Chapter 9 and 10 without pictures

during the conversion of pyruvate to acetyl CoA before the citric acid cycle there is a release of _____ and synthesis of _____

...

What are the 4 major steps of cellular respiration?

1.Glycolysis- (occurs in the cytosol) 2. Pyruvate Oxidation - Formation of Acetyl Co-enzyme A (occurs in the mitochondrion) 3. Citric Acid Cycle 4. Oxidative phosphorylation - Electron Transport Chain and Chemiosmosis - (occurs in the inner membrane of the mitochondrion)

How many ATP are produced by the citric acid cycle for each molecule of glucose?

2

How many NADH are produced by glycolysis?

2

In glycolysis there is a net gain of _____ ATP.

2 (It takes 2 ATP to produce 4 ATP.)

Glyceraldehyde 3-phosphate (G3P)

A three-carbon carbohydrate that is the direct product of the Calvin cycle; it is also an intermediate in glycolysis.

In cells, what is usually the immediate source of energy for an endergonic reaction?

ATP (The hydrolysis of ATP provides the energy needed for an endergonic reaction.)

The light reactions of photosynthesis supply the Calvin cycle with

ATP and NADPH.

Why is ATP production during cellular respiration characterized as indirect?

ATP is not produced directly by the ETC but instead via the proton gradient generated during electron transport through the ETC.

autotroph vs. heterotroph

Autotrophs can nourish themselves with CO2 and inorganic nutrients

Compare and contrast aerobic and anaerobic respiration

Both processes include glycolysis, the citric acid cycle, and oxidated phosphorylation. In aerobic respiration the final electron acceptor is molecular oxygen O2; in anaerobic respiration the final electron Accceptor is a different substance.

What processes in your cells produce the CO2 that you exhale

CO2 is released from the pyruvate that is the end product of glycoloysis, and CO2 is also released during the citric acid cycle

What are the three phases of The Calvin cycle?

Carbon Fixation, Energy Consumption and Redox, Release of G3P; Regeneration of RuBP

Into which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration?

Carbon dioxide

What provides the carbon atoms that are incorporated into sugar molecules in the Calvin cycle?

Carbon dioxide (CO2) (Carbon dioxide provides the carbon atoms that are incorporated into sugars in photosynthesis. Carbon dioxide initially combines with RuBP, and RuBP is regenerated to continue the Calvin cycle.)

Which process or processes return carbon to the atmosphere?

Cellular Respiration

How do allosteric regulation and competitive inhibition compare?

Competitive inhibition involves binding of a regulatory molecule to the active site; in allosteric regulation a regulatory molecule binds to a different location

Which stage of glucose metabolism produces the most ATP?

Electron transport and chemiosmosis

describe the electron transport chain

Electrons are passed from one carrier to another, releasing a little energy at each step.

Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria?

Electrons moving down the electron transport chain

The function of cellular respiration is to _____.

Extract usable energy from glucose.

How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen?

Four (There is a net gain of two ATP from glycolysis and one per each molecule of acetyl CoA oxidized in the citric acid cycle for a total of four per glucose.)

During the redox reaction in glycolysis, Which molecule acts as the reducing agent?

G3P

A substrate-level phosphorylation occurs in the Krebs cycle when _____.

GDP is phosphorylated to produce GTP

Which molecule is most often metabolized in a cell to produce energy for performing work?

Glucose

Which of the part of the cellular respiration process takes place in the cytosol of a eukaryotic cell?

Glycolysis

Which step of the cellular respiration pathway can take place in the absence of oxygen?

Glycolysis

The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the

H+ concentration across the membrane holding ATP synthase.

What provides electrons for the light reactions?

H2O (Electrons are stripped from water in the light reactions of photosynthesis. Light provides the energy to excite electrons.)

Which of the following sequences correctly represents the flow of electrons during photosynthesis?

H2O → NADPH → Calvin cycle

What is the fate of the phosphate group that is removed when ATP is converted to ADP?

It is acquired by a reactant in an endergonic reaction

Which part of a eukaryotic cell is involved in cellular respiration?

Mitochondria

Describe the difference between the two processes in cellular respiration that produce ATP: oxidative phosphorylation and substrate-level phosphorylation

Most of the ATP produced in cellular respiration come from oxidative phosphorylation, in which the energy released from redox reactions in an electron transport chain is used to produce ATP. In substrate level phosphorylation, an enzyme dirctly transfers a phosphate group to ADP fro an intermediate substrate. All ATP production in glycolysis occurs by substrate-level phosphorylation, this form of ATP production also occurs at one step in the citric acid cycle.

