Question

Carbohydrates are stored in plants and animals in which of the following forms respectively?

• A. Glycogen, Starch
• B. Glycogen, Glycogen
• C. Starch, Starch
• D. Starch, Glycogen

Hint:

Plants store excess glucose as starch, whereas animals store it as glycogen in liver and muscle tissues.

Answer 1

The Correct Option is D

Step 1: Recall the forms of stored carbohydrates in living organisms.
Carbohydrates are the primary energy reserves in both plants and animals, but they are stored in different polysaccharide forms depending on the organism.
Step 2: Identify carbohydrate storage in plants.
In plants, excess glucose produced during photosynthesis is stored as STARCH. Starch consists of two components: amylose (unbranched, helical chains of $\alpha$-glucose) and amylopectin (branched chains). Starch is found in seeds, tubers, and other plant parts.
Step 3: Identify carbohydrate storage in animals.
In animals (including humans), glucose is stored as GLYCOGEN, sometimes called animal starch. Glycogen is highly branched and is stored mainly in the liver and muscles. It can be rapidly mobilised when the body needs quick energy.
Step 4: Compare the structures briefly.
Starch (amylopectin) is moderately branched with branch points every 24-30 glucose units. Glycogen is more highly branched (branch points every 8-12 glucose units), allowing faster glucose release in animals that need quick energy for movement.
Step 5: Evaluate the options.
Option 1: Glycogen/Starch (reversed, incorrect). Option 2: Glycogen/Glycogen (incorrect). Option 3: Starch/Starch (incorrect). Option 4: Starch (plants)/Glycogen (animals) - this is CORRECT.
Step 6: Confirm the answer.
Starch is stored in plants; glycogen is stored in animals. Option 4 is correct.
\[ \boxed{\text{Starch (plants) and Glycogen (animals)}} \]