Unit 5 - Respiration Flashcards
Respiration
Process by which energy stored in complex organic molecules is released and immediately transferred to ATP
Energy is released through hydrolysis (making new bonds)
Why do animals need energy
Active transport Endo/exocytosis Synthesis of protein DNA replication Cell division Movement Activation of a chemical (phosphorylation)
Catabolic
Releasing energy
Anabolic
Energy consuming
ATP
Intermediary between catabolic and anabolic reactions
Relatively stable, only broken down by hydrolysis by enzyme catalysis (energy released can be controlled)
Easily moved around a cell when in solution
Hydrolysis of ATP
Catalysed by ATPase
ATP is hydrolysed to produce ADP then again to produce AMP
ATP –> ADP (-30.5), ADP –> AMP (-30.5), AMP —> A (-13.8)
Structure of ATP
Ribose attached to adenine (phosphodiester bond)
3 inorganic phosphate groups
Phosphorylated nucleotide
Processes in aerobic respiration
Glycolysis
Link reaction
Krebs cycle
Oxidative phosphorylation
Glycolysis
Occurs in cytoplasm
Phosphorylation —> hexose biphosphate (2 phosphate groups from 2 ATP)
Hexose biphosphate splits into two
Oxidation (removal of H atoms) - accepted by NAD to make NADH
Breaks down glucose into pyruvate (3C), 2 NADH and 2 ATP
Where does glycolysis occurs
Cytoplasm
Why are ATP used in the first stage of glycolysis
Provide activation energy
Where does oxidative phosphorylation occur
Cristae
Role of ATP in the cell
Universal currency of energy
Phosphates can be removed by hydrolysis to release 30 kJ/mol energy
Energy used in metabolic reactions
Energy released in small quantities to prevent cell damage
Where does the Kreb’s cycle occur
Matrix of mitochondria
Coenzymes in leaf
- NAD and FAD can be reduced to NADH and FADH2 and act as hydrogen carriers
- NADPH reduces molecules by adding electrons
- ATP phosphorylates
- Coenzyme A carries acetate to Kreb’s cycle
Link reaction
Pyruvate is decarboxylated to acetate (+ CO2)
Combines w/ CoA to make acetyl coenzyme A
Happens twice for glycolysis
Produces 2 NADH
Kreb’s cycle
CoA is recycled back to link reaction
Acetate combines with oxaloacetate to make citrate
Decarboxylated 2x to give orig. 4C compound, oxaloacetate
Produces 6 NADH, 2 FADH2 , 2 ATP and 4 CO2 (substrate level phosphorylation)
Which cofactor is part of the ETC
Fe^2+
What’s found in the matrix
Enzymes NAD FAD Oxaloacetate Mitochondrial DNA Mitochondrial ribosomes