In glycolysis in the absence of oxygen, cells need a way to regenerate which compound?

NAD+

During the redox reaction in glycolysis, which molecule acts as the oxidizing agent? Which molecule acts as the reducing agent?

NAD+ acts as the oxidizing agent in step 6, accepting electrons from G3P, which thus acts as the reducing agent

Following glycolysis and the Krebs cycle, but before the electron transport chain and oxidative phosphorylation, the carbon skeleton of glucose has been broken down to CO2 with some net gain of ATP. Most of the energy from the original glucose molecule at that point in the process, however, is in the form of _____.

NADH

After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of _____.

NADH (The citric acid cycle produces three NADH per turn of the cycle)

In the Cellular Respiration Process, which coenzymes is an electron carrier?

NADH and FADH2

____ and _____ donate their electrons in the electron transport chain

NADH and FADH2

products of the citric acid cycle

NADH, H+, ATP, CO2, FADH2

_____ and _____ are both electron carriers that donate their electrons to the electron transport chain. The electrons ultimately reduce __ to _____ in the final step of electron transport. However, the amount of ATP made by electrons from an _____ molecule is greater than the amount made by electrons from an _____ molecule.

NADH; FADH2; O2; water; NADH; FADH2 (because fewer protons are pumped across the inner mitochondrial membrane when FADH2 is the electron donor than when NADH is the electron donor)

during chemiosmosis ____ is oxidized to ___ which then goes back and picks up a H from all three of the pathways

NADH; NAD+;

What transports electrons from the light reactions to the Calvin cycle?

NADPH (NADPH is an electron carrier that picks up electrons in the light reactions and releases them in the Calvin cycle. An electron transport chain conveys electrons from one photosystem to the other within the light reactions.)

Glucose and _______ are consumed during cellular respiration

Oxygen

_____ is the three-carbon sugar that is produced as an end product of glycolysis.

Pyruvate

In a eukaryotic cell, most of the ATP derived from glucose during cellular respiration is produced by ...

The Electron Transport Chain

Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?

The citric acid cycle (Both NADH and FADH2 are produced during the citric acid cycle.)

What is the major (but not the only) energy accomplishment of the citric acid cycle?

The formation of NADH and FADH2 (Each turn of the citric acid cycle releases carbon dioxide, forms one ATP by oxidative phosphorylation, and passes electrons to three NAD+ and one FAD.)

Why is the citric acid cycle called a cycle?

The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the cycle.

how do we use exergonic flow of electrons?

The free energy from electron flow is used to move hydrogen ions across a membrane against their gradient

Carbon Fixation

The initial incorporation of carbon from CO2 into an organic compound by an autotrophic organism (a plant, another photosynthetic organism, or a chemoautotrophic prokaryote).

Where do the reactions of the citric acid cycle occur in eukaryotic cells?

The matrix of the mitochondrion (The citric acid cycle, which takes place in the mitochondrial matrix, completes the degradation of glucose.)

Oxygen gas (O2) is one of the strongest oxidizing agents known. The explanation for this is that _____.

The oxygen atom is very electronegative.

Photophosphorylation

The process of generating ATP from ADP and phosphate by means of chemiosmosis, using a proton-motive force generated across the thylakoid membrane of the chloroplast or the membrane of certain prokaryotes during the light reactions of photosynthesis.

Calvin cycle

The second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate.

The energy of electron transport serves to move (translocate) protons to the outer mitochondrial compartment. How does this help the mitochondrion to produce energy?

The translocation of protons sets up the electrochemical gradient that drives ATP synthesis in the mitochondria.

Why are fermentation reactions important for cells? They generate oxygen. They regenerate NAD+ so that glycolysis can continue to operate. They allow the cell to conserve oxygen for the Krebs cycle. They produce alcohol which enhances the permeability of their mitochondrial membranes to proton translocation

They regenerate NAD+ so that glycolysis can continue to operate.

How would you describe glycolysis?

This process splits glucose in half and produces 2 ATPs for each glucose.

Describe Carbon Fixation in the Calvin Cycle

Three molecules of carbon dioxide are added to three molecules of a five-carbon sugar abbreviated RuBP. These molecules are then rearranged to form six molecules called 3-PGA, which have three carbons each.

