BSMT Cytogenetics Chapter 2

Study Notes

Rough Endoplasmic Reticulum (RER) consists of membranous tubules and flattened sacs with attached ribosomes.
RER synthesizes proteins and transports them to the Golgi apparatus for secretion or incorporation into the plasma membrane and lysosomes.
It is the primary site for the synthesis of most membrane-bound proteins.
Smooth Endoplasmic Reticulum (SER) lacks ribosomes and is involved in manufacturing lipids and carbohydrates.
SER detoxifies harmful chemicals and stores calcium, playing a significant role in carbohydrate metabolism.

Cells are the basic unit of the human body, with approximately 68 trillion cells (30 trillion human cells and 38 trillion bacterial cells).
Red Blood Cells (RBCs) make up 80% of human cells, while neurons comprise around 100 billion cells.
Cell differentiation allows cells to become specialized and organized into tissues, often altering their shapes.

Robert Hooke was the first scientist to discover cells by observing plant cell walls.

The plasma membrane acts as a selective barrier, regulating the entry and exit of materials in and out of the cell.
It facilitates the transport of specific molecules.

Membrane proteins serve crucial roles in cell recognition and signaling functions, enabling interactions between cells and their environment.
Membrane phospholipids are amphiphilic, with hydrophilic (water-attracting) heads and hydrophobic (water-repelling) tails.

The Golgi apparatus comprises flattened membrane sacs organized in stacks.
It modifies, packages, and distributes proteins and lipids, completing post-translational modifications of proteins produced in the RER.
Has two functional sides: the cis face (receiving region) and the trans face (shipping region).

Lysosomes are membrane-bound vesicles pinched off from the Golgi apparatus and contain digestive enzymes.
They are the primary site for intracellular digestion and the turnover of cellular components, housing about 40 hydrolytic enzymes.