Cell Organelle Quiz: Functions & Importance Explained

Study Notes

Removal of phosphate from the 6th carbon of Glucose-6-Phosphate converts it to glucose.
Sarcoplasmic reticulum (SR) in muscle cells stores Ca²⁺; analogous to smooth endoplasmic reticulum (E.R.).
SR utilizes pumps to release calcium into the cytoplasm for muscle contraction and transport processes.

Functions as the packaging organelle for proteins and lipids received from the rough and smooth E.R. respectively.
Composed of two sides:
- Cis Golgi: Receives vesicles from E.R.
- Trans Golgi: Releases vesicles towards lysosomes, cell membrane, etc.
Modifies proteins through processes such as:
- Glycosylation: Adding sugar residues; includes N-type (on nitrogen) and O-type (specific to Golgi on oxygen).
- Phosphorylation: Relevant in diseases like I-cell disease.
Packages modified proteins and lipids, creating vesicles that can form lysosomal proteins, membrane proteins, or be excreted from the cell.

Composed of a phospholipid bilayer:
- Polar hydrophilic heads facing outward and inward.
- Nonpolar hydrophobic tails pointing towards each other.
Contains cholesterol that regulates membrane fluidity. Increased cholesterol reduces fluidity by decreasing space between phospholipids, while decreased cholesterol increases fluidity.

Integral and peripheral proteins serve various functions:
- Transporters for molecules.
- Enzymes facilitating biochemical reactions.
- Linker proteins connecting cells.

Acts as a selectively permeable barrier, regulating the internal and external environment of the cell.
Facilitates transport processes including:
- Simple Diffusion
- Facilitated Diffusion
- Vesicular Transport