Learning catalytics 1

A typical blood concentration of glucose is 100 mg/dL. The molecular weight of glucose is approximately 180 Daltons. What is the molarity of this solution in millimoles?

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How many grams of NaCl (molecular mass = 58.5 Daltons) are the molar equivalent to 90 g of glucose (molecular mass = 180 Daltons)?

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What is the free hydrogen ion concentration of a solution of acetic acid (CH3COOH, pKa = 4.76) in distilled water if the pH is 5.50?

3.16E-6

Which of the following statements about carbohydrates are true? A. Simple sugars include galactose, glucose, and ribose. B. Cellulose is the most abundant polysaccharide on earth. C. Glycogen is a storage polysaccharide made by animal cells. D. Polysaccharides are important both for energy storage and to provide structure to cells. E. Glycogen is important both for energy storage and to provide structure for cells.

A, B, C, and D

Which of the following could be examples of phenotypes in humans that were once beneficial but are now harmful? A. Foods with high caloric content, especially from sugars and fats, are pleasurable to us. B. Our immune system only develops normally if we are exposed to a variety of potential pathogens early in infancy and childhood. C. Our cardiovascular and respiratory systems are only maintained in optimal condition by regular, strenuous physical activity. D. Sodium retention by the kidneys increases survival in hot, dry climates, such as the African savannah. E. When we are provided sufficient food, we store all possible excess energy as fat.

All the above

Match each definition with the bond type that it best describes. Attraction between adjacent atoms due to constantly fluctuating electron clouds Equal sharing of four electrons between two atoms Equal sharing of two electrons between two atoms One atom or compound donates an electron to another atom or compound Attraction between a hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule Non-uniform or unequal sharing of a pair of electrons between two atoms

Attraction between adjacent atoms due to constantly fluctuating electron clouds - Van der Waals Equal sharing of four electrons between two atoms - Double covalent Equal sharing of two electrons between two atoms - Nonpolar covalent One atom or compound donates an electron to another atom or compound - Ionic Attraction between a hydrogen attached to an electronegative atom of one molecule and an electronegative atom of a different molecule - Hydrogen Non-uniform or unequal sharing of a pair of electrons between two atoms - Polar covalent

Which of the following is the smallest container that could hold one mole of NaCl? A. Teaspoon B. Coffee mug C. Bucket D. Bathtub E. Empty swimming pool

B. Coffee mug

In regard to lipids, the term unsaturated refers to... A. the lack of double bonds between adjacent carbon atoms in a fatty acid. B. the presence of double bonds between adjacent carbon atoms in a fatty acid. C. the ring structure of steroids. D. glycerol, which acts as an anchor for joined fatty acids. E. fats, such as butter and lard, which come from animal sources.

B. the presence of double bonds between adjacent carbon atoms in a fatty acid.

Which of the following is the smallest container that could hold 1 mole of H2O molecules as a vapor? A. Teaspoon B. Coffee mug C. Bucket D. Bathtub E. Empty swimming pool

Bathtub

Which of the following is indicated by a cough? A. Infecting bacteria have been captured in mucus and the body is attempting to remove the bacteria from the lungs by coughing out the mucus. B. Infecting bacteria are manipulating the body to cough in order to increase the spread of the infection. C. It is impossible to determine with the information provided.

C. It is impossible to determine with the information provided.

Which of the following is indicated by diarrhea? A. The body is trying to eliminate infecting bacteria in the GI tract by rapidly flushing it. B. Infecting bacteria are manipulating the body to produce copious, watery stools in order to increase the spread of the infection. C. It is impossible to determine with the information provided.

C. It is impossible to determine with the information provided.

Which of the following is indicated the combination of extremely high heart rate and low blood pressure? A. The heart is pumping very fast to try to compensate for low blood pressure. B. The heart is pumping so fast that it does not have time to completely fill between contractions, so the volume ejected per heart beat is insufficient. C. It is impossible to determine with the information provided.

C. It is impossible to determine with the information provided.

A fatty acid that contains three double bonds in its carbon chain is said to be... A. saturated. B. monounsaturated. C. polyunsaturated. D. hydrogenated. E. carboxylated.

