HES 101 (Sept. 11) Cellular Level

what are separated by tissue membranes (serous membranes)?

the body's cavities/compartments

what lines the surface of every cell?

membranes line them

the cell membrane acts as a what?

selectively permeable barrier

body fluid can be separated into what categories?

intracellular and extracellular fluid

what is intracellular fluid?

all the fluid inside cells

what is extracellular fluid?

all the fluid outside the cells

blood plasma is...

the liquid matrix of blood

intersitial fluid=

fluid between cells

what is plasma fluid?

The fluid component of blood

what are in osmotic equilibrium?

ECF and ICF (extracellular fluid and intracellular fluid)

what is in the cytosol?

intracellular fluid (water, dissolved solutes, proteins)

what is the cytoskeleton?

network of protein filaments:maintains cell shape, holds organelles in place, transportation of substances within the cell

what does the nucleus contain?

Contains DNA, site of RNA production

what is metabolism?

Chemical reactions in the cell to sustain life

what are anabolic reactions?

building reactions from small molecules to macromolecules

what are catabolic reactions?

breaking down reactions from macromolecules to smaller molecules

what are oxidation-reduction reactions?

converting energy in chemical bonds of nutrients into ATP through the transfer of electrons

where does the transport of substances work?

Within the cell, into and out of the cell

what is autocrine?

cell communicates with itself

what is paracrine?

communication with nearby cells and tissues

what is long distance communication?

hormones in the blood and nerves

what does cell division do?

replacement of old damaged cells, growth & development

what do red cells not have?

they don't have a nucleus (concave in nature)

plasma membrane must be able to:

Interact with water in both fluid compartments, repel water keeping ECF and cytosol separated

phospholipids are...

amphiphilic (amphipathic molecule)

in the phospholipid what is facing the fluid compartment?

the polar phosphate group (hydrophilic head)

in the phospholipid what is facing one another?

the non polar two fatty acid tails (hydrophobic tails)

how does glucose get into our muscle cells?

through facilitated diffusion

what do phospholipids do?

form the membrane barrier

the plasma membrane is...

a dynamic fluid structure with multiple components

what are glycolipids and glycoproteins?

Polysaccharides attached to membrane lipids or membrane proteins for cell recognition

What is a amphiphilic molecule?

possesses hydrophilic and hydrophobic components in their structure

in the membrane what is cholesterol considered?

a membrane structure

what are the main components of plasma membranes?

the main components are membrane proteins

what are the 2 basic membrane proteins?

integral (transmembrane) proteins, peripheral proteins

where are integral proteins found?

they span the entire membrane

where are peripheral proteins found?

found only on one side of membrane or other

what do protein channels do?

Transmembrane proteins that allow certain substances to cross membrane and pass into or out of cell

what do protein channels allow to pass through?

H2O, K+, Na+, both K+ and Na+,etc)

"Always" open protein channels are like what?

pores in the membrane. Substances that can pass will flow down their gradient.

what type of gated-channels are there?

chemically, electrically, or mechanically gated

what is a chemically gated channel?

gating controlled by a ligand (a molecule) that binds to a receptor (also called Receptor proteins)

what is a electrically gated channel?

gating controlled by voltage differences across the plasma membrane

what is Mechanically-gated channel?

physical forces put pressure on the membrane and the channel pops open

what is a protein carrier?

integral proteins bind, change shape, and directly transport substances into and out of cell

are carrier proteins selective?

carrier proteins are also selective with what substance they allow to go through

what are 3 basic types of carrier proteins?

uniporter, antiporter, and symporter

how many substances do uniporter carrier proteins transport?

transports a single substance

how many substances do antiporter carrier proteins transport?

moves 2 different substances in opposite directions

how many substances do symporter carrier proteins transport?

moves 2 different substances in the same direction

what happens when ligand binds to receptor?

if it's a channel, it opens/closes OR if not a channel, an intracellular response is triggered

what do membrane receptors bind to?

they bind to chemical messengers

what do enzymes do?

catalyze (speed up) chemical reactions

some proteins are found to what?

maintain the shape and structure of the cell, might be bound to cytoskeleton in the cytoplasm

some membrane proteins link what together?

they link cells to one another

membrane linker proteins allow for what?

quick cell-to-cell communication

cells are tightly connected by what?

linker cells

what is selectively permeable?

the phospholipid bilayer is

what is passive transport?

Energy is NOT required for transport

what is active transport?

The cell needs to expend energy for transport

what 3 variables determine how substance is able to move across plasma membrane? (either active/passive transport)

Type of substance, plasma membrane permeability to the substance, the concentration gradient

Passive transport processes:

simple diffusion, facilitated diffusion and omsosis

what is simple diffusion?

small and nonpolar solutes (oxygen, carbon dioxide, lipids, and hydrocarbons) pass through phospholipid bilayer without the use of a membrane protein

simple diffusion, diffuses which way on the concentration gradient?

Solutes will diffuse down their concentration gradient (from an area of high concentration to low concentration)

what is facilitated diffusion?

larger and charged/polar solutes (ex. ions and glucose) cross phospholipid bilayer with help of membrane protein (carrier/channel). No energy required.

facilitated diffusion, diffuses which way on the concentration gradient?

Solutes will diffuse down their concentration gradient (from an area of high concentration to low concentration)

what is osmosis?

solvent (usually water) moves across membrane

osmosis, follows which way on the concentration gradient?

Water moves from area with lower concentration of solute (more water molecules) across membrane to area with higher concentration of solute (less water molecules)

Water moves across the plasma membrane by which 2 methods?

Directly through the phospholipid bilayer(small amounts), or through aquaphorins (Through channel proteins)