BIO 122 Lecture Notes - Lecture 4: Phosphoglycerate Kinase, Pyruvate Dehydrogenase, Dihydroxyacetone Phosphate

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fuchsiacoyote139

30 May 2018

School

Drexel University

Department

Bioscience & Biotechnology

Course

BIO 122

Professor

Gurney

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Prior to Week 4 – Chapter 9 – Cellular Respiration

Know

• what redox reactions are

o know that glucose is oxidized to CO2 and O2 is reduced to water

• the difference between respiration (breathing) and cellular respiration, but that the two are inherently

connected

• what substrate-level phosphorylation is

o used by glycolysis and citric acid cycle

o produced by phosphorylation by enzyme-catalyzed

• what biochemical feedback means

• glucose

o used for glycolysis

o cell resp input

• ATP

o Releases energy

• NADH

o Electron carrier

• NAD+

o Reduced to make electron carrier

• FAD+

o Reduced to make electron carrier

• FADH2

o Electron carrier

• the 4 overall stages of respiration

o glycolysis

o pyruvate

o citric acid

o etc

• the 3 main phases of glycolysis and inputs and outputs

o glucose to glucose-6-phosphate

▪ by hexokinase

o glucose-6-phosphate to fructose-6-phosphate

o fructose-6-phosphate to fructose- 1,6 – bisphosphate

▪ by phosphofructokinase

o to glyceraldehyde 3-phosphate (G3P) and dihydroxyacetone phosphate (DAP)

o to 2 G3P

o to 1,3 biphosphoglycerate (1,3 BPG)

o to 3-phosphoglycerate (3PG)

▪ by phosphoglycerate kinase

o to 2-phosphoglycerate (2PG)

o to phosphoenolpyruvate (PEP)

o to pyruvate

▪ by pyruvate kinase

• that enzymes in glycolysis can be regulated to limit the rate of glucose oxidation

o hexokinase – if too much G6P is available, it will not proceed

o phosphofructokinase – if too much ATP is available, ATP allosterically inhibits PFK activity

• that pyruvate dehydrogenase removes CO2 from pyruvate, attaches coenzyme A, resulting in Acetyl-CoA

and NADH

• The citric acid cycle

o ultimately produces 2CO2, 1ATP, 3NADH and 1 FADH2 and oxaloacetate

• TCA cycle starts with oxaloacetate. Acetyl (coA removed) will get added to oxaloacetate to form citrate

o By citrate synthetase

• isocitrate dehydrogenase takes 6 carbon isocitrate and generates 5 carbon alpha-ketoglutarate and

releases CO2 and NADH

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Related Questions

Why does an electron have lower potential energy in an H-O bondthan in an O=O bond?

H has a higher electronegativity than O.

O=O is not stable.

O=O contains a double bond.

The electrons are closer to the oxygen atom in the H-O bond.

None of the answers are correct.

How is the energy from the electron transport chain used mostdirectly?

to form the bonds of a water molecule

to pump hydrogen ions across the mitochondrial inner membraneinto the mitochondrial intermembrane space

to join ADP with a phosphate

to decompose glucose into pyruvate

to rotate ATP synthase

Which process provides the energy needed to pump protons acrossthe mitochondrial membrane during oxidative phosphorylation?

the transfer of electrons in redox reactions

the breakdown of ATP to ADP

the rotation of the ATP synthase rotor

oxidation of isocitrate

None of the answers are correct.

What causes the ATP synthase rotor to spin?

the passing of electrons through ATP synthase

the movement of protons across the mitochondrial membrane

the movement of electrons across the mitochondrial membrane

the synthesis of ATP from ADP and a phosphate group

None of the answers are correct.

What of the following generates the proton-motive force duringoxidative phosphorylation?

buildup of NADH molecules at protein complex I

movement of H⁺ ions across the mitochondrial membraneduring electron transport

rotation of the ATP synthase rotor

joining of H⁺ ions with oxygen to form water

None of the answers are correct.

Suppose a microorganism invades a cell, causing damage to ATPsynthase. How would cellular respiration be affected?

Electrons could not be passed down the electron transportchain.

ADP could not be joined with a phosphate to form ATP.

Hydrogen ions could not be pumped into the mitochondrialintermembrane space.

The cell could not release any energy from the glucosemolecule.

Glucose could not be broken down into pyruvate.

Which molecules transport electrons from the citric acid cycleto the electron transport chain?

NADH and FADH₂

ATP and ADP

GTP and GDP

oxaloacetate and citric acid

None of the answers are correct.

Which type of reactions control the energy release from glucoseduring the citric acid cycle?

acid-base reactions

redox reactions

random reactions

All answers are correct.

None of the answers are correct.

What is the role of NAD⁺ in cellular respiration?

to receive electrons from the citric acid cycle and deliver themto the electron transport chain

to catalyze the synthesis of ATP from ADP

to accumulate in the mitochondrial intermembrane space tofacilitate ATP synthesis

to serve as a substrate to bind to acetyl-CoA at the beginningof the citric acid cycle

None of the answers are correct.

10.

Which molecule enters the citric acid cycle?

glucose

pyruvate

ATP

acetyl-CoA

None of the answers are correct.

apricotgoose897

Which of the following is common to both aerobic and anaerobicmicrobes?

	Fermentation
	An electron transport chain
	Pyruvate oxidation
	Glycolysis
	All of the above

The primary purpose of catabolism is

	generation of ADP.
	generation of ATP.
	oxidation of NADH to NAD⁺.
	degradation of organic molecules.
	biosynthesis.

What is a fate of pyruvate during alcoholic fermentation byyeast?

	It is reduced to lactic acid.
	It is oxidized to form glucose and carbon dioxide
	It is cleaved to form acetylaldehyde and carbon dioxide.
	It is catabolized in glycolysis.
	It is oxidized to form lactic acid and carbon dioxide.

Electrons needed to reduce an oxidized electron acceptor areprovided by

	a) externally provided compounds such asH<sub>2</sub>, lactate or formate.
	b) an intermediate electron carrier such as NADH.
	c) 0<sub>2</sub>.
	d) Both a and b
	e) All of the above

How are aerobic respiration and anaerobic respirationsimilar?

	Both use oxygen as a terminal electron carrier.
	These are other names for glycolysis.
	Both utilize inorganic molecules as terminal electronacceptors.
	Neither receives electrons from glycolysis.
	Anaerobic respiration does not exist in microbes.

The conversion of phosphoenolpyruvic acid (PEP) topyruvate

	a) releases CO<sub>2</sub>.
	b) involves the conversion of ADP and ATP.
	c) involves substrate-level phosphorylation.
	d) Both a and b
	e) Both b and c

Which of the following is the best definition offermentation?

	The reduction of glucose to pyruvic acid
	The complete catabolism of glucose to CO₂ andH₂O
	The oxidation of a carbohydrate with organic molecules servingas electron donors and acceptors
	The production of ATP from glucose
	The production of ethanol from glucose

A reaction that yields energy has a

	positive ?G_o?.
	negative ?G_o?.
	positive ?E_o?.
	negative ?E_o?.
	negative ?H_o?.

Oxidation and reduction reactions are always coupledbecause

	a) electrons generally accompany protons.
	b) protons generally accompany protons.
	c) electrons cannot exist free in solution.
	d) Both a and b
	e) All of the above

10.

Which of the following is true of aerobic respiration?

	It involves the reduction of oxygen.
	It involves the oxidation of oxygen.
	It involves the reduction of lactic acid.
	It involves the oxidation of lactic acid.
	It does not generate ATP.