Overview
This lecture explains the key differences and similarities between eukaryotic and prokaryotic cells, focusing on their structures and genetic material.
Eukaryotic Cells
- Eukaryotic cells have their genetic material enclosed within a nucleus.
- Examples include animal and plant cells.
- All eukaryotic cells contain a nucleus, cytoplasm, and a cell membrane.
- The nucleus houses the DNA (genetic material).
- The cell membrane surrounds the cell but is distinct from a cell wall.
- Cytoplasm is present inside the cell, within the membrane.
Prokaryotic Cells
- Prokaryotic cells do not have their genetic material enclosed in a nucleus.
- Bacteria are examples of prokaryotic cells.
- The genetic material is usually a single loop of DNA, not in a nucleus.
- Prokaryotic cells may have additional small rings of DNA called plasmids.
- These cells are much smaller than eukaryotic cells.
- Prokaryotic cells have a cell membrane and a bacterial cell wall.
- Cytoplasm is also present inside prokaryotic cells.
Similarities Between Eukaryotic and Prokaryotic Cells
- Both have a cell membrane.
- Both contain cytoplasm.
- Both contain genetic material (DNA).
Differences Between Eukaryotic and Prokaryotic Cells
- Eukaryotic cells have a nucleus; prokaryotic cells do not.
- Eukaryotic cells are generally larger than prokaryotic cells.
- Prokaryotic cells may have plasmids (extra DNA loops); eukaryotic cells do not.
- Prokaryotic cells have a bacterial cell wall, which differs from the plant cell wall.
Key Terms & Definitions
- Eukaryotic cell — Cell with genetic material enclosed in a nucleus.
- Prokaryotic cell — Cell without a nucleus; genetic material is free in the cytoplasm.
- Nucleus — Organelle in eukaryotic cells that contains DNA.
- Plasmid — Small ring of DNA found in some prokaryotic cells.
- Cell membrane — Structure surrounding the cell, controlling what enters and leaves.
- Cytoplasm — Jelly-like substance inside the cell where most activities occur.
Action Items / Next Steps
- Learn and memorize the definitions of eukaryotic and prokaryotic cells.
- Review the structure of both cell types.
- Prepare for questions on similarities and differences between these cells.