CELLULAR RESPIRATION Flashcards
____________ is a process that all living things use to convert glucose into energy.
Cellular respiration
three unique metabolic pathways of cellular respiration
glycolysis,
the citric acid cycle, and
the electron transport chain
Oxygen is present in __________
aerobic respiration
Oxygen is absent in __________
anaerobic respiration
______ is the first pathway in cellular respiration.
Glycolysis
where does glycolysis takes place
in the cytoplasm of the cell
glycolysis breaks down _____
1 glucose molecule
glycolysis produces ________
2 pyruvate molecules
first half of glycolysis
“energy requiring” steps
This half splits glucose, and uses up 2 ATP.
first half // energy requiring step
the second half of glycolysis can proceed if ________________________________________
the concentration of pyruvate kinase is high enough
Glycolysis has a net gain of __ ATP molecules and _ NADH.
2 ATP molecules and 2 NADH
______ takes place in the cytosol of the cell’s cytoplasm.
Glycolysis
The enzyme ____________ phosphorylates or ADDS A PHOSPHATE GROUP to glucose in a cell’s cytoplasm. In the process, a phosphate group from ATP is transferred to glucose producing glucose 6-phosphate or G6P. One molecule of ATP is consumed during this phase.
hexokinase
Enzyme ___________ ISOMERIZES G6P into its isomer fructose 6-phosphate or F6P. Isomers have the same molecular formula as each other but different atomic arrangements.
phosphoglucomutase
The kinase ________________ USES ANOTHER ATP MOLECULE to transfer a phosphate group to F6P in order to form fructose 1,6-bisphosphate or FBP. Two ATP molecules have been used so far.
phosphofructokinase
The enzyme __________ SPLITS FRUCTOSE 1,6-bisphosphate into a ketone and an aldehyde molecule. These sugars, dihydroxyacetone phosphate (DHAP) and glyceraldehyde 3-phosphate (GAP), are isomers of each other.
aldolase
The enzyme __________ isomerase RAPIDLY CONVERTS DHAP into GAP (these isomers can inter-convert). GAP is the substrate needed for the next step of glycolysis.
triose-phosphate
The enzyme ______________________________ serves TWO FUNCTIONS in this reaction. First, it dehydrogenates GAP by transferring one of its hydrogen (H⁺) molecules to the oxidizing agent nicotinamide adenine dinucleotide (NAD⁺) to form NADH + H⁺. Next, GAPDH adds a phosphate from the cytosol to the oxidized GAP to form 1,3-bisphosphoglycerate (BPG). Both molecules of GAP produced in the previous step undergo this process of dehydrogenation and phosphorylation.
glyceraldehyde 3-phosphate dehydrogenase (GAPDH)
The enzyme __________________ TRANSFERS A PHOSPHATE from BPG to a molecule of ADP to form ATP. This happens to each molecule of BPG. This reaction yields two 3-phosphoglycerate (3 PGA) molecules and two ATP molecules.
phosphoglycerokinase
The enzyme ____________ RELOCATES the P of the two 3 PGA molecules from the third to the second carbon to form two 2-phosphoglycerate (2 PGA) molecules.
phosphoglyceromutase
The enzyme __________ REMOVES A MOLECULE OF WATER from 2-phosphoglycerate to form phosphoenolpyruvate (PEP). This happens for each molecule of 2 PGA from Step 8.
enolase
The enzyme __________ transfers a P from PEP to ADP to form pyruvate and ATP. This happens for each molecule of PEP. This reaction yields two molecules of pyruvate and two ATP molecules.
pyruvate kinase
The citric acid cycle is also known as
KREBS CYCLE
