Cell Respiration Flashcards
Stages of Cellular Respiration
- Glycolysis
- Pyruvate Oxidation
- Krebs Cycle/Citric Acid Cycle
- Electron Transport Chain
What is the chemical formula of Cell Respiration?
C6H12O6 + 6O2 = ATP + 6H2O + 6 CO2 + heat
Step-by-step breakdown of high energy glucose molecule to release energy
Cellular Respiration
The energy currency of the cell
ATP (adenosine triphosphate)
This cycle is fundamental mode of energy exchange in biological systems
ATP-ADP cycle
How many kilocalories of energy is released when ATP breaks down into ADP + P
7 kilocalories
Anaerobic process of cellular respiration that occurs in the cytosol. Breakdown of glucose into 3 carbon pyruvate.
Glycolysis
The ancient pathway that harvests energy and is the starting point for all cellular respiration.
Glycolysis
Glycolysis are composed of how many reactions?
10 reactions
Total product gain of glycolysis
4 ATP, 2 NADH
Total net gain of glycolysis
2 ATP, 2 NADH
1st half of glycolysis that prepares the glucose for splitting by phosphorylation
Glucose Priming
Enzyme that phosphorylates glucose
Hexokinase
The 2nd half of glycolysis where production of NADH and ATP occurs as G3P is converted in to pyruvate
Energy Harvest stage
What is G3P?
glyceraldehyde 3 - phosphate
PEP or phosphoenolpyruvate is converted to pyruvate by pyruvate kinase through:
Substrate-level phosphorylation
_____ is formed when an enzyme transfers a phosphate group from a substrate to ADP
ATP
Energy accounting for glycolysis
1 glucose molecule = (2) 3 carbon pyruvate
Organisms survived using glycolysis for __________ years
1 billion
Glycolysis on harvests ____% of the total energy stored in glucose
3.5%
more ______ to strip = more _______ to harvest
carbon, energy
NADH is recycle to NAD+ by two ways:
Krebs cycle(aerobic) and fermentation(anaerobic)
Fermentation of pyruvate into ethanol + CO2
Alcohol Fermentation
Yeast dies at ____% of alcohol concentration
12%
Alcohol fermentation is: reversible or irreversible
Irreversible
Conversion of pyruvate in to lactic acid.
Lactic Acid Fermentation
Lactic Acid can be converted back to pyruvate when _______ is present
O2(oxygen gas)
Alcohol and Lactic Acid Fermentation occurs due to the absence of _______
Oxygen(O2)
Enzyme that powers the bonding of phosphate group to ADP using the H+ gradient. (ATP synthesis)
ATP Synthase
When oxygenated, pyruvate is converted into:
acetyl CoA (acetyl coenzyme A)
A 3 step oxidation process that releases 1 molecule of CO2 and reduces 2 NAD+ into 2 NADH
Oxidation of pyruvate
complete formula of oxidation of pyruvate
2x [pyruvate = two carbon acetyl CoA + NADH + CO2]
Process that occurs in the mitochondrial matrix with an 8-step pathway that is catalyzed by specific enzymes.
Krebs Cycle aka Citric acid cycle
He discovered the Krebs Cycle
Hans Krebs
Eukaryotes evolved _____________ years ago to perform aerobic respiration.
1.5 billion years ago
Why does Krebs Cycle occur twice?
2 acetyl CoA are used for the reaction
What are the electron carriers produced in Krebs Cycle?
NADH and FADH2
Chemical compounds involved in the Krebs Cycle
acetyl CoA, Citrate, Isocitrate, α-Ketoglutarate, Succinyl CoA, Succinate, Fumarate, Malate, and Oxaloacetate
Chemical Formula of Krebs Cycle
2x [acetyl CoA = 1 ATP + 4 NADH + 1 FADH2]
Energy account of Krebs Cycle
2 ATP, 8 NADH, 2 FADH2
If Krebs only produces 2 ATP, why is it then an important part of Cellular Respiration?
production of valuable electron carriers to be used in the Electron Transport Chain
A working muscle recycles over ____________ ATP’s per second
10 million
Transport of electrons that powers the pumping of H+ to create an H+ gradient by the series of molecules imbedded in the mitochondrial membrane.
Electron Transport Chain
The fold in the inner membrane of mitochondria where the molecules for ETC is built into
Cristae
3 proteins involved in ETC
- NADH Dehydrogenase
- Cytochrome bc complex
- Cytochrome c oxidase complex
Mobile Carriers in ETC
- coenzyme q/ubiquinone q
- cytochrome c
Electrons are stripped from ____ atoms, converting it to ____+ (a proton)
H atoms, H+
Transport proteins in the membrane pumps H+ across the inner membrane to the _________________
intermembrane space
What pulls down the electrons from the transport membrane proteins in the ETC?
Presence of Oxygen molecule
Serves as the final electron receptor in the ETC?
Oxygen(O2)
What is the byproduct of ETC?
Water molecule(H2O)
Force that allows the protons(H+) to flow through the ATP synthase to synthesize ATP
Proton-motive force
The diffusion of ions across a membrane (e.g. movement of proton gradient through ATP synthase, forming ATP)
Chemiosmosis
Links the Electron Transport Chain to ATP Synthesis
Chemiosmosis
Proposed the idea pf Chemiosmosis hypothesis
Peter Mitchell
Reaction that synthesizes the bond between phosphate group and ADP, creating ATP
Oxidative Phosphorylation
Total net gain of ETC
32 ATP per glucose molecule
Total net gain of Cellular Respiration
2 ATP + 2 ATP + 32 ATP = 36 ATP per 1 glucose molecule
What happens when O2 is absent during ETC?
Electron can’t be pulled, NADH and FADH2 can’t unload H = no ATP produced = Cell death = organism death
Use of excess intermediates that can be used to build necessary molecules.
Biosynthesis
________ can be produced from acetyl CoA
Lipids
Excess pyruvate can be synthesized into ____________
Glycogen
__________ are generated from different Krebs Cycle stages.
Amino Acids
