Lecture 7 Flashcards
HD
Most microorganisms oxidize ________ as their primary source of cellular energy
carbohydrates
The breakdown of carbohydrate molecules to produce energy Glucose is the most common carbohydrate energy source used by the cells
Carbohydrate catabolism
To produce energy from glucose, microorganisms use two general processes which are what? Both processes start with the same first step which is what?
Cellular respiration and Fermentation. Glycolysis
The Embden-Meyerhof pathway is more commonly known as what?
Glycolysis
What is another pathway that many bacteria, including E. coli and Bacillus subtilis could use for glucose oxidation?
Pentose phosphate pathway
What are the 2 basic stages of glycolysis?
The Preporatory Stage and the Energy Conserving Stage
After glucose is broken down into pyruvic acid what are the next possible 2 steps?
Cellular respiration or fermentation
Respiration is defined as an ATP-generating process in which molecules are oxidized and the final electron acceptor is (almost always) a what?
an inorganic molecule
An essential feature of respiration is the operation of the what?
electron transport chain.
In the electron transport chain electrons are transferred from where to where?
higher-energy compounds to lower energy compounds
What are the two types of respiration?
Aerobic respiration
Anaerobic respiration
In aerobic respiration among prokaryotes, a total of ____ molecules of ATP can be generated from one molecule of glucose.
38
Aerobic respiration among Eukaryotes produces a total of only _____ molecules of ATP
36
Why are there fewer ATP in Eukaryotes?
Energy is lost when electrons are shuttled across the mitochondrial membranes that separate glycolysis in the cytoplasm from the ETC. Prokaryotes don’t have this separation.
In anaerobic respiration, the final electron acceptor is an what?
inorganic substance other than oxygen
Why is the ATP yield never as high as in aerobic respiration?
Not all carriers in the electron transport chain participate in anaerobic respiration. This is why anaerobes tend to grow more slowly.
During glycolysis, the ______ phase of lactic acid fermentation, a molecule of glucose is oxidized to two molecules of ________. This oxidation generates the energy that is used to form two molecules of ______. In the next step, the two molecules of pyruvic acid are reduced by two molecules of _______to form two molecules of ________. Because lactic acid is the end-product of the reaction, it undergoes no further oxidation, and most of the energy produced by the reaction remains stored in the lactic acid
first, pyruvic acid, ATP, NADH, lactic acid
Two important genera of lactic acid bacteria are?
Streptococcus and Lactobacillus.
Microbes that only produce lactic acid are referred to as what
homolactic or homofermentative
Two examples of homolactic bacteria?
Streptococcus and Lactobacillus.
Lactic acid fermentation can spoil food however it can be used to produce what?
yogurt from milk, sauerkraut from fresh cabbage and pickles from cucumbers
Alcohol fermentation also begins with the glycolysis of a molecule of glucose to yield two molecules of pyruvic acid and two molecules of ATP. In the next reaction, the two molecules of pyruvic acid are converted to two molecules of ____________. Then the two molecules of __________ are reduced by two molecules of _______ to form two molecules of ___________
acetaldehyde. acetaldehyde, NADH, ethanol.
Alcohol fermentation is also ________ process because most energy contained in the initial glucose molecule remains in the ethanol, the end-product.
low-energy-yield
The ethanol and carbon dioxide produced by the yeast ___________ are waste products for yeast cells but can be used in industry. Ethanol made by yeasts is the alcohol in alcoholic beverages, and carbon dioxide made by yeasts causes bread dough to rise
Saccharomyces
Organisms that produce lactic acid as well as other acids or alcohols are known as
heterolactic or heterofermentative.
Fermentation products of infectious microrganisms can be used in _________
diagnosis.
An intermediate in butanediol fermentation, helps to detect the bacterium Klebsiella pneumoniae (test)
Voges-Proskauer test for acetoin
The production of butyric acid by Clostridium perfringens is an important cause of the severe tissue damage of _________.
gangrene