Anatomy/Physiology

Active require the expenditure of metabolic energy by the cell while passive do not require any energy of the cell membrane.

the net movement of molecules from a region of higher concentration to a region of lower concentration.

a measurable difference in concentration from one area to another.

a dissolved substance

• hypotonic solutions are at lower pressure to the intracellular fluid. they will cause a cell to swell because of the they absorb more water
• hypertonic solutions are at a higher pressure to the intracellular fluid. this will cause the cell to shrivel as water leaves the cell

• the diffusion of water through a selectively permeable membrane.
• ex. diffusion of water in and out of cells

• simple diffusion
• osmosis
• channel mediated passive transport(facilitated diffusion)
• carrier-mediated passive transport(facilitated diffusion)

• diffusion of particles through a membrane by means of channel structures in the membrane. They move down a concentration gradient.
• ex. diffusion of Na ions into nerve cells

• diffusion of particles through a membrane by means of carrier structures in the membrane.
• ex. diffusion of glucose molecules into most cells.

• channel-mediated passive transport
• carrier-mediated passive transport

• pumping
• phagocytosis(endocytosis)
• pinocytosis(endocytosis)
• exocytosis

• phagocytosis
• pinocytosis
• exocytosis

moving a substance into the cell by means of a vesicle

• the moving of a substance out of the cell by means of a vesicle.
• ex. secretion of the hormone prolactin by the pituitary cells

• microorganisms or other large particles are engulfed by the plasma membrane and enter the cell in vesicles.
• ex. trapping of bacterial cells by phagocytic WBC's

• "condition of cell drinking"
• fluid and the substance dissolved in it enter a cell.
• ex. trapping of lrg protein molecules by some body cells

• carry out transport process in which cellular energy is used to move molecules uphill through the cell membrane.
• ex. the pumping of Ca ions in muscle cells

set of chemical reactions in a cell

• catabolism
• anabolism

• breaks large molecules into smaller ones.
• usually releases energy

• builds large molecules from smaller ones.
• usually consumes energy

a chemical that reduces the amount of activation energy needed to start a chemical reaction.

are functional proteins whose molecular shape allows them to catalyze chemical reactions.

• oxidation-reduction
• hydrolyzing enzymes or hydrolases
• phosphorylating enzymes
• carboxylases or decarboxylases
• mutases or isomerases
• hydrases

known as oxidases, hydrogenases, and dehydrogenases. the energy released for muscular contraction and all physiological work depends on these.

• digestive enzymes belong to this group.
• ex. lipase, sucrase, and maltase

they add or remove phosphate groups and are know as phosphorylases or phosphatases.

enzymes that add or remove carbon dioxide

enzymes that rearrange atoms within a molecule.

enzymes that add water to a molecule without splitting it.

a molecule or other agent that alters enzyme function by changing its shape.

the pathway by which cells break down glucose(C₆H₁₂O₆) or a nutrient that has been converted to glucose or one of it simpler products into carbon dioxide(CO₂) and water (H₂O).

• glycolysis
• citric acid cycle
• electron transport system

• James Watson-American
• Frances Crick-UK
• Maurice Wilkins-UK
• Rosalind Franklin-UK

the beginning of protein synthesis starts with transcription, process where an mRNA molecule forms along one gene sequence of DNA. It exits through the nuclear pores. Outside the nucleus ribosome subunits attach to the beginning of the mRNA molecule and begin the process of translation.

• transcription is the synthesis of any RNA molecule, it copies a portion of the DNA code.
• translation is when the genetic code is translated and forms a specific sequence of amino acids.

water pressure that develops in a solution as a result of osmosis into that solution.

• small hydrophobic molecules(O₂ & CO₂), uncharged molecules can easily pass.
• Water and urea can diffuse only slightly.
• Larger uncharged molecules and ions may not pass at all.

Na ions pass only through Na channels and Cl ions can only pass through Cl channels.