Chapter 2: Physical, Chemical and Cellular Basis of Life
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116 terms
Terms | Definitions |
|---|---|
 Carbohydrate | organic compounds composed of carbon, hydrogen, and oxygen in a ratio of 2H:1O |
| Protein | organic compounds composed mainly of carbon, hydrogen, oxygen and nitrogen |
| Amino Acid | the 20 monomer building blocks of proteins |
| Lipid | fats-large, nonpolar molecules that do not dissolve in water |
| Nucleic Acid | very large and complex organic molecules that store important information in the cell |
| Nucleotide | monomers that compose DNA and RNA |
| Organic Compound | contain carbon bonded to other carbon and to other elements- H, O and N |
| Carbon Bonding | Carbon bonds with itself, forming straight chains, branched chains or rings |
| Monomer | a repeated, single-molecule unit- a building block |
| Polymer | more complex carbon molecules consisting of repeated, linked monomers |
| Condensation reaction | allows monomers to link together to form polymers- result in a "leftover" OH- and an H+, that bond to form a water molecule |
| Hydrolysis | results in the breakdown of complex molecules like polymers-a reversal of a condensation reaction- water is added and can break the bonds that hold molecules together |
| Monosaccharide | a monomer of a carb- also called a simple sugar- contains carbon, hydrogen and oxygen in a ratio of 1:2:1 |
| Isomer | compounds with a single chemical formula but different forms |
| Disaccharide | a double sugar formed when two monosaccharides combine |
| Polysaccharide | a complex sugar composed of three or more monosaccharides |
| Dipeptide | the bonding of two amino acids through a condensation reaction |
| Polypeptide | a long chain of amino acids bonded together |
| Fatty acid | unbranched carbon chains that make up most lipids |
| Hydrophilic | water loving- refers to the carboxyl end of the fatty acid chain that is attracted to water |
| Hydrophobic | water fearing- refers to the hydrocarbon end of the fatty acid chain that tends not to interact with water molecules |
| Saturated fatty acid | fatty acids with carbons single bonded to four molecules |
| Unsaturated fatty acid | fatty acids with carbons double bonded to themselves instead of four individual molecules |
| Triglyceride | three molecules of fatty acid joined to one molecule of the alcohol glycerol |
| Phospholipid | composed of two fatty acids joined together by a molecule of glycerol |
| Lipid bilayer | cell membranes are composed of two layers of phospholipids |
| DNA | deoxyribonucleic acid- contains information that is essential cell activities-genetic information |
| RNA | ribonucleic acid- stores and transfers information that is essential for making proteins |
| Parts of a Nucleotide | a phosphate group, a five-carbon sugar, and a ring-shaped nitrogen base |
| Microscope | an instrument that produces an enlarged image of an object |
| Magnification | the apparent increase in an object's size when looking through a microscope |
| Resolution | the power to show details very clearly |
| Compound light microscope | uses light to shine through a very thin slice of a specimen. |
| Electron microscope | a beam of electrons rather than a beam of light produces an enlarged image of the specimen |
| Transmission electron microscope | transmits a beam of electrons through a thin slice of specimen |
| Scanning electron microscope | provides 3-D images by scanning the surface of the object with a beam of electrons |
| Homeostasis | the ability of a cell or organism to regulate its internal conditions despite changes to the environment |
| pH | the pH of a solution describes whether it is an acid or a base |
| Acid | if the number of hydronium ions in a solution is greater than the number of hydroxide ions |
| Base | if the solution contains more hydroxide ions than hydronium ions |
| Metabolism | the sum total of the body's chemical activities |
| Diffusion | the simplest type of passive transport-the movement of molecules from an area of higher concentration to an area of lower concentration |
| Osmosis | passive transport- the process by which water molecules diffuse across a cell membrane from an area of high concentration to an area of low concentration |
| Facilitated diffusion | passive transport- a process used for molecules that cannot diffuse rapidly across a membrane, even when there is a concentration gradient |
| Concentration gradient | the difference in the concentration of molecules across a pace |
| Hypertonic | when the concentration of molecules in solution outside the cell is higher-water diffuses out of the cell to establish equilibrium |
| Hypotonic | when the concentration of molecules in solution inside the cell is higher-water diffuses into the cell to establish equilibrium |
| Isotonic | when the concentration of molecules in solution is equal inside and outside the cell |
| Equilibrium | when the concentration of the molecules of a substance is the same throughout a space |
| Passive transport | some substances can cross the cell membrane without any input of energy by the cell |
| Active transport | movement of materials across the cell membrane from an area of lower concentration to an area of higher concentration (i.e. against the concentration gradient) |
| Dissociation of water | The breaking apart of a water molecule into two ions of opposite charge is called dissociation. H2O↔ H++OH - |
| Hydroxide ion | OH- |
| Hydronium ion | H3O+ |
| pH scale | scale from 0-14: pH of '0' is very acetic, pH of '7' is neutral, pH of '14' is very alkaline |
| Buffer | a weak acid or base that can react with strong acids or bases to prevent sudden changes in pH -buffers help to resist changes in pH |
| Autotroph | organisms that obtain their energy by making their own foods (plants) |
