17-19

The oxidizing agent during glycolysis is ______________. NAD+ pyruvate NADH oxygen

NAD+

In the Krebs cycle, the electrons from acetyl CoA leave via _________. carbon dioxide only NADH and FADH2 mostly ATP only NADH only

NADH and FADH2 mostly

We recently discussed that organismal development is the flow of irreversible events from zygote until death and results in an increase in complexity. Does this process violate the 2nd law of thermodynamics? No - because a living organism represents an open system. No - because living organisms respond to their environment. Yes, but "life finds a way". Yes, but a living organisms stops violating this law when aging becomes apparent. Living organisms are not affected by the laws of thermodynamics.

No - because a living organism represents an open system.

Many organisms (including ourselves) break down (catabolize) glucose to obtain energy to do cellular work. The overall reaction in the presence of oxygen is: glucose + oxygen --> carbon dioxide + water How much energy is released by this reaction? A two-step process is necessary to solve this problem. First, you need to know how much energy is required to break the bonds. Second, you need to compute how much energy is released. The difference is the amount of energy available to do work. In this molecule of glucose, the bonds of energetic interest are the C-C and the C-H bonds. Each C-C bond requires 76 kcal/mole to break, and each C-H bond requires about 91 kcal/mole to break. How much energy is required to break all of these bonds in glucose? 637 kcal/mole 380 kcal/mole 1017 kcal/mole 500 kcal/mole

1017 kcal/mole

How many degrees would your body temperature increase if all the energy in one mole of glucose were released as heat, and if your body did not regulate this temperature increase? 1.3 deg 0.1 deg 130 deg 13 deg

13 deg

How many molecules of ATP are produced during glycolysis? 1 2 4 3

4

When oxygen acts as a terminal electron acceptor, about 40 kcal of energy are associated with the oxidation of NADH. If a minimum of 10 kcal of energy are required to synthesize one molecule of ATP, how many ATP molecules could be produced under these conditions from one molecule of NADH? (Assume 100% efficiency.) 2 1 8 4

4

The delta G for the oxidation of glucose is about -686 kcal/mole. Under optimal conditions, about 38 molecules of ATP can be produced during the complete oxidation of glucose by cellular respiration. However, a number of factors can actually cause this number to decrease. If only 28 molecules of ATP are produced, then how efficient is this process? (Assume that it takes about 10 kcal to synthesize one mole of ATP.) 10% 40% 100% 80%

40%

How much energy, in calories, would be required to raise your body temperature by one degree if you weighed 50 kg (110 lbs)? 50 calories 50,000 calories 50,000 Calories 500 calories

50,000 calories

Now that you know how much energy is required to break all of the bonds in glucose, let's calculate the net energy change after the bonds reform around oxygen. (A total of 1703 kcal/mole of energy are released after all of the bonds associated with the breakdown of glucose in the presence of oxygen reform.) 1017 kcal/mole 686 kcal/mole 380 kcal/mole 500 kcal/mole

686 kcal/mole

In the previous question you calculated the amount of energy can be obtained from the complete breakdown of glucose (in the presence of oxygen). Eventually much of this energy is stored in ATP. Typically each mole of ATP can release about 7 kcals of energy. If energy were transferred from glucose to ATP with 100% efficiency (which, as you will learn, does not happen), how many ATP molecules harbor the energy contained in one molecule of glucose? 38 molecules of ATP 150 molecules of ATP 98 molecules of ATP 2 molecules of ATP

98 molecules of ATP

The voltage between the inner mitochondrial membrane and matrix is variable. Which of the following conditions would lead to a decrease in voltage? An increase in NADH A decrease in ATP synthesis An increase in oxygen A decrease in oxygen

A decrease in oxygen

The Second Law of Thermodynamics states that the entropy in the universe is increasing. With this in mind, how do living organisms create macromolecules, organelles, cells, tissues, and complex higher-order structures? The laws of thermodynamics do not apply to living organisms. All living organisms create order by using energy directly from the sun. All living organisms create order locally, but the energy transformations generate waste heat that increases the entropy of the universe.

All living organisms create order locally, but the energy transformations generate waste heat that increases the entropy of the universe.

You have a friend who lost 15 pounds of fat on a diet. Where did the fat go? It was released as CO2 and H2O. It was converted to heat and then released. It was converted to ATP, which weighs less than fat. It was broken down into amino acids and eliminated from the body. It was converted to urine and eliminated from the body.

It was released as CO2 and H2O.

