics

Please write clear grammatically correct answer. Answers that are not grammatically correct will be counted wrong....

Please write clear grammatically correct answer. Answers that are not grammatically correct will be counted wrong. Simplify your answers as much as possible. Do not write long paragraphs. Answer all 4 questions.

14. Name the two most important environmental changes during the Miocene and describe their effects on primate evolution.

a.

b.

15. Name and describe the two phases of the walking cycle and the three main aspects of bipedal locomotion.

1.

2.

a.

b.

c.

16. Compare ape-human differences in vertebral column, pelvis, femur, feet and hands and how they affect locomotion.

a. Vertebral Column

Ape:

Human:

b. Pelvis

Ape:

Human:

c. Femur

Ape:

Human:

d. Feet

Ape:

Human:

e. Hands

Ape:

Human:

17. Name and justify the importance of the five most significant Australopithecine features that contribute to our understanding of human evolution.

a.
b.

c.

d.

e.

In: Biology

Which of the following statements are true? a. Amides react with methyl alcohol in the presence...

Which of the following statements are true?

a. Amides react with methyl alcohol in the presence of an acid catalyst to form an ester.
b. Amides are hydrolyzed in strong acids or strong bases to form carboxylic acids or carboxylate anions.
c. Amides react with thionyl chloride to form acid chlorides.
d. Amides are too stable to undergo any reactions, with the exception of polymerization.

The IR spectrum of an unknown compound has a sharp, medium intensity peak at 2250 cm-1. The compound belongs to the following class of chemicals?

an alkane
an aldehyde
an amide
a nitrile

What is the first step in the general mechanism for nucleophilic acyl substitution?

Protonation of the carbonyl group
Removal of an alpha proton
Addition of the nucleophile to the carbonyl group
Loss of the leaving group

Compound A (C9H10O) reacts with methylmagnesium bromide, followed by hydrochloric acid in water to form compound B. Compound B (C10H14O) has the following 1H NMR spectrum: delta (ppm): 0.8 (triplet, 3H), 1.5 (singlet, 3H), 1.6-1.8 (multiplet, 2H), 1.9 (singlet, 1H), 7.2 (triplet, 1H), 7.3 (triplet, 2H), 7.4 (doublet, 2H). What is the structure of compound A?

a. 2-methyl-1-phenylpropan-1-one
b. 3-phenylbutan-2-one
c. 2-methyl-2-phenylpropanal
d. propiophenone

Cyclic acetals are used as protecting groups for ketones and aldehydes, because they are inert to all of the following reagents, with the exception of?

a. nucleophiles
b. aqueous bases
c. oxidizing agents
d. aqueous acids
e. reducing agents

In: Chemistry

When the blood glucose concentration is low, the pancreas secretes glucagon to signal the liver to...

When the blood glucose concentration is low, the pancreas secretes glucagon to signal the liver to produce glucose and glucose-1-phosphate. Which metabolic steps are involved in this biosignaling pathway?

I.

Inactivation of glycogen synthase via phosphorylation by protein kinase A

II.

Activation of glycogen synthase via phosphorylation by protein kinase A

III.

Activation of phosphofructokinase-2 via phosphorylation by protein kinase A

IV.

Activation of fructose-2,6-bisphosphatase via phosphorylation by protein kinase A

V.

Activation of phosphofructokinase-1 by fructose-2,6-bisphosphate

VI.

Inhibition of fructose-1,6-bisphosphatase by fructose-2,6-bisphosphate

VII.

Inactivation of pyruvate kinase via phosphorylation by protein kinase A

A. I, IV, and VII.

B. II

C. I and IV.

D. I, III, V, VI, and VII.

Which biochemical steps are involved in the glucagon-triggered activation of gluconeogenesis?

I.

Activation of fructose-2,6-bisphosphatase via phosphorylation by protein kinase A

II.

Inactivation of fructose-2,6-bisphosphatase via phosphorylation by protein kinase A

III.

Activation of phospholipase C

IV.

Inactivation of phospholipase C

V.

Release of calcium

VI.

Sequestration of calcium

VII.

Phosphorylation of FoxO1

VIII.

Dephosphorylation of FoxO1

IX.

Increased expression of PEP carboxykinase

X.

Phosphorylation of PEP carboxykinase

XI.

Formation of additional PEP, which is a glycolytic intermediate

XII.

Degradation of PEP, which is a glycolytic intermediate

A. I, III, V, VII, X, and XI.

B. II, III, V, VII, IX, and XI.

C. I, III, VI, VII, IX, and XII.

D. I, III, V, VII, IX, and XI.

When the blood glucose concentration is high, the level of cAMP in the liver decreases and glycolytic flux increases. Which biochemical steps occur under this condition?

I.

Protein kinase A is activated.

II.

Protein kinase A is not activated.

III.

Phosphofructokinase-2 is activated via phosphorylation by protein kinase A.

IV.

Phosphofructokinase-2 is activated due to the lack of phosphorylation by protein kinase A.

V.

Fructose-2,6-bisphosphatase is activated via phosphorylation by protein kinase A.

VI.

Fructose-2,6-bisphosphatase is activated due to the lack of phosphorylation by protein kinase A.

VII.

Phosphofructokinase-1 is activated by fructose-2,6-bisphosphate.

VIII.

Phosphofructokinase-1 is inhibited by fructose-2,6-bisphosphate.

IX.

Fructose-1,6-bisphosphatase is activated by fructose-2,6-bisphosphate.

X.

Fructose-1,6-bisphosphatase is inhibited by fructose-2,6-bisphosphate.

A. II, IV, VIII, and IX.

B. II, IV, VII, and X.

C. I, III, VII, and X.

D. II and V.

After glucagon stimulates glucose production via glycogenolysis and/or gluconeogenesis in a liver cell, which steps are required to transport glucose to other cells in the body?

A. Glucose is transported to other cells by the carrier protein GLUT-1.

B. Glucose-6-phosphate is converted to glucose by GLUT-1.

C. Glucose cannot leave the liver cell.

D. Glucose exits the liver cell via GLUT-1 and enters the bloodstream.

In certain smooth muscles, glucagon increases the amount of glucose available for glycolysis; under this condition, which enzyme is required to convert glucose-1-phosphate into a glycolytic intermediate?

A. No enzyme is needed for this conversion.

B. G6Pase.

C. Glucokinase (or hexokinase).

D. Phosphoglucomutase.

In: Biology

. Why was Escherichia coli thought to be a dominant member of the human gut microbial...

. Why was Escherichia coli thought to be a dominant member of the human gut microbial community in the past? What populations ARE important in the human gut and what evidence do we have that the specific bacteria present are important for human health?

In: Biology

To what extent can psychologists fully understand human behavior? We say that the basis of psychological...

To what extent can psychologists fully understand human behavior? We say that the basis of psychological research is to understand human behavior, but how is this possible considering that all human beings are separate individuals and no two people are alike?

In: Psychology