Cell Structure Quiz

Study Notes

Cell is the fundamental unit of life, forming the building blocks of all living organisms.
Despite variations in shape, size and function, cells share common features.
Plasma membrane encloses the cell, acting as a barrier and controlling what enters and exits.
The plasma membrane is too thin for light microscopy, but electron microscopy reveals a double dark line with a light space in between
The nucleus lies at the center of the cell, acting as the control center.
Cytoplasm encompasses the space between the plasma membrane and nucleus, containing structures responsible for various cellular functions.
Organelles are structures within the cytoplasm crucial for maintaining cell life and performing specific functions.

Phospholipids form a double layer with hydrophobic tails pointing inward and hydrophilic heads facing outward.
Cholesterol inserts within the phospholipid bilayer.
Integral proteins are embedded within the lipid bilayer, either fully or partially.
Peripheral proteins associate with the inner lipid bilayer but do not penetrate it.
Carbohydrates attach to proteins, forming glycoproteins, and to lipids forming glycolipids, both found on the outer surface of the membrane, contributing to the cell coat.

A delicate coating on the cell surface.
Composed of oligosaccharide chains attached to both lipid and protein components of the plasma membrane.
Plays a vital role in protecting the cell surface, facilitating cellular recognition, acting as an antigen, and filtering substances.

Membranous organoids are enclosed by a membrane, including rough and smooth endoplasmic reticulum, Golgi apparatus, lysosomes, mitochondria, secretory vesicles, and coated vesicles.
Non-membranous organoids lack a membrane and include ribosomes, centrosome, microtubules, microfilaments, and intermediate filaments.

Characterized by the presence of ribosomes on its surface, giving it a "rough" appearance.
Appears as flattened stacks known as cisternae.
Function: Synthesizes proteins for export from the cell.

Lacks ribosomes, resulting in a "smooth" appearance under the microscope.
Consists of tubules and vesicles.
Functions:
- Lipid synthesis (especially steroids)
- Mineral metabolism (e.g., HCl production)
- Detoxification of toxins
- Muscle contraction (e.g., sarcoplasmic reticulum of striated muscle cells)