EXAM 1

A diver stands on top of the platform then dives into the water below. Which is true? Kinetic energy is transformed to potential energy. Potential energy is transformed to kinetic energy. The energy associated with the dive is the same energy stored in chemical bonds and concentration gradients. More than one of the above.

B

A large Kd for a binding protein and its ligand means the protein has required allosteric activators. low affinity for the ligand. multiple antagonists. multiple isoforms. binding site that requires cofactors.

B

During a fever, the temperature of the body rises due to a change in ______. the temperature sensor the set point the controller the effectors

B

Following the IV infusion of 1L of a 600 mosmol/L NaCl solution, what will be the volume of the ECF compartment? Assume that there is not sufficient time for water or solutes to be eliminated from the body.

15.6

In a hypothetical animal, the ECF compartment has 200 mosmol of NP solute and an initial volume of 1L and the ICF compartment has 400 mosmol of NP solute and an initial volume of 1 L. What is the total body osmolarity (total mosmol / total volume in liters)?

300

Which tissue or cell type is not paired with the correct effect? epithelial: reabsorption in the kidney tubules smooth muscle: vasoconstriction of blood vessels connective: secretion of hormones into the blood cardiac muscle: increase force of heart contraction skeletal muscle: knee jerk reflex

C

What does "Physiology is an integrative science" mean?

Physiology integrates body function across all levels of organization and emphasizes the coordinated function of body systems.

List the four kinds of biomolecules. Give an example of each kind that is relevant to physiology.

Proteins (collagen, hemoglobin, enzymes); carbohydrates (glucose, sucrose); lipids (cholesterol, phospholipids); and nucleic acids (ATP, DNA, RNA).

To make 1 liter of a 1% KCl solution, you will use ___ g KCl. 0.01 0.1 1 10 100

D

The reactions of glycolysis occur in the cell's ________; the reactions of the citric acid cycle occur in the ________. mitochondrial matrix, cytoplasm cytoplasm, cytoplasm mitochondrial matrix, mitochondrial matrix cytoplasm, mitochondrial intermembrane space mitochondrial intermembrane space, cytoplasm cytoplasm, mitochondrial matrix mitochondrial intermembrane space, mitochondria matrix

F

True or false? All organic molecules are biomolecules.

False. All biomolecules are organic molecules, but the reverse is not true.

Distinguish between the items in each group of terms. tissues and organs x-axis and y-axis on a graph dependent and independent variables teleological and mechanistic approaches the internal and external environments for a human blind, double-blind, and crossover studies the target and the sensor in a control system

(a) Tissues—collections of cells that carry out related functions. Organs—collections of tissues that form structural and functional units. (b) x-axis—independent variable; y-axis—dependent variable. (c) Independent variable is manipulated to change the dependent variable. (d) Teleological—functional approach, the "why" of a system. Mechanistic approach—physiological mechanisms, the "how" of a system. (e) Internal environment—extracellular fluid; external environment—the world outside the body. (f ) Blind study—subjects do not know the treatment they are receiving. Double-blind study—neither subjects nor experimenters know which treatment is the active one. Crossover study—each subject serves as both control and experimental. (g) Sensors receive signals. Targets respond to signals.

"Why does blood flow?" Which answers are teleological and which are mechanistic? (Not all answers are correct, but they can still be classified.) Because of gravity To bring oxygen and food to the cells Because if it didn't flow, we would die Because of the pumping action of the heart

(a) incorrect mechanistic answer, (b) correct teleological answer, (c) correct teleological answer, (d) correct mechanistic answer

The molecular mass for glucose is 180 g per mole. What is the molarity of a 5% glucose solution?

0.278

In the same hypothetical animal, what will the volume of the ICF compartment be at equilibrium in liters?

1.33

A solution in which [H+]=10^−3 M is (acidic/basic), whereas a solution in which [H+]=10^−10 M is (acidic/basic). Give the pH for each of these solutions.

