Biology Answers

Explain the structural basis of the high group transfer potential of ATP.

In vitro, is it possible to get back the substrate given to an enzyme?

The ________ controls when the gene is transcribed by RNA polymerase. 

In class we are studying action potentials, repolarization, hyperpolarization, etc.

My teacher told us how once a certain membrane potential is reached and the action potential is fired, potassium channels open and potassium ions flood out of the axon, making it more negative and helping it reach resting potential again. My teacher said that the protein has to be "pumped" out using ATP because it is moving against the concentration gradient. However, looking online it seems like the potassium passes through voltage-gated potassium channels along/following the concentration gradient and therefore doesn't require energy. So does the potassium exiting the cell in repolarization require ATP or no? Does the potassium go through a "pump" or just voltage-gated ion channels?

.

Calculate the transpiration rate for the grape leaf above with a leaf surface area of 18 cm

2

.

Air

temperature was

21 degrees C, reference relative humidity was 35%, experimental relative humidity

was 43%

,

and barometric pressure was

759

mm Hg (1 mm Hg = 1.33322 mbar).

Flow rate was 125mL/

min