Which statement in the following is correct ?

Options

A. Cellulose are linear polymers of `beta` - glucose molecules with `beta-1,4`- linkages
B. Starches are polymers of `alpha` - glucose molecules with `beta - 1 , 4 ` - linkages and some `beta -1 , 6 ` - cross - linkages
C. Proteins are polyamides of `beta ` - amino acids
D. The structural information about carbohydrate biosynthesis is contained in a class of compounds called nucleic acids , e. g . RNA and DNA

Answer

To solve the question of which statement is correct, we will analyze each option provided in the question based on the information given in the video transcript.

### Step-by-Step Solution:

1. **Understanding Cellulose**:
- Cellulose is a polysaccharide made up of linear chains of beta-glucose molecules.
- These glucose units are linked by beta-1,4 glycosidic linkages.
- This means that cellulose is indeed a linear polymer of beta-glucose.

2. **Understanding Starch**:
- Starch is also a polysaccharide, but it is composed of alpha-glucose units.
- Starch consists of two components: amylose (a linear polymer of alpha-glucose linked by alpha-1,4 glycosidic linkages) and amylopectin (a branched polymer with both alpha-1,4 and alpha-1,6 glycosidic linkages).
- The statement claiming that starch is made of alpha-glucose with beta-1,4 linkages is incorrect.

3. **Understanding Proteins**:
- Proteins are polymers formed from amino acids.
- They are connected by peptide bonds, which are formed between the carboxyl group of one amino acid and the amino group of another.
- The amino acids that make up proteins are alpha-amino acids, not beta-amino acids.
- Thus, the statement that proteins are polyamides of beta amino acids is incorrect.

4. **Understanding Nucleic Acids**:
- Nucleic acids (DNA and RNA) contain genetic information, not structural information regarding carbohydrate biosynthesis.
- Therefore, the statement about nucleic acids containing structural information for carbohydrate biosynthesis is also incorrect.

5. **Conclusion**:
- The only correct statement among the options is that cellulose is a linear polymer of beta-glucose molecules linked by beta-1,4 glycosidic linkages.

### Final Answer:
The correct statement is: **Cellulose is a linear polymer of beta-glucose molecules which combine with beta-1,4 glycosidic linkage.**

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