bio.txt

Lipid is a catch-all term for carbon containing compounds that are found in organisms and are largely nonpolar and hydrophobic (don�t dissolve in water, but in liquids with nonpolar organic compounds)

hydrocarbon chains without double bonds. (max number of hydrogen,more chemical energy, higher melting point)

contain double bond, fewer than max number of hydrogen atoms attached.

family of lipids distinguished by the bulky four ring structure. Differ by functional groups

composed of three fatty acids that are linked to a three carbon molecule(glycerol) ( also called triglycerols, triglcerides) not polymers

consist of a glycerol that is linked to a phosphate group, and to either two chains of isoprene or two fatty acids. Phosphate also bonded to small organic molecule that is charged or polar.

Contain both hydrophilic and hydrophobic elements

The tendency of a structure to allow a given substance to pass across

• �Small nonpolar molecules move across bilayers quickly.
• �Large molecules and charge substances cross the membrane slowly.
• �Sometimes they don�t cross at all.
• � Large molecules and charge molecules can�t pass through the
• Non polar hydrophobic tails of the lipid bilayer.

• �In a lipid bilayer membrane with unsaturated phospholipids the hydrophobic part is less tight
• �Hydrophobic interactions become stronger as saturated hydrocarbon tails increase in length.
• �Membranes compose of phospholipids with long saturated tails are more stiffer and less permeable.
• �The reason is that the interaction between the tails are stronger.

dissolved molecules or ions

difference across space in the concentration of a dissolved substance

liquid in which one or more solids can dissolve

spontaneous movement of a substance from a region of high concentration to one of low concentration (down gradient)

- diffusion of water across a selectively permeable membrane from a region of high water concentration (low solute) to region of low water [] (high solute)

movement of a substance across a plasma membrane down its concentration gradient with the assistance of transmembrane carrier proteins of channel protteins

movement of ions or molecules across a plasma membrane against an electrochemical gradient. Requires energy (hydrolysis of atp) and assistance of transport protein

measure of the osmotic pressure (as defined by the water potential of the two solutions) of two solutions separated by a semipermeable membrane.

solution that has a lower solute concentration, therefore higher water concentration. Water flows into cell,cell swells or burts

solution that has the same solute concentration and water concentration. No change

solution that has a greater solute concentration, lower water concentration. Water flows out of cell, cell shrinks

diffusion of a substance across a plasma membrane or organelle membrane. When this occurs with the assistance of a membrane protein, facilitated diffusion.

selective, each protein has a structure that allows it to admit a particular type of ion or small molecule. (pore like)

transporter) membrane protein that facilitiates diffusion of a small molecule (glucose) across the plasma membrane by a process involving a reversible change in the shape of the protein

membrane protein that can hydrolyze ATP to power active transport of a specific ion or small molecule across a plasma membrane against its electrochemical gradient

complex, composes animal, plants, fungi, protists. either single or multi-celled. Has nucleus, DNA, membrane bound organelles

composes all bacteria and Archaea, lack membrane bound nucleus. Only has one membrane (plasma membrane) genetic material naked, ribosomes only organelle, always single celled

Only in prokaryotes. Where chromosomes are found, center of cell, not separated by membrane

In eukaryotic, plant and animal cells. Consists of flattened, membranous sacs called cisternaw, has distinct polarity.. Functions in processing and sorting proteins and lipids destined to be secreted or directed to other organelles

In eukaryotic cells. Interior of the rough ER. Where newly manufactured proteins undergo folding and other types of processing

In prokaryotic cells. Usually circular, supercoiled DNA molecules. Contain genes but are physically independent of the main, cellular chromosome. Help cells adapt to unusual circumstances (auxiliary geetic elements)

In eukaryotic cells. Has two membranes, outer and inner with cristae. Solution inside mitochondrial matrix. Site of aerobic respiration, where most ATP is produced

• In eukaryotic cells
• Complex double embrane, encloses nucleus and is studded with pore like openings, inside surface linked to nuclear lamina

In eukaryotes- long cellular projection that undulates. In prokaryotes- rotates To move the cell through an aqueous environment

In plant cells. Chlorophyll containing organelle, bounded by double membrane. Where photosynthesis occurs

Prokaryotic and In plant cells, fibrous layer found outside plasma membrane of most bacter and archaea annd eukaryotes. defines shape f a plant cell.

