Bio Master Vocab

Polar

a molecule (such as water) with an uneven distribution of charges in different regions of the molecule

Nonpolar

a molecule with an even distribution of charges in different regions of the molecule

Polar Covalent Bond

a covalent bond between atoms that differ in electronegativity. The shared electrons are pulled closer to the more electronegative atom, making it slightly negative and the other atom slightly positive

Nonpolar Covalent Bond

a type of covalent bond in which electrons are shared equally between two atoms of similar electronegativity

Covalent Bond

a type of strong chemical bond in which two atoms share one or more pairs of valence electrons

Ionic Bond

a chemical bond resulting from the attraction between oppositely charged ions

Hydrogen Bond

a type of weak chemical bond that is formed when the slightly positive hydrogen atom of a polar covalent bond in one molecule is attracted to the slightly negative atom of a polar covalent bond in another molecule or in another region of the same molecule

Dehydration Synthesis

a chemical reaction in which two molecules become covalently bonded to each other with the removal of a water molecule

Hydrolysis

a chemical reaction that breaks bonds between two molecules by the addition of water; functions in disassembly of polymers to monomers

Monomer

the subunit that serves as the building block of a polymer

Polymer

a long molecule consisting of many similar or identical monomers linked together by covalent bonds

Carbohydrates

a sugar (monosaccharide) or one of its dimers (disaccharides) or polymers (polysaccharides)

Monosaccharide

the simplest carbohydrate, active alone or serving as a monomer for disaccharides and polysaccharides. Also known as simple sugars, monosaccharides have molecular formulas that are generally some multiple of CH2O

Polysaccharide

a polymer of many monosaccharides, formed by dehydration reactions

Cellulose

a structural polysaccharide of plant cell walls, consisting of glucose monomers joined by beta glycosidic linkages

Cohesion

the linking together of like molecules, often by hydrogen bonds

Adhesion

the clinging of one substance to another, such as water to plant cell walls, in this case by means of hydrogen bonds

Specific Heat

the amount of heat that must be absorbed or lost for 1g of that substance to change its temperature by 1 degree celsius

Heat of Vaporization

the quantity of heat a liquid must absorb for 1 g of it to be converted from the liquid to the gaseous state

Lipid

any of a group of large biological molecules, including fats, phospholipids, and steroids, that mix poorly, if at all, with water

Phospholipid

a lipid made up of glycerol joined to two fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as a nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head. Phospholipids form bilayers that function as biological membranes

Steroid

a type of lipid characterized by a carbon skeleton consisting of four fused rings with various chemical groups attached

Saturated Lipid

a fatty acid in which all carbons in the hydrocarbon tail are connected by single bonds, thus maximizing the number of hydrogen atoms attached to the carbon skeleton

Unsaturated Lipid

a fatty acid that has one or more double bonds between carbons in the hydrocarbon tail. Such bonding reduces the number of hydrogen atoms attached to the carbon skeleton

Isomer

one of two or more compounds that have the same numbers of atoms of the same elements but different structures and hence different properties

Structural Isomer

one of two or more compounds that have the same molecular formula but differ in the covalent arrangements of their atoms

Cis-Trans Isomer

one of two or more compounds that have the same molecular formula and covalent bonds between atoms but differ in the spatial arrangements of their atoms owing to the inflexibility of double bonds; formerly called a geometric isomer

Enantiomer Isomer

one of two compounds that are mirror images of each other and that differ in shape due to the presence of an asymmetric carbon

Nucleus

houses DNA

Nuclear Envelope

porous outer structure of Nucleus. Controls what gets in and out of nucleus.

Nucleolus

site of Ribosome synthesis.

Cytoplasm

area from Plasma Membrane to the Nucleus filled with cytolsol - the jelly-like material organelles are suspended in.

Plasma (Cell) Membrane

semi-permeable outer structure of cell; controls what goes in/out of cell.

Ribosome

site of protein synthesis.

Golgi Apparatus

\-synthesizes, Modifies, & Sorts cell products. Secretes products into vesicles for transport

\-produces Lysosomes

\-flattened membrane sacs called cisternae

Rough Endoplasmic Reticulum

\-covered in Ribosomes (aids protein synthesis)

\-compartmentalizes Cell (produces membrane)

\-mechanical Support for Cell

\-intracellular Transport

Smooth Endoplasmic Reticulum

\-site of phospholipid synthesis

\-packages enzymatic content of lysosomes, peroxisomes, and other secretory vesicles.

