A&P1 - LP#3 Flashcards
Cellular Level of Organization: Parts of the cell; Transport Across the Plasma Membrane; Cytoplasm
What are the THREE main parts of the cell?
- Plasma Membrane
- Cytoplasm
- Nucleus
This forms the cells flexible outer surface separating the cells internal and external environment.
Plasma Membrane
Regulates the flow of material into and out of the cell
Plasma Membrane
Plays a key role in communication among cells and between their external environment.
Plasma Membrane
Consists of all the cellular contents between the plasma membrane and the nucleus:
Cytoplasm
A large organelle which houses most of the cell’s DNA’s
Nucleus
Chromosomes are found within the ____________ and contain 1000’s of genes responsible for cellular structure and function.
Nucleus
The molecular arrangement of the plasma membrane resembles an ever-moving sea of fluid lipids that contain a mosaic of many different proteins.
The Plasma membrane is best described by using this structural model. It is called __________________
Fluid Mosaic Model
Plasma Membrane has 2 main structures:
- Lipid Bilayer
2. Membrane Proteins
This is the basic structural framework of the plasma membrane.
Lipid Bilayer
The lipid bilayers consists of THREE types of molecules
- Phospholipids
- Cholesterol (steroid)
- Glycolipids
The lipid bilayer is AMPHIPATHIC - What does this mean?
It has both polar and non-polar parts.
There are TWO categories of membrane proteins according to whether or not they are firmly embedded into the membrane. What are these 2 categories?
- Integreal Proteins
2. Peripheral Proteins
This category of membrane protein is firmly embedded within the hydrophobic regions of the plasma membrane It extends through the lipid bilayer and can be transmembrane
Integral Proteins
This category of membrane protein is NOT firmly embedded in the plasma membrane. It associates more loosely with the polar heads or with other proteins inner or outer surface.
Peripheral Proteins
These proteins can also be found in the plasma membrane. These proteins have carbohydrate groups attached to their ends that protrude into the extracellular fluid.
Glycoproteins
The carbohydrate portions of glycoproteins and glycolipids form this extensive sugary coat. It acts as a molecular signature that enables cells to recognize each other.
Glycocalyx
What are the three functions of Glycocalyx?
- Enable cells to recognize each other
- Enables cells to adhere to one another in some tissues
- Protects cells from being digested by enzymes in extracellular matrix.
What are the SIX functions of membrane proteins?
- Ion Channels
- Carriers
- Receptors
- Enzymes
- Linkers
- Cell-Identity Markers
When a structure permits the passage of substances through it
Permeable
When a structure does NOT permit the passage of substances through it.
Impermeable
When the plasma membranes permit some substances to pass more readily through it than others
Selective Permeability
________________ is a difference in the concentration of a chemical from one place to another, such as from the inside to the outside of the plasma membrane.
Concentration Gradient
________________ is a difference in the electrical charges between the inner and outer surfaces of the membrane.
Electrical Gradient
There are TWO methods of transport across the membrane
Passive and Active Transport
THREE types of Passive Transport
- Simple Diffusion
- Facilitated Diffusion
- Osmosis