AP bio

What Is the role of oxygen in cellular respiration?

acts as the final electron acceptor in the ETC. It combines with hydrogen ions and electrons to make water.

what is oxidized in the cellular respiration reaction

C₆H₁₂O₆ (glucose) is oxidized into 6CO₂ (carbon dioxide)

what is reduced in the cellular respiration reaction

6O₂ (oxygen) is reduced to 6H₂O (water)

where does glycolysis take place

the cytosol

where does the Krebs cycle take place

the matrix of the mitochondria

where does ETC take place

the intermembrane surface of the mitochondria

how does ATP generation in glycolysis and the Krebs cycle different from ATP generation via the ETC

glycolysis and Krebs cycle are substrate level phosphorylation ATP while ETC is oxidative phosphorylation ATP

how many ATP molecules per molecule of glucose are generated during glycolysis

2

how many ATP molecules per molecule of glucose are generated during Krebs cycle

2

how many ATP molecules per molecule of glucose are generated during ETC

32-34

how many ATP molecules per molecule of glucose are generated during the entire cellular respiration

38

the difference between substrate level phosphorylation and oxidative phosphorylation

Substrate-level phosphorylation directly transfers a phosphate from a substrate to ADP via an enzyme, occurring in cytoplasm (glycolysis) or mitochondria (Krebs cycle) and needing no oxygen, while oxidative phosphorylation indirectly generates lots of ATP using the ETC in mitochondria, driven by NADH/FADH₂ and requiring oxygen as the final acceptor, producing a proton gradient for ATP synthase

Electron carriers NAD+ what is considered the oxidized form and reduced form and explain that

NAD+ is the oxidized form as its not storing electrons so it can accept them whereas NADH is the reduced form as its storing electrons that it gained through reduction

FAD is the oxidized form as its not storing electrons so it can accept them whereas FADH2 is the reduced form as its storing electrons that it gained through reduction

why is the krebs cycle important if your only making a small amount of ATP

it produces electron carriers for oxidative phosphorylation it produces 6 NADH and 2 FADH2 and they transport electrons to the ETC feeding them into the ETC allowing for much larger amounts of ATP to be produced it is also important to producing CO2 to be exhaled keeping a proper carbon balance

where you get the most energy in all the areas

oxidative phosphorylation, specifically via the process of chemiosmosis in the ETC. This occurs in the intermembrane surface of the mitochondria in eukaryotes

Why do you think the glycolysis to be thought the first metabolic pathway to be evolved

its anaerobic so it doesn't require oxygen which life on earth first evolved without free oxygen in the atmosphere

its found in nearly all organisms (bacteria, plants, animals)

Occurs in the cytoplasm, not requiring organelles which prokaryotes don't have

Produces ATP and NADH, essential for basic cellular functions

Prokaryotes that evolved glycolysis are ancestors of all modern life All cells still utilize glycolysis

Why do you feel muscle burn after sprinting

your muscles working so hard they use ATP faster than oxygen can be delivered to produce move so cells switch to performing anaerobic respiration to produce ATP this involves lactic acid fermentation in order to recycle NADH back to NAD⁺ through pyruvate accepting electrons from NADH allowing glycolysis to continue producing ATP this produces lactic acid and a build up of this in muscle cells is what produces muscle burn

describe how Catabolism of glucose in glycolysis and pyruvate oxidation contributes to ATP synthesis

breaks down glucose to generate ATP directly (small amount via substrate-level phosphorylation) and produce electron carriers (NADH, FADH₂) that power oxidative phosphorylation in ETC. Glycolysis produces 2 ATP and NADH, while pyruvate oxidation converts pyruvate to Acetyl-CoA, producing more NADH Acetyl-CoA is produced for entry into Kreb's cycle for further electron carrier production, ultimately leading to massive ATP generation.

describe how Oxidation of intermediates in the Krebs cycle contribute to ATP synthesis

releasing electrons that are transferred to the electron carriers NAD⁺ and FAD reducing to NADH and FADH₂ these reduced carriers shuttle the electrons to the ETC as the electrons move down the chain energy is released and used to pump protons across the intermembrane surface creating a proton gradient it also produces 2 ATP through substrate level phosphorylation of ADP

describe how formation of a proton gradient by the electron transport chain contributes to ATP synthesis

as electrons move through the ETC energy is released and used to pump H⁺ from the mitochondrial matrix into the intermembrane space forming a proton gradient across the inner mitochondrial membrane creating a electrochemical gradient storing potential energy which drives protons back into the matrix through ATP synthase energy released from this movement drives the oxidative phosphorylation of ADP to ATP

what are the exergonic reations

exergonic releases energy which is when glucose is oxidized to carbon dioxide during glycolysis, Krebs cycle, and the ETC releasing energy that is captured in ATP NADH and FADH₂ the movement of electrons down the ETC is exergonic

what are the endergonic reations

endergonic receives energy which is when in glycolysis ATP is used to phosphorylate glucose and the synthesis of ATP from ADP and p_i these reactions are driven by energy released from exergonic reactions demonstrating energy coupling