10^−3 M=pH 3; acidic. 10^−10 M=pH 10; basic.

A protein binding to only one kind of molecule or group of closely related molecules is called specificity. competition. affinity. saturation. facilitation.

A

Down-regulation" refers to increased programmed removal of proteins. programmed production of proteins. transport of nutrients into cell. cell division. synthesis of membrane.

A

Each comment is true about enzymes EXCEPT: Enzymes lower the free energy (G) of the system. Enzymes are unchanged by the reaction. Enzymes speed up reactions by lowering their activation energy. Enzymes can be inhibited or activated by allosteric binding. It is often the tertiary structure of the enzyme that makes its binding site available.

A

Each is part of the cytoplasm except the nucleus. cytosol. organelles. cytoskeleton. inclusions.

A

Glycerol plus three fatty acids produces a ______. triglyceride eicosaniod steriod phospholipid

A

Hepatocytes, the main functional cells of the liver, are very active in protein synthesis. Which organelle would you expect to be the increased in their cytoplasm? rough endoplasmic reticulum lysosome Golgi complex smooth endoplasmic reticulum centrosome

A

If a swimmer cuts his foot on a seashell while wading in the ocean and bleeds into the seawater, his erythrocytes will shrink. What does this tell us about the relative tonicities of the solutions? The ocean is hypertonic to the erythrocytes. The erythrocytes are hypertonic to the ocean. The erythrocytes are isotonic to the ocean. The cell membrane is not permeable to seawater.

A

In the same hypothetical animal, which compartment will gain water due to osmosis? The ICF compartment will gain water. The ECF compartment will gain water. Neither compartment will gain water.

A

Metabolic regulation in which the last product of a metabolic pathway (the end product) accumulates ad slows or stops reactions earlier in the pathway is called ______. feedback inhibition reciprocal inhibition feedforward inhibition reversible inhibition

A

Normal blood C a2+ concentration is about 4.8 m e q/L. This concentration is the same as 2.4 mM. 4.8 mM. 9.6 mM. 0.48 Eq/L. 0.048 Eq/L.

A

On a cold day, the body temperature drops. In response, shivering occurs -- skeletal muscle shake in small movements, creating heat which increases the body temperature. This is an example of ______. negative feedback positive feedback feedforward control retrograde control

A

On a hot day, an increase in body temperature leads to sweating. Sweating leads to a reduction in body temperature due to evaporative cooling. This is an example of ______. negative feedback positive feeback feed forward control retrograde control

A

Production of ATP in mitochondria is most directly coupled to movement of H+ into the matrix. transfer of electrons along the electron transport system. oxygen combining with H+ to make water. transport of high-energy electrons by NADH and FADH2.

A

The disappearance of _________ junctions may occur when cancer cells metastasize. anchoring occluding tight communicating protective

A

The exergonic hydrolysis of maltose yields glucose. Which is true? Free energy is released. The reaction requires an input of energy. The reaction is anabolic. The free energy of glucose is greater than the free energy of maltose. None of the above

A

Which is NOT an example of negative feedback? uterine contractions during childbirth regulating body temperature regulating blood sugar regulating blood pH regulating blood volume

A

Which stimulates the most rapid intracellular responses? Ligand-gated channels Catalytic receptors (receptor-enzymes) protein-coupled receptor integrin receptor

A

If you place a red blood cell containing 300 mOsM (300 mOsmole/L) of nonpenetrating solutes in a solution of 100 mM NaCl and 100 mM urea. Assuming that the NaCl fully dissociates, the solution is ______ and ______. hypotonic isotonic hypertonic hyposmotic isosmotic hyperosmotic

A,E

Which is the correct sequence for G protein-coupled signal transduction?

