Chapter3-review_sheet.docx

Chapter 3: Everyday Chemistry of Life Periodic table- is a list of the elements and contains more than 100 elements Element – a substance that cannot be broken down into simpler format. Distinguished by a unique atomic number. Elements are organized by their atomic number in the periodic table. Atom...

Chapter 3: Everyday Chemistry of Life Periodic table- is a list of the elements and contains more than 100 elements Element – a substance that cannot be broken down into simpler format. Distinguished by a unique atomic number. Elements are organized by their atomic number in the periodic table. Atom – The smallest unit of matter that retains all of the chemical properties of an element. Atomic number – number of protons (also equals the number of electrons in a neutral atom) Atomic weight – number of protons plus number of neutrons Label the following diagram: Write a definition for each labeled part. All are subatomic particles A- Electrons – negatively charged subatomic particle 1 negative unit, mass is negative. Located outside of nucleus. Outer shell is the valence shell. React to other atoms B- Neutorns – in the nucleus, does not have a charge, mass is 1 Atomic Mass Unit C- Protons – in the nucleus, 1 positive unit, mass is 1 Atomic Mass Unit What does the rule for diagramming an atom state? The first shell will hold up to 2 electrons Any shell after the 1st shell will hold up to 8 electrons Define Isotopes Atoms with the same number of protons but different number of neutrons, resulting in different atomic masses. Differentiate between C12, C13 and C14 C12 – different weights, number of neutrons C13 - different weights, number of neutrons C14 – used to make fossils, radioactive, unstable Define radioisotope Unstable isotope that emits radiation. Radiation can be very harmful causing the death of cells or very beneficial as evidenced by its use in medicine. Dyes injected into the body, images of the brain, thyroid gland. Octet Rule – states that atoms desire 8 electrons in their outer shell past the first shell and will react together to get that number and achieve a complete outer shell. First shell has 2 electrons. Molecules – chemical reactions that occur between atoms to form compounds and molecules. Chemical structure held together by covalent bonds The chemical structure shows the number of each element forming the molecule. Define Ionic reaction – atoms transfer electrons in order to complete their outer shell. Define Ions – a charged atom that loses the electron carries a positive charge. Atom that gains the electron carries a negative charge Define Covalent reaction – the atoms share electrons to complete their outer shells Compare hydrogen, covalent, ionic and polar bonds. Polar bonds – when the electrons of a covalent bond are shared unequally, the bond is called a polar bond and the resulting molecules are called polar molecules. Ex: Water molecule Hydrogen bond – is a weak bond formed netween a slightly positively charged hydrogen atom and another slightly negatively charged atom Covalent bond – sharing of electrons between atoms may be equal or unequal Name the groups of Inorganic molecules discussed. Small in size Do not contain carbon Usually have Ionic bonds Often associated with non-living things Water, acids, bases, salts, and buffers Some uses of water: Water is liquid at room temperature Good solvent (dissolves many substances) Water is cohesive (has the ability to stick to itself) Water is adhesive (has the ability to stick to other surfaces) Helps regulate body temperature Transport substances -ex. Movement of substances in body fluids Help remove waste products from the body Define Acids, Bases and Salts Acids – substance that breaks down in water and releases hydrogens ions H+ Base – substance that breaks down in water and releases hydroxide ions OH- Salts – substance that breaks down in water and release ions other than hydrogen and hydroxyl ions Define pH Measures the concentration of Hydrogen ions to hydroxyl ions in a solution The pH scahle ranges from 0 to 14 pH 7 is neutral. Water The lower the pH on the pH scale the greater the acidity The higher the pH, the more basic (alkaline) a solution Blood is slightly basic or alkaline at pH of 7.35-7.45 Characteristic Acid Base Behavior in Water Releases H+ Releases OH-- pH Less than 7 Greater than 7 Example HCI (hydrochloric acid) NaOH (sodium hydroxide) What is a buffer? Chemical substance that prevents dramatic changes in pH Bicarbonate Ion (HCO-3) is a common buffer in body fluids Organic Molecules – Always contain carbon and hydrogen Contain covalent bonds Large molecules Associated with living things Carbohydrates Proteins Lipids Nucleotides Name