Biology Terms

1.Nucleus

a. consists of Chromosomes

b. largest and highly organized of all organelles

I. enclosed by a structure which has a complex double membrane called the Nuclear Envelope

a. studded with pore- like opening, which inside contains fibrous proteins that form a lattice-like sheet called the Nuclear Lamina (stiffens the structure and maintains its shape).

II. The nucleus also had specific sites where gene products are processed and included is a Nucleolus, where RNA molecules found in Ribosomes are manufactured and the large and small ribosomal subunits are assembled.

1. Ribosomes

a. CYTOPLASM consist of everything in the PM besides the nucleus.

b. In Eukaryotic cells, Ribosomes are complex large machines that manufacture proteins, however aren’t classified as organelles because they are not surrounded by membranes.

2. Endoplasmic Reticulum

a. Portions of nuclear envelope goes into cytoplasm which forms the the ER.

b. Though ER is a single membrane it has two regions in the nuclear envelope, which has a double membrane that consists of;

A. RER (Rough Endoplasmic Reticulum)

1. Has ribosomes attached to the membrane. (FREE Ribosomes are in Cytoplasm)

2. Ribosomes that are associated with the RER synthesize proteins that will be inserted to the PM, secreted to the cell exterior, or shipped to an organelle.

3. As being manufactured by ribosomes, the proteins move to the interior of the sac-like component of the RER.

4. The interior of the RER is called the lumen which manufactures the proteins by undergoing a folding or other types of processes.

5. RER products are packaged into Vesicles and transported to different destinations.

B. SER (Smooth Endoplasmic Reticulum)

1. Is the manufacturing site for phospholipids