Exam #1 Flashcards
(285 cards)
What are the basic components of a cell?
Plasma membrane, cytoplasm, extracellular fluid and extracellular matrix
what is the plasma membrane composed of?
phospholipids, cholesterol, proteins
What percent of Plasma membrane is made up of lipids?
98%
What percent of the lipids that make up the plasma membrane are phospholipids?
75%
What is the function of cholesterol in a phospholipid?
To hold phospholipids still and stiffen the membrane
What kind of lipids attach to the heads of a phopholipid?
Glycolipid
Phospholipids are nonpolar and polar which makes them what?
Amphipathic
The head of the phospholipid is while the tail is what?
Hydrophilic head and hydrophobic tails
what is tissue fluid also known as?
Interstitial fluid
What is the fluid outside of the cells that includes interstitial fluid?
Extracellular fluid
What is the extracellular matrix?
Space around the outside of the cell adjacent to the plasma membrane
What is the cell theory?
- All cells only arise from cells
- Every living organism is composed of cells
- Cell is the smallest unit of life
The plasma membrane has permeability because of what two things?
Phospholipids and integral proteins
Membrane proteins are also known as what?
Integral proteins
What is the purpose of a channel protein?
Allows for movement of specific substances across the plasma membrane
What are the two types of channel proteins?
A leak channel and a gated channel
what is a leak channel?
a channel that is always open to allow material to pass through continually
what is a gated channel?
A channel that opens and closes under different circumstances
What are the three types of gated channels
Ligand, voltage and mechanical gated
what is a ligand gated channel?
A channel that responds to chemical messengers
what is a voltage gated channel?
Senses a change in potential voltage across the plasma membrane
what is the purpose of a receptor protein?
it binds extracellular substances via Chemical signals by which cell communicate and can enter the target cell
A receptor protein is ____ because it binds on to a unique active site
specific
What is a cell identity marker or recognition protein?
tells which cells belong and which are foreign invaders