organelles, cell membrane and membrane transport

simple diffusion

movement of molecules from an area of high concentration to an area where they are less concentrated. until equilibrium is reached.

directly through the membrane.

facilitated diffusion

The passive movement of molecules across membranes down their concentration gradient.

By Channel proteins and Carriers protein

osmosis

The movement of water molecules across a selectively permeable membrane from an area of Higher water concentration to an area of lower water concentration.

active transport

Movement of substances across membranes against their concentration gradient, requiring the use of energy in the form of ATP. Active transport usually involves the use of transport proteins

ATP

Adenosine triphosphate - a molecule used to store energy temporarily in organisms. The molecule is broken down to adenosine diphosphate + phosphate to release energy to drive metabolic processes.

concentration gradient

The gradient in molecular concentration (the difference in concentrations) that allows diffusion to occur

channel proteins

Passageways a protein pore that spans a membrane, May have an open or closed gate. Used for water soluble molecules.

carrier protein

Molecules move down their concentration gradient (kinetic movement) through a transport protein e.g. Glucose or Amino acids (water soluble molecules)

endocytosis

The process of taking materials into a cell (form a vesicle inside the cell.) This is an active process requiring ATP . Can be Pinocytosis or Phagocytosis.

exocytosis

Substance enclosed in a membranous vesicle which

fuses with the plasma membrane and ruptures,

releasing the substance to the exterior

Filtration

Molecules are pushed across a membrane from high pressure to lower pressure

Passive Transport

Kinetic energy, down concentration gradient - Simple diffusion, Osmosis, Facilitated diffusion. No ATP needed

Pinocytosis

Endocytosis: Drinking droplets of fluid (vesicles formed around liquid matter)

Phagocytosis

Endocytosis: Eating particles. (vessicles formed around solid matter)

Cell membrane

Covers the cells cytoplasm, Controls what moves in and out, Connects to other cells, allows body cells to 'recognise' each other.

structure of the cell membrane

Phospholipids, proteins, cholesterol, glycoproteins, glycolipids.

Phospholipid

Allows some things through and stops others!

Hydrophilic (water loving) Polar head and Hydrophobic (water fearing) non-polar tail.

Proteins in Cell membrane

Ion Channels, Carriers and Receptors

Ion channels (Cell membrane protein)

Allow ions to move into or out of the cell

Carriers (Cell membrane protein)

Selectively move substances through the membrane

Receptors (Cell membrane protein)

protein on the cell membrane to allow for recognition of cell and provide sites for hormones, neurotransmitters to bind

Cell Membrane Permeability

Phospholipid bilayer is selectively permeable, Small Lipid-soluble substances can pass freely, large water soluble substances cannot.

Isotonic Solutions

have the same concentration of solutes as each other, Na+ will draw water to it (by osmosis). Normal Saline is isotonic to blood cells.

Hypotonic Solutions

Any Solution that has a lower concentration of solutes (higher conc. of H2O) - RBC will expand/swell

Hypertonic Solutions

any Extracellular solution that has a higher concentration of solutes (lower conc. of H2O) - RBC will shrink

Ribosome

site of protein synthesis

Endoplasmic Reticulum

A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids.

Golgi apparatus

stack of membranes in the cell that modifies, sorts, and packages proteins from the endoplasmic reticulum

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Lysosome

cell organelle filled with enzymes needed to break down certain materials in the cell

Centriole

one of two tiny structures located in the cytoplasm of animal cells near the nuclear envelope

Cilia

Hairlike projections that extend from the plasma membrane and are used for locomotion

Flagella

A long, whip-like filament that helps in cell motility. Many bacteria are flagellated, and sperm are flagellated.

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Nucleolus

Found inside the nucleus and produces ribosomes

Chromatin

granular material visible within the nucleus; consists of DNA tightly coiled around proteins

carrier proteins

bind to molecules and change shape to shuttle them across the membrane

diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration. Across a concentration gradient.

osmosis

Diffusion of water through a selectively permeable membrane

glycoproteins

Membrane carbohydrates that are covalently bonded to proteins.

glycolipids

Membrane carbohydrates that are covalently bonded to lipids.

integral proteins

Integral proteins that span the membrane.

peripheral proteins

The proteins of a membrane that are not embedded in the lipid bilayer; they are appendages loosely bound to the surface of the membrane.

organelle

any of a number of organized or specialized structures within a living cell.

receptor-mediated endocytosis

extracellular substances bind to specific receptor proteins, enabling the cell to ingest and concentrate specific substances in vesicles. Often specific to hormone and cholesterol uptake