C. polyunsaturated.

Which of the following is the smallest container that could hold 1 mole of H2O molecules as a solid or liquid? A. Teaspoon B. Coffee mug C. Bucket D. Bathtub E. Empty swimming pool

Coffee mug

These result when the carbon atoms in phospholipids share a pair of electrons. A. a Van der Waals attraction B. an ionic bond C. a hydrogen bond D. a covalent bond E. a potassium bond

D. a covalent bond

Increased blood glucose stimulates insulin secretion. Insulin then stimulates the uptake, use, and storage of glucose by cells. This results in decreased blood glucose levels which then decreases insulin secretion. The decreased insulin secretion in response to decreased blood glucose levels is an example of: A. negative feedback B. positive feedback C. feedforward control

Negative feedback occurs when the response decreases, inhibits, or removes the signal. The signal of increased blood glucose leads to insulin secretion which results in decreased blood glucose, removing the signal for insulin secretion.

An adult female begins to sweat upon entering a hot room and continues sweating while she remains in the room, but her body temperature remains constant. Which of the following best describes her condition? A. She is in an equilibrium state. B. She is not using energy to maintain a constant temperature. C. She is in a steady state. D. She is using a positive feedback mechanism.

She is in a steady state.

Certain "rules" of chemistry are used to simplify concepts for students, but some of these rules have important exceptions. Match the "rules" below with their exception. Violate the rule that electrons and protons are equal in number for each atom. Violate the rule that the number of neutrons always equals the number of protons. This name was originally intended to indicate that it is indivisible but this didn't account for the discovery of radioactive decay.

Violate the rule that electrons and protons are equal in number for each atom. - Ions Violate the rule that the number of neutrons always equals the number of protons. - Isotope This name was originally intended to indicate that it is indivisible but this didn't account for the discovery of radioactive decay. - Atoms

You conduct an experiment on twenty 18-year-old male subjects to see how a history of binge drinking affects cognitive performance. Match the parameters on the left with the types of variable on the right. age of subjects frequency of binge drinking sex of subjects cognitive performance

age of subjects - Controlled variable frequency of binge drinking - Independent variable sex of subjects - Controlled variable cognitive performance - Dependent variable

Each amino acid differs from others in the... A. number of central carbon atoms. B. size of the amino group. C. number of carboxyl groups. D. chemical structure of the R group. E. number of peptide bonds in the molecule.

chemical structure of the R group.

If a reaction which is stopped by substance X can recover when a lot more of the native activator is supplied, substance X would be considered which of the following? covalent modulator competitive inhibitor allosteric modulator irreversible antagonist a phosphotase

competitive inhibitor

Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time, so an up regulation of enzymes would be expected to... increase the cell's response that is produced by the reaction catalyzed by the enzyme. decrease the level of productivity of chemical reactions that rely on them. have no effect on the rate of reactions catalyzed by the enzymes. decrease the rate of reactions catalyzed by the enzymes. both decrease the level of productivity of chemical reactions that rely on them and decrease the rate of reactions catalyzed by the enzymes.

increase the cell's response that is produced by the reaction catalyzed by the enzyme.

Describing a physiological variable as "homeostatic," means that it... A. has varied from the normal value, and will remain constant at the new value. B. never varies from an exact set point value. C. is in an equilibrium state that requires no energy input to stay at the normal value. D. is in a state of dynamic constancy that is regulated to remain near a stable set point value. E. has no normal range, but will just change to match the outside environmental conditions.

is in a state of dynamic constancy that is regulated to remain near a stable set point value.

When blood glucose is high, the pancreas secretes insulin, causing blood glucose to decline. When blood glucose is low, the pancreas secretes glucagon, causing blood glucose to rise. This is an example of... A. catalytic feedback. B. positive feedback. C. negative feedback. D. bioinformatic regulation. E. autocatalytic homeostasis.

negative feedback.

The normal pH range of arterial blood in humans is 7.35-7.45. How much of a difference is that in terms of [H+]? Express your answer numerically as the proportional difference between pH 7.35 and pH 7.45.

pH 7.35 - 7.45 nmol/L = 35.5 - 44.7 nmol/L [H+] This is a proportional change of 1.26, or 26%.