The working cell

Membrane

Fluid mosaics of lipids and proteins with many functions

Selective permiabilty

Allowing some substances to pass easier than others

Attachment proteins

Attach to the extracellular matrix and cytoskeleton. help support the membrane, and can coordinate external and internal changes

Receptor Proteins

Signaling molecules bind to them, and relay the message by activating other molecules inside the cell

Junction Proteins

Form intercellular junctions that attach adjacent cells

Glycoproteins

Serve as ID tags, may be recognized by membrane proteins of other cells

Diffusion

The tendecy of particles to spread out evenly in an availible space

Passive transport

Movement that does not require energy

Concentration gradient

Movement of molecules from high to low concentration

Solute

The material in a solution that gets disolved

Solvent

The material in a solution that acts as the disolving agent

Osmosis

The diffusion of water across a semipermeable membrane

Tonicity

Describes the ability of a surrounding solution to cause a cell to gain or lose water

Hypertonic

Type of solution that has a higher solute concentration that the cell, which causes the cell to shrink

Hypotonic

Type of solution with a lower solute concentration than the cell, causing the cell to swell

Isotonic

Solution with an equal concentration to the cell, which makes animal cells normal and plant cells flaccid

Osmoregulation

Control of water balance within a cell

Facilitated diffusion

Moving hydrophilic molecules and ions across membranes

Transport proteins

Proteins that facilitate diffusion across membranes

Carrier proteins

Transport protein that binds, reshapes, and releases molecules being transported

Aquaporin

Specific transport protein for water

Active transport

Moving a solute against the concentration gradient, uses energy

Cytosis

Transporting large molecules across membranes

Exocytosis

Used to export bulky molecules, such as proteins or polysaccharides

Endocytosis

Used to take in large molecules

Phagocytosis

Endosystosis that engulfs the particle by the cell wrapping cell membrane around it, forming a vacuole

Receptor-mediated endocytosis

Endosytosis that uses membrane receptors for specific solutes

Kinetic Energy

Energy of motion

Thermal energy

Type of kinetic energy associated with movement of atoms and molecules, can transform one object to another through heat

Potential Energy

Energy stored in the location or structure of matter, includes chemical energy

Laws of thermodynamics

Energy cannot be created of destroyed, and energy tranfering increases disorder/entropy with some energy being lost as heat

Exergonic

Type of reaction that releases energy

Endergonic

Type of reaction that requires energy and yields products rich in potential energy

Metabolism

Encompasses all of the cell chemical reactions, both exergonic and endogonic

Metabolic pathway

A series of chemical reactions

Energy coupling

The use of energy from exergonic reactions to power endergonic reactions

ATP

Protein that powers nearly all forms of cellular work

Phosphorylation

The transfer of a phosphate group from ATP that is involved in chemical, transport, and mechanical work

Enzyme

Protein catalysts that decrease the activation energy required to begin a reaction

Active site

Part of the enzyme where the substate goes in order to make a product

Apoenzyme

The strucutre of the enzyme that is always presents and highly specific, protein path speeds up the reacton

Coenzyme

Part of most enzymes that is needed to fully activate the apoenzyme, not specific to an enzyme

Denature

The process where an enzyme loses its shape due to high temperature of a low/high pH

Inhibitors

Molecules that stop subtrates from bonding to the active site

Competitive Inhibitors

Inhibitors that competes with the substrate for the active spot

Noncompetitive inhibitor

Inhibitor that alters the enzyme’s function by changing its shape

Feedback inhibitor

Inhibitor that helps regulation metabolism