Review for Biochemistry

Transcription

1 Review for Biochemistry

2 A student records the ph values of three samples and is asked to predict the ph of a fourth sample. The student is told that Sample Z is less acidic than Sample X but more acidic than Sample Y. Which of the following is a valid conclusion about the ph of Sample Z? F It is less than 3.3. G It is between 3.3 and 5.2. H It is between 5.2 and 7.1. J It is greater than 7.1.

3 Answer G. between 3.3 and 5.2

4 A solution having an equal number of H+ ionsand OH ions will have a ph of A 3 B 7 C 9 D 11

5 Answer: B.7 if you rewrite HOH you have one H+ (acid) and one OH- (base)

6 A student investigates the effects of five brands of fertilizer on plant growth and concludes that Brand X works best. Which of the following would best communicate this conclusion? A A list of the ingredients in each brand of fertilizer used B A graph showing the growth rate of plants grown with the different fertilizers C A description of the role of different nutrients in plant growth D A diagram showing the conditions in which each plant grew

7 Answer: B A graph can display the results of an experiment and communicate the results better than just a list of ingredient.

8 The table shows the results of growing a yeast culture in a 5% glucose solution. The number of bubbles produced was used to indicate the extent of respiration by the yeast. If all other factors are held constant, how many bubbles should be produced in Tube 3 after 4 minutes? A 20 C 27 B 24 D 36

9 Answer: D 9 X2 =18 18X2= 36 therefore the answer is 36

10 The diagram on the right shows water molecules and ions from an NaCl crystal. What is the most likely reason that each water molecule is arranged so that the oxygen part of the molecule faces a sodium ion? F The oxygen in a water molecule contains a partial negative charge. G Gravity rotates the oxygen atoms to face the more-massive sodium ions. H Hydrogen atoms create repulsive forces with chloride ions. J Oxygen atoms form covalent bonds with sodium ions.

11 Answer: F Oxygen is a larger molecule than H and has 6 negative electrons. This makes it polar and it will pull apart other molecules that are neutral or polar

12 Proteins are produced according to a special code put together following a specific order of A. Sugars B. lipids C. Starches D. Amino Acids

13 Answer : D Remember that just like the alphabet, amino acids need to be put in a specific order so that your eyes don t end up on your toes. (or worse?)

14 There are four major macromolecules: lipids, carbohydrates, proteins, Nucleic acids. Which one provides the waxy coats on plants? A. Carbohydrates B. Proteins C. Lipids D. Nucleic Acids

15 Answer: C lipids. Lipids also provide long term energy storage along with large amounts of hormones.

16 The purpose of enzymes is? A. provide vitamins B. Break down minerals C. act as a catalyst

17 Answer: C Act as a catalyst to encourage reactions to happen faster such as setting a test on fire

18 A certain commercial product used for cleaning ovens must be handled with rubber gloves. The product is slippery and turns litmus paper blue. It probably contains F an acid G a base H a salt J an isotope

19 Answer: G Above 7 to 14 is a base. Bases are generally slippery: soaps, shampoos, house cleaners

20 Water acts as a solvent of ionic compounds because A water is liquid over a wide range of temperatures B water molecules are polar C water is found in three states of matter D water takes the shape of its container

21 Answer: B because of the size of oxygen and the number of electrons in the oxygen atom, it has more a negative pull than the hydrogen and is therefore polar.

22 The structure of pure water makes it a good F solvent G catalyst H conductor J nutrient

23 Answer: F Water is known as the universal solvent. It can dissolve other polar items or charged compounds.

24 The picture shows a model of the element A fluorine B helium C beryllium D oxygen

25 Answer: C. This atom has 4 protons. Protons are equal to the number of the elements atomic number. Element number 4 is Beryllium

26 An unidentified element has many of the same physical and chemical properties as magnesium and strontium but has a lower atomic mass than either of these elements. What is the most likely identity of this element? F Sodium G Beryllium H Calcium J Rubidium

27 Answer: G elements in the same family look alike and act alike

28 A certain atom has a nucleus containing six protons and eight neutrons and has six electrons orbiting the nucleus. This atom is a form of the element A silicon B carbon C magnesium D calcium

29 Answer: B Please tell me after all this knew that carbon has 6 protons so its atomic number is 6

30 The model above shows how an unidentified element, X, forms covalent bonds with oxygen. In which group on the periodic table does Element X most likely belong? F Group 6 G Group 12 H Group 14 J Group 18

31 Answer: H Group 14 remember that the last number of the family number tells how many valence electrons an atom has. Every atom wants eight this one has 4 so is 4 electrons short from family 18. This element is carbon or in the family carbon

32 The bonding characteristics of oxygen are most similar to the bonding characteristics of A hydrogen B silicon C helium D sulfur

33 Answer: D Oxygen is the family so every element under oxygen will act like Oxygen when bonding Fools gold made from sulfur and iron. Also known as iron piryte.

34 The elements in which of these sets have chemical properties that are the most similar? A K, Ca, Sc B O, S, Se C Na, Ca, Y D P, S, Cl

35 Answer: B same family. Bonds similiarly

36 Inorganic molecule needed in small amount A. protiens B. Lipids C. vitamins D. Minerals

37 Answers: D minerals do not have C, H, or O so are not organic

38 Are the instructions for protein body plan. Make up the two storage molecules for the human body. A. Proteins B. Nucleic Acids C. Lipids d. Carbohydrates

39 Answer: B Nucleic Acids contain DNA or RNA. DNA are the instructions for the protein plan. This gets translated into RNA so the cell can read it.

40 For your test you will: (WRITE THIS DOWN) Need to know how to read a graph know the difference between acids and bases know what the different macromolecules (proteins, lipids, carbohydrates, Nucleic acids) do or how they are identified what are the properties of water (polar, polar, polar) do I need to say it again, Polar. It what is behind waters funky properties: cohesive, adhesive, capillary What is the difference between vitamins and minerals. Which one is a coenzyme. What is an enzyme Read the first page of your lab, it will help with knowledge on macromolecules. You will have a couple of minutes after the test to finish conducting your lab. You will then need to share information and finish the questions at home. There will be a lab test on Friday.