A - Ligand B - GPCR C - G protein D - adenylyl cyclase E - cAMP F - protein kinase G - phosphorylated protein H - tissue response

Steroid hormones can potentially bind which types of receptor? cytosolic receptors nuclear receptors membrane receptors

A,B,C

Norepinephrine (NE) and epinephrine (E) both activate alpha adrenergic receptors. NE and E are _______. agonists antagonists competitors

A,C

What do NADH, FADH2, and NADPH have in common? They are carriers of high-energy electrons. They are important enzymes in metabolism. They are involved in energy coupling. They take energy from ATP.

A,C

Which of the following is true regarding the oxidation of glucose? C6H12O6 + 6O2 → 6CO2 + 6H2O Oxygen is reduced. Water and carbon dioxide are substrates. Glucose is oxidized. Oxygen is oxidized.

A,C

Which of the following statements about calcium ions is true? Ca2+ enters cells through Ca2+ channels that can be voltage-, ligand- or mechanically-gated. Most intracellular Ca2+ is stored within the nucleus. Ca2+ binds to the protein calmodulin. Ca2+ binding to the regulatory protein troponin initiates muscle relaxation. Ca2+ binding to regulatory proteins triggers endocytosis of secretory vesicles. The Ca2+ concentration is higher in the ECF compared with the ICF.

A,C,F

When a chemical reaction is at equilibrium ______. the concentrations of substrates and products are constant the amount of substrate equals the amount of product the reaction stops the reaction continues there is no net change in substrates and products.

A,D,E

Given the chemical reaction catalyzed by carbonic anhydrase, CO2 + H2O ⇋ H2CO3 ⇋ HCO3- + H+, which is often simplified to CO2 + H2O ⇋ HCO3- + H+, an increase in CO2 leads to ______. decrease in H2O an increase in H2O decrease in HCO3- an increase in HCO3- decrease in H+ an increase in H+

A,D,F

Name three nucleotides or nucleic acids, and tell why each one is important.

ATP: usable energy in a high-energy bond. DNA stores genetic information. RNA translates genetic information into proteins. cAMP: transfer of signals into cells. NAD and FAD transfer energy.

Each of the following is true about cell membranes except the lipid:protein ratio varies widely depending on the metabolic activity of the cell. phospholipids are arranged with hydrophobic ends facing the extracellular space. phospholipids are arranged with hydrophilic ends facing the intracellular space. phospholipids, sphingolipids, and cholesterol are all found in cell membranes.

B

How many grams of CaCl2 (M.W. 110 Da) do you need to make 300 m L of a 1 M solution? 110 grams 33 grams 330 grams 55 grams 0.3 grams

B

In most resting cells, the concentration of sodium ions is higher outside of cells compared with the intracellular fluid. When cells are stimulated, sodium ion channels open, and sodium diffuses from the outside of the cell to the inside of the cell. Sodium ion concentrations in a resting cell are an example of ___________, and sodium ion movement in a stimulated cell is an example of ___________. the energy of motion; stored energy potential energy; kinetic energy chemical work; energy stored in chemical bonds kinetic energy; potential energy

B

In the same hypothetical animal, the ECF compartment has 200 mosmol of NP solute and an initial volume of 1L and the ICF compartment has 400 mosmol of NP solute and an initial volume of 1 L. In which direction will there be osmotic flow of water? From the ICF compartment to the ECF compartment From the ECF compartment to the ICF compartment There will be no net movement of water between the two compartments.

B

Leydig cells are specialized testosterone-producing cells in the testes. Which organelle would you expect to be increased in their cytoplasm? Golgi complex smooth endoplasmic reticulum peroxisome rough endoplasmic reticulum mitochondrion

B

Nico is waiting at the start line for the race to begin. His heart rate is starting to increase, and he is breathing a little faster. This is an example of positive feedback. feedforward control. negative feedback. reflex control. local control.

B

Using this equation, predict what would happen if pH of the blood decreased. CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3- The decrease in H+ concentration would lead to the removal of excess CO2 by the lungs. The increase in H+ concentration would lead to the removal of excess CO2 by the lungs. The decrease in H+ concentration would result in excess HCO3-. There would be no change.

