Term
Passive Transport Processes
|
|
Definition
| Do not require and energy (ATP) expenditure of the cell membrane. |
|
|
Term
|
Definition
|
|
Term
| Molecules move from an area of: |
|
Definition
| an high concentration to an area of low concentration, down a concentration gradient. |
|
|
Term
|
Definition
| a state of equililbrium will occur |
|
|
Term
|
Definition
| Molecules cross through the phospholipid bilayer |
|
|
Term
|
Definition
| Diffusion of water through a selectively permeable membrane; limits diffusion of at least some of the solute particles |
|
|
Term
|
Definition
| water pressure that develops as a result of osmosis |
|
|
Term
| Potential Osmotic Pressure |
|
Definition
| The maximum pressure that could develop in a solution when it is separated from pure water by a selectively permeable membrane |
|
|
Term
|
Definition
| describes a fluid having the same potential osmotic pressure as cytosol |
|
|
Term
|
Definition
Higher pressure
cells placed in sloutions that are hypertonic always shrivel as water flows out of them |
|
|
Term
|
Definition
lower pressure
cells placed in a hypotonic slotuin may swell as water flows into them |
|
|
Term
Facilitated Diffusion
(mediated passive tranport) |
|
Definition
| energy required comes from the collision energy of the solute (no metabolic energy needed ATP) |
|
|
Term
| Channel Mediated Passive Transport |
|
Definition
| Channels are specific-allow only one type of solute to pass through. |
|
|
Term
|
Definition
| may be open or closed or inactive may be triggered by any of a variety of stimuli |
|
|
Term
| Channels allow membranes to |
|
Definition
|
|
Term
|
Definition
| Are water channels that permit rapid osmosis |
|
|
Term
| Carrier Mediated Passive Transport |
|
Definition
| Carriers attract and bind to the solute, change shape, and release the solute out the other side of the carrier |
|
|
Term
|
Definition
| Reversible depending on the directions of the concentration gradient |
|
|
Term
| Role of passive transport processes |
|
Definition
| Move substances down their concentration gradient, thus maintaining equilibrium-and homeostatice balance |
|
|
Term
| Types of passive transport: |
|
Definition
| Simple and facilitated diffusion (channels and carriers) |
|
|
Term
| A special example of channel mediated passive tranport of water |
|
Definition
|
|
Term
|
Definition
| Pumps are membrane transporters that move a substance against their concentration gradient-opposite of diffusion |
|
|
Term
|
Definition
| calcium pumps and sodium potassium pumps |
|
|
Term
|
Definition
| Allows substances to enter or leave the interior of cell without actually moving through its plasma membrane |
|
|
Term
|
Definition
| The plasma membrane "traps" some extracellular material and brings it into the cell in a vesicle |
|
|
Term
| Two basic types of endocytosis |
|
Definition
| Phagocytosis and pinocytosis |
|
|
Term
|
Definition
| "Condition of cell eating" large particles are engulfed by the plasma membrane and enter the cell in vesicles; the vesicles fuse with lyosomes, which digest the particles |
|
|
Term
|
Definition
| "Condition of cell drinking" fluid and the substances dissolved in it enter the cell |
|
|
Term
| Receptor mediated endocytosis |
|
Definition
| membrane recpetor molcules recongnize substances to be brought into the cell |
|
|
Term
|
Definition
| Process by which large molecules, notably proteins, can leave the cell even though they are too large to move out through the plasma membrane. |
|
|
Term
| Large molecules are enclosed in membranous vesicles and then |
|
Definition
| pulled to the plasma membrane by the cytoskeleton, where the contents are released |
|
|
Term
| Exocytosis also provides a way for |
|
Definition
| new material to be added to the plasma membrane |
|
|
Term
| Role of active transport processes |
|
Definition
| requires energy by the membrane; pumps-concentrate substances on one side of membrane, as when storing an ion inside an organelle |
|
|
Term
Vesicle mediated
(endocytosis, exocytosis) |
|
Definition
| move large volumes of substances at once, as in secretion of hormones and neurotransmitters |
|
|
Term
|
Definition
| chemical reactions in a cell |
|
|
Term
|
Definition
| Breaks large molecules into smaller ones; usually releases energy |
|
|
Term
|
Definition
| Builds large molecules from smaller ones; usually consumes energy |
|
|
Term
|
Definition
| Enzymes are chemical catalysts that reduce the activation energy needed for a reaction. Enzymes regulate cell metabolism. |
|
|
Term
|
Definition
| Proteins of a complex shape. The active site is where the enzyme molecule fits the substrate molecule-the lock and key model. |
|
|
Term
| Enzymes usually have an -ase ending |
|
Definition
| with the first part of the word signifying the substrate or the type of reaction catalyzed |
|
|
Term
| Enzymes regulate cell functions by |
|
Definition
| regulating metabolic pathways |
|
|
Term
| Various chemical and physical agents known as allosteric effectors affect enzyme action by |
|
Definition
| changing the shape of the enzyme molecule |
|
|
Term
| Allosteric effectors include |
|
Definition
| Temp, hydrogen ion H+ concentration (pH), ionizing radiation, cofactors, end products of certain metabolic pathways |
|
|
Term
| Most enzymes catalyze a chemical reaction in |
|
Definition
|
|
Term
| Enzymes are continually being destroyed and |
|
Definition
| continually being replaced |
|
|
Term
| Most enzymes are first synthesized as |
|
Definition
|
|
Term
| Cellular respiration, the pathway by which glucose is broken down to yield its stored energy |
|
Definition
| is an important example of cell catabolism |
|
|
Term
| Cellular respiration has three pathways that are chemically linked |
|
Definition
| Glycolysis, citric acid cycle, electron transport system. |
|
|
Term
| Citric Acid Cycle (Krebs Cycle) Pyruvic acid (from glycolysis) is converted into |
|
Definition
| acetyl CoA and enters the citric acid cycle after losing CO2 and transferring some energy to NADH |
|
|
Term
| Citric acid cycle is a repeating cyclic sequence of reactions that occur inside the inner chamber of the mitochondrion; acetyl splits from |
|
Definition
| CoA and is broken down to yield waste CO2 and energy (in form of energized electrons) which is tranferred to ATP, NADH, and FADH2 |
|
|
Term
| Electron transport system ETS |
|
Definition
| Energized electrons are carried by NADH and FADH2 from glycolysis and the citric acid cycle to electron acceptors embedded in the cristae of the mitochondrion |
|
|
Term
|
Definition
| As electrons are shuttled along a chain of electom accepting molecules in the cristae, their energy is used to pump accompanying protons H+ into the spaces between mitochondrial membranes |
|
|
Term
| ETS: protons flow back into the inner chamber through pump molecules in the cristae, |
|
Definition
| and their energy of movment is transferred to ATP |
|
|
Term
| Low-energy electrons coming off the ETS bind to |
|
Definition
| oxygen and rejoin their protons to form water |
|
|
