29. Carbohydrate metabolism- Fermentation

T/F: fermentation is an alternate to nonoxidative phosphorylation

false; alternate to OXIDATIVE phosphorylation

what can fermentations produce

* lactate
* ethanol
* VFA

T/F: Fermentation is not important in absence of O2

false; fermentation is important in the absence of O2

T/F: oxidative is not anaerobic

true; it is aerobic

T/F: O2 does not serve as final electron acceptor, cells can not perform oxidative phosphorylation because it is an aerobic respiration

that is all true

T/F: reduced coenzymes (NADH and FADH2) from glycolysis and TCA cycle slowly build up

false; reduced coenzymes (NADH and FADH2) from glycolysis and TCA cycle QUICKLY build up

T/F: oxidized coenzymes (NAD+ and FAD+) are slowly depleted

false; oxidized coenzymes (NAD+ and FAD+) are QUICKLY depleted

What does fermentation use?

it uses pyruvate or other organic compounds as electron accepter

T/F: Fermentation to lactate is important in a few organism

FALSE; it is important to many organisms

What is the summary of fermentation to lactate

* pyruvate reduced to lactate in single step
* consumes 1 NADH/pyruvate
* allows glycolysis to continue with no O2
* glycolysis produces 1 NADH/pyruvate

How is fermentation to lactate important in animals?

* muscle during intense exercise
* not enough O2 to sustain oxidative phosphorylation
* erythrocytes
* lack mitochondria for TCA cycle
* cancerous cells
* Warburg effect

how is fermentation to lactate important in microbes

* bacteria in yogurt and other fermented products
* microbes from cow rumen during lactic acidosis
* produce lactate when quickly changed to high grain
* lower rumen pH to dangerous levels (

what is the summary of fermentation to ethanol

* pyruvate reduced to ethanol in two steps
* consumes 1 NADH/pyruvate
* allows glycolysis to continue with no O2
* same as lactate

how is fermentation to ethanol important in microbes

* yeast
* used in production of most alcohol
* zymomonas mobilis
* bacterium used production of tequila

summary or how fermentation to VFA in cattle happens

* Volatile fatty acid (VFA)
* acetate
* propionate
* butyrate
* formed by microbes in the rumen of cattle from feed carbohydrate
* absorbed and metabolized by cow
* fulfill up to 70% of total energy needed by host

what does propionate do in regards of fermentation to VFA which is important to cattle

* formed from phosphoenolpyruvate in 9 steps
* dont need to know details
* consumes NADH (NADred)
* also produces ATP

what does acetate do in regards of fermentation to VFA which is important to cattle

* formed from pyruvate in 3 steps
* dont need to know details
* produces ATP
* also produces ferredoxin (Fd red)
* does not consume NADH
* doesnt have same role as other fermentation pathways
* can be formed using a second pathway
* forms same products as first pathway, but last two enzymes differ

what does butyrate do in regards of fermentation to VFA which is important to cattle

* formed from pyruvate in 7 steps
* don’t need to know details
* produces ATP
* consumes NADH and produces reduced ferredoxin

how is fermentation important to industry

* fermentation to produce biofuels and chemicals
* ethanol
* butanol
* acetone
* done with microbes at large scale in tanks

what are alternates to oxidative phosphorylation

* anaerobic respiration

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what is anaerobic respiration

* respiration without oxygen (O2)
* uses inorganic electron acceptors other than O2
* nitrate (forms nitrite)
* sulfate (forms sulfide)
* CO2 (forms methane)
* important in microbes

T/F: fermentation is used when oxidative phosphorylation is possible

false; fermentation is used when oxidative phosphorylation is NOT possible

how does glycolysis continue

by oxidizing NADH, fermentation re-generates NAD+ and allows glycolysis to continue

T/F: Anaerobic respiration is not an alternative to oxidative phosphorylation

false; it is an alternative