Question

Q1.1 - What is the difference between actual change in free energy (delta G) and standard change in free energy (delta Gº') with regard to the spontaneity of a given reaction in a living cell?

Review of Enzyme Function and Regulation

Q1.2 - Name three processes affecting enzyme bioavailability and three mechanisms controlling catalytic efficiency.

Plants Harvest Energy from the Sun

Q1.3 - How do eukaryotic plants obtain energy at night to maintain sufficiently high levels of ATP?

Answer 1

1.1. The standard free energy can predict the spontaneity of any reaction in the standard conditions. If the standard free energy is less than zero than the reaction is spontaneous under standard conditions.

The sum of the standard free energy and the mass-action ratio function is known as the actual change in the free energy. It includes the reactants' and products' concentrations under steady conditions.

1.2. The three process that affect the enzyme bioavailibility are: Gene transcription (RNA synthesis), protein synthesis (translation), and protein degradation.

The three mechanisms that control the catalytic efficiency are: covalent modification, binding of regulatory molecules, and proteolytic processing.

1.3. The plants maintain sufficiently high levels of ATP at night with the help of mitochondrial respiration and glycolysis.