Chapter 12: energy and respiration Flashcards
what are anabolic reactions?
reactions that build large molecules
give 5 examples of uses of energy
- ) DNA replication
- ) protein synthesis
- ) active transport
- ) movement
- ) maintenance of body temp
why is ATP the universal energy currency?
- releases energy in small, manageable amounts
- reversible reaction
- small so can easily enter cell
- water soluble so can be compartmentalised
- easily hydrolysed because phosphate molecules repel
give the two ways in which ATP is made
- using energy released during glycolysis/ the kerbs cycle
- using electrical potential energy from the transfer of electrons in the mitochondria
give the role of NAD
carry H atoms, which can later be split into H+ and e-
give the role of CoA
carries acetate groups made from pyruvate from the link reaction to the Krebs cycle
why do lipids have a greater energy density than carbohydrates/ proteins?
- most energy comes from H +2[O] –> H2O
- the greater the number of H in the structure, the greater the energy value
give the formula for the respiratory quotient
(Vol of CO2 released) / (Vol O2 taken in)
where does glycolysis take place?
cytoplasm
where does the link reaction/ Krebs/ oxidative phosphorylation take place?
the matrix of the mitochondria
summarise glycolysis
glucose –> 2x pyruvate
summarise the link reaction
- pyruvate is dehydrogenated and decarboxylated
- pyruvate –> acetate
summarise the Krebs cycle
- acetate is decarboxylated and dehydrogenated
summarise oxidative phosphorylation
ADP is phosphorylated to ATP
give the intermediates from glucose - pyruvate
glucose fructose phosphate fructose biphosphate 2x triose phosphate 2x pyruvate
give the net gain of glycolysis
2 ATP
2 NADH
give the two enzymes involved in the link reaction
- pyruvate dehydrogenase
- pyruvate decarboxylase
give the intermediates involved with the link reaction
pyruvate - acetyl CoA (2C) - acetate (2C)
give the overall reaction for the link reaction
pyruvate + NAD+ + CoA –> CO2 + acetyl CoA + NADH
give the intermediates involved with the Krebs cycle
acetate citrate (6C) 5C compound 4C compound 4C compound 4C compound oxaloacetate
give the three main processes involved in some steps of the Krebs cycle
- decarboxylation
- dehydrogenation
- reduction of NAD and FAD
where does oxidative phosphorylation take place?
the inner mitochondrial membranes
during anaerobic respiration of yeast, what is pyruvate converted to?
ethanol
during anaerobic respiration of mammals, what is pyruvate converted to?
lactate
how are rice plants adapted to grow submerged in water?
- stems contain loosely-packed cells (aerenchyma) which allows the diffusion of gases
- leaves have ridges to trap air/ are corrugated and hydrophobic
- can tolerate more ethanol
- contain more alcohol dehydrogenase to break down the ethanol
how is the matrix adapted?
- contains enzymes, NAD, oxaloacetate, mitochondrial DNA and ribosomes
how is the outer membrane adapted?
- contains carrier/ channel proteins to allow the passage of pyruvate
how is the inner membrane adapted?
- impermeable to small ions (H+)
- folded into cristae to give a large SA
- many electron carriers and ATP synthase
