The Cell Flashcards
What are the three major classes of lipids that make up the plasma membrane?
Phospholipids, cholesterol, and glycolipids.
What are the two major classes of proteins that make up the plasma membrane?
Integral-embedded in or pass through the lipid bilayer
Peripheral-associate noncovalently with the membrane proteins. Basically just chill on the surface of the bilayer.
What does cholesterol do in the plasma membrane?
Intercalates (gets between} phospholipids in order to reduce membrane fluidity.
Glycolipids
Contain sugar. Found exclusively in the outer monolayer and help with cell recognition, self v non self, etc.
What are the 6 general categories of integral membrane proteins?
1) Pumps/carriers/transporters (transport ions or metabolic precursors)
2) Channels (passive defusion, etc)
3) Receptors
4) Linkers (anchor proteins)
5) Enzymes
6) Structural proteins (hold cells together)
What are the three types of endocytosis?
Receptor medicated, pinocytosis, and phagocytosis.
Regulated vs. constitutive exocytosis
Regulated is in response to a stimulus and constitutive is a substance that is continuously delivered to the plasma membrane for export.
Receptor Mediated Endocytosis
Selective uptake of large molecules, depends on Cathrin to make a Cathrin coated pit which drives the vehicle formations. Then dynamin causes the visible to pinch off from the plasma membrane.
Endosomes
Membrane enclosed structure associated with the Endocytosic pathway
Early endosome
Functions to sort and recycle proteins
Late endosome
Receives proteins for degradation and matures into a lysosome with help from the Golgi (Golgi gives it lysosomal enzymes).
Pinocytosis
Cell drinking, non specific ingestion of small vesicles. Constitutive, clathrin independent, found a lot in smooth muscle.
Phagocytosis
Ingestion of large particles, generally performed by specialized phagocytes, dependent on action and independent of clathrin.
Glycocalyx
Carbohydrate rich zone on the cell surface (sugar coating) that helps to establish the micro environment of the cell surface. It provides protection from mechanical and chemical damage, cell recognition, and cell to cell interactions. Made up of glycolipids attached to a glycoprotein.
Neoplasm
New growth, usually a tumor, abnormal mass of cells
What are some characteristics of malignant neoplasms?
Grow rapidly and may invade invade other areas, ignore restraints on cell division, unregulated growth
How are malignant neoplasms classified?
Based on the cell type from which they originate, usually the epithelium or connective tissue
Carcinoma
Malignant tumor of the epithelium
Sarcoma
Malignant tumor growing from connective tissue
Leukemia
Cancer of the blood/bone marrow
Sarcoma
Naming used for connective tissue tumors
Metastasis
When tumors are invasive and can spread into other tissues
Why are carcinomas so prevalent?
The epithelial tissue covers a lot of area and is constantly reproducing so there is greater chance of it mutating. It is also frequently exposed to physical and chemical damage.
Clonal Evolution theory
idea that tumors develop through repeated rounds of mutation and proliferation and eventually take over neighbor cells