B

Which cell junctions are paired with a correct example and description? tight junctions (cardiomyocytes); prevent movement of materials between cells anchoring junctions (cardiomyocytes); contribute to the mechanical strength of the tissue gap junctions (epidermis); allow direct and rapid cell-to-cell communication More than one of the above

B

Which is true for both muscle and neural tissues? ability to contract and generate force can generate and propagate electrical signals have extensive extracellular matrix lack gap junctions support is provided by glial cells

B

Which of the following statements are true about cytokines? They may be produced by specialized epithelial cells. They may be produced by any nucleated cell. They are always peptides. They are never peptides. They are made on demand. They are made and stored inside of the cell until needed. They may act on the cells that secrete them (autocrine action). They may act on the nearby cells (paracrine action). They may act on distant cells (i.e., transported via the circulatory system).

B, C, E, G, H, and I They may be produced by any nucleated cell. They are always peptides. They are made on demand.They may act on the cells that secrete them (autocrine action).They may act on the nearby cells (paracrine action). They may act on distant cells (i.e., transported via the circulatory system).

An epithelial cell of a nephron absorbs both glucose and Na+ from the lumen and move them to the interstitial fluid. A epithelial cell has apical membrane that faces the lumen and basolateral membrane that faces the interstitial fluid. Which of the following transporters should be located on the basolateral membrane: SGLT transporter, GLUT transporter, Na+ / K+ ATPase, and K+ leak channel? Hint: The loss of potassium in the urine should be limited. SGLT transporter GLUT transporter Na+ / K+ ATPase K+ leak channel

B, C, and D

Without a constant input of energy, a cell loses its organization and ability to carry out normal functions so it dies. This is an example of the first law of thermodynamics. entropy. the second law of thermodynamics. kinetic energy.

B,C

A ligand is a chemical signal that ______. stimulates the same response regardless of the target cell type. obeys general rules of specificity, affinity, competition, and saturation. stimulates the same response regardless of the receptor type. may stimulate different responses in different target cells or after binding with different receptor types.

B,D

Given the chemical reaction catalyzed by carbonic anhydrase, CO2 + H2O ⇋ H2CO3 ⇋ HCO3- + H+, which is often simplified to CO2 + H2O ⇋ HCO3- + H+, an increase in HCO3- leads to ______. decrease in H2O an increase in H2O decrease in CO2 an increase in CO2 decrease in H+ an increase in H+.

B,D,E

If you place a red blood cell containing 300 mOsM (300 mOsmole/L) of nonpenetrating solutes in a solution of 150 mM NaCl. Assuming that the NaCl fully dissociates, the solution is ______ and ______. Hypotonic isotonic hypertonic hyposmotic isosmotic hyperosmotic

B,E

CO2 + H2O ⇋ H2CO3 ⇋ H+ + HCO3- If the CO2 concentration in the body increases, what happens to the concentration of carbonic acid (H2CO3)? What happens to pH? The concentration of carbonic acid will decrease, and the pH will increase. The concentration of carbonic acid will decrease, and the pH will decrease. The concentration of carbonic acid will increase, and the pH will decrease. The concentration of carbonic acid will increase, and the pH will increase.

C

Carbonic acid is generated by bubbling CO2 into a beaker of water. If it took 5 minutes for this reaction to reach equilibrium, how would the results differ if the enzyme carbonic anhydrase was added to the beaker of water? Equilibrium would be reached in more than 5 minutes. Equilibrium will never be reached. Equilibrium would be reached in less than 5 minutes. Equilibrium would be reached in 5 minutes.

C

Compared with aerobic metabolism, anaerobic metabolism is ______ and does not require ______. Compared with aerobic metabolism the energy yield from anaerobic metabolism is ______. slower, oxygen, higher slower, oxygen, lower faster, oxygen, lower faster, oxygen, higher faster, glucose, higher slower, glucose, higher

C

Glycoproteins are made up of proteins and lipids. lipids and carbohydrates. proteins and carbohydrates. lipids and nucleotides.