Specific site in nucleus where gene products are processed. Where RNA molecules found in ribosome�s are manufactured and the large and small ribosomal subunits are assembled

Animal cells. Function as digestive centers. Interior acidic, has enzymes that catalyze hydrolyss reactions and can digest large molecules

eukaryotic. Free of ribosome�s Contains enzymes that catalyze reactions involving lipids. ( lipids may be needed by organism or break down lipids that are poisonous.. Manufacturing site for phospholipids used In plasma membrane. Resevoir for calcium ions that act as a signal

eukaryotic. Has ribosome�s attached to membrane. Protein manufacturing center

In prokaryotic cells. To fit in cell, DNA double helix coils on itself with the aid of enzymes to form supercoiled structure

Transport, eukaryotic

Complex of DNA and protiens, that compose eukaryotic chromosomes. Can be highly compact or loosely coiled

Found in most eukaryotic cells. Contain enzymes for oxidizing fatty acids and other copounds including may toxins, rendering them harmless

In plant and fungal cells. Usually is used for bulk storage of water, pigments, oils, or other substances. Some contain enzymes that have digesive function similar to lysosomes in animal cells

SYNTHESIZES PROTEINS BY USING GENETIC INFORMATION ENCODED IN MRNA STRANDS. TWO SUBUNITS. both

both. gene carrying structure consisting of single long molecule of DNA and associated proteins. Prokaryotic contain single, circular Eukaryotic contain multiple linear located in nuclues

Both All of the content of a cell, excluding nucleus bounded by the plasma membrane

in eukaryotic cells, one of two small cylindrical structurs, found together within the centrosome near the nucleus

Eukaryotic cells. Network of protein fibers in the cytoplasm that are involved in cell shape, support, locomotion, and transport of materials withincell. Prokaryotic cells have similar but much less extensive netowrk

long fiber, one of three types of cytoskeletal fibers. involved in cell movement

long fiber, one of three types of cytokeletal fibers. help maintain cell shape and hold nucleus in place

involved in cell movement and transport of materials within the cell

Any one of a class of motor proteins that use ATP to move along microfilaments in muscle contraction, cytokinesis, and vesicle transport

type of motor protein, uses ATP to transport vesicles, particles, or chromosomes along microtubules

proteins bound for the endomembrane system have a molecular zip code analogous to the nuclear localization signal.

receives products from the rough ER carried by vesicles

ships products out toward the cell surface

damaged organelle is surrounded by a membrane, delved to the lysosome, and digested and recycled into cytosol

plasma membrane of a cell surrounds a smaller cell or food particle and engulfs it, forming a structure called a phago some. Delivered to a lysosome and digested

uptake by a cell of extracellular fluid by pinching off the plasma membrane to form small membrane bound vesicles, type of endocytosis

secretion of intracellular molecules contained within membrane-bound vesicles, to the outside of the cell by fusion of vesicles, to the outside of the cell by fusion of vesicles to the plasma membrane

general term for any pinching off of the plasma membrane that results in the uptake of material from outside the cell. Includes phagocuosis, pinocytosis, receptor-mediated endocytosis

opening in the nuclear envelope that contains the inside of the nucleus with the cytoplasm and through which molecules such as mRNA and some proteins can pass

• microfibril synthesized by a complex of enzymes in the plasma membrane, forming a crisscrossed network. Peptines are synthesize in the rough ER and Golgi apparatus
• and secreted into the extracellular space.

structural support. animal ECM contains much more protein that a cel wall. structure correlates with the cell's function.

where gaps in cel walls create direct connections between cytoplasm of adjacent cells in plant cells. plasma membrane and cytoplasm of two cell continuous, smooth er runs through the hole.

The actin filaments in the cytoskeleton are connected to transmembrane proteins (integrins.) The integrins bind to nearby proteins in the ECM, including fibronectins, which in turn bind to collagen fibers. Helps adjacent cells adhere to each other via their common connection to the ECM, keep individual cells in place

cell-cell attachment composed of specialized proteins in the plasma membrane of adjacent animal cells. (water tight seal, common in cells that form barrier)

cell-cell attachments common in animal epithelial cells and certain muscle cells. consist of proteins that bind the cytoskeletons of adjacent animal cells together. found where cells are strongly attached to each other

cell-cell attachment that directly connects the cytoplasms of adjacent animal cells, allowing the passage of water, ions, and small molecules between the cellos.

small information carrying molecules that are secreted from a plant or animal cell, circulate in the body, and act on target cells far from the original cell that sent the signal

hormone binds to a receptor in the plasma membrane, which is coupled to a peripheral G preen on the membrane's inner surface. The receptor changes shapes. TThe shape change activates the G protein,releasing GDP that kept in an inactive state and binds to GTP. When GTP is attached, the G protein splits into two parts. One part activates a nearby enzyme that is embedded in the plasma membrane, which catalyzed the production of a second messenger.

hypertonic

They will be recognized by receptors in the cell membrane. lipids and hydrophilic hormones have two general qualities; Receptor are dynamic. Receptor can be blocked.

