Cells Flashcards
Living Structural and functional unit that is enclosed by a membrane
Cell
3 main parts of a cell
- Plasma membrane
- cytoplasm
- nucleus
Forms a cell’s flexible outer surface, separating the cell’s internal environment from its external environment
Plasma membrane
Regulates the flow of materials into and out of a cell to maintain the appropriate environment for normal cellular activities
Plasma membrane
Plays a key role in communication among cells and between cells and their external environment
Plasma membrane
Basic framework of plasma membrane?
- Lipid bilayer
- proteins
- Selectively permeable
What is the Lipid bilayer made up of?
Two tail to tail layers made up of phospholipids, cholesterol, and glycolipids
Two types of (membrane) proteins
Integral
peripheral
Protein that…
- extend through the lipid bilayer
- allow small and medium sized water-soluble materials to cross the membrane
Integral
Protein that…
- loosely attached to the exterior or interior surface of the membrane
Peripheral
Framework of plasma membrane that….
- allows some substances to move into and out of the cell but restricts the passage of other substances
Selectively permeable
Framework of plasma membrane that….
- not permeable to ions and large, uncharged polar molecules such as glucose and amino acids
Selectively permeable
[type of body fluid] fluid in body cells
intracellular fluid (ICF)
[type of body fluid] Fluid outside cells
Extracellular fluid (ECF)
[type of body fluid] ECF between cells in tissues
Interstitial fluid
[type of body fluid] ECF in blood vessels
Blood plasma
[type of body fluid] ECF in lymphatic vessels
Lymph
[type of body fluid] Surrounds the brain and spinal cord
Cerebrospinal fluid
[type of body fluid] Any material dissolved in a fluid
Solute
[type of body fluid] Fluid that dissolves materials
Solvent
Two methods for substances to move across the plasma membrane
Passive processes
Active processes
In this process, substance moves down its concentration gradient through the membrane, using only its own energy of motion (kinetic energy)
Passive processes
In this process, cellular energy, usually in the form of ATP, is used to “push” the substance through the membrane “uphill” against its concentration gradient
Active processes
movement of substances down a concentration gradient until equilibrium is reached; do not require cellular energy in the form of ATP
Passive process
Passive movement of a substance through the Lipid bilayer of the plasma membrane
Simple diffusion
Movement of substance by kinetic energy down a concentration graduate until equilibrium is reached
Diffusion
Passive movement of a substance down its concentration gradient aided by ion channels and carriers
Facilitated diffusion
Movement of water molecules across a Selectively permeable membrane from an area of higher water concentration to an area of lower water concentration
Osmosis
Movement of substances against a concentration gradient; requires cellular energy in the form of ATP
Active processes