Intro to Bio Quiz #3 Review

Approximately how many molecules of ATP can be produced from the oxidation of a 20 carbon fatty acid, including those produced in the Krebs cycle?

136

What is the net production of ATP, pyruvate, and NADH when one molecule of glucose undergoes glycolysis?

2 ATP, 2 NADH, and 2 pyruvate

List in Order: -Electrons are transferred to molecules in the beginning of the ETC -H+ ions flow down the gradient to generate ATP -Electrons are transferred to O2, causing it to split and take up H+ to form water -H+ ions are pumped across the mitochondrial membrane to establish a gradient

1) Electrons are transferred to molecules in the beginning of the ETC 2)H+ ions are pumped across the mitochondrial membrane to establish a gradient 3)Electrons are transferred to O2, causing it to split and take up H+ to form water 4)H+ ions flow down the gradient to generate ATP

Photosynthesis Equation

6CO2 + 6H2O + light → C6H12O6 + 6O2

Porphyrin

A ring on the "head" of a chlorophyll molecule.

Identify each of the following molecules as reactants or products of the Krebs cycle. Acetyl CoA Carbon dioxide NAD+ NADH FADH2 FAD

Acetyl CoA - Reactant Carbon dioxide - Product (4) NAD+ - Reactant NADH - Product (6) FADH2 - Product (2) FAD - Reactant

Which product of pyruvate oxidation enters the Krebs cycle?

Acetyl-CoA Acetyl-CoA acts as the fuel for the Krebs cycle during cellular respiration. The coenzyme A helps activate the acetyl group, preparing it to undergo the necessary reactions to enter the Krebs cycle.

Which of the following is true of electron carriers NADH and FADH2? A FADH2 is a better electron donor than NADH because it allows more H+ ions to be pumped across the membrane. B All of the electrons that enter the transport chain (ETC) come from NADH and FADH2 molecules which are produced during earlier phases of cellular respiration. C NADH and FADH2 are single-use molecules so once they donate their electrons, they cannot be used again. D NADH is the oxidized form of NAD+ and FADH2 is the reduced form of FADH.

All of the electrons that enter the transport chain (ETC) come from NADH and FADH2 molecules which are produced during earlier phases of cellular respiration. Reduced electron carriers NADH and FADH2 are produced during glycolysis, pyruvate oxidation, and the Krebs cycle. They then provide the electrons that begin the ETC.

Heterotroph

An organism that cannot make its own food; organic carbon

Autotroph

An organism that makes its own food using sun, CO2, and H20; inorganic carbon, photoautotrophs use the sun's energy

Cellular Respiration Equation

C6H12O6 + 6O2 → 6CO2 + 6H2O + ATP

What part of the cell does glycolysis take place

Cytosol

Based on their compositional differences, different lipoproteins serve very different biological roles; what physical quality of lipoproteins most likely determines their function?

Density

From where are the nine essential amino acids utilized by humans derived?

Dietary protein only

What is the basic order of events in the digestion and mobilization of dietary fats?

Emulsified by bile→ degradation by lipases→ absorption and conversion into triacylglycerols→ incorporation into chylomicrons

ATP/ADP

Energy is released when a phosphate group is removed, exergonic

A deficiency of oxaloacetate would most likely increase the catabolism of what potential energy source?

Glucogenic amino acids Ketogenic amino acids, as well as fatty acids, are principally metabolized to form acetyl-CoA.

Which of the following statements is true regarding glycolysis? A Glycolysis can occur without the presence of oxygen. B Glycolysis takes place in the mitochondria of a cell. C Glycolysis is the final step in aerobic respiration. D Glycolysis produces a net of 1 ATP, 1 NADH, and 2 pyruvate

Glycolysis can occur without the presence of oxygen. The process of glycolysis can occur with or without oxygen. In fact, many anaerobic organisms (organisms that do not use oxygen) use glycolysis as a step in their respiration processes,

What is the main transformation that occurs during glycolysis?

Glycolysis produces ATP, pyruvate, and NADH by oxidizing glucose

What is the rate limiting step in the production of energy from free fatty acids?

In addition to its contribution to fatty acid synthesis, malonyl-CoA also inhibits fatty acid oxidation at a key regulatory point.

What are the major products of amino acid catabolism?

Ketone bodies and glucose

What chemical properties describe a free fatty acid molecule capable of producing the most energy when used as a fuel source, relative to other free fatty acids?

Longer hydrocarbon tail with a lesser number of unsaturated bonds More carbon atoms indicates a greater number of potential acetyl-CoA molecules, and therefore more reactant for the production of ATP.

In what part of the cell does the Krebs cycle take place?

Mitochondria The Krebs cycle takes place in the inner space of the mitochondria.

NADP+/NADPH

Molecule that carries and releases hydrogen ions and electrons

Which of the following occur during the Krebs cycle? Choose 2 answers: A NAD+ is reduced to form NADH. B FADH2 accepts two electrons in order to form FAD. C Acetyl-CoA combines with oxaloacetate to form citrate. D Pyruvate is converted into acetyl-CoA.

