A&P Chapter 4.txt

• Does not require energy to move thru a cell membrane
• High concentration to low concentration

• Diffusion
• Simple Diffusion
• Osmosis
• Facilitated Diffusion

• Molecules spread thru the membranes
• Molecules move from an area of high concentration to an area of low concentration
• Does not require a membrane

• Small uncharged molecules cross through a phospholipid bilayer
• This requires diffusion thru a membrane

• Diffusion of water through a selectively permeable membrane.
• Water pressure develops as a result of osmosis and is called osmotic pressure

Na+

K+

Towards the concentrated solution

The maximum pressure that could develop in a solution when it is separated from pure water by selectively permeable membrane

When two fluids have the same potential osmotic pressure. Water moves in equal amounts in the same direction

• “higher pressure”
• Cells placed in solution that are hypertonic to intracellular fluid ALWAYS shrivel as water flows out of the cell (FROM LOW OSMOTIC PRESSURE TO HIGH OSMOTIC PRESSURE)
There are more solutes than water. More water is needed here, so water will be taken from the ever is put in the solution

• “lower pressure”
• Cells placed in a hypotonic solution may swell as water flows into them.
• There is more water in the solution. To even it out, water is going to enter the cell.

• Movement of molecules is made more efficient by the action of transporters embedded in a cell membrane.
• Proteins assist in the transportation of substances down a concentration gradient

Breaks large molecules into smaller ones to release energy

Carbohydrate breakdown- breakdown glucose to get ATP to be stored in mitochondria.

• Glycolosis
• Citric Acid Cycle
• Electron Transport System

Mitochondria

In the mitochondria with use of oxygen

In the cytoplasm

The pathway in which glucose if broken down to yield its stored energy

Builds large molecules from smaller one. This normally consumes energy

Protein manufacture- DNA

• Chemical catalysts that reduce the activation energy needed for a reaction
• Regulates a cell meatabolism

Enzymes

Channels are specific allowing only one type of solute to pass thru

Water channels that permit rapid osmosis

• Require ATP
• Transport by Pumps
• Transport by Vesicles

• Calcium pump
• Sodium- Potassium pump

• Endocytosis
• Exocytosis

Allows substances to enter or leave the interior of the cell without actually moving through its plasma membrane

Move substance against a concentration gradient from low concentration to high concentration

The plasma membrane traps some extracellular material and brings it into the cell in a vesicle

• Phagocytosis
• Pinocytosis

• Condition of cell eating
• Once in the cell the vesicle fuses with a lysosome

Condition of cell drinking

Membrane receptor molecules recognizes substance to be brought into cell

Process in which large molecules, mostly proteins, can leave the cell even they are too large to pass thru the plasma membrane

Exocytosis

Enzymes regulate cell functions by regulating metabolic pathways

• Temp
• Hydrogen Ions
• Ionizing radiation
• Cofactors

They change the shape of the enzyme molecule activation site

The product of one enzyme-regulated reaction becomes the substrate for the next reaction. Thus, a whole series of enzymes is required to keep the pathway functioning.

Inactive proenzymes

YES

A double-helix polymer that functions to transfer information, encoded in genes, that directs the synthesis of proteins

A segment of DNA molecule that consists of aprx 1000 pairs of nucleotides and they determine the cell structure and function

Cell division that occurs in all body cells where the daughter cells have the same number of chromosomes as the mother cells

• Cell division where the daughter cells have half the number of cells as the mother cells.
• THIS ONLY OCCURS IN SEX CELLS

Depends on using genetic information in DNA to make the structural and functional proteins needed for cell survival

Ensures that genetic information is passed from one generation to the next

Division of cytoplasm