Cells Flashcards
The study of the structure and function of cells is called ?
Cytology
Fluid present inside the cell is called
intracellular fluid (ICF)
The cytosol is the
intracellular fluid.
. Fluid present outside the cells is
extracellular fluid (ECF)
ECF includes 2 different fluid areas (called
compartments):
the fluid that stands between cells, called
interstitial fluid
the fluid that flows through blood vessels called
plasma
The structure of the plasma membrane is described by the
Fluid Mosaic model
The basic component of the plasma membrane is a
bilayer of phospholipids
hydrophilic (water-loving) Face water are the
Polar heads
hydrophobic (water-hating) Face inward; water kept out are the
Non-polar tails
: maintains fluidity of plasma membrane
Cholesterol
: identify cells of the body to immune cells
Glycolipids and glycoproteins
: do not span the plasma membrane, located either on the inside or outside of the cell
Peripheral proteins
various functions. Most abundant molecule after phospholipids and most functionally important.
Integral (transmembrane) proteins
Permeability is the ___ of the plasma membrane
leakiness
what determines which substances can enter or leave the cytoplasm.?
Permeability of the plasma membrane
if the substance can cross it without difficulty the membrane is ?
freely permeable
if it permits free passage of some materials, and restricts the passage of others the membrane is ?
selectively permeable
if nothing can cross it the membrane is
impermeable
Factors that affect whether a molecule can cross a membrane are?
Size & shape ,Electric charge, Lipid solubility
___of the molecule: smaller molecules faster
Size & shape
___Ions are not allowed to pass through; will require channel proteins
Electric charge
___lipid membrane allows lipophilic molecules; discourages hydrophilic substances (polar and lipophobic); they require channel or carrier proteins
Lipid solubility
In addition to membrane permeability, transport requires a __ to move the substance.
force
Uses the CONCENTRATION GRADIENT for the substance to transport it. That is, it moves the substance from an area of higher to lower concentration. This is described as moving the substance ‘down’ or ‘along’ its concentration gradient.
PASSIVE FORCE
Uses ATP as an energy source to transport the substance, moving them from an area of lower to higher concentration. This is described as moving the substance ‘up’ or ‘against’ its concentration gradient. And, therefore, it requires ATP energy.
ACTIVE FORCE
Any type of transport that uses the passive force is referred to as
passive transport.
any type of transport that uses the active
force is called
active transport
Any solution contains a __(solid) and a__(liquid).
solute solvent
is the movement of solute molecules from an area of higher to lower concentration down their concentration gradient.
. Diffusion
can diffuse through the plasma membrane easily as they are able to diffuse through the lipid portions of the membrane.
Lipid soluble molecules
create a ‘tunnel’ for small solutes to move into or out of the cell.
. Channels
are needed to allow the movement down their concentration gradient. These molecules are insoluble in lipids and too large to pass through membrane
carrier proteins
The molecules ___ to a receptor site on carrier protein. The carrier protein ___ and releases the molecule to the other side.
binds changes shape
Diffusion of water (solvent) across a selectively permeable membrane is called
osmosis.
Diffusion of water molecules across a selectively permeable membrane
Occurs across a selectively permeable membrane that is freely permeable to water, but not freely permeable to all solutes
Water flows from low solute concentration to high solute concentration
this is the 3
characteristics of osmosis
measure of solution concentration in number of solute particles per Liter (p/L) of solution
Osmolarity:
The force with which pure water moves into a solution as a result of its solute concentration. The higher the concentration of non-penetrating solutes in a solution, the higher its osmotic pressure. A solution with higher osmotic pressure pulls water into it.
Osmotic Pressure
measure of the osmotic pressure of a solution, determined by solute particles that do not penetrate the plasma membrane
Tonicity
is the ability of an extracellular solution to cause a cell to gain or lose water; based on the concentration of solutes.
Tonicity
Solution with higher solutes
HYPERTONIC SOLUTION
Solution with lower solutes
HYPOTONIC SOLUTION
If solutes are equal in both
ISOTONIC SOLUTION
There are two types of active transport
Primary and Secondary
the pump directly hydrolyzes ATP for energy
Primary transport
pump indirectly uses energy from ATP
Secondary transport
An___move two ions in opposite directions
Exchange pump
moves substances either into or out of cell in small membrane sacs called vesicles.
Vesicular transport
Vesicular transport requires
energy from ATP
Two major categories of vesicular transport are
Endocytosis: and Exocytosis
: vesicles enter into cells is
Endocytosis
vesicles exit the cells is
Exocytosis
Phagocytosis means
“cell eating
Pinocytosis means
cell drinking”.