NAD+ is reduced to form NADH. Several intermediates in the Krebs cycle are oxidized, causing NAD+ to be reduced to NADH in the process Acetyl-CoA combines with oxaloacetate to form citrate. Following pyruvate oxidation, acetyl-CoA joins with the 4-carbon oxaloacetate, forming the 6-carbon molecule called citrate.

Which of the following statements best is true of the Krebs cycle? A The Krebs cycle occurs as part of both cellular respiration and photosynthesis. B Oxygen and water are produced in the Krebs cycle. C The Krebs cycle is the first step in cellular respiration. D Not all living things engage in the Krebs cycle.

Not all living things engage in the Krebs cycle. The Krebs cycle is a process that only occurs in eukaryotes.

Classify each statement as a property of the electron transport chain (ETC) or chemiosmosis. Oxidizes NADH to NAD+ Creates a proton gradient Makes ATP using a proton gradient Oxidizes FADH2 to FADH

Oxidizes NADH to NAD+: ETC Creates a proton gradient: ETC Makes ATP using a proton gradient: Chemiosmosis Oxidizes FADH2 to FADH: ETC

final electron acceptor of ETC

Oxygen

Light reaction

Part of photosynthesis that involves light. ATP and NADPH are produced. Takes place on the thylakoid membrane.

Chemiosmosis

Process by which a Hydrogen pump pumps protons into the thylakoid membrane. H+ passively flows through the ATP synthase which leads to the creation of ATP.

What 3-carbon molecule is one of the final products of glycolysis?

Pyruvate

Which of the following is true regarding chemiosmosis? A The energy from a proton gradient is used to make ATP. B Chemiosmosis regenerates electron carriers like NADH and FAHD2. C ATP synthesis creates a proton gradient that causes electron flow through an electron transport chain (ETC). D A temperature gradient drives ATP synthesis.

The energy from a proton gradient is used to make ATP. The proton gradient created during the electron transport chain (ETC) is then used for chemiosmosis. As H+ ions flow down their gradient, they pass through an enzyme called ATP synthase, which uses the flow of protons to make ATP.

Which of the following is true of the ETC? A The movement of electrons down the ETC drives the formation of a proton gradient. B The movement of H+ ions across the inner membrane of the mitochondria drives the transfer of electrons down the ETC. C The movement of H+ ions through ATP synthase drives the transfer of electrons down the ETC. D The movement of electrons down the ETC drives the movement of ADP and phosphate through ATP synthase.

The movement of electrons down the ETC drives the formation of a proton gradient. As electrons move down the ETC, some of the carriers transport H+ ions from one side of the membrane to the other which causes a H+ gradient to form across the membrane. This gradient is then used to drive ATP synthesis as the H+ ions move along their concentration gradient through the ATP synthase protein found in the membrane.

How do the majority of fatty acids enter the outer membrane of the mitochondria?

Transferase facilitated entry of carnitine bound fatty acids First, acyl-CoA synthetase links coenzyme A with the fatty acid, made favorable by the hydrolysis of two bond in ATP (to make AMP). Second, fatty acid acyl-CoA is attached to carnitine via carnitine acyltransferase I, and the acyl-carnitine enters the outer membrane.

What dietary source of energy contains the most energy per gram (kcal/g)?

Triglycerides

Substrate-level phosphorylation

When an enzyme transfers a phosphate group is transferred from an organic molecule to ADP.

Oxidative phosphorylation

When energy is released at each step of the chain is stored in a form the mitochondrion can use to make ATP.

Photon

a particle of light; absorbing porphyrin ring

Citric Acid Cycle (Krebs Cycle)

completes the breakdown of glucose; takes place in mitochondria

NAD+

these electrons are high-energy electrons usually carried to the electron transport chain; accepts 2 electrons and a hydrogen to become NADH

Pyruvate

end product of glycolysis

Reduction

gain of electrons

ATP synthesis

large protein that uses energy from H+ ions to bind ADP and a phosphate group together to make ATP

Oxidation

loss of electrons

Pyruvate Oxidation

pyruvate molecules are oxidized and produces acetyl-CoA, CO2, and NADH; takes place in mitochondria

Calvin Cycle

reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars

Electron Transport Chain

series of electron carrier proteins that shuttle high-energy electrons during ATP-generating reactions

FAD

sometimes used instead of NAD+; accepts 2 electrons and a hydrogen to become FADH

Glycolysis

the breakdown of glucose (6 Carbon) into two molecules of pyruvate (3 Carbon)

Catabolism

the breakdown of molecules

Anabolism

the building of new molecules

Absorption/Reflection of light

the colors we see are the light reflecting off an object; plants use chlorophyll a, Chlorophyll b and accessory pigments to capture the energy from the sun

Chloroplast structure includes

thylakoids; stroma