BIO-1 Lecture Notes - Lecture 11: Light-Dependent Reactions, Atp Synthase, Electrochemical Gradient

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lemonwasp425

4 Dec 2020

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Only way that atp is made in eukaryotes outside of mitochondria and chloroplasts involves transfer of high energy phosphate group from a carbon compound to adp. Relatively little atp is made this way in eukaryotes. Chemiosmotic production of atp occurs in mitochondria and chloroplasts and in bacteria. Energy from an electrochemical gradient is used to drive the direct phosphorylation of adp by inorganic phosphate. Active transport is in reverse: ions moving down a gradient generate atp rather than atp used to drive ions against a gradient. Most atp is made this way in eukaryotes. Energy from high energy electrons produced by oxidation of chemical compounds (in. Is stored in an electrochemical gradient and used to drive the transport of protons (h+) Protons may transported out of the cell, across the bacterial plasma membrane, or into an. This process results in the formation of an electrochemical gradient across the membrane.

Related Questions

According to the chemiosmotic theory, an electrochemical proton gradient is used to synthesize ATP in mitochondria. The enzyme that does this is located on the inside of the mitochondrial membrane. The oxidation of carbohydrates and fats is used to pump protons outside the mitochondrial membrane until the steady-state membrane potential is -140 mV and the pH gradient âpH = 1.5. Inside the mitochondrion, pH = 7.0, [ATP] = 1 mM, [Pi] = 2.5 mM, [ADP] = 1 mM, and T = 298 K.

a) Howw much chemical potential is required to synthesize ATP inside mitochondria? Hint: here the question refers to the chemical potential difference between products and reactants = âG of the reaction ADP + Pi -> ATP.

b) How much free energy is made available by moving 1 mol of protons from the outside to the inside? Is this enough to drive ATP synthesis?

c) How many protons must be translocated per ATP synthesized?

violetyellowjacket662

Creatine (Cr) is made in the liver and kidneys and then transported to the muscles, where it serves as a high energy storage compound via phosphorylation by creatine kinase. Two forms of this enzyme exist, mitochondrial and cytoplasmic. In mitochondria there is net synthesis of creatine phosphate (CrP). In the cytosol, the phosphate is transferred from CrP to ADP to supply ATP to power the muscles. Table 3.2 of your G&G text lists ÎGËÌ for hydrolysis of creatine phosphate: -43.3 kJ/mol at 25Â°C. creatine phosphate + H2O ----> creatine + Pi

a. Calculate the KeqÍ for this hydrolysis.

c. In mouse muscle cells at 25Â°C, [Cr] is 10 mM, and [CrP] is 20 mM. What concentration of Pi would be needed to maintain this level of phosphorylation by reversal of the hydrolysis reaction? Is this concentration of Pi a reasonable expectation? Why?

d. Coupling ATP hydrolysis (ÎGËÍ-35.7 kJ/mol at 25Â°C) to an unfavorable reaction is often used to drive biochemical reactions. Write the chemical equations for the CrP reverse hydrolysis and ATP hydrolysis and add them together to give the coupled reaction. Then calculate ÎGËÍfor the coupled reaction. Is this reaction favorable? Justify your answer.

e. Considering ÎGÍin the muscle cells rather than under 1M standard state conditions, what ratio of ATP/ADP would be needed inside mitochondria to make the coupled reaction for CrP synthesis produce the concentrations of Cr and CrP observed in mouse muscle? Is this ratio reasonable? Why?

crimsonduck531

QUESTION 1

Which of the following is the correct order of the three stages of cellular respiration?

	a.	Krebs cycle, glycolysis, electron transport
	b.	electron transport, glycolysis, Krebs cycle
	c.	Krebs cycle, electron transport, glycolysis
	d.	glycolysis, Krebs cycle, electron transport
	e.	electron transport, Krebs cycle, glycolysis

1 points

QUESTION 2

Consider a bacterial cell that performs anaerobic respiration. If that bacterial cell had access to six molecules of glucose to use, how many ATP molecules would it be able to produce?

	a.	2
	b.	34
	c.	36
	d.	6
	e.	12

1 points

QUESTION 3

The oxygen that organisms need to live is used exclusively in which of the following metabolic pathways?

	a.	Electron transport chain
	b.	Anaerobic respiration
	c.	Glycolysis
	d.	Krebs cycle
	e.	ATP-Synthase

1 points

QUESTION 4

The electron transport chain uses the energy in NADH and FADH₂ to pump H⁺ ions from the matrix to the innermembrane space. The H⁺ gradient is then used to power ATP-Synthase. Enough H⁺ is pumped from the energy in a molecule of NADH to produce ______ ATP molecules, while enough H⁺ is pumped from the energy in a FADH₂ molecule to produce ______ ATP molecules.

	a.	three; two
	b.	three; three
	c.	two; two
	d.	two; three

1 points

QUESTION 5

Which of the following list contains only products of cellular respiration?

	a.	glucose, oxygen, ADP
	b.	ATP, carbon dioxide
	c.	oxygen, ADP, carbon dioxide
	d.	ATP, glucose, oxygen
	e.	glucose, ATP

1 points

QUESTION 6

What powers the enzyme ATP-Synthase?

	a.	NADH molecules
	b.	oxygen (O₂)
	c.	ATP
	d.	NADH and FADH₂ molecules
	e.	The H⁺ gradient between the matrix and inner-membrane space

1 points

QUESTION 7

Organisms exist which are able to survive using only glycolysis (i.e. without using oxidative phosphorylation).

True

False

1 points

QUESTION 8

Each ADP molecule contains ________ phosphates, and each ATP molecule contains ________ phosphates.

	a.	three; three
	b.	two; two
	c.	one; two
	d.	two; three
	e.	one; three

1 points

QUESTION 9

Adding a phosphate group to ADP to form ATP is an endergonic reaction.

True

False

1 points

QUESTION 10

The majority of ATP produced during cellular respiration is produced during glycolysis.

True

False

1 points

QUESTION 11

Glycolysis occurs:

	a.	on enzymes located in the inner-membrane.
	b.	in the cytosol.
	c.	in the inner-membrane space.
	d.	in the nucleus of the cell.
	e.	in the matrix of mitochondria.

1 points

QUESTION 12

Muscle soreness associated with strenuous exercise is due to:

	a.	the production of alcohol during anaerobic respiration.
	b.	a buildup of lactic acid.
	c.	an excessive amount of ATP that builds up during exercise.
	d.	the large amounts of CO₂ building up in the muscle.

1 points

QUESTION 13

A required reactant for glycolysis is:

	a.	the electron transport chain.
	b.	carbon dioxide.
	c.	oxygen.
	d.	NAD+.
	e.	mitochondria.

1 points

QUESTION 14

NADH is produced in all of the following except:

	a.	the electron transport chain.
	b.	the Krebs cycle.
	c.	glycolysis.

BIO-1 Lecture Notes - Lecture 11: Light-Dependent Reactions, Atp Synthase, Electrochemical Gradient

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