Which of the following is an example of mechanical cellular work? The breaking down of glucose into CO2, H2O, and energy. The contraction of facial muscles to raise eyebrows. The production of ATP from ADP and an inorganic phosphate. The movement of sugar molecules into the cell's cytoplasm.

The contraction of facial muscles to raise eyebrows.

The oxidation of glucose to CO2 and H2O is highly exergonic: ΔG = -636 kcal/mole. Why doesn't glucose spontaneously combust? The glucose molecules lack the activation energy at room temperature. There is too much CO2 in the air. CO2 has higher energy than glucose. The formation of six CO2 molecules from one glucose molecule decreases entropy. The water molecules quench the reaction.

The glucose molecules lack the activation energy at room temperature.

Pyruvate is converted to _______ before entering the Krebs cycle. ethyl alcohol lactic acid reduced electron carriers acetyl coenzyme A (acetyl CoA)

acetyl coenzyme A (acetyl CoA)

The voltage between the inner mitochondrial membrane and the mitochondrial matrix is variable. Which of the following conditions would lead to a decrease in this voltage? an increase in NADH concentration a decrease in oxygen availability to the mitochondria an increase in oxygen availability to the mitochondria a decrease in the synthesis of ATP

a decrease in oxygen availability to the mitochondria

The electron transport chain creates _______ reduced electron carriers oxidized electron carriers oxygen a voltage across the inner mitochondrial membrane

a voltage across the inner mitochondrial membrane

The oxygen in aerobic respiration _________________. phosphorylates ATP attracts electrons forms CO2 moves protons

attracts electrons

Products of the Krebs cycle include _______________. acetyl coenzyme A carbon dioxide and reduced electron carriers oxygen and water pyruvate and oxygen

carbon dioxide and reduced electron carriers

In the eukaryotic cell, glycolysis occurs in the _____________. cytosol mitochondrion nucleus cell membrane

cytosol

As an electron moves closer to oxygen in the electron transport system, the electron's free energy _____________. increases stays the same equilibrates decreases

decreases

ATP performs work by ____________. direct transfer of a phosphate group breaking down completely into all of its component parts releasing a sugar molecule to its surroundings hydrolyzing the molecule it is acting on

direct transfer of a phosphate group

The hydrolysis (breakdown) of ATP to ADP is a(n) _________ reaction. unfavorable exergonic endergonic non-spontaneous

exergonic

A reaction with a ΔG of -1.6 is __________ . endergonic, and work needs to be done in order for the reaction to proceed exergonic, and work can be done with energy released from the reaction endergonic, and work can be done with energy released from the reaction exergonic, and work needs to be done for the reaction to proceed

exergonic, and work can be done with energy released from the reaction

Which has less energy, ten milliliters of water or ten cubic centimeters of ice? (Note: one cubic cm = one ml) ice water

ice

We take water for granted because we deal with it every day. What is its behavior at the molecular level? The three states, gas (steam), liquid (water) and solid (ice), obviously have very different physical properties. These properties are basically described by the two laws of thermodynamics. Based on the second law of thermodynamics (and temperature), predict the order of entropic states from lowest to highest? steam, water, ice ice, water, steam water, steam, ice water, ice, steam

ice, water, steam

In eukaryotes, the electron transport chain is located in the ________________. outer membrane of the mitochondrion inner mitochondrial membrane cytosol of the cell mitochondrial matrix

inner mitochondrial membrane

Oxygen is important in the oxidation of glucose because it ___________. can be oxidized to form carbon dioxide gives off energy for various activities donates electrons to make water is highly electronegative

is highly electronegative

NADH differs from NAD+ because it has _____________. two more hydrogen atoms and one more electron two more hydrogen atoms and two more electrons one more hydrogen atom (with electron) and an additional electron one more hydrogen ion and one more electron

one more hydrogen atom (with electron) and an additional electron

The catabolism of glucose in cellular respiration involves the _______ of glucose and the ________ of NAD+. oxidation / oxidation reduction / oxidation oxidation / reduction reduction / reduction

oxidation / reduction

A molecule that has lost electrons has been ________. reduced oxidized energized phosphorylated

oxidized

During cellular respiration in aerobic organisms, ____________ serves as the terminal electron acceptor of the Electron Transport chain. carbon dioxide water oxygen NADH

oxygen

Entropy is a measure of __________. randomness spontaneity heat favorability

randomness

Substrate-level phosphorylation describes __________________________. the synthesis of ATP by build-up of hydrogen ions across a membrane how ATP drives the work of the cell the direct synthesis of ATP from a phosphorylated substrate how ATP is produced by oxidative phosphorylation

the direct synthesis of ATP from a phosphorylated substrate