Chapter 3

Exocytosic

method by which cells export products for use in another location

Cholesterol

helps the membrane retain its flexability

Consumed by the cell by endocytosis, inside the cell, the cholesterol is broken down and used to make a variety of other useful molecules, such as the

hormones estrogen and testosterone

diffusion

in which a particle, called a solute is dissolved in a gas or liquid ( a solvent) and moves from an area of high solute concentration to an area of lower concentration

Primary active transport

occurs when energy from ATP is used to fuel the transport of molecules

What are the types of endocytosis

phagocytosis, pinocytosis, and receptor mediated enocytosis

2 types of active transport

primary and secondary

Recognition proteins

provide a "fingerprint" for the cell, so it can be recognized by other cells.

Transport proteins

provide a passage way for molecules to travel into and out of the cell

isotonic solution

solute concentration are balanced (water movement is balanced)

hypertonic

solute concentration are higher in the extracellular fluid (water diffuses out of cell)

The direction of osmosis is determined by the total amount of

solutes on either side of the membrane

Receptor protiens

surface or trans membrane protein, bind to external chemicals in order to regulate process within the cell.

The largest human cell is

the egg cell

is water polar or non polar

Polar molecule b/c other polar molecules mix easily with water

Pinocytosis

"drink and container" the process of cells taking in dissolved particles and liquids

Prokaryotic cells

1st cells on earth, no nucleus- DNA in the cytoplasm , single celled organisms, no organelles, contain cytoplasm. contain ribosomes, can conduct phtosythesis

Cell Theory

All living organisms are made up of one or more cells. The cell is the smallest thing that is alive. cells arise from other, preexisting cells.

what are the types of molecules used in the plasma membrane?

Carbohydrate chains, cholesterol

Robert Hooke Named Cells

Cellulae, from the Latin name meaning small rooms

Most molecules, however, cant get through plasma membrnaes on their own. They may be _____ and, hence, are repelled by the ____ middle region of the ______.

Electrically charged, hydrophobic, phospholipid bilayer

Molecules that can mix with water are described as

Hydrophilic "water loving"

hypotonic

Lower, solute concentration are lower in the extracellular fluid (water diffuses into cell)

Eukaryotic cells

Nucleus, DNA, multicellular and unicellular, we are eukaryotes, Plant, Animal, Fungi and Protist cells are all eukaryotic, bigger than prokaryotes

What are the molecules that are small and carry no charge and can pass directly through phospholipid bilayer of the membrane with out the assistance of any other molecules

Oxygen and carbon-dioxide

____ is the spontaneous diffusion of molecule across membrane.

Passive transport

The two process are largely the same, except that the vesicles formed during _____ are generally much smaller than those formed during______.

Pinocytosis Phagocytosis

Every cell is bordered by

Plasma Membrane (gate keepers) regulates what enters and exits the cell.

Carbohydrate chains

Provide "fingerprints" for the cell, so it can be recognized by other cells

what are the types of membrane proteins?

Receptor proteins, recognition, transport, enzymatic

Passive transport

The molecular movement occurs spontaneously, with out the input of energy

Who uses phagocytosis to consume entire organisms either as food or as their way of defending against pathogens

amoebas and other unicellular protists, as well as white blood cells, use phagocytosis to consume entire organisms either as food or as a way of defending against pathogens (disease causing organism or substance)

For every 50-100 phospholipids in the membrane, there is one protein molecule called

Transmembrane proteins which penetrate right through the lipid bilayer from one side to the other -surface proteins or peripheral proteins, reside primarily on the inner or outer surface of the membrane

Osmosis

Type of passive transport by which water diffuses across a membrane, in order to equalize the concentration of water inside and outside the cell.

endocytosis

a cellular process in which large particles, solid or dissolved, outside the cell are surrounded by a fold of the plasma membrane, which pinches off, forming a vesicle, and the enclosed particle now moves into the cell.

each molecule of LDL is

a cholesterol globlue coated by phospholipids

Phospholipids

a layer of lipid molecules all packed together

All these types of endocytosis form

a vesicle, and then pinching off the vesicle so that it is inside the cell but seprated

Enzymatic proteins

accelerate intracellular and extracellular reactions on plasma membrane

Secondary Active Transport

active transport in which there is no direct involvement of ATP (adenosine triphosphate) , the transport protein simultaneously moves one molecule against its concentration gradient while letting another flow down its concentration gradient

Receptor mediated endocytosis

by which cells engulf specific particles

What kind of proteins are attached to the phospholipid bilayer?

carbohydrates and lipid molecules

The 2 tails of the Phospholipids are long chains of ____ and ___ atoms. B/c the electrons in these bonds are shared equally, the carbon- hydrogen chains are ___.

carbon and hydrogen nonpolar

exocytosis

cells the manufacture molecules( such as digestive enzymes) for use elsewhere in the body must get those molecules out of the cell

active transport

cells use energy to move small molecules into and out of the cell

one of the most important receptor mediated endocytosis is

cholesterol which circulates in the bloodstream is in the form of particles called low density lipoprotiens

What are the types of passive transport?

diffusion and osmosis

Hydrophobic

do not mix with water

Polar

electrons are not shared equally among atoms

What is a cell?

the most basic unit of any organism, smallest unit of life that can function independently and perform all the necessary functions of life, including reproducing itself.

Low Density Lipoproteins coat are recognized by receptor built into

the plasma membrane of liver cells

Phagocytosis

the process by which relatively large particles are engulfed by cells by which cells engulf large particles

With the heLp of a channel or carrier molecule

these molecules may still be able to diffuse across the membrane, down their concentration gradient

Facilitated diffusion

when a spontaneous diffusion across a plasma membrane requires a transport protein