Lysosome

\-digests Macromolecules using hydrolytic enzymes

\-controls programmed cell death (Apoptosis)

Mitochondria

\-site of Cellular Respiration (ATP Production)

\-double membrane with folds (cristae) to increase SA for max. cellular respiration capability

Peroxisome

Involved in metabolism; produces hydrogen peroxide (H2O2) which then gets converted into water & oxygen gas.

Cytoskeleton

maintains Cell Shape: Composed of microtubules & microfilaments

Cell Wall

outer structure of Plant cells; made of cellulose. Provides rigidity and support.

Chloroplast

site of photosynthesis.

Plasmodesmata

channels through cell walls that connect cytoplasms of adjacent plant cells

Vacuole

storage structure. Large Central Vacuole in Plants. In plants, enlargement = plant growth.

Chromatin

uncondensed genetic material inside the nucleus.

Flagellum

some animal cells; motility structure.

Microvilli

projections of Plasma Membrane; increase SA.

Centrosome

region where microtubules made; centrioles found here.

Centrioles

rod-like structures used in Cell Division of Animal Cells.

Eukaryote

\-larger cell. Holds DNA in nucleus

\-many organelles including an innermembrane system

\-EX: Plants & Animals & Yeast

Prokaryote

\-smaller cells. Do NOT have a nucleus to hold DNA

\-fewer organelles

\-EX: Bacteria

Diffusion

the random thermal motion of particles of liquids, gases, or solids. In the presence of a concentration or electrochemical gradient, diffusion results in the net movement of a substance from a region where it is more concentrated to a region where it is less concentrated

Osmosis

the diffusion of free water molecules across a selectively permeable membrane

Hypotonic Solution

referring to a solution that, when surrounding a cell, will cause the cell to take up water

Hypertonic Solution

referring to a solution that, when surrounding a cell, will cause the cell to lose water

Isotonic Solution

referring to a solution that, when surrounding a cell, causes no net movement of water into or out of the cell

Facilitated Diffusion

the passage of molecules or ions down their electrochemical gradient across a biological membrane with the assistance of specific transmembrane transport proteins, requiring no energy expenditure

Surface Area: Volume

as a cell GROWS, The VOLUME of a cell increases more rapidly than the SURFACE AREA of a cell. As a cell INCREASES in size, its SA:V DECREASES. Cells want HIGH SA : V so that you have plenty entry/exit points with as little distance as possible to transport within the cell

Endocytosis

cellular uptake of biological molecules and particulate matter via formation of vesicles from the plasma membrane

Exocytosis

the cellular secretion of biological molecules by the fusion of vesicles containing them with the plasma membrane

Active Site

the specific region of an enzyme that binds the substrate and that forms the pocket in which catalysis occurs

Water Potential

the physical property predicting the direction in which water will flow, governed by the solute concentration and applied pressure

Phospholipids

a lipid made up of glycerol joined to two fatty acids and a phosphate group. The hydrocarbon chains of the fatty acids act as nonpolar, hydrophobic tails, while the rest of the molecule acts as a polar, hydrophilic head. Phospholipids form bilayers that function as biological membranes

Glycoproteins

a protein with one or more covalently attached carbohydrates

Glycolipids

a lipid with one or more covalently attached carbohydrates

Integral Protein

a transmembrane protein with hydrophobic regions that extend into and often completely span the hydrophobic interior of the membrane and with hydrophilic regions in contact with the aqueous solution on one or both sides of the membrane (or lining the channel in the case of a protein)

Peripheral Protein

a protein loosely bound to the surface of a membrane or to part of an integral protein and not embedded in the lipid bilayer

Aquaporins

a channel protein in the plasma membrane of a plant, animal, or microorganism cell that specifically facilitates osmosis, the diffusion of free water across the membrane

Flaccid

lacking turgor (stiffness or firmness), as in a plant cell in surroundings where there is a tendency for water to leave the cell. (A walled cell becomes flaccid if it has a higher water potential than its surroundings, resulting in the loss of water)

Turgid

swollen or distended, as in plant cells. (A walled cell becomes turgid if it has a lower water potential than its surroundings, resulting in entry of water)

Lysed

occurs when a cell bursts due to an osmotic imbalance that has caused excess water to diffuse into the cell. Water can enter the cell by diffusion through the cell membrane or through selective membrane channels called aquaporins, which greatly facilitate the flow of water.

