Question

write the structure that illustrates glucose and fructose (open chain form)

Answer 1

Glucose and fructose, both monosaccharides, can be represented in their open-chain forms as follows:

### Glucose (D-Glucose)

The open-chain structure of D-glucose (an aldose) is:

```
CHO
|
HOCH2 - C - OH
|
HO - C - H
|
H - C - OH
|
HO - C - H
|
CH2OH
```

In this structure:
- The top carbon (C1) is part of the aldehyde group (CHO).
- There are four chiral centers at the second (C2), third (C3), fourth (C4), and fifth (C5) carbons.
- The bottom carbon (C6) is part of the -CH2OH group.

### Fructose (D-Fructose)

The open-chain structure of D-fructose (a ketose) is:

```
CH2OH
|
C=O
|
HO - C - H
|
H - C - OH
|
H - C - OH
|
CH2OH
```

In this structure:
- The second carbon (C2) is part of the ketone group (C=O).
- There are three chiral centers at the third (C3), fourth (C4), and fifth (C5) carbons.
- The top carbon (C1) is part of the -CH2OH group.

### Summary
- Glucose has an aldehyde functional group, while fructose has a ketone functional group, resulting in different structural characteristics despite both being simple sugars.