Glycolysis Flashcards
What is the first step of cellular respiration?
Glycolysis
How is breathing related to cellular respiration?
- In breathing, the lungs exchange CO2 and O2 between the body and the atmosphere
- In cellular respiration, the cells consume the O2 in extracting the energy from food and release CO2 as a waste product
Cellular respiration is a term that refers to?
The biochemical pathway by which cells release energy from the chemical bond of the food molecules and provide that energy for the essential processes of life
Prokaryotic cells carry out cellular respiration __________. Meanwhile, eukaryotic cells carry out cellular respiration in the ______________.
Cytoplasm; Mitochondrion
Similarities of Aerobic and Anaerobic Respiration
- Both undergo glycolysis in the cytoplasm of the cell.
- Both undergo substrate-level phosphorylation and oxidative phosphorylation and chemiosmosis in producing ATP molecules.
- Both split the 6- carbon glucose into two molecule of pyruvate, the three carbon molecule.
- Both involved a series of enzyme-controlled reactions that takes place in the cytoplasm.
- Both use NAD+ (nicotinamide adenine dinucleotide), a redox coenzyme that accepts two electrons plus a (H+) that becomes NADH
- Both performed by eukaryotic and prokaryotic cells
Main Functions of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Production of ATP from food such as carbohydrate, lipid and protein
Anaerobic Respiration: Production of ATP without the use of oxygen
Site of reaction of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Cytoplasm and Mitochondrion
Anaerobic Respiration: Cytoplasm
Production of ATP of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: 36 to 38 ATP per glucose molecule
Anaerobic Respiration: 2 ATP per glucose molecule
Sustainability of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Long Term
Anaerobic Respiration: Short Term
Production of Lactic Acid of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Does not produce
Anaerobic Respiration: Produces
Oxygen Requirement of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Needs O2
Anaerobic Respiration: Does not need O2
Recycling of NADH of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Through the electron transport system
Anaerobic Respiration: In lactic acid fermentation, (i.e, muscle cells; in alcohol fermentation (pyruvate is converted to carbon dioxide and ethanol)
Participating Cells of Aerobic Respiration and Anaerobic Respiration
Aerobic Respiration: Most cells
Anaerobic Respiration: Yeast, other fungi, prokaryotes, and muscle cells
Glycolysis occurs where?
It occurs in the cytoplasmic fluid of the cell, that is, outside the organelles
Where does Krebs Cycle occur?
Within the mitochondria
What does the Krebs Cycle do?
It completes the breakdown of glucose by decomposing a derivative of pyruvic acid to carbon dioxide
Three main stages of Respiration
- Glycolysis
- Krebs Cycle
- Electron Transport Chain
What happens in the Electron Transport Chain?
It obtains electrons from the hydrogen carrier NADH, the reduced form of NAD+
FAD also shuttles some ________ from the Krebs cycle to the electron transport chain. The reduced form of FAD is FADH2
Electrons
Glycolysis and the Krebs cycle
are energy-releasing stages that?
Extract electrons from food molecules
while breaking these molecules down
to CO2
NAD+ and FAD temporarily capture the electrons and relay them to where?
The top of the Electron Transport Chain
What is the reduced form of FAD?
FADH2
The chain uses the _______________ of
electrons from NADH and FADH2 to O2
to pump H+ ions across a membrane.
Downhill Flow
Glycolysis means?
“Splitting of Sugar”
How does Glycolysis begin?
Glycolysis begins with a single molecule of glucose and concludes with two molecules of another organic compound, pyruvic acid
What is Glycolysis?
It is the metabolic process that serves as the foundation for both aerobic and anaerobic cellular respiration
What happens to glucose in Glycolysis?
It is converted into pyruvate
Glucose is a six-membered ring molecule that is found where?
In the blood
Additional Info: Glucose is usually a result of breakdown of carbohydrates into sugars
Overall Equation of Glycolysis
Glucose + 2 NAD+ 2 ADP + 2Pi
->
2 Pyruvate + 2 NADPH + 2 ATP + 2H+ + 2 H20
In Glycolysis, there is a net gain of _____ ATP and, ____ pyruvates are formed
two; two
The first step in glycolysis is the conversion of D-glucose into glucose-6-phosphate. This is catalyzed by what enzyme?
Hexokinase
When the glucose ring is phosphorylated, how many molecule/s of ATP is consumed?
1
The second reaction of glycolysis is the rearrangement of glucose-6-phosphate into fructose-6-phosphate by what enzyme?
Glucose phosphate isomerase
(Phosphoglucose isomerase)
What does G6P mean?
Glucose-6-phosphate
What does F6P mean?
Fructose-6-phosphate
What does FBP mean?
Fructose 1,6-bisphosphate
______________, with magnesium as a cofactor, changes fructose-6-phosphate into fructose 1,6-bisphosphate.
Phosphofructokinase
Fructose-6-phosphate is converted to?
Fructose 1,6-bisphosphate (FBP)
What is the enzyme that catalyzes the reaction between F6P and FBP?
Phosphofructokinase (PFK)
The enzyme ________ splits fructose 1, 6-bisphosphate into two sugars that are isomers of each other. These two sugars are dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3-
phosphate (GAP) or Phosphoglyceraldehyde (PGAL)
Aldolase
What does DHAP mean?
Dihydroxyacetone Phosphate
What does PGAL mean?
Phosphoglyceraldehyde
What does GAP stand for?
Glyceraldehyde-3-phosphate
The enzyme ______________________ rapidly inter-converts the molecule
dihydroxyacetone phosphate (DHAP) and glyceraldehyde-3phosphate or phosphoglyceraldehyde. Glyceraldehyde-3-phosphate or phosphoglyceradehyde is removed and used in next step of Glycolysis
Triosphosphate isomerase or Phosphotriose isomerase
_________________ dehydrogenates and adds an inorganic phosphate to glyceraldehyde 3-phosphate or phosphoglyceraldehyde producing 1, 3- bisphosphoglycerate
Glyceraldehyde-3-phosphate
dehydrogenase (GAPDH)
What does GAPDH mean?
Glyceraldehyde-3-phosphate
dehydrogenase
__________________ transfers a
phosphate group from 1,3-bisphosphoglycerate to ADP to form ATP and 3 phosphoglycerate
Phosphoglycerate kinase or Phosphoglyceric acid kinase
The enzyme ____________________
mutase relocates the P from the 3-
phosphoglycerate from the 3rd carbon to the 2nd carbon to form 2-
phosphoglycerate
Phosphoglycerate Mutase or Phosphoglycerate Acid Mutase
The enzyme _______ removes a molecule of water from 2 phosphoglycerate to phosphoenolpyruvate (PEP) or phosphoenol pyruvic acid
Enolase
What does PEP mean?
Phosphoenolpyruvate
How does Enolase work?
It works by removing a water group, or dehydrating the 2 phosphoglycerate
The enzyme _____________________________ transfers a P from phosphoenolpyruvate (PEP) or phosphoenolpyruvic acid to ADP to form pyruvic acid and ATP
Pyruvate Kinase or Pyruvic Acid Kinase
How many ATPs are produced in the steps of Glycolysis?
Step 1 and 3 = -2ATP
Step 7 and 10 = +4 ATP
Net “visible” ATP produced = 2 ATP
A single glucose molecule in glycolysis produces a total of ___ molecules of pyruvate, ___ molecules of ATP, ___ molecules of NADH and ___
molecules of water.
two; two; two; two
