3.3 Cellular Complexity and Specialization Flashcards
How many different cell types exist in the human body, and what causes cell differentiation?
There are over 200 different cell types, and cell differentiation occurs as cells activate certain genes, leading to distinct structures and functions.
What is the analogy used to describe the cell’s structure?
The cell is likened to a medieval city with walls (cell membrane), compartments (different cell areas), and a ruler (nucleus).
What is the primary function of the cell membrane?
The cell membrane regulates the movement of materials between the cell and its environment.
What are the main components of the cytoplasm?
The cytoplasm includes cytosol, inclusions, and protein fibers; actin fibers, intermediate filaments, microtubules.
What is cytosol, and what does it contain?
Cytosol is a semi-gelatinous fluid containing dissolved nutrients, proteins, ions, and waste products, suspending other cytoplasmic components.
Where are fixed and free ribosomes found, and what is their function?
Fixed ribosomes are attached to organelles, while free ribosomes are suspended in cytosol, often forming polyribosomes. They synthesize proteins based on DNA instructions.
What are inclusions in the cytoplasm, and do they have boundary membranes?
Inclusions are particles of insoluble materials, such as nutrient stores; glycogen, lipid droplets, and they do not have boundary membranes.
What are the three types of protein fibres in the cytoplasm, and what are their sizes?
The three types are actin fibres (microfilaments), intermediate filaments, and microtubules, with microtubules being the largest.
How do cilia and flagella differ in structure and function?
Cilia are short, hairlike structures moving fluids across surfaces with a 9+2 microtubule arrangement; flagella are longer and move entire cells, like sperm.
What would happen if a sperm cell lacked a flagellum?
The sperm would lose its ability to swim and fertilize an egg.
What are the three types of motor proteins, and what is their function?
The three types are myosins, kinesins, and dyneins, and they convert ATP energy into directed movement along cytoskeletal fibres.
What are primary cilia, and what are ciliopathies?
Primary cilia are sensory structures in various tissues, and ciliopathies are disorders caused by mutations in ciliary proteins affecting multiple organ systems.
What are the key features and functions of mitochondria?
Mitochondria have a double membrane, produce ATP, contain their own DNA, and replicate by budding.
What are the five main functions of the cytoskeleton?
1) Provides mechanical strength and determines cell shape
2) Stabilizes organelle positions
3) Facilitates transport
4) Supports tissue structure
5) Aids in cells and internal movement.
What are the functions of the rough and smooth endoplasmic reticulum (ER)?
Rough ER is involved in protein synthesis, while smooth ER is involved in lipid production, detoxification, and calcium storage in muscles.
