MB C2 Self Quiz

tokia's version from 2016-04-29 03:54


2. Define atom (A) element (E) molecule (M) and compound (C).Place the appropriate letters next to each of the following
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1. The smallest unit of an element that retainss all the prperties of thet element isAtom
3. How do ions differ from atomsIon are atoms that have gained or lost one or more electrons
4. Atoms consist of _____ that are positively charged,neutrons which carry a _____ charge and _____ which carry a negative charge.The protons and neutrons tgether form the atomic _____ while the electrons _____ the nucles.Atomic weight refers to the number of _____ and _____ found in an element.Atomic _____ refers to the number of protons found in an atom of a given elementProtons... neutral...electrons... nucleus... orbits...protons and neutrons...number
5. How do isotopes of an element differ from each otherAn isotope of the same elementcontains a different number of neutrons


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6. Solutethe substance dissolved in the solvent
MixtureTwo or more substances that combine in any proportion and are not chemicaly bound
Solutiona mixture of two or more substances in which the molecules of the substances are ebenly distributed
Solventthe medium in which substances are dissolved


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7. Which of the following are properties of water that make it important for living cells(e)
8. (a)How is the pH scale used to measure acidity?Among the pH values 3...5...7...11...13 which represents (b) the strongest acid and (c) the strongest base/ (d) At what pH do you think the bacterium Thiobacillus thioparis can damage ancient marbic stone(a) An acid is a hyrogen ion (H*) or proton donor. The Ph scale is a logarithmic scale that measures the (H*) concentration. This means the concentration of (H*) changes by a factor of 10 for each unit of the scale a solution goes from pH7 to pH 0 it is increasing its acidity. (b) pH3 (c)pH13 (d) The production of sulfuric acid by Thiobacillus thioparis would produce a pH of 3 or lower within the marble stone environment
9. Organic compounds are present in all living cells.They all share the following characteristicAre composed of carbon atom backbone surrounded by hydrogen atoms
10. (a)What is the basic structure of a monosaccharide (b)How are disaccharides and polysaccharides different from monosaccharides(a) Monosaccharides are carbon chains or rings with attached alcohol group plus one other functional group such as an aldehyde or ketone group (b) Disaccharides are formed from two mosaccharides that are connected by the formation of a glycosidic bond (sugar alcohol/sugar linkage) Polysaccharides are formed from multiple (greater that two) glycosidic linkages of monosaccharides


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11. The most immediate source of energy forl living cells is generally in the form ofCarbohydrates
12. In what ways are carbohydrates used in living organismsLiving organisims use carbohydrates as a direct source of energy(glucose) energy storage (glycogen) cellular structure and support (cellulose) cell marking and signaling...and in the genetic code (nucleic acids)
13. Describe the structure ad uses in the body of simple lipids phospholipids and steroidsLipids constitute a chemical diverse froup of sustances that include fats, phospholipids...steroids. Simple lipids (fats) are composed of a three-carbon-glycerol and one or more fatty acids (a fatty acids consists of a long chain of carbonatoms with associated hydrogen atoms and carboxyl group at one end of the chain) Many fats are used as a source of energy. Some lipids contain one or more other molecules in addition to fatty acids and glycerol. One example of this is phospholipids which differ from fats by the substitute phosphoric acid for one of the fatty acids. Phospholipids are integral structural component of cell membranes. Steroids are lipids with a characteristics four-ring structure that have different chemical groups attached to the rings depending on the specific steroid. An example of a steroid is cholesterol. Steroids play many roles including cellular membrane composition...cell signaling(hormones and in metabolic reactions such as vitamins.


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14. Lipids are generallyHydrophobic...Present in cell mebranes...Composed of fatty acids...A high energy source
15. A peptide bond is formed between two amino acids by the reaction of the _____ of one amino acis with the _____ of the other-H of the amino group/-OH of the carboxyl group
16. Describe the four levels of protein structure.How is each maintainedThe primary structure of a protein consists of the specific sequence of amino acids in a polypeptide chain and is maintained by peptide bonds. The secondary structure of a protein consists of the folding or coiling of amino acid chain into a particular pattern such as ana-helix or b-pleated sheet and is maintained by hydrogen bonding between different amino acids. Tertiary structure consists of further bending and folding of the protein molecule into globular shapes or fibrous thread like strands. Quaternary structure is formed by the association of several separate tertiary-structured polypeptide chains. Tertiary and quartenary structures are maintained by disulfide linkages...hydrogen bonds...and other forces between R groups of amino acids
17. Enzymes are biological catalysts.They all share which of the following characteristicsAre not consumed in chemical reactions...Lower the activation energy of reactions...Increase the rate of reactions...Allow reactions to occur that would otherwise require a higher temperature
18. (t/f)At high tenperature and pH extremes enzymes are generally denatures and lose their functionalityTrue


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19. Energy inside all living cells is rapidly consumed and generated in metabolic reactions.In what form is energy traded inside these cellsATP
20. Nucleotides areBuilding block of DNA


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21. Adeninepresent in RNA and ATP
Thyminepresent in only DNA
Phosphatepresent in both DNA and RNA
Ribosepresent in only RNA
Nucleotidepresent in DNA RNA and ATP
Deoxynucleotidepresent in DNA RNA and ATP
Uracilpresent in only RNA
Guaninepresent in both DNA and RNA
Nitrogeneous basepresent in DNA RNA and ATP


22. Indicate which base the complementary paired base for each of the following
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Adenineuracil or thymine


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23. PolysaccharidesCarbohydrate
PolypeptideProtein synthesis
Fat Lipids


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24. Which of the following statements is true about anabolism and catabolismThe synthesis of a compound is known as anabolism and is an enderginic reaction while the breakdown of a compound is known as catabolism and is an energonic reaction
25. Which of the folowing is not a property of waterWater provides themedium for most cellular reactions but does not participate in them
26. What is the chemical nature of this compound...Identify each of the circled parts of the moleculesThis stucture shows two amino acids joined together by a peptide bond making it a dipeptide (a) Amino group (b) Peptide bond...remove the singly bonded oxygen (c) Side group of amino acid 2 (d) Carboxyl group