3. Energy Reaction in Cells Flashcards
Define metabolism.
The set of processes which derive energy and raw materials from food stuffs and use them to support repair, growth and activity of the tissues of the body to sustain life.
Give three key points of catabolic pathways.
Break down large molecules into smaller ones, releases large amounts of free energy, and it is oxidative.
Give three points of anabolic pathways.
Synthesise larger cellular components from intermediary metabolites, uses energy to do this, and it is reductive.
What needs to be supplied by the metabolism of fuel molecules?
Building block materials, organic precursors, bio synthetic reducing power, energy for cell function.
What three types of work is energy needed for?
Biosynthesis work, transport work (maintenance of ion gradients and nutrient uptake) and specialised functions (mechanical, electrical or osmotic).
Name the six forms of energy.
Heat, light, mechanical, electrical, osmotic and chemical bond.
Which is the key form of energy that’s used directly?
Chemical bond energy.
Define isothermal.
Can’t use heat energy for work.
What is the difference between exergonic and endergonic chemical reactions?
Endergonic reactions (/\G bigger than 0) require energy. So exergonic reactions are spontaneous but endergonic reaction aren’t.
What is a redox reaction?
An oxidation reaction (removal of electrons) accompanied by a reduction reaction (gain of electrons).
What are the major carrier molecules of electrons and protons in their oxidised and reduced forms respectively?
NAD+, NADH + H+
NADP+, NADPH + H+
FAD, FADH2
What is the effect on anabolic or catabolic pathways in the following scenarios:
a. [ATP] is high?
b. [ATP] is low, but [ADP] and [AMP] are high?
c. [NADH] is high and [NAD+] is low?
d. [NADPH] and [FADH2] are low, but [NADP+] and [FAD] are high?
a. Anabolic pathways are activated.
b. Catabolic pathways are activated.
c. Anabolic pathways are activated.
d. Catabolic pathways are activated.
What does adenylate kinase catalyse?
Phosphorylation.
What is the reaction that occurs when ATP levels are too high including Creatine?
Creatine + ATP –> phosphocreatine + ADP (creatine kinase)
How is creatinine formed?
Breakdown of Creatine or phosphocreatine, which is a spontaneous reaction.
