Eukaryote Cell Organization PDF

V- Organization of the eukaryotic cell  INTRODUCTION Eukaryotic cells are structurally and functionally more complex than prokaryotic cells. They are characterized by several membrane-bound organelles that perform specialized functions Eukaryotic cells, whether found in animals or plants, share m...

V- Organization of the eukaryotic cell  INTRODUCTION Eukaryotic cells are structurally and functionally more complex than prokaryotic cells. They are characterized by several membrane-bound organelles that perform specialized functions Eukaryotic cells, whether found in animals or plants, share many common features due to their shared eukaryotic ancestry. However, there are also several key differences between animal and plant cells.  Similarities between Animal and Plant Cells: 1. Cell Membrane 2. Nucleus 3. Cytoplasm 4. Endoplasmic Reticulum (ER) 5. Golgi Apparatus 6. Mitochondria 7. Lysosomes (in animal cells) present in animal cells but are less common in plant cells. 8. Ribosomes  Differences between Animal and Plant Cells: 1. Cell Wall: Plant cells have a rigid cell wall made of cellulose, providing structural support and protection. Animal cells lack a cell wall. 2. Chloroplasts: Plant cells contain chloroplasts, which are the sites of photosynthesis. Chloroplasts contain chlorophyll and convert light energy into chemical energy. Animal cells lack chloroplasts. 3. Vacuole: Plant cells have a central vacuole that stores water, ions, nutrients, and waste products. Animal cells may have smaller, sometimes multiple vacuoles, but they are not as prominent as the central vacuole in plant cells. 4. Centrioles: Animal cells typically have centrioles, which are involved in cell division. Plant cells do not have centrioles. 5. Peroxisomes: Both animal and plant cells have peroxisomes, but their functions and numbers can vary between the two cell types (in animal cells primarily participate in fatty acid metabolism, detoxification, and bile acid synthesis. In plant cells, their key roles include photorespiration, purine metabolism, and fatty acid metabolism).  (B) (A) Fig.1. Eukaryotic cell (A)- plant cell (B)- animal cell Tab.2. comparison table between animal and plant cells: Tab.1. comparison table between prokaryotic and eukaryotic cells:  Organisation of virus Viruses have a simple and organized structure, but it differs from that of living cells. Their basic components include: Genetic Material: Viruses contain either DNA or RNA as their genetic material. This genetic material carries the instructions for the virus to replicate and produce new virus particles. The genetic material can be single-stranded or double-stranded and may be linear or circular, depending on the type of virus. Capsid: The protein coat that surrounds the genetic material is called a capsid. The capsid is composed of protein subunits called capsomers. It serves to protect the genetic material and helps the virus attach to and enter host cells. The capsid provides the virus with its characteristic shape and structure. Envelope (in some viruses): Some viruses have an outer lipid envelope derived from the host cell's membrane. This envelope is studded with viral proteins and helps the virus infect host cells. Not all viruses have an envelope; those without one are called non-enveloped or "naked" viruses. Viral Proteins: Viruses typically have specific proteins on their surfaces that are essential for host cell recognition, attachment, and entry. These proteins often play a crucial role in the infection process and are specific to the host cell type the virus can infect.  The organization of a virus is relatively simple compared to a living cell, which has a much more complex and organized structure with organelles and cellular machinery. Viruses lack the machinery necessary for metabolism, energy production, and independent replication. Instead, they rely on host cells to replicate and produce new virus particles. The specific structure and organization of a virus can vary greatly between different types of viruses, reflecting their diversity. Understanding the organization of a virus is essential for developing antiviral treatments and vaccines, as targeting specific viral components can disrupt the viral life cycle and prevent infection. Fig.2. Human immunodefigiency virus - HIV