Determine whether each phrase describes glucokinase, hexokinase isozymes I–III, or all hexokinase isozymes. Note: Assume that the kinetic behavior of hexokinase isozymes in vivo is similar to in vitro. Glucokinase (hexokinase IV) Hexokinase I, II, or III All hexokinase isozymes (I–IV)

- Subcellular localization is regulated by frutose 6-phosphate

- present in tissues that sense blood glucose levels

- not sensitive to inhibition by glucose 6-phosphate

- plays an important role in liver regulation of blood glucose level

- when blood glucose levels fall below normal range, maintains maximum velocity

- when blood glucose is low, will cause cells to trap glucose by phosphorytation

- wil be saturated by normal blood glucose concentrations

- will phosphorylate several hexoses including glucose

Glucokinase ( Hexokinase IV): Plays significant role, not sensisitve

Hexokinase I II or III : In tissues,

Explanation:

A) Plays a significant role in liver regulation of blood glucse levels. (It is present within liver).

B) It is not sensitive to inhibition by glucose-6-phoaphate(remians active even when glucose is abundant and is not effected by allosteric inhibition.)

C) Subcellular localisation is regulated by fructose-6-phosphate (when fructose -6-phosphate concentration is high causes localisation of hexokinase IV to nucleus as it is inhibited by high Fructose-6-phosphate concentration and releases into cytosol when glucose concntration is high)

2. Hexokinase I II or III :

A)Present in tissues that sense blood glucose levels.

B) When blood glucose levels fall below normal range maintains maximum velocity. ( since it has high affinity for glucose and low glucose concentration favors low Km for hexokinase I II III) .

what's the question ?

answer: the correct option is d. enzyme

lactase and carbonic anhydrase are the examples of enzymes.

lactase is an enzyme, which is present in the small intestine of mammals. it in the digestion of the disaccharide, lactose ( milk sugar) by converting it into two monosachharide, which are glucose and galactose.

carbonic anhydrase is present in the red blood cells. this enzyme plays significant role in the transport of co₂. it in the conversion of co₂ and h₂o into carbonic acid, which is then dissociated into bicarbonate ions and hydrogen ions.