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Anatomy Ch2
Chicken scratch about mostly chemistry
Term | Definition |
---|---|
Elements | simplest types of matter with certain chemical properties. 98 naturally occurring elements |
Atoms | smallest particles of an element that have properties of that element |
Bulk elements | required by the body in large amounts (C,O,H) |
Trace elements | required by the body in small amounts (Fe,I) |
Ultratrace elements | required by the body in very minute amounts (As) |
Proton | carries a single positive charge |
Neutron | carries no electrical charge |
Electron | carries a single negative charge |
Nucleus | Central part of atom;Composed of protons and neutrons; Electrons move around the nucleus |
Nucleus has these subatomic particles | neutrons and protons |
Outer energy shell has these subatomic particles | electrons |
Atomic number | Number of protons in the nucleus of an atom of a specific element |
Number of protons is equal to the number of _____ in the atom | electrons |
Atomic weight | The number of protons plus the number of neutrons in one atom |
Isotopes are... | atoms with the same atomic numbers but with different atomic weights |
Isotopes contain ____ number of neutrons. But ____ number of protons and elections | Different; Same |
Radioactive isotopes are... | unstable, releasing energy or atomic fragments (atomic radiation) until they gain stability |
Molecule particle formed when... | two or more atoms chemically combine |
Compound particle formed when... | two or more atoms of different elements chemically combine |
Molecular formulas | depict the elements present and the number of each atom present in the molecule (H20) |
Double bond | two pairs of electrons are shared between two atoms |
Single bond | one pair of electrons is shared between two atoms. |
Chemical bonds form when ... | atoms combine with other atoms. They result from interactions between the electrons of the atoms |
Electrons of an atom occupy regions of space called... | ELECTRON SHELLS (energy shells), which circle nucleus |
atomic numbers of 18 or less, the following rules apply to the energy shells | The first shell can hold up to 2 electrons; Second shell up to 8 electrons; Third shell up to 8 electrons |
Ion | an atom that gains or loses electrons to become stable; electrically charged atom |
Cation | a positively charged ion; Formed when an atom loses electron |
Anion | A negatively charged ion; Formed when an atom gains elecron |
Ionic bonds Formed when... | electons are transferred from one atom to another atom |
The attraction between a cation and an anion forms a very strong bond between the ions, called a(n) ____ | Ionic bond; When they form a bond, one atom loses an electron the other gains |
Covalent bond | strong chemical bonds, formed between atoms that share electron |
Structural formulas show ... | how atoms bond and are arranged in various molecules (H-H, O=O) |
Polar molecules | molecules with a slightly neg and slightly positive end; Results from unequal sharing of electrons in covalent bonds |
Hydrogen bond | weak attraction between the slightly positive (H) end of one polar molecule and the slightly negative (N or O) end of another polar molecule |
Chemical reactions occur when ... | chemical bonds form or break between atoms, ions or molecules |
Reactants | the starting materials of a chemical reactions: the atoms, ions or molecules |
Products | the substances formed at the end of the chemical reaction |
Synthesis reaction: | more complex chemical structure is formed (bond formed) A+B->AB |
Decomposition reaction | chemical bonds are broken to form a simpler chemical structure AB-> A+B |
Exchange reaction: | chemical bonds are broken and new bonds are formed AB+CD-> AD+CB |
Reversible reaction: | the products can change back to the reactants A+B <-> AB |
Electrolytes | substances that release ions in water. The solution can conduct and electric current, so it is called an electrolyte |
Acids: | Electrolytes that dissociate to release hydrogen ions in water NaCl-> Na+ + Cl- |
Bases | substances that release ions that can combine with hydrogen ions HCl -> H+ + Cl- |
Salts | Electrolytes formed by the reaction between an acid and a base. HCl+NaOH-> H2O+NaCl |
When an ionically bonded substance is put into water... | charged ions are attracted to slightly charged ends of the polar water molecules. This dissociates the substance, and the ions become surrounded by water molecules. The substance is now called an electrolyte, since it can now carry an electric current. |
pH scale | pH scale runs from 0-14; each number represents a tenfold difference in H+ ion concentration |
Acids have a pH | <7 |
bases have a pH | >7 |
A pH of 7 is... | neutral |
The higher the H+ concentration... | the lower the pH, and the higher the acidity |
The lower the H+ concentration... | the higher the pH and the lower the acidity (which corresponds to higher alkalinity) |
Acidosis | occurs when blood pH drops to 7.0- 7.3; Caused by vomiting of alkaline intestinal contents, diabetes, lung disease with impaired CO2 exhalation |
Alkalosis | occurs when blood pH rises to 7.5- 7.8; Caused by high altitude breathing, vomiting of acidic contents, high fever, taking excess antacids |
buffers | chemical systems which act to resist pH changes; bind and release H+ ions to regulate pH |
Organic molecules | Contain C and H; Dissolve in water and organic liquids; Water-soluble organic compounds do not release ions, and are non-electrolytes |
Inorganic molecules: | Generally do not contain C and H Usually dissolve in water and dissociate, forming ions and are electrolytes |
Carbohydrates | Main source of cellular energy ; Supply materials to build cell structures; Contain C,H,O |
Monosaccharides | (single sugars) glucose, fructose |
Disaccharides | (double sugars) sucrose, lactose |
Polysaccharides | (complex carbs) starch, glycogen, cellulose |
Lipids | Insoluble in water, but soluble in organic solvents; Include triglycerides (fats), phospholipids, steroids; Important component of cell membranes, and have several functions in cell |
Most abundant lipids are ... | Triglycerides (fat) |
Triglycerides | Used for cellular energy; Contain more energy per gram than carbohydrates; Contain C,H, and O, but less O than carbs; Consist of 1 molecule of glycerol and 3 fatty acids |
Saturated fatty acids | have only single carbon-carbon bonds. Most are solid at room temp and are animal origin |
Unsaturated fatty acids | Unsaturated fatty acids have on or more carbon-carbons double bonds. Most are liquid at room temp and are plant origin |
Phospholipids | Consist of 1 glycerol, 2 fatty acids, and 1 phosphate; Have hydrophilic and hydrophobic ends; Major component of cell membranes |
Steroid | 4 connected rings of carbon; Widely distributed in the body, various functions; Component of cell membranes; Used to synthesize adrenal and sex hormones; Cholesterol is main steroid in body |
Proteins | used structural materials, energy source, hormones, receptors, enzymes, antibodies; Consist of building blocks called amino acids; |
An amino acid contains... | an amino (-NH2) group, a carboxyl (COOH) group, and a unique R (side chain) group |
Peptide bonds | form between the amino group of one amino acid, and the carboxyl group of the adjacent amino acid. |
4 levels of protein structure | Primary, Secondary, Tertiary, Quaternary |
Primary: | Amino acid sequence |
Secondary | Pleated or twisted structure formed by hydrogen bonding between nonadjacent amino acids |
Tertiary | Unique 3-dimensional folded shape of the protein |
Quaternary | Structure formed by some proteins, when 2 or more polypeptide chains are connected to become 1 protein |
Nucleic acids | carry genetic code (D N A) or aid in protein synthesis (R N A); encode amino acid sequences of proteins; Building blocks are called nucleotides, which consist of a sugar (S), a phosphate group (P), and an organic base (B). |
D N A: | Stores the genetic code; Contains the sugar deoxyribose; Structure—double helix; Composed of nucleotides. |
R N A: | Interacts with D N A to conduct protein synthesis; Contains the sugar ribose; Structure—single strand; Composed of nucleotides. |