Chapter 4: Respiration Flashcards
phosphorylated intermediates
molecules that couple energy from ATP hydrolysis with an endergonic reaction, resulting in an exergonic reaction, thus making the reaction able to occur spontaneously
phosphorylation
the addition of a phosphate group to a molecule
respiration
the process in which ATP is generated and stored from the breakdown of organic molecules, namely glucose
glycolysis
the first step of respiration, in which enzymes break down glucose, and use the released energy to make ATP. This process takes place in the cytoplasm, and is anaerobic.
pyruvate
a three-carbon substance produced by glycolysis
oxidation
the loss of electrons, resulting in a positive charge on the ion
reduction
the gain of electrons, resulting in a negative charge on the ion
oxidizing agent
the ion that is reduced
reducing agent
the ion that is oxidized
NAD+
a cofactor/coenzyme that is a dinucleotide derived from niacin, a type of B vitamin. This molecule gains a hydrogen atom during an oxidation-reduction reaction, and thus helps transport electrons.
high-energy bond
a bond that, when broken, releases large amounts of energy
aerobic
requiring oxygen
anaerobic
not requiring oxygen
cofactor
a nonprotein molecule or ion that is required for an enzyme’s function
dehydrogenase
an enzyme that transfers hydrogen atoms from food to NAD+
hexokinase
the enzyme that is responsible for the first step of glycolysis, in which glucose is phosphorylated into a glucose-6-phosphate
phosphoglucoisomerase
an isomerase enzyme that is responsible for the second step of glycolysis, in which glucose-6-phosphate becomes fructose-6-phosphate
isomerase
a specific type of enzyme that converts a molecule into one of its isomers
phosphofructokinase
the enzyme that is responsible for the third step of glycolysis, in which fructose-6-phosphate is phosphorylated into fructose 1,6-biphosphate
substrate-level phosphorylation
the process by which ATP is produced by transferring a phosphate group from a substrate molecule to ADP
triose phosphate dehydrogenase
a three-carbon sugar phosphate enzyme that is responsible for the sixth step of glycolysis, in which G3P is oxidized and phosphorylated to produce 1,3-bisphosphoglycerate and 2 NADH + H+ molecules are produced
phosphoglycerokinase
the enzyme that is responsible for the seventh step of glycolysis, in which a phosphate group is removed from each 1,3-biphosphoglycerate, forming a 3-phosphoglycerate and 2 ATP
phosphoglyceromutase
the enzyme that is responsible for the eighth step of glycolysis, in which the remaining phosphate group of a 3-phosphoglycerate molecule is transferred to the middle carbon of a 2-phosphoglycerate molecule
enolase
the enzyme that is responsible for the ninth step of glycolysis, in which 2-phosphoglycerate becomes phosphoenolpyruvate (PEP) by the removal of a water molecule, and a double bond is formed on both 2-phosphoglycerate molecules
pyruvate kinase
the enzyme that is responsible for the tenth step of glycolysis, in which PEP molecules are dephosphorylated to produce 2 pyruvates and 2 ATP
facultative anaerobes
organisms that are able to undergo fermentation when deprived of oxygen (hint: yeast)
alcohol fermentation
the anaerobic process in which a pyruvate molecule is decarboxylated, hydrogen from NADH + H+ is used to convert acetaldehyde to ethanol, resulting in NAD+, CO2, and 2 ATP
lactic acid fermentation
the anaerobic process in which 2 pyruvates are converted to 2 lactic acid molecules, and then the lactic acid molecules are ionized to form lactate, and 2 NADH + H+ becomes 2 NAD+, and 2 ATP
isomerization
the process in which a molecule is converted into its isomer
G3P
glyceraldehyde-3-phosphate
PEP
phosphoenolpyruvate
decarboxylation
the removal of a carbon dioxide molecule
Electron transport chain
A sequence of electron carrier membrane proteins that move electrons through a series of redox reactions that release energy to make ATP
Phosphorylated intermediates
the energy from ATP is transferred to another molecule to feul a reaction
ATP synthase
a protein complex that is able to make ATP from the movement of H+ down a concentration gradient
Chemiosmosis
the movement of protons across the membrane and through ATP synthase which drives the production of ATP
Oxidative phosphorylation
the process of ATP production that is driven by oxidation (redox) reactions