C

The linking together of many glucose molecules to form the polymer glycogen is a(n) exergonic reaction. decomposition reaction. endergonic reaction. oxidation reaction.

C

What is the function of a protein kinase? It opens channels. It activates cAMP. It transfers phosphate groups to proteins. It removes phosphate groups.

C

What will happen to the cells of a patient who is given an intravenous (IV) solution, containing nonpenetrating solutes, that is isosmotic to intracellular fluids? The cells will swell, because isosmotic solutions are hypotonic. The cells will shrink, because isosmotic solutions are hypertonic. The cells will keep their normal shape, because isosmotic solutions result in no net change in water concentration. The question cannot be answered with certainty without knowing which solutes are present in the IV solution.

C

What will happen to the cells of a patient who is provided with an intravenous solution that is isosmotic to intracellular fluids? The cells will retain their normal shape, because isosmotic solutions result in no net change in water concentration. The cells will swell, because isosmotic solutions are hypotonic. The question cannot be answered with certainty without knowing the identity of the solutes present in the IV solution. The cells will shrink, because isosmotic solutions are hypertonic.

C

Which is NOT an example of a homeostatic response? Body temperature increases, and sweating decreases body temperature. The oxygen level in the blood decreases, and breathing harder increases the oxygen level in the blood. Sweating increases loss of body fluids, and urination increases the loss of body fluids. Glucose level in the blood decreases, and eating increases the glucose level in the blood.

C

Which is most likely to be solid at room temperature? polyunsaturated fats monounsaturated fats saturated fats

C

How are water molecules oriented around a chloride in solution?

Cl, H, O

A 2 M NaCl solution is placed in compartment A and a 2 M glucose solution is placed in compartment B. The compartments are separated by a membrane that is permeable to water but not to NaCl or glucose. Complete the following statements. The salt solution is ______ osmotic to the glucose solution. There is a net movement of water from compartment ______ to compartment ______. hyposmotic, A, B hyposmotic, B, A hyperosmotic, A, B hyperosmotic, B, A

D

Cell membranes are made up of mainly of which two molecules? proteins and carbohydrates lipids and carbohydrates lipids and nucleotides lipids and proteins

D

In an oxidation-reduction reaction, in which electrons are moved between molecules, the molecule that gains an electron is said to be ______, and the one that loses an electron is said to be ______. oxidized, oxidized oxidized, reduced reduced, reduced reduced, oxidized

D

In the reversible reaction A + B = C + D, adding more A will change the reaction to an irreversible forward reaction. change the reaction to an irreversible backward reaction. not affect the rate of production of C and D unless more B is added as well. drive the forward reaction to make more C and D. slow the forward reaction, making less C and D.

D

Oubain, a toxic compound obtained from certain trees, is a specific inhibitor of the Na+ / K+ ATPase ion pump. When oubain is applied to one side of the epithelium, if affects only the side where it was originally applied. When oubain is applied to the apical membrane the rate of glucose transport from the lumen of a nephron to the interstitial fluid ______. When oubain is applied to the basolateral membrane the rate of glucose transport from the lumen of a nephron to the interstitial fluid ______. decreases over time, remains constant over time remains constant over time, remains constant over time decreases over time, decreases over time remains constant over time, decreases over time

D

During aerobic metabolism of glucose, most ATP is made during which phase of chemical reactions? During aerobic metabolism of glucose, most ATP is made during which phase of chemical reactions? Citric acid cycle Conversion of pyruvate to acetyl CoA Electron transport system

D The electron transport system yields 26-28 molecules of ATP per molecule of glucose.