some functional groups found in organic molecules? Subunit on an organic molecule that helps determine how it reacts with other chemicals Explain the difference between dehydration synthesis and hydrolysis? Dehydration Synthesis – large molecules (polymers) are made by joining smaller molecules together by the removal of water Glucose + Fructose = Sucrose + Water Hydrolysis – adding of water Name 3 major groups of carbohydrates and list examples for each. Monosaccharides – May contain 3-7 carbon atoms in their structure Most common monosaccharides contain 5 or 6 carbons in their structures Pentoses – 5 Carbon sugars (Ribose, Deoxyribose) Hexoses – 6 Carbon sugars (Glucose, Galactose, Fructose) Disaccharides – Formed when 2 monosaccharides join together by dehydration synthesis Polysaccharides – A chain (polymer) of glucose molecules Name 3 major groups of lipids. list examples and characteristics for each group. Lipids – insoluble in water, will not dissolve, store long-term energy, protect vital organs, and form cell membranes Triglycerides – Glycerol +3 fatty acid produces fat plus 3 water molecules Fatty acids may be saturated or unsaturated Saturated fatty acid has single bonds between carbon atoms, solid at room temp, mostly come form animal sources. Trans is when its hydrogenated Unsaturated fatty acids has at least one double bond in the carbon chain. Solid at room temp, come from plants. Phospholipids – Critical to cell membranes Made up of glycerol + phosphate + 2 fatty acids Glycerol is polar and water soluble (hydrophilic) Fatty acid tails are nonpolar and water insoluble (hydrophobic) Steroids – Are a unique group of lipids that consist of 4 ring compounds Cholesterol is believed to be the parent steroid in the body and is used to make other steroids Too much cholesterol is implicated in heart disease Estrogen – female sex hormone (Estradiol) Responsible for development of female reproductive system Secondary sex characteristics such as wide hips, breast development, increase in body fat, decrease in body hair and soft voices Testosterone – male sex hormone Responsible for development of male reproductive system Secondary sex characteristics such as narrow hips, lack of breast development, increase in muscle mass, increase in body hair and deep voices What are the characteristics of proteins? Some important functions of proteins in the body: Found in hair, nails, cell membranes, different tissues such as muscle tissues and skin Act as hormones, buffers, enzymes, antibodies, and carrier molecules Made of building blocks called amino acids Each amino acid has the same amino group (H2N) and the same carboxyl group (COOH). They differ from one another by their R Group. Dipeptide – 2 amino acids joined by a peptide bond Polypeptide – chains of 10 or more amino acids are called polypeptides Proteins are polypeptide chains of at least 75 amino acids that provide structure, transport, and movement for the body What are the 4 levels of structure of a protein? Primary structure – amino acid sequence, long chain of amino acids, held by peptide bond Secondary structure – twisting and folding of neighboring amino acids, stabilized by hydrogen bonds. Twisting of primary structure Tertiary structure – three-dimensional shape of polypeptide chain again held in place by hydrogen bonds between adjacent amino acid “R” Groups. Keeps folding to create 3D shape Quaternary – Arrangement of two or more polypeptide chains. Proteins are very complex Denaturation – abnormal body temp and abnormal pH of body fluids can cause a protein to lose its normal shape or configuration Loss in structure results in a loss of function Define Enzyme Proteins can act as enzymes, they serve as catalysts for chemical reactions. Speeds up reaction Define Nucleotides Group of organic molecules made up of a pentose sugar, phosphate group and nitrogen base Nucleic Acids (DNA, RNA) ATP – Adenosine Triphosphate 24. List the nucleotides studied and define each one. 1. DNA – Deoxyribonucleic Acid is located on the chromosomes; commonly called genes. Genetic Information 2. RNA – Ribonucleic Acid is made from DNA and controls protein synthesis in cells Sugar + phosphate is the backbone of DNA 25. What are the nitrogen bases in DNA? In RNA? 1. DNA – Adenine and Thymine bond together. Guanine and Cytosine bond together 2. RNA – Adenine and Uracil bond together. Guanine and Cytosine bond together 26. Adenosine Triphosphate – ATP 1. energy molecule in cells 2. energy is stored in its phosphate to phosphate bonds 3. when energy is needed the tail phosphate is broken off ATP producing ADP +P 4. Most ATP is made in a part of the cell called the mitochondria through a process called aerobic cellular respiration