Metabolism Flashcards
Redox Reactions
Electrons are transferred from one reaction to another
1: oxidation: loss of electrons
2: reductions: gain of an electron
Electron carriers
- NADH and FADH2
- accept electrons during chemical reactions
- drop them off at the electron transport chain
Adenosine Triphosphate (ATP)
- energy currency
- stores energy in two high energy bonds
- when bonds are broken down energy is released
Carbohydrate Catabolism
- oxidizing carbohydrate (glucose)
- energy can be obtained by either respiration or fermentation
Respiration (which types)
- aerobic 2. anaerobic
Aerobic Respiration
electrons released by oxidation are passed down electron transport system to an oxygen electron receptor
General equation for aerobic respiration
glucose+ oxygen –> carbon dioxide+ H2O+ ATP
Chemical Equation for aerobic respiration
C6H12O6 + 6O2 –> 6CO2 + 6H2O
38 ADP + 38 P 38 ATP
Steps of Aerobic Respiration
- Glycolysis
- Transition Reaction
- Krebs Cycle
- Electron Transport Chain
Glycolysis (what it is, location, cost, end products)
- splitting of glucose
- oxidation of glucose –> 2 molecules of pyruvic acid
- Location: cytoplasm
- Cost: 2 ATP
- End products
- 2 pyruvic acid
- 2 ATP (net gain0
- 2 NADH
Transition Reaction ( what it is, location, end products)
- connects glycolysis to the Krebs cycle
- decarboxylation (removal of carbon) of pyruvic acid into acetyl coenzyme A
- Location: mitochondrial matrix
- End Products:
- 2 Acetyl Coenzyme A
- 2 CO2
- 2 NADH
Krebs Cycle (what it is, location, end products)
- a series of chemical reactions that begin with oxaloacetic acid (4C) and acetyl coA (2C) –> citrate (6C)
- Decarboxylation of acetyl group in a cycle –> regernate oxaloacetic acid
- Location: mitochondrial matrix
- End Products:
- 2 ATP
- 2 FADH2
- 4 CO2
- 6 NADH
Electron Transport Chain (What it is, location, ATP produced)
- a chain of coenzymes
- receives H+ from NADH and FADH2
- transports electrons to terminal acceptor O2 –> H2O
- Location: inner mitochondrial membrane
- ATP produced:
- NADH –> 3 ATP
- FADH2 –> 2 ATP
Chemiosmotic Mechanism of ATP Generation
-ATP is produced during electron transport
- protons actively transported into intermembrane space
- protons diffuse back through membrane channels with ATP synthase to produce ATP
Energy math
Glycolysis -2 NADH --> 6 ATP -2 ATP --> 2 ATP Transition Reaction -2 NADH --> 6 ATP Krebs Cycle -2 ATP --> 2 ATP -6 NADH --> 18 ATP -2 FADH2 --> 4 ATP
Total= 38 ATP
BUT it costs 2 ATP to bring NADH from glycolysis into mitochondria making it a TOTAL OF 36 ATP
Glucose Catabolism in the Absence of O2
- ETC backed up
- Krebs cycle backed up
- Glycolysis can continue if NAD+ if regernated from NADH
Lactic acid fermentation
- pyruvic acid + NADH –> lactic acid dehydrogenase –> lactic acid + NAD+
- allows glycolysis to continue –> 2 ATP
Lactic acid
- increased amounts –> acidification of ICF and ECF
- If O2 is available, reverse reaction will change lactic acid into pyruvic acid
- excess lactic acid can leave the cell to the liver and be converted back into glucose (gluconeogenesis)
Lipid Catabolism (what it is and where the parts enter?
-triglycerides –> glycerol and 3 fatty acids
- glycerol enters glycolysis
- fatty acids –>beta oxidation –> acetyl coA –> krebs cycle
Beta- Oxidation
- fatty acid chains broken down into (2c) acetyl coA
- each enters krebs cycle (worth 12 ATP)
- breakdown also produces 1 NADH and 1 FADH2
Protein catabolism
Proteolysis: Proteins –> amino acids
Deamination
- removal of amino group from amino acid
- produces NH3 –> ammonia
- can enter various stages
