U2T1 - Keywords Flashcards
Respiration
Oxidation
Gain of oxygen, loss of electrons, loss of hydrogen.
Reduction
Loss of oxygen, gain of electrons, gain of hydrogen.
Redox Reaction
When reduction + oxidation occur in the same reaction.
Dehydrogenation
Removal of hydrogen.
Decarboxylation
Removal of carboxyl group. (CO2)
Phosphorylation
ATP synthesised from ADP + inorganic phosphate by condensation (removing 1 molecule water), making ATP energy rich. Addition of phosphate.
Aerobic Respiration
Respiration using oxygen, releasing lots of ATP from glucose. Long term.
Anaerobic Respiration
Respiration not using oxygen, releasing small amount of ATP from glucose + lactic acid/ethanol. Short term.
ATP
Nucleotide ‘adenosine triphosphate’. Contains 3 phosphate groups with nucleotide base (adenine) + pentose sugar (ribose). Immediate + short term energy store. Has high free energy of hydrolysis. Drives metabolism.
ADP
Adenosine Diphosphate.
High free energy of hydrolysis
When ATP hydrolysed, large amount of energy released. Catalysed by ATPase.
Substrate level phosphorylation
Direct transfer of phosphorylated substance to ADP. Occurs during krebs cycle + glycolysis. 1 molecule ATP produced from transfer of phosphate group from intermediate compound to ADP.
Oxidative phosphorylation
ATP produced from ADP + Pi as electrons transferred along carriers - the ETC. Formation of ATP by oxidation of H atoms (lose electrons). Free phosphate groups. Energy required derived from redox reactions in ETC.
Glycolysis
Splitting of hexose sugar (glucose) into 2 3-carbon pyruvate molecules. Occurs in aerobic + anaerobic resp as doesn’t require oxygen. Occurs in cytoplasm.
NAD
Nicotinamide adenine dinucleotide. Coenzyme. When reduced, forms reduced NAD (NADH) Needed for dehydrogenases to pass on hydrogen they remove.
Link Reaction
Before Kreb’s Cycle. Forms acetyl coenzyme A (acetyl CoA) from pyruvate to allow entry of 2 carbon molecule into mitochondrial matrix.
Krebs Cycle
Involves cyclical series of reactions. ADP converted to ATP. Most energy released here. Feeding of acetyl CoA into cycle of oxidation + reduction.
FAD
Flavin Adenine Dinucleotide. Hydrogen carrier.
ETC
Electron Transport Chain. In cristae. Accepts H2 produced from Krebs cycle, link reaction + glycolysis by dehydrogenation. System made up of cytochromes + coenzymes which can pass on electrons produced from H2 splitting into electrons + protons (arrive as NADH and H+ and FADH2) + energy in H2 + electrons converted to ATP.
Cytochrome oxidase
Enzyme responsible for passing H2 to O2, inhibited by cyanide.
Beta Oxidation
Involves 2 carbon fragments being broken off fatty acids + converted to acetyl CoA.
Acetyl CoA Stage
Point at which most respiratory substrates enter so considered hub of various respiratory pathways.
Oxygen Debt
Reason why you continue to breath heavily after ceasing strenuous exercise. Lactate builds up + needs O2 to metabolise/convert to glucose so repays debt.
Respiratory Quotient
RQ is ratio of volume of CO2 produced to volume of O2 used in respiration.
Respirometer
Piece of apparatus used to measure resp rate.
Energy
What is required to do work.
Mitochondrial Matrix
Gel like matrix in mitochondrion, more viscous than the cell’s cytoplasm as it contains less water.
Cytochromes
Compound consisting of haem bonded to protein. Function as electron transfer agents in metabolic pathways, especially respiration.
Coenzyme Q
Electron transfer agent in respiration.
Temperature Coefficient
Q10 = rate of reaction at (T + 10)°C/Rate of Reaction at T°C.
Generally for every 10°C rise, reaction rate doubles so usually 2.
