transport

what is the cell membrane

what is the cell membrane

controls what comes in and out of the cell

what is cholesterol

Cholesterol is a steroid imbedded into the cell membrane. Cholesterol helps
regulate fluidity in the cell membrane.

what is a glycolipid

• lipids that have a carbohydrate attached to it by glyosidic linkages

• help with cell energy, cell membrane stability, and cell recognition

what is glycoprotein

• proteins that have a sugar chain attached to it

• help with signaling and immune response

what are receptor proteins

• allow cells to communicate with the environment

• hormones and neurotransmitters will bind to these proteins because they cannot pass the cell membrane on their own

what are integral proteins

• they are embedded in the cell membrane

• help pass materials across the membrane and send signals to the cell

what are peripheral proteins

• found on either the surface of the cell membrane

• mostly help with signaling and structural support

what are surface proteins

• found ONLY on the outside of the cell membrane

• help with cell recognition

• are a type of peripheral protein

what are channel proteins

• have a channel spanning through the cell membrane

• move large and charged molecules that don’t cross by themselves without using energy

• specific and open and close to molecules

what are carrier proteins

• have a channel spanning through the membrane

• more specific than protein channels and must change shape to let molecules pass

what are gap junctions

• channels that connect the cytoplasm of adjacent cells through the cell membrane using membrane proteins to form a channel

what are the two types of transports

active and passive

passive transport

• does NOT require energy

• moves WITH the concentration gradient (high to low)

• 3 types: osmosis, simple diffusion, and facilitated diffusion

active transport

• requires energy

• moves AGAINST the concentration gradient (low to high)

• two types: endocytosis and exocytosis

what is osmosis

The movement of water with the concentration
gradient (high to low) without using energy.

what is simple diffusion

The movement of molecules with the concentration gradient (high to low) without using energy directly across the cell membrane until equilibrium is reached.

what is facilitated diffusion

The movement of molecules with the concentration gradient (high to low) without using energy but uses proteins to help the molecules cross.

what is tonicity

a measure of how a solution affects the volume of cells by changing their water content

what is a hypertonic solution

When a cell is placed in a hypertonic solution, this means there are more solutes OUTSIDE the cell than inside. Because of this, water will LEAVE the cell.

what is a hypotonic solution

When a cell is placed in a hypotonic solution, this means there are more solutes INSIDE the cell than outside. Because of this, water will ENTER the cell.

what is an isotonic solution

When a cell is placed in a isotonic solution, this means there are an equal amount of solutes outside the cell and inside the cell. This means the cell will stay the same size and water will move into and out of the cell AT THE SAME RATE.

what is active transport

The movement of molecules against the concentration gradient (low to high) using energy and proteins to help the molecules cross.

what is endocytosis

• The cell takes in large molecules (like macromolecules) by pinching off part of the cell membrane to act as vesicles to carry particles.

• There are two types: pinocytosis and phagocytosis

what is pinocytosis

• extracellular fluid is engulfed with water and salts (“cell drinking”)

what is phagocytosis

• large solid particles are engulfed (“cell eating”)

what is exocytosis

• expels large molecules by having vesicles carrying particles combine with the cell membrane and push out materials

sodium-potassium pump

• moves 3 sodium (Na+) out of the cell and 2 potassium (K+) into the cell

• requires energy

• important for physiological processes

• if malfunctions, it can cause cell swelling/shrinking or disrupted signals

• important for energy usage and homeostasis and cell signaling