| Heterotroph | organisms that must take in food to meet their energy needs (animals, fungi, bacteria) |
| Ectotherm | reptiles, fish and amphibians- organisms who warm their bodies by absorbing heat from their surroundings |
| Endotherm | mammals and birds-organisms who have a rapid metabolism and generate the heat needed to warm the body |
| Chemical reaction | occurs when one or more chemical substances are converted into new substances |
| Reactant | compounds or elements in a chemical reaction that are combining or separating. The reactants are located on the left side of a chemical equation |
| Product | compounds or elements that are the result of a chemical reaction. The products are located on the right side of a chemical equation |
| Exothermic reaction | chemical reactions that involve a net release of free energy |
| Endothermic reaction | chemical reactions that involve a net absorption of free energy |
| Activitation energy | the energy necessary to start a chemical reaction |
| Free energy | the energy in a system that is available for work |
| States of matter | determined by the rate at which the atoms or molecules in a substance move • solid- slow moving • liquid- medium moving • gas- fast moving |
| Energy | the ability to do work or cause change |
| Catalyst | certain chemical substances that reduce the amount of activation energy that is needed for a chemical reaction |
| Enzyme | an important class of catalysts that occur in living things |
| Redox reaction | short for reduction-oxidation reaction- reactions in which electrons are transferred between atoms |
| Reduction reaction | a reactant gains one or more electrons and becomes more negative in charge |
| Oxidation reaction | a reactant loses one or more electrons and becomes more positive in charge |
| Substrate | the reactants being catalyzed by an enzyme |
| Active site | the location on the enzyme where the substrate binds |
| Anaerobic respiration | begins with glycolysis, but the absence of oxygen at that point, glycolysis leads to fermentation |
| ATP-ADP Cycle | The continuous process of forming new ATP from ADP |
| Glycolysis | the first step in cellular respiration- a biochemical pathway in which one six-carbon molecule is oxidized to produce two three-carbon sugars of pyruvic acid |
| Cellular Respiration | the complex process in which cells make ATP by breaking down organic compounds producing carbon dioxide and water C6H12O6 + 6O2 → CO2 + H2O + Energy |
| Aerobic | requires oxygen |
| Anaerobic | does not require oxygen |
| Krebs Cycle | The part of aerobic respiration that produces: six NADH, two FADH2, two ATP and four CO2 molecules |
| Electron Transport Chain | the high energy electrons from the Kreb's Cycle (in the form of hydrogen) are passed along the ETC to convert ADP to ATP |
| ATP | adenosine triphosphate- a compound that contains a large amount of energy in its overall structure and provides energy to cell. Composed of adenine (a nucleotide), ribose (a sugar) and three phosphate groups (PO4) |
| Aerobic respiration | cellular respiration that requires oxygen |
| Lactic Acid Fermentation | an enzyme converts the pyruvic acid from glycolysis into a compound called lactic acid- produces yogurt, cheese |
| Alcohol Fermentation | pyruvic acid from glycolysis is broken down by single-celled organisms (yeast) and converted into ethyl alcohol- produces beer, wine and bread |
| Photosynthesis | Carbon dioxide from the air is combined with water in the presence of sunlight to produce organic compounds (glucose) and oxygen 6CO2 + 6H2O+ Light Energy → C6H12O6 + 6O2 |
| Chlorophyll | the most common pigment, absorbs all wavelengths of light except green |
| Producers | organisms in an ecosystem that produce food- plants |
| Consumers | organisms in an ecosystem that consume food- animals, fungi |
| Chloroplast | the organelle where photosynthesis takes place |
| Stomata | pores located on the undersides of leaves |
| Cell | the smallest unit of matter than can carry on the processes of life |
| Organelle | a cell component that performs specific functions for the cell |
| Nucleus | contains genetic information; directs activities of the cell; brain of the cell |
| Cell membrane | surrounds the cell, acts as a barrier between the inside and outside of cell |
| Semipermeable | the characteristic of the cell membrane that allows certain things to pass through and keeps others out |
| Cytoplasm | the jelly-like liquid (cytosol) between the cell membrane and the nucleus-contains all organelles |
| Ribosome | site of protein synthesis |
| Endoplasmic reticulum | system of membranes and sacs that acts like a highway to move molecules within and between cells |
| Golgi apparatus | packages substances produced by the cell; the post office of the cell |
| Mitochondria | makes ATP; the power plant of the cell |
| Lysosome | digests molecules, old organelles and foreign substances; the trash collector of the cell |
| Cell Wall | supports and protects the plant; the plant's skeleton |
| Vacuole | store enzymes, water and wastes |
| Plastid | storage organelles that can store starches or colors |
| Eukaryote | organisms whose cells contain a membrane-bound nucleus and other organelles |
| Prokaryote | unicellular organisms that lack a membrane-bound nucleus and other organelles |
| Unicellular | organisms that are composed of only one cell |
| Multicellular | organisms composed of more than one cell |
| Tissue | groups of cells that carry out specific functions |
| Organ | several types of tissues that interact to perform a specific function |
| Organ system | a group of organs that work together to perform a set of related tasks |
| Cell Theory | 1.All living things are composed of cells 2.Cells are the basic units of structure and function in an organism 3.Cells come only from the reproduction of existing cells |
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