Plasmolyzed

a phenomenon in walled cells which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall; occurs when the cell loses water to a hypertonic environment

ATP

an adenine-containing nucleoside triphosphate that releases free energy when its phosphate bonds are hydrolyzed. This energy is used to drive endergonic reactions in cells

Gibbs Free Energy

the portion of a biological system's energy that can perform work when temperature and pressure are uniform throughout the system. It can be calculated by the equation ΔG \= ΔH - TΔS, where ΔH is the change in enthalpy (in biological systems, equivalent to total energy), T is the absolute temperature, and ΔS is the change in entropy

Enthalpy

a measure of total energy

Entropy

a measure of molecular disorder, or randomness

Photosynthesis

the conversion of light energy to chemical energy that is stored in sugars or other organic compounds; occurs in plants, algae, and certain prokaryotes

Chemiosmosis

an energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP. Under aerobic conditions, most ATP synthesis in cells occurs by chemiosmosis

ATP Synthase

a complex of several membrane proteins that functions in chemiosmosis with adjacent electron transport chains, using the energy of a hydrogen ion (proton) concentration gradient to make ATP. ATP synthases are found in the inner mitochondrial membranes of eukaryotic cells and in the plasma membranes of prokaryotes

Proton Gradient

electrons are passed from one member of the transport chain to another in a series of redox reactions. Energy released in these reactions is captured as a proton gradient, which is then used to make ATP in a process called chemiosmosis

Cellular Respiration

the catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules and use an electron transport chain for the production of ATP

Aerobic

a catabolic for organic molecules, using oxygen as the final electron acceptor in an electron transport chain and ultimately producing ATP. This is the most efficient catabolic pathway and is carried out in most eukaryotic cells and many prokaryotic organisms

Anaerobic

a catabolic pathway in which inorganic molecules other than oxygen accept electrons at the "downhill" end of electron transport chains

Glycolysis

a series of reactions that ultimately splits glucose into pyruvate. Glycolysis occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration

Krebs Cycle

a chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing acetyl CoA (derived from pyruvate) to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and in the cytosol of prokaryotes; together with pyruvate oxidation, the second major stage in cellular respiration

Electron Transport Chain

a sequence of electron carrier molecules (membrane proteins) that shuttle electrons down a series of redox reactions that release energy used to make ATP

Fermentation

a catabolic process that makes a limited amount of ATP from glucose (or other organic molecules) without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid

Chlorophyll

a green pigment located in membranes within the chloroplasts of plants and algae and in the membranes of certain prokaryotes. Chlorophyll a participates directly in the light reactions, which convert solar energy to chemical energy

Light Dependent Reactions

the first of two major stages in photosynthesis (preceding the Calvin cycle). These reactions, which occur on the thylakoid membranes of the chloroplast or on membranes of certain prokaryotes, convert solar energy to the chemical energy of ATP and NADPH, releasing oxygen in the process

Calvin Cycle

the second of two major stages in photosynthesis (following the light reactions), involving fixation of atmospheric CO2 and reduction of the fixed carbon into carbohydrate

Thylakoid

a flattened, membranous sac inside a chloroplast. Thylakoids often exist in stacks called grana that are interconnected; their membranes contain molecular "machinery" used to convert light energy to chemical energy

Stroma

the dense fluid within the chloroplast surrounding the thylakoid membrane and containing ribosomes and DNA; involved in the synthesis of organic molecules from carbon dioxide and water

Mitochondria

an organelle in eukaryotic cells that serves as the site of cellular respiration; uses oxygen to break down organic molecules and synthesize ATP

NADH

the reduced form of nicotinamide adenine dinucleotide, which temporarily stores electrons during cellular respiration. NADH acts as an electron donor to the electron transport chain

NAD+

the oxidized form of nicotinamide adenine dinucleotide, a coenzyme that can accept electrons, becoming NADH. NADH temporarily stores electrons during cellular respiration

NADPH

the reduced form of nicotinamide adenine dinucleotide phosphate, which temporarily stores energized electrons produced during the light reactions. NADPH acts as "reducing power" that can be passed along to an electron acceptor, reducing it

NADP+

the oxidized form of nicotinamide adenine dinucleotide phosphate, an electron carrier that can accept electrons, becoming NADPH. NADPH temporarily stores energized electrons produced during the light reactions

Oxidative Phosphorylation

the production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of cellular respiration

Substrate Level Phosphorylation

the enzyme-catalyzed formation of ATP by direct transfer of a phosphate group to ADP from an intermediate substrate in catabolism