In response to an increase in body temperature, sensors in the hypothalamus detect the temperature change and a control center of hypothalamus causes blood vessels in the skin to vasodilate, leading to increased blood flow near the surface of the body. This increase in blood flow causes an increase in heat loss and a reduction in body temperature. In this system, the response is ______. temperature sensors in the hypothalamus a control center of hypothalamus blood vessels in the skin vasodilation increased blood flow near the surface of the body increase in heat loss reduction in body temperature

D,E,F,G

The storage form of glucose for animals is called ______. starch chitin glucose lactose glycogen

E

Which affects the speed at which reactants disappear and products appear during an enzyme reaction? substrate concentration temperature presence of cofactors pH all of the above

E

Which are involved in cell-matrix interactions? hemidesmosomes tight junctions focal adhesions desmosomes A and C

E

Which of the following molecules are nonpenetrating? urea glycerol fatty-acids ethanol protein sodium potassium chloride steroid hormones bicarbonate (HCO3-)

E, F, G, H, and J

An atom of carbon has four unpaired electrons in an outer shell with space for eight electrons. How many covalent bonds will one carbon atom form with other atoms?

One carbon atom needs to share four electrons to fill its outer shell; therefore, it will form four covalent bonds.

You know that two soluble proteins are isoforms of each other. What can you predict about their structures, functions, and affinities for ligands?

Isoforms are structurally similar, with similar functions but differing affinities for ligands. They may function best under different conditions.

Name two elements whose presence contributes to a molecule becoming a polar molecule.

Oxygen and nitrogen strongly attract electrons and tend to form polar bonds.

Name as many organs or body structures that connect directly with the external environment as you can.

Nasal and oral cavities; external ear; lacrimal (tear) ducts; sweat, sebaceous, and mammary gland ducts; lumens of esophagus, stomach, small and large intestines; ducts of the salivary glands, pancreas, liver and gall bladder; urinary tract, reproductive, and respiratory organs.

Explain the differences among positive feedback, negative feedback, and feedforward mechanisms. Under what circumstances would each be advantageous?

Negative feedback—feedback signal turns response loop off; helps maintain homeostasis. Positive feedback—feedback keeps the response loop going; makes a change bigger. Feedforward—starts response loop before the stimulus does; minimizes change.

Based on what you know from experience about the tendency of the following substances to dissolve in water, predict whether they are polar or nonpolar molecules: table sugar, vegetable oil.

Table sugar dissolves easily, so it is polar. Vegetable oil does not dissolve in water, so it is nonpolar.

Define homeostasis. Name some regulated variables that are maintained through homeostasis.

The maintenance of internal stability. Examples: body temperature and water balance.

Define physiology. Describe the relationship between physiology and anatomy.

The normal functioning of a living organism. Anatomy is the study of structure.

the ability of a protein to bind one molecule but not another the part of a protein molecule that binds the ligand the ability of a protein to alter shape as it binds a ligand

a. specificity b. binding site c. induced fit

A negatively charged ion is called a(n) , and a positively charged ion is called a(n) .

anion, cation

Name the different levels of organization in the biosphere.

atoms, molecules, cells, tissues, organs, organ systems, organisms, populations of one species, ecosystem of different species, biosphere

A molecule that moderates changes in pH is called a .

buffer

An ion, such as Ca2+ or Mg2+, that must be present in order for an enzyme to work is called a(n) .

cofactor

In a(n) bond, electrons are shared between atoms. If the electrons are attracted more strongly to one atom than to the other, the molecule is said to be a(n) ..... molecule. If the electrons are evenly shared, the molecule is said to be a(n) molecule.

covalent; polar; nonpolar

A molecule that binds to another molecule is called a(n) .

ligand

Proteins combined with fats are called , and proteins combined with carbohydrates are called .

lipoproteins; glycoproteins

When atoms bind tightly to one another, such as H2O or O2, one unit is called a(n) .

molecule

Define the pH of a solution. If pH is less than 7, the solution is ; if pH is greater than 7, the solution is .

pH=H+ concentration. pH<7 is acidic. pH>7 is basic or alkaline.