Cytoskeleton and Cell Movement

Cytoskeleton

• Composed of protein filaments: microtubules, microfilaments, and intermediate filaments.
• Provides structural support and enables movement in eukaryotic cells.

Flagella and Cilia

• Flagella are elongated structures enabling locomotion in liquid; cilia are shorter and create coordinated flows on the cell surface.

Centrosomes

• Organize spindle fibers during cell division in mitosis and meiosis.
• Present in animal cells.

Microtubules

• Serve as structural components and are crucial during cell division.
• Exclusively found in animal cells.

Storage and Transportation

• Manage nutrients, eliminate waste, and regulate metabolic processes.

Vacuoles

• Membrane-bound organelles in plant and some animal cells.
• Store nutrients, water, ions, and waste while regulating turgor pressure and osmotic balance.
• Involved in substance digestion and serve as a defense mechanism by containing toxins.

Vesicles and Endosomes

• Membranous structures that transport specific materials between organelles and cell membranes.
• Vesicles transport materials from endoplasmic reticulum and Golgi apparatus.
• Endosomes capture and distribute materials for degradation, recycling, or incorporation into metabolic pathways.

Differences Between Plant and Animal Cells

• Plant cells have a cell wall; animal cells have only a cell membrane.
• Plant cells contain larger vacuoles; animal cells contain centrioles.

Endoplasmic Reticulum (ER)

• Rough ER: Studded with ribosomes for protein synthesis and modification.
• Smooth ER: Specializes in lipid synthesis, carbohydrate metabolism, and detoxification.

Golgi Apparatus

• Composed of flattened sacs called cisternae.
• Functions as the 'shipping center' of the cell, sorting and packaging proteins into vesicles for transport.

Mitochondria

• Present in both animal and plant cells.
• Generate energy via cellular respiration (ATP production) and have a double membrane structure for respiratory chain organization.

Chloroplasts

• Exclusive to plant cells; conduct photosynthesis to convert solar energy into chemical energy.
• Synthesize glucose and release oxygen as a byproduct.

Cellular Digestion

• Involves breaking down molecules and unwanted materials for recycling and maintenance.

Lysosomes

• Contain digestive enzymes that break down cellular materials and nutrients, including bacteria and damaged cells.

Peroxisomes

• Detoxify harmful molecules and break down hydrogen peroxide.
• Involved in lipid metabolism and regulating overall homeostasis.

Cell Membrane

• Outer layer composed of phospholipid bilayer embedded with proteins.
• Regulates passage of substances, acting as a selective barrier.

Cell Wall (in Plants)

• Strong outer layer that protects and maintains internal structure.

Cytoplasm

• Gel-like substance containing water, salts, proteins, and other molecules.
• Occupies space between the cell membrane and nucleus.

Nucleus

• Central organelle within eukaryotic cells; stores and safeguards DNA.
• Controls gene expression and DNA replication.

Nucleolus

• Found inside the nucleus; consists of RNA and protein.
• Involved in ribosome synthesis and looks like a smaller nucleus.

Ribosomes

• Essential for protein synthesis, found in cytoplasm and rough ER.
• Known as the "protein builders" of the cell.

Endoplasmic Reticulum

• Network of membranes extending from the nuclear membrane to the cell membrane.
• Fundamental for transport, processing, and distribution of proteins and lipids within the cell.

This quiz covers key components of the cytoskeleton, including microtubules, microfilaments, and intermediate filaments. It also explores specialized structures such as flagella and cilia that facilitate movement in cells, as well as the role of centrosomes in cell division. Test your understanding of these essential cellular structures.