Chapter 3 Anatomy Test

Passive Transport

does not require energy as substances move along their gradient

Active Transport

requires energy to move substances against a concentration

Concentration Gradient

the gradual change in the concentration of solutes in a solution as a function of distance through a solution.

Equilibrium

the state of balance and stability.

Channel Protein

a protein that allows the transport of specific substances across a cell membrane.

Carrier Protein

bind the specific solute to be transported and undergo a series of conformational changes to transfer the bound solute across the membrane.

Na/K Pumps

Powered by ATP, the pump moves sodium and potassium ions in opposite directions, each against its concentration gradient.

Diffusion

the natural movement of particles from an area of higher concentration to an area of lower concentration, due to random molecular motion.

Facilitated Diffusion

molecules diffuse across the plasma membrane with assistance from membrane proteins, such as channels and carriers.

Osmosis

movement of water molecules from a region of higher concentration to a region of lower concentration through a semipermeable membrane.

Aquaporon

channel proteins which facilitate the passive diffusion of water and small neutral molecules across biological membranes; also transports glycerol.

Solute

the substance that is being dissolved.

Solvent

a substance that dissolves a solute, resulting in a solution.

Tonicity

the ability of an extracellular solution to make water move into or out of a cell by osmosis.

Isotonic

there will be no net flow of water into or out of the cell, and the cell’s volume will remain stable.

Hypertonic

there will be a net flow of water out of the cell, and the cell will lose volume. (has more solutes)

Hypotonic

there will be a net flow of water into the cell, and the cell will gain volume. (has less solutes)

Cell/Plasma Membrane

a barrier; decides what can enter or leave the cell.

Phospholipids

Lipids (fats) that make up the cell membrane. They have a polar head with two non-polar tails.

Semipermeable

Allows certain things to pass through and prevents other things from passing through.

Hydrophilic

Will mix with water; polar phospholipid heads

Hydrophobic

Will not mix with water; nonpolar phospholipids tails

Phospholipid bilayer

Double layer of lipids; heads face outward, tails are in the middle

Cholesterol

Molecules embedded throughout the membrane; help to stabilize the phospholipids and keep them in position, and help to maintain the cell membrane's flexibility

Golgi Apparatus

packages, modifies, and ships vesicles throughout the cell.

Mitochondria

Known as the “powerhouses of the cell,” mitochondria produce the energy necessary for the cell's survival and functioning.

Phosphate

an important component of the lipid bilayer (phospholids) of cell membranes, DNA, RNA, and proteins.

Cilia

The bronchus in the lungs are lined with hair-like projections that move microbes and debris up and out of the airways.

Microvilli/Villi

finger-like projections that extend from the surface of epithelial cells to increase the surface area in order to absorb more nutrients.

Lysosomes

the digestive system of the cell, contains powerful enzymes that are capable of breaking down molecules of nutrient or foreign particles that enter cells.

Nucleus

store and protect the cell's genetic material (DNA)

Ribosomes

tasked with synthesizing proteins, therefore they are known as the protein factory of the cell.

Cytosol

a jelly-like fluid that fills the interior of a cell, surrounding the organelles and other subcellular compartments.

Cytoplasm

provides shape to the cell. It fills up the cells thus enabling the organelles to remain in their position.

Endoplasmic Reticulum

a collection of tubes that make, package, and transport proteins and fats.

Vesicle

a structure within or outside a cell, consisting of liquid or cytoplasm enclosed by a lipid bilayer.

Lipid

are fatty, waxy, or oily compounds that are soluble in organic solvents and insoluble in polar solvents such as water.

Integral Membrane Protein

proteins being associated or attached to the membrane of a cell or an organelle inside the cell.

Receptor Protein

a special class of proteins that function by binding a specific ligand molecule. When a ligand binds to its receptor, the receptor can change conformation, transmitting a signal into the cell

Cell Surface Proteins

play a critical role in cell-cell interactions, nutrients and metabolite transport as well as translation of extracellular signals into intracellular responses

Enzymes

proteins that help speed up chemical reactions in our bodies.

Animal Cell

are eukaryotic cells with membrane-covered organelles, a nucleus, and mitochondria. Animal cells are found in all organisms belonging to the animal kingdom.

Organelle

a subcellular structure that has one or more specific jobs to perform in the cell, much like an organ does in the body.

Active transport

the movement (as across a cell membrane) of substances from regions of lower concentration to regions of higher concentration by the use of energy.

Bulk transport

a mode of transport of large quantities of materials and food particles across the membrane.

Endocytosis

a process by which cells take in substances from outside of the cell by engulfing them in a vesicle; receptor-mediated (endo = inside)

Pincocytosis

the process where fluid and dissolved substances and molecules are taken up by the cell. (cell drinking)

Phagocytosis

a process wherein a cell binds to the item it wants to engulf on the cell surface and draws the item inward while engulfing around it. (cell eating)

Exocytosis

the process of vesicles fusing with the plasma membrane and releasing their contents to the outside of the cell. (exo = outside)

Aquaporon

proteins made of amino acids that form a narrow pore in the cell membrane for water to pass through.

Transcytosis

combines endocytosis and exocytosis; moves substances across barriers formed by tightly connected cells.