The d (+)lactic acid is obtained from:

Options

A. fermentation of cane sugar
B. green vegetables
C. muscles
D. fermentation of milk sugar

Answer

To determine the source of d (+) lactic acid, we can follow these steps:

### Step 1: Understand the Structure of Lactic Acid
Lactic acid, also known as 2-hydroxypropanoic acid, has the molecular formula C3H6O3. It contains a hydroxyl group (-OH) and a carboxylic acid group (-COOH).

### Step 2: Identify the Isomer
Lactic acid has two enantiomers: L-lactic acid (levorotatory) and D-lactic acid (dextrorotatory). The D-lactic acid is the one that rotates plane-polarized light to the right.

### Step 3: Sources of Lactic Acid
Lactic acid can be produced through various biological processes, primarily fermentation. It is commonly produced by bacteria during the fermentation of carbohydrates.

### Step 4: Specific Source for d (+) Lactic Acid
D (+) lactic acid is specifically obtained from the fermentation of sugars by certain bacteria. One of the most notable sources is the fermentation of glucose by Lactobacillus species, particularly Lactobacillus delbrueckii.

### Conclusion
Thus, the d (+) lactic acid is obtained from the fermentation of sugars, especially glucose, by lactic acid bacteria such as Lactobacillus delbrueckii.

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