intracellular signals that spread the message carried by the hormone. concentration increases as a result of the signal trigger by the first messenger (hormone) effective because small and diffuse the signaling rapidly inside the cell. No t proteinsNot restricted to a signal role/ activate protein kinases.

making and breaking of chemical bonds, leading to changes in the composition of matter. Affected by if the reactants collide in a precise orientation and if enough kinetic energy is involved in the reaction to overcome the repulsion between electrons that come into contact as bonds form

bring the reactant molecules together in a precise orientation, allowing the electrons to interact. Also affect amount of kinetic energy that reactant must have for a reaction to proceed.

reactant on which an enzyme works

combination of old and new bonds that are formed when reactants collide

amount of energy reactant must absorb before a chemical reaction will start

substance that lowers the activation energy of a reaction and increases the rate of the reaction

portion of an enzyme where substrates bind and react

changes in shape of the active site of an enzyme, result of the initial weak binding of a substrate so that it binds more tightly

initiation (enzymes orient the reactants precisely as they bind specific location in the active site) transitional state facilitations (binding of a substrate in the active site facilitate the transition state) and termination (the reaction product have less affinity for the active site)

a metal ion that is required for an enzyme to function normally. may be bound tightly to an enzyme or associate wih it transiently during catalysis

small organic molecule that is a required cofactor for an enzyme-catalyzed reaction. Often donates or receives electrons or functional groups during the reaction

occurs when a molecule that is similar in size and shape to the substrate binds to the active site (competes with the substrate for the active site

regulation of a proteins function by binding of a regulatory molecule, usually to a specific site distinct from the active site, causing a change in the proteins shape

• and the rate of reaction.
• as concentration of the substrate increase the increase in speed reaction slows, will plateau at a max speed, active site cannot accept substrate any faster temperature affects the movement of enzymes and substrate (only work at optimum temperature) pH affects makeupand charge of amino acids side chain that contain carboxyl groups or amino acids, also affects active site ability to participate in proton transfer or electron transfer reaction (have optimum pH)

the amount of potential energy that an electron has is based on its position relative to other electrons and to the rtonselectron close to negative charges and far from positive, has high potential energy

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exergonic and endergonic reactions are coupled. allows the endergonic reaction to become eexrgonic when the substrate or enzyme are phosphorylated

• �oxidized� and �reduced.�
• redox- class of chemical reaction that involve loss or gain of an electron. atom that loses electron iodized, atone that gains are reduced

breakdown of a glucose molecule. breakes into molecules of pyruvate, the cell must pen 2 ATP to start and 4 ATP are gnerated(2 net ATP gain) and two molecules of NAD+ enter pathways and become NADH

2 ATP

the pyruvate molecule (which is a three carbon molecules) enter the pathway and subsecuently it gets transform into a six carbon molecules called citrate. As the cycle continues, the carbon atoms get rearrange and decarboxylated (which means that carbon is removed in the form of carbon dioxide). The Kreb cycles produces 1 ATP, 4 NADH, 1 FADH2 and 3 CO2. Notice that because two molecules of pyruvate were created these amounts should be multiply by two to get the total amounts of these molecules per molecule of glucose. At this point in cellular respiration the entire molecule of glucose has been catabolised

• Why not oxidize glucose in one BIG step, get it over with already, instead of all those
• annoying little steps?

• inside mito lumen, outside in cytoplasm, etc.)
• Glycolisis which occurs in the cytoplasm of the cell. Krebs Cycle- which occurs in the matrix of the mitochondria. electron transfer system which occurs in the mitochondria innermembranes.

The energy in glucose is stored in the covalent bonds between the molecules, and most importantly, in the hydrogen electrons. T

NAD+ when reacted with 2 H produces NADH plus 1 H, FAD when reacted with 2 H produces FADH@. Molecules are important because they are carrying electrons that will transfer to the next metabolic reaction known as the electron transport system

set of membrane bound protein complexes and smaller soluble electron carriers involved in a coordinated series of reduce reactions in which potential energy of electrons transferred from reduced donors is successively decreased and used to pump protons from one side of a membrane to the other protein

Most molecules in the electron transport chain are proteins that contain distinctive chemical groups where the redox events take place. arranged in a sequence according to elecronegativity, lower to higher

• electrons will pass from molecules of lower electronegativity to molecules of higher electronegativity via a redox reaction.
• A small amount of energy will be release in each step and the potential energy in each successive step will be lessen.

energetic coupling mechanism where energy stored in an electrochemical proton gradient is used to drive an energy-requiring process such as production of ATPfavor the movement of protons back into the matrix.

organism that use oxygen as their final electron acceptor, fermentation is use as a way of obtaining energy when the oxygen supply temporary ran out.

metabolic pathway that regenerate NAD+ molecules from stock piles of of NADH allows glycolysis to continue

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