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A&P I Chap. 2
Question | Answer |
---|---|
Matter | Solid, liquid or gas |
Atom | Smallest particle that exhibits the chemical properties of an element |
# of neutrons | Atomic mass - atomic # |
Atomic # | Number located on top of the element symbol |
Atomic mass | Number located below the element symbol |
Proton # | Also the atomic # |
Electron # | Equals proton # |
Nucleus | Made up of protons and neutrons |
Orbit (outer shell) | Electrons orbit the nucleus |
Protons | Positively charged |
Neutrons | Neutral |
Electrons | Negatively charged |
Radioisotopes | Are unstable because they contain excess neutrons |
Half-life | The time for 50% of radioisotopes to become stable |
Number of electrons in each orbit | 2, 8, 8, 2 |
Chemical compounds | Stable associations between two or more elements combined in a fixed ratio. Classified as ionic or molecular. |
Ionic compounds | Structures composed of ions held together in a lattice of ionic bonds |
Ions | Group of atoms with a positive or negative charge. Produced from the loss or gain of an electron. Used in body for significant functions - Na+ for electrical signals, Ca2+ for blood clotting and muscle contraction, Cl in stomach acid |
Most common elements in humans | (CHON) Carbon, Hydrogen, Oxygen & Nitrogen |
Na+ | Conducting nerve impulses in neurons and muscles |
K+ | Conducting nerve impulses (action potential) in neurons and muscles |
Ca2+ | Hardness of bone and teeth, muscle contraction, exocytosis, blood clotting |
Covalent bond | Atoms share electrons, can be single, double or triple bond |
Carbon chains | Straight, branched or circular |
Polar bond | Bond between two atoms that share electrons UNEQUALLY |
Nonpolar | Bond between two atoms that share electrons EQUALLY |
Intermolecular attraction | Weak chemical attractions between molecules. Important in maintaining the shape of complex molecules such as proteins and DNA |
Hydrogen bond | Example of weak chemical attraction, individually weak, collectively strong, influences how water molecule behaves |
Water | Composes 2/3 of the human body weight, polar bond, can form up to four hydrogen bonds, universal solvent |
Phases of water | Gas, liquid, solid |
Functions of liquid form of water | Transports (substances dissolved in water throughout body), lubricates (decreases friction between body structures), cushions (absorbs sudden force of body movements), excretes wastes (unwanted substances dissolved in water ex: urine) |
Hydrophilic | Attracted to water, dissolves in water |
Hydrophobic | Repelled by water, does not dissolve in water |
Acid | Dissociates in water to produce H+ and an anion, called a proton donor. pH level would be 0-6.6 (HCl, wine, grapefruit, tomato juice |
Base | Accepts H+ when added to solution, called a proton acceptor. pH level would be 8.0 - 14.0 (sea water, bleach, NaOH) |
pH | Measurement of whether something is either an acid, base or neutral, scale of 0-14. |
Neutral pH | Measurement would be 7.0 - 7.4 (blood, pure water) |
Neutralization | Occurs when an acid or base is returned to a neutral level. Acids are neutralized when a base is added, visa versa |
Buffers | Help prevent pH changes if excess acid or base is added. (ex: carbonic acid - weak acid and bicarbonate - weak base, buffer blood pH |
Water mixtures | Formed by combining two or more substances. Substances mixed are not chemically changed, can be separated by physical means |
Mixture categories | Suspension, colloid, solution |
Emulsion | A polar substance such as water and a nonpolar substance like oil form an emulsion when agitated. (salad dressing) |
Suspension | Large solutes or cells that scatter light and settle if mixture is not in motion. (blood) |
Colloid | Smaller solutes that scatter light but do not settle. (gelatin) |
Solution | Smallest solutes do not scatter light or settle. (soda) |
Organic molecules | Molecules that contain hydrocarbons, most are a component of living organisms |
Inorganic molecules | All other molecules |
Four classes of biomolecules | Lipids, carbohydrates, nucleic acids, proteins |
Dehydration synthesis (condensation) | Occurs during synthesis of biomolecules, one subunit loses an H, other subunit loses an OH, new covalent bond formed and water is produced. |
Hydrolysis reaction | Occurs during the breakdown of biomolecules, an H is added to one subunit, an OH is added to another subunit |
Carbohydrates | An H and an OH usually attached to every carbon, chemical formula (CH2O)n - n represents the number of carbon atoms. |
Monosaccharides | Simple monomers |
Disaccharides | Formed from two monosaccharides |
Polysaccharides | Formed from many monosaccharides |
Nucleotide monomer | Three components - sugar, phosphate group and a nitrogenous base |
ATP (adenosine triphosphate) | Nucleotide composed of nitrogenous bases adenine, ribose sugar and three phosphate groups, covalent bond between last two phosphate groups (release energy when broken), central molecule in chemical energy transfer within cells |
Catalyst | Component that is used to speed up a process without being used up - class of protein (enzyme), ex: hydrolytic enzymes (cleave polysaccharides), DNA polymerase (synthesizes DNA) |
Defense | Class - immunoglobulins, ex: antibodies "tag" foreign proteins for elimination |
Transport | Class - circulating transporters, ex: hemoglobin carries O2 and CO2 in blood, ex: sodium-potassium pump - participates in establishing a resting membrane potential |
Support | Class - supporting proteins, ex: collagen - forms ligaments, tendons ex: keratin - forms hair, nails ex: fibrin - forms blood clots |
Movement | Class - contractile, ex: Actin - contraction of muscles, ex: myosin - contraction of muscle fibers |
Regulation | Class - osmotic proteins, ex: albumin - maintains osmotic concentration of blood Class - Hormones, ex: insulin - controls blood glucose levels, ex: ADH - (antidiuretic hormone) increases water retention by kidneys, ex: oxytocin - uterine contractions |
General protein structure | One of more stands of monomers |
Monomers | Amino acids |
Glycoprotein | proteins with carbohydrate attached, ex: glycoproteins on erythrocytes determining ABO blood groups |
Lipids | Triglycerides are the most common form of lipid in living things. Used for long-term energy storage, structural support, cushioning and insulation of the body. |
Carbohydrates | Two important examples - glucose (monomer), glycogen (polymer). The liver stores glucose as glycogen and breaks down glycogen to glucose as needed. |
Nucleotides | Monomers that make up the nucleic acid of DNA and RNA. |
DNA | Adenine, Guanine, Cytosine, Thymine |
RNA | Adenine, Guanine, Cytosine, Uracil |
Protein - primary structure | Linear sequence of amino acids joined by peptide bonds |
Protein - secondary structure | Alpha helix (spiral coil), beta sheet (planar, pleated) basically forms an H shape |
Protein - tertiary structure | Three dimensional shape, formed with a multitude of repeating secondary structures. Globular proteins (compacted formation), Fibrous protein (extended linear) |
Protein - quaternary structure | Present in proteins with two or more polypeptide chains, ex: hemoglobin with its four polypeptide chains |
Prosthetic groups | Non-protein structures covalently bonded, ex: hemoglobin protein |
Denaturation | Conformational change to a protein, disturbs protein activity, usually irreversible, can occur during heating |
pH Changes | Can cause denaturation |