Chapter 5 Flashcards
(27 cards)
Oxidation
The partial or full loss of electrons (e-)from a substance
Reduction
The partial or full gain of electrons to a substance(e-)
Electron Carrier NAD+
- NAD+ carries electrons. When it gains two electrons and a proton, it turns into NADH.
- Goes under reduction
Combustion and cellular respiration
- Cellular respiration is controlled combustion
- Both are exergonic
3 stages of cellular respiration
- Glycolysis (cytosol)
- Pyruvate oxidation and the
citric acid cycle (mitochondria) - Oxidative phosphorylation
(mitochondria)
Glycolysis
- Anerobic process
- OCCURS IN CYTOPLASM
- Key inputs (e.g. 1 glucose, 2 ATP, 2 NAD+, 2 H2O )
- Key outputs (2 pyruvate, 2 ATP, 2 NADH)
3 reactions of glycolysis
- First ATP consuming reaction
- Second ATP consuming reaction
- A 6 carbon sugar is split into two 3 carbon molecules.
Substrate level phosphorylation
- Enzyme catalyzed reaction
- ATP is made by transferring a phosphate from a high-energy molecule to ADP or GDP.
Pyruvate oxidation
-OCCURS IN MITOCHONDRIA
- pyruvate(3C) is oxidized to an acetyl group (2C) —->co2 is produced
- Produces: 1 CO2, 1 NADH, and 1 acetyl CoA.
- Delivered to citric acid cycle
- Pyruvate oxidation links glycolysis and the citric acid cycle
ATP
- Produced in glycolysis
- Result from substrate level phosphorylation
Citric acid cycle/ Krebs cycle
- acetyl CoA enters the cycle and gets oxidized produces; 3 NADH, 2 CO2, 1 ATP, 1 FADH2
- A cycle of reactions in the mitochondria breaks down glucose, fats, and proteins for energy.
3 stages of electron carriers
Stages 1+2: Glucose oxidation generates ATP and electron carriers.
Stage 3: Electron carriers help make ATP through the electron transport chain.
Electron Transfer System
- Electrons pass from NADH2 and
FADH2 to O2 - Electron Transport Chain includes
->4 protein complexes
-> 2 smaller shuttle carriers - Electrons move spontaneously along the electron transport chain
Respiratory Electron Transport Chain
- 3 major protein complexes (i,iii, iv)
- Pump H+ from matrix and IMS(intermembrane space)
- Contain’s prosthetic groups that switch between reduced and oxidized states
Electron Transport Chain (ETC)
- The electron transport chain consists of four complexes (I to IV) in the inner mitochondrial membrane.
- NADH and FADH2 donate electrons and are transported along the series of ETC complexes
Chemiosmosis
The movement of hydrogen ions across the membrane via ATP synthase
Oxidative Phosphorylation
A metabolic process that generates ATP
ATP synthase
An enzyme located in the mitochondria of animal cells, and it produces ATP
Major Pathways Oxidizing
Carbohydrates, Fats, and Proteins
Energy can also be extracted from fats, proteins, and carbohydrates at various points in the respiratory chain.
Respiratory intermediates
- Glycolysis and citric acid cycle intermediates are used to make amino acids, fats, and nucleic acid bases.
- Provide carbon building blocks for hormones, growth factors, and essential cell components.
Control of cellular respiration
Various molecules regulate the respiratory pathway, balancing supply and demand.
Fermentation
2 types of fermentation exists: lactate fermentation and alcoholic fermentation(both anaerobic)
- In eukaryotic cells, low oxygen levels result in fermentation
- Breaks down fuel without oxygen.
Lactate fermentation
- Lactic acid fermentation occurs in animals and bacteria (In muscle cells)
- NADH transfers electrons to pyruvate, forming lactic acid and regenerating NAD⁺.
- Makes ATP in the absence of oxygen by converting glucose to lactic acid
Alcoholic fermentation
- Ethanol fermentation occurs in plants and fungi
- NADH donates electrons to pyruvate, producing ethanol and NAD+.
