Chapter 7 Cellular Respiration

Substrate-level phosphorylation

A phosphorylated organic molecule directly transfers to a phosphate group to AP. The free energy difference of hydrolysis of these phosphorlylated molecules is more negative than that of ATP hydrolysis and so can drive the synthesis of ATP by energetic coupling.

Glycolysis

Breakdown of glucose to make pyruvate

Catabolic

Cellular respiration is one of the major sets of ____ reactions in a cell.

In stages 1-3,

Chemical energy is transferred to two types of energy-storying molecules; ATP and electoncarriers.

2.5

An approximation of ____ molecules of ATP are produced for each NADH that donated electrons to the chain.

At the end of the citric acid cycle, but before the subsequent steps of cellular respiration, which molecules contain the energy held in the original glucose molecule?

At the end of the citric acid cycle, the energy in the original glucose molecule is held in ATP, NADH, and FADH2.

Complex I, or Complex II

Electrons enter the electron transport chain by either ____ or ___

Glycogen, and starch

Excess glucose is stored as ______ in animals and ____ in plants.

anaerobic organisms that live without oxygen

Fermentation pathways are important for

Steps of conversion of Pyruvate to acetyl-CoA

First, part of the pyruvate molecule is oxidized and splits off to form carbon dioxide, the most oxidized (and therefore the least energetic) form of carbon. The electrons lost in this process are donated to NAD+, which is reduced to NADH. The remaining part of the pyruvate molecule—an acetyl group (CH3OC—)—still contains a large amount of potential energy that can be harnessed. It is transferred to coenzyme A (CoA), a molecule that carries the acetyl group to the next set of reactions.

Stage 1 of cellular respiration

Glucose, fatty acids, or amino acids are partially broken down and a small amount of energy is released, glucose then breaks down to pyruvate in a process known as glycolysis.

Cytoplasm and mitochondria.

In eukaryotes glycolysis takes place in the ____. and the citric acid cycle and oxidative phosphorylation takes place in the _______________

Cellular respiration

Is a series of chemical reactions that convert the energy stored in fuel molecules into a chemical form that can be readily used by cells.

Stage 3 of cellular respiration

Is the citric acid cycle. During this stage acetyl-CoA is broken down and more carbon dioxide is released

Glycolysis(2nd phase)

Is the cleavage phase. The 6-carbon molecule fructose 1,6-bisphoshate is split into two 3-carbon molecules. Then dihydroxacetone phosphate is converted to glyceraldehyde 3-phosphate.

Stage 4 of cellular respiration

Oxidative phosporylation. In this tage the electron carriers generated in stages 1-3 donate their high-energy electrons to an electron transport chain.

Glycolysis (1st phase)

Prepares glucose for the next tow phases by the addition of two phosphate groups to glucose producing fructose 1,6-biphosphate. this phase require the input of energy.

Electron transport chain compostition

Protins associated with the inner mitochondiral membrane.

Stage 2 of cellular respiration

Pyruvate is converted to another molecules called acetyl-coenzyme A and carbon dioxide is produced

Reduction is ?

The gain of electrons

Potential energy

The proton gradient is a source of

Glycolysis (3rd phase)

This phase ends with the production of two molecules of pyruvate. It is sometimes called the payoff phase because ATP and the electron carrier NADH are produced.

Electron transport chain

Transfers electrons along a series of membrane associated proteins to a final electron acceptor and harness the energy of the electrons to produce a large amount of ATP.

ATP

Universal currency for all cells.

The loss of electrons

What is oxidation

Electron acceptor

When oxygen gains electrons its called a

Fermentation

____ Extracts energy from glucose in the absence of oxygen.

Glycolysis

_____ is the partial breakdown of glucose. It begins with a molecule of glucose and produces two-carbon molecules of pyruvate and net totaal of two molecules of ATP and two molecules of the electron carrier NADH.

Pyruvate

__________ is transported into the mitochondrial matrix, where it is converted into acetyl-CoA

Electron carries

are moleules that store and transfer energy in the form of ;high-energy or 'excited' electrons.

Summary of Glycolysis

glycolysis begins with a single molecule of glucose (six carbons) and produces two molecules of pyruvate (three carbons each). These reactions yield four molecules of ATP and two molecules of NADH. However, two ATP molecules are consumed during the initial phase of glycolysis, resulting in a net gain of two ATP molecules and two molecules of NADH

Overview

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Lactic acid fermentation occurs

in animals and bacteria. During lactic acid fermentation, electrons from NADH are transferred to pyruvate to produce lactic acid and NAD+

Citric acid cycle results

in the complete oxidation of the acetyl group of acetyl-CoA

Citric acid cycle

is the step in cellular respiration in which fuel molecules are completely oxidized. It is also called the Krebs cycle and the tricarboxylic acid (TCA) cycle. During the citric acid cycle, the chemical energy in the bonds of acetyl-CoA is transferred to ATP by substrate-level phosphorylation and to the electron carriers NADH and FADH2.

Two major fermentation pathways are

lactic acid fermentation and ethanol fermentation

Ethanol fermentation occurs in

plants and fungi. During ethanol fermentation, pyruvate releases carbon dioxide to form acetaldehyde, and electrons from NADH are transferred to acetaldehyde to produce ethanol and NAD+