Ch 5 Metabolism Part 2 Flashcards
most of the energy released during what is trapped within the cell by the formation of ATP
redox reaction
this is the addition of a phosphate group to a chemical compound
there are three mechanisms of this to generate ATP from ADP
phosphorylation
ATP is generated when a high energy phosphate group is directly transferred from a phosphorylated compound to ADP (glycolysis)
substrate level phosphorylation
electrons are transferred from organic compounds to one group of electron carriers (typically NAD+ and FAD)
oxidative phosphorylation
sequence of electron carriers used in oxidative phosphorylation
electron transport chain
transfer of electrons from one electron carrier to the next releases energy
chemiosmosis
occurs only in photosynthetic cells
converts light energy to chemical energy of ATP and NADPH(used to synthesize organic molecules)
photophosphorylation
this is the breakdown of carbohydrate molecules to produce energy (important in metabolism)
carbohydrate catabolism
what is the most common carbohydrate energy source
glucose
to produce energy from glucose microbes use what
cellular respiration and fermentation
this is oxidation of glucose to pyruvic acid (splitting of sugar)
first stage in carbohydrate catabolism
glycolysis
does glycolysis require oxygen
no
how much ATP starts glycolysis and how much is generated
starts with 2 ATP, ends with 4
what is the net gain of ATP for each molecule of glucose that is oxidized
2 molecules of ATP
this operates simultaneously with glycolysis and provides a means for the breakdown of 5 carbon sugars as well as glucose
pentose phosphate pathway
what does pentose phosphate pathway produce
important intermediate pentoses used in the synthesis of nucleic acids, glucose from CO2 in photosynthesis, and certain amino acids
what is pentose phosphate pathway an important producer of
the reduced coenzyme NADPH from NADP+
this produces two molecules of NADPH and one molecule of ATP for use in cellular biosynthetic reactions
no glycolysis, found in some gram neg
entner doudoroff pathway
what can entner doudoroff pathway metabolize without
glycolysis or pentose phosphate pathway
this is an ATP generating process in which molecules are oxidized and the final electron acceptor is an inorganic molecule
cellular respiration
what are the two types of cellular respiration
aerobic and anaerobic
what do the types of cellular respiration depend on
whether an organism is an aerobe (O2) or an anaerobe (no O2)
in this respiration the final electron acceptor is O2
aerobic respiration
in this respiration the final electron acceptor is an inorganic molecule
anaerobic respiration
this is a series of biochemical reactions in which the large amount of potential chemical energy stored in acetyl CoA is released step by step
Krebs cycle (TCA)
in the Krebs cycle what is oxidized and what is reduced
pyruvic acid derivatives are oxidized and coenzymes are reduced
can pyruvic acid enter the krebs cycle directly
no, must lose one molecule of CO2 (decarboxylation)
what is NAD+ reduced to in the krebs cycle
NADH
what does the krebs cycle produce
2 NADH2, 6 NADH, ATP and CO2
this consists of a sequence of carrier molecules that are capable of oxidation and reduction
electron transport chain
what is the goal of the electron transport chain
to release energy as electrons are transferred from higher energy compounds to lower energy compounds
what are the three classes of carrier molecules
flavproteins, cytochromes, ubiquinones
these are capable of performing alternating oxidations and reductions
flavoproteins
small nonprotein carriers
ubiquinones (coenzyme Q)
the mechanism of ATP synthesis using the electron transport chain
energy released when a substance moves along a gradient is used to synthesize ATP
chemiosmosis