A small amount of ATP is made in glycolysis by which of the following processes?

Transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation

NADP is an electron ______ that as NADPH stores _____ _______ produced during the _____ _____

acceptor; energized electrons; light reactions

During aerobic respiration, molecular oxygen (O2) is used

at the end of the electron transport chain to accept electrons and form H2O

Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. In the absence of oxygen, _____ _______ stops. ____ is no longer converted to _____, which is needed for the first three stages of cellular respiration.

electron transport stops; NADH; NAD+

Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step _____.

enables the cell to recycle the reduced NADH to oxidized NAD+

The reaction ADP + P --> ATP is a(n) _____ reaction.

endergonic

The reaction A --> B + C + heat is released in a(n) _____ reaction.

exergonic

The energy for an endergonic reaction comes from a(n) _____ reaction.

exergonic (the energy released by an exergonic reaction can be used to drive an endergonic reaction = energy coupling)

In the overall process of glycolysis and cellular respiration, _____ is oxidized and _____ is reduced.

glucose ... oxygen (In cellular respiration, electrons and hydrogen are removed from glucose and added to oxygen.)

What is the correct sequence of steps as energy is extracted from glucose during cellular respiration.

glycolysis → acetyl CoA → citric acid cycle → electron transport chain

When ATP is _____ into ADP and inorganic phosphate, a large amount of energy is released.

hydrolyzed

Substrate-level phosphorylation occurs within a metabolic pathway where sufficient energy is released by a given chemical reaction to drive the synthesis of ATP from ADP and phosphate. In which of the following metabolic pathways is substrate-level phosphorylation exhibited?

in both glycolysis and the citric acid cycle

During respiration in eukaryotic cells, the electron transport chain is located in or on the _____.

inner membrane of the mitochondrion

during chemiosmosis, the hydrogen ions are pumped as a result of the electron flow from the ____ to the _____ and therefore the hydrogen ion concentration inside the cell _____

matrix; inter membrane space; decreases

The reactions of pyruvate processing, the citric acid cycle, and the electron transport chain occur within the _____ in the cell.

mitochondria

does a re-oxidation reaction produce ATP

no, it provides ADP+ so glycolysis can continue

In cellular respiration, glucose is _____ and oxygen is _____.

oxidized, reduced

The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is

oxygen.

In fermentation _____ is reduced and _____ is oxidized. pyruvate ... NADH lactate ... ethanol NAD+ ... pyruvate NADH ... lactate lactate ... NADH

pyruvate ... NADH

Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?

pyruvate, ATP, and NADH

Light Reactions

reactions which occur on the thylakoid membranes of the chloroplast convert solar energy to the chemical energy of ATP and NADPH and release oxygen in the process (The first of two major stages in photosynthesis... happens before the calvin cycle)

carbohydrate synthesis takes place in the

stroma

In the citric acid cycle, ATP molecules are produced by _____.

substrate-level phosphorylation

In glycolysis, ATP molecules are produced by _____.

substrate-level phosphorylation (A phosphate group is transferred from glyceraldehyde phosphate to ADP.)

Most CO2 from catabolism is released during

the citric acid cycle

in the absence of CO2, which pathways shut down?

the citric acid cycle, electron transport pathway, and production of acetyl CoA (aka oxidation of pyruvate)

Where do the reactions of glycolysis occur in a eukaryotic cell?

the cytosol

Where does the Calvin Cycle take place?

the stroma

What is energy coupling?

the use of energy released from an exergonic reaction to drive an endergonic reaction

in photosynthesis, the electron transport proteins are in the

thylakoid membranes

The light reactions take place in the _________ and the Calvin cycle takes place in the _________.

thylakoids; stroma (Within the chloroplast, the light reactions take place in the flattened sacs called thylakoids and the Calvin cycle takes place in the thick fluid called the stroma.)

In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2 are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle?

two ATP, six NADH, two FADH2

chemiosmosis

use of energy of the flow of H+ ions down their gradient (electron transport chain to ATP synthesis)

what is the ultimate electron donor in the calvin cycle?

water (donates new electrons and chlorophyl passes them on all the way to the sugar)

The Citric Acid Cycle begins ___; occurs ____;

with glycolysis by oxidyzing acetyl CoA (derived from pyruvate) to carbon diozide; within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes