In which epidermal layer do cells continue to divide and change shape, while enzymes create lipids and proteins?

The correct answer is grounded in the role and characteristics of the stratum spinosum, which is part of the epidermis. Within this layer, keratinocytes, the primary cell type, continue to divide and differentiate. As they move through this layer, they undergo a transformation in shape, becoming more polygonal.

At the same time, enzymes present in the stratum spinosum facilitate the production of essential lipids and proteins, contributing to the skin's barrier function and overall health. This process is vital for the formation of keratin, which provides strength and resilience to the skin, and lipids that aid in hydration and protection against environmental damage.

In contrast, the stratum lucidum, found only in thick skin areas like the palms and soles, is primarily composed of dead keratinocytes and does not actively participate in division or lipid/protein synthesis. The stratum corneum consists of layers of dead, flattened cells that are mostly keratin, serving a protective function rather than being involved in cell division. The stratum germinativum, also known as the basal layer, is where initial cell division occurs, but it does not encompass the broader activities of differentiation and lipid production seen in the stratum spinosum.