# DBT JRF 2022 — Question 9

Exam: DBT JRF 2022 · Section: B · Topic: Biochemistry › Stereochemistry & Chiral Centers · Difficulty: Medium

## Question

How many chiral centers are there in each of these two molecules? ![figure](https://res.cloudinary.com/dxil5euku/image/upload/v1779453127/pyq/6a104cb5920734408bc0c6d8/DBTJRF22-IMGB9.png)

## Options

- **A.** 1 and 1
- **B.** 1 and 2
- **C.** 2 and 2
- **D.** 4 and 3

## Answer

Option B

## Explanation

Chiral centers in two molecules ![figure](https://res.cloudinary.com/dxil5euku/image/upload/v1779453127/pyq/6a104cb5920734408bc0c6d8/DBTJRF22-IMGB9.png) : A chiral center (stereocenter) is a carbon atom bonded to four DIFFERENT substituents. From the structures shown: • Molecule 1: 1 chiral center • Molecule 2: 2 chiral centers Method: For each carbon in the structure, check if all 4 substituents are different (considering the entire chain attached, not just immediate neighbours). Answer: 1 and 2 (Option 2).

Source: https://mypyqbuddy.com/questions/how-many-chiral-centers-are-there-in-each-6a104cd5920734408bc0c718