If the acid-secreting cells of the stomach wall are damaged, the digestion of proteins would be affected to a greater extent. The stomach secretes gastric acid, which plays a vital role in the digestion of proteins. The acidic environment created by the stomach acid helps in the denaturation of proteins and activates the enzyme pepsinogen to convert it into its active form, pepsin. Pepsin is responsible for breaking down proteins into smaller polypeptides and peptides.

Although the stomach also plays a role in the digestion of carbohydrates and lipids, the absence of stomach acid would have a lesser impact on their digestion. Carbohydrates are primarily broken down in the mouth and small intestine by enzymes such as amylase, while lipids are primarily digested in the small intestine by bile salts and enzymes like lipase. However, the stomach acid does contribute to the overall digestive process by ensuring optimal pH levels for the subsequent digestion of these biomolecules.

In summary, if the acid-secreting cells in the stomach are damaged, the digestion of proteins would be affected to a greater extent compared to carbohydrates and lipids.