Pick out the incorrect statements (s) from the following
(1) Glucose exists in two different crystalline forms, `alpha`-D-glucose and `beta`-D-glucose
(2) `alpha`-D-glucose and `beta`-D-glucose are anomers
(3) `alpha`-D-glucose and `beta`-D-glucose are enantiomers
(4) Cellulose is a straight chain polysaccharide made of only `beta`-D-glucose units
(5) Starch is a mixture of amylose and amylopecting, both contain unbranched chain `alpha`-D-glucose unit

Options

A. 1 and 2 only
B. 2 and 3 only
C. 3 and 4 only
D. 3 and 5 only

Answer

To solve the question of identifying the incorrect statements, we will analyze each statement one by one.

### Step-by-Step Solution:

1. **Statement 1: Glucose exists in two different crystalline forms, `alpha`-D-glucose and `beta`-D-glucose.**
- **Analysis**: This statement is correct. Glucose does exist in two anomeric forms: `alpha`-D-glucose and `beta`-D-glucose, which differ in the orientation of the hydroxyl group on the first carbon atom.
- **Conclusion**: Correct statement.

2. **Statement 2: `alpha`-D-glucose and `beta`-D-glucose are anomers.**
- **Analysis**: This statement is also correct. Anomers are a type of stereoisomer that differ in configuration at the anomeric carbon (the carbon that was the carbonyl carbon in the open-chain form). In `alpha`-D-glucose, the hydroxyl group on the first carbon is down, while in `beta`-D-glucose, it is up.
- **Conclusion**: Correct statement.

3. **Statement 3: `alpha`-D-glucose and `beta`-D-glucose are enantiomers.**
- **Analysis**: This statement is incorrect. Enantiomers are stereoisomers that are non-superimposable mirror images of each other. `alpha`-D-glucose and `beta`-D-glucose are not mirror images; they differ only at one specific carbon (the anomeric carbon), making them anomers, not enantiomers.
- **Conclusion**: Incorrect statement.

4. **Statement 4: Cellulose is a straight chain polysaccharide made of only `beta`-D-glucose units.**
- **Analysis**: This statement is correct. Cellulose is indeed a linear polysaccharide composed exclusively of `beta`-D-glucose units linked by β(1→4) glycosidic bonds.
- **Conclusion**: Correct statement.

5. **Statement 5: Starch is a mixture of amylose and amylopectin, both contain unbranched chain `alpha`-D-glucose units.**
- **Analysis**: This statement is incorrect. While amylose is an unbranched polymer of `alpha`-D-glucose, amylopectin is a branched polymer. Therefore, saying both are unbranched is incorrect.
- **Conclusion**: Incorrect statement.

### Final Conclusion:
The incorrect statements are:
- Statement 3: `alpha`-D-glucose and `beta`-D-glucose are enantiomers.
- Statement 5: Starch is a mixture of amylose and amylopectin, both contain unbranched chain `alpha`-D-glucose units.