A:P: Chapter 3.1 flashcards

phospholipid

• Head= hydrophilic (polar)

• tail= hydrophobic (non-polar); fatty acids

• Both create a barrier for things to not get through

why we need phospholipids

• To protect it from environment

• Selective permeability 

  • Ability to pass through

  • Certain things can get through or not

Extracellular matrix

Everything outside the cell

electrical gradient

• Both sides of the membrane have different electrical charges

  • Electrical potential

    • When channels open there is potential for action, communication, etc

chemical gradient

• More on the outside vs inside

  • Chemical potential

    • When certain doors open, things can happen

• the difference in the concentration of a chemical substance between two areas

membrane proteins functions

• Make it dynamic

• Pass things in and out

• Transport stuff 

• Attach to neighbors

• Attach to extracellular (outside the cell) matrix (structure)

  • Bone cell lives inside an extracellular matrix

marker molecules (membrane protein)

• Allow cells to identify other cells or other molecules

  • Ex: glycoprotein

attachment proteins (membrane proteins)

• Anchor cells to other cells (cadherins) or to extracellular molecules (integrins)

  • Ex: skin cells

channel proteins

Form passageways through the plasma membrane, allowing specific ions or molecules to enter or exit the cell; may be leak or gated

leak channel

• Always open

• Responsible: permeability of plasma membrane

• Always allows potassium ions to move through the gradient (a higher concentration to a lower concentration)

gated ion channels

• Open or close by certain stimuli (in response to chemical or electrical signals)

  • Need something attached to it to open the gate

carrier proteins (transporters)

Move ions or molecules across the plasma membrane; binding of specific chemicals to carrier proteins causes changes in the shape of the carrier proteins. The carrier proteins then move to the specific chemical across the plasma membrane.

ATP-powered pumps

• Move specific ions or molecules across the plasma membrane; require ATP molecules to function

  • Must use energy to be useful

receptor proteins

Function as binding sites for chemical signals in the extracellular fluid; binding of chemical signals to receptors triggers cellular responses

tihngs that can pass through easily through a cell membrane

• Lipids (O2, CO2)

  • Easily able to dissolve

passive transport

• The cell does not extend ATP; movement of substance from higher concentration to lower concentration

• Diffusion, osmosis, facilitated diffusion

active membrane transport

• ATP used to move substance from lower concentration to higher concentration

• Active transport, secondary active transport

vesicular transport

• Involves a membrane-bound sac (vesicle)

• Endocytosis and exocytosis

diffusion

• High concentration of substance that allows itself to dissolve (to an area of lower concentration)

• Becomes an equilibrium solution

osmosis

Diffusion of water across a selective permeable membrane

hypertonic

cell shrinks b/c red blood cell loses water

isotonic

same amount of salt inside the water as the outside

hypotonic

cell gets bigger because it gains water

facilitated diffusion

1. A glucose molecule enters a carrier protein from the extracellular fluid. The glucose binds to the carrier protein

2. The carrier protein changes shape and releases the glucose molecule into the cell. The carrier protein then resumes its original shape to transport additional glucose molecules.

active transport

• Needs ATP

• Substance moved against their concentration gradient (from low to high), allowing the substance to accumulate on one side of the plasma membrane

• Sodium,-potassium pump

  • a vital membrane protein that uses energy from ATP to move three sodium ions out of the cell and two potassium ions into the cell

secondary active transport

• Use of potential energy in concentration gradient of one substance to help move another substance against its gradient

• Allows sodium and glucose to go in the cell

vesicular transport

• Requires ATP
  Movement of larger substances by formation or release of a vesicle

• Endocytosis

  • movement into cell

    • phagocytosis

    • pinocytosis

phagocytosis

• Solid particle is ingested and large vesicle is formed

• Create an opening and wrap itself around the particle, pinch itself off, and eat the particle

pinocytosis

• Dissolved molecules ingested and small vesicles are formed

• a cellular process known as "cell drinking," where a cell engulfs small drops of extracellular fluid and dissolved nutrients

exocytosis

• Movement out of cell

• Secretion