Prokaryotic vs. eukaryotic cells, plant cell structure

1. Introduction

1. A cell is the basic structural and functional unit of life.
2. The study of cells is known as Cell Biology.
3. Cells can be classified into Prokaryotic and Eukaryotic cells based on their structure.
4. Plant cells have unique structures such as a cell wall, chloroplasts, and a large central vacuole.

2. Prokaryotic vs. Eukaryotic Cells

2.1 Prokaryotic Cells

1. Prokaryotes are unicellular organisms lacking a membrane-bound nucleus.
2. They have a simple cell structure with no membrane-bound organelles.
3. Their genetic material is present in the form of a single, circular DNA in the nucleoid region.
4. Reproduce mainly by binary fission.
5. Examples: Bacteria and Cyanobacteria (Blue-green algae).

2.2 Eukaryotic Cells

1. Eukaryotic cells have a well-defined nucleus enclosed by a nuclear membrane.
2. They possess multiple membrane-bound organelles such as mitochondria, endoplasmic reticulum, Golgi apparatus, etc.
3. The genetic material is in the form of linear DNA associated with proteins inside the nucleus.
4. Reproduce by mitosis or meiosis.
5. Examples: Plant cells, animal cells, fungi, and protists.

3. Differences Between Prokaryotic and Eukaryotic Cells

4. Structure of a Plant Cell

1. Plant cells are eukaryotic cells with a rigid cell wall and specialized organelles.
2. They have a large central vacuole for storing nutrients and maintaining cell pressure.
3. Chloroplasts enable photosynthesis by converting sunlight into energy.
4. Cell division occurs through mitosis in somatic cells and meiosis in reproductive cells.

4.1 Major Components of a Plant Cell

1. Cell Wall

1. Made up of cellulose, providing structural support.
2. Absent in animal cells.

2. Plasma Membrane

1. A semi-permeable membrane controlling the movement of substances.
2. Composed of a phospholipid bilayer and proteins.

3. Nucleus

1. Contains DNA and regulates cell functions.
2. Surrounded by a nuclear membrane.

4. Cytoplasm

1. Jelly-like fluid where all organelles are suspended.

5. Chloroplasts

1. Contains chlorophyll and performs photosynthesis.
2. Absent in animal cells.

6. Mitochondria

1. Known as the powerhouse of the cell, generating ATP energy.

7. Endoplasmic Reticulum (ER)

1. Network of membranes involved in protein and lipid synthesis.
2. Two types: Rough ER (with ribosomes) and Smooth ER (without ribosomes).

8. Golgi Apparatus

1. Processes and packages proteins and lipids.

9. Vacuole

1. A large fluid-filled sac storing water, nutrients, and waste.

5. Conclusion

1. Prokaryotic cells are simple and lack a nucleus, while eukaryotic cells are complex with membrane-bound organelles.
2. Plant cells have distinct features such as a cell wall, chloroplasts, and a large vacuole.
3. Understanding cell structure helps in various fields like medicine, genetics, and biotechnology.