Exam 2 Practice. The atoms found in a carbohydrate are Carbon, Hydrogen, and Oxygen. Carbohydrates are used in biological systems as the primary

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1 Key 1. (4) Fill-in the correct word to complete the following sentences. The atoms found in a carbohydrate are Carbon, Hydrogen, and Oxygen. Carbohydrates are used in biological systems as the primary energy source. 2. Animals store glucose as? for energy demands. A. starch B. glycogen C. lipid D. cellulose 3. The carbohydrate that contains nitrogen and is found in the exoskeleton of an insect is A. cellulose. B. glycogen. C. chitin. D. wax. 4. The characteristic that separates lipids structurally from carbohydrates is the? the molecule. A. nitrogen in B. amount of oxygen in C. ringed nature D. molecular size of 5. Saturated versus unsaturated neutral fats differ in amount of? in the molecule. A. nitrogen B. carbon C. hydrogen D. bacon 6. (3) Name the molecule that forms the backbone of a tri-glyceride and explain how neutral fats are used by human biological systems. A molecule of glycerol forms the backbone with one (monoglyceride), two (diglyceride, or three (triglyceride) fatty acid chains forming the tails attached to the glycerol. Neutral fats are used to build insulation barriers, used to build other macro molecules, and/or act as a secondary energy source behind carbohydrates. 7. (3) Cite a function for a phospholipid and a function for a steroid in biological systems. Phospholipids are used primarily to build cell membranes and some are found as a hormone precursor, while steroids are used to build hormones or be part of membranes in biological systems. 1

2 8. In a phospholipid molecule the? of the molecule is said to be hydrophilic. A. back B. tail C. head D. middle 9. (2) Distinguish between an essential and a non-essential amino acid. The twenty amino acids are divided into two groups essential or non-essential based on whether an organism can make them from precursor molecules (building blocks) or have to ingest them. The non-essentials are the ones you can make out of raw materials while the essential amino acids are the ones that you have to ingest being made by other organisms, but all twenty are needed for homeostasis. 10. All of the following atoms can be found in a protein chain except A. nitrogen. B. hydrogen. C. potassium. D. sulfur. 11. A proteins folding characteristics are dictated by the? groups of the chain. A. amino B. acid C. rock D side, variable, or R 12. (2) Explain how a proteins conformation can be changed. Proteins need be maintained in a relatively stable environment because changes in temperature or ph can alter or unravel the bonds of the protein and prevent it from doing its function. 13. (2) Cite two structural differences between the nucleic acids DNA and RNA. DNA molecules have the sugar called deoxyribose sugar while RNA has ribose sugar. DNA has the bases called A (Adenine), T (thymine), G (Guanine), & C (cytosine), while RNA has A, U (Uracil), G. and C. DNA is double stranded (RNA single stranded) and is found contained by a nuclear membrane in eukaryotic cells. DNA is only one type of molecule, whereas RNA has three different types (m (messenger), r (ribosomal), & t (transfer)). DNA is a huge molecules compared to RNA. DNA houses the genetic code instructions for the cell, whereas RNA is a copy of a portion of DNA. 14. The scientist that designed the first microscope, when he was a glass blower, was A. Hooke. B. van Leeuwenhoek. C. Darwin. D. your Mom. 15. Which of the following scientists disproved the idea of spontaneous generation? A. Hooke B. Schwann C. van Leeuwenhoek D. Virchow 2

3 16. (2) Explain the concept of the homunculus. Antonie van Leeuwenhoek claimed to have found a tiny organism (He called it an homunculus.) inside the head of a sperm (either male sperm develops into a boy or female sperm develops into a girl) cell that would develop into an offspring of the species once placed into the proper environment. 17. (2) Cite two points of what is known as the cell theory of life. 1. All living things consist of a cell(s). 2. Cells are the smallest functional units that define life. 3. Cells only arise from preexisting cells. 18. The term resolution means?, when applied to a microscopic image. A. magnification B. cost C. contrast D. clarity 19. The advantage of staining cells with antibodies lies in the? of the images. A. magnification B. cost C. specific contrast D. clarity 20. The advantage of an Environmental EM over other electron microscopes is the A. magnification. B. resolution. C. ability to view living specimens. D. smaller size. 21. (2) Cite two differences between a prokaryotic and a eukaryotic cell structure strategy. Cell size (Eukaryotes are bigger), number of flagella (Prokaryotes have many), nucleus (only in Eukaryotes), internal membrane structures (only in Eukaryotes), pili (only with Prokaryotes), capsule (only with Prokaryotes) are the main differences between a prokaryotic and a eukaryotic cell. 22. The molecules of a cell membrane the has a polar head and a non-polar tail is the A. protein. B. cholesterol. C. phospholipid. D. carbohydrate. 23. The membrane amount of this molecule helps to change the fluidity of the membrane? A. old socks B. cholesterol C. phospholipid D. carbohydrate 24. The molecule of a cell membrane that acts as a kind of cell marker is the A. carbohydrate. B. cholesterol. C. phospholipid. D. little one. 3

4 25. (2) Cite two requirements for passive transport to occur across a cell membrane. Passive movement only occurs when molecules moves with the concentration gradient (from high to lower), have a small molecular size, are relatively non-polar, and no energy is used or needed for the movement to occur. 26. If a cell were placed into a hypo-tonic solution it would? water. A. make B. lose C. gain D. balance 27. Water moves across a cell membrane by a process known as A. facilitated diffusion. B. simple diffusion. C. osmosis. D. active transport. 28. Charged molecules and ions move across a cell membrane via the membrane A. proteins. B. cholesterols. C. phospholipids. D. variances 29. A cell that would move bulk items from inside to outside its membrane practices the fine art of A. endocytosis. B. exocytosis. C. molecular dumping. D. translocation. 30. (2) Cite two requirements for active transport to occur across a cell membrane. Active movement across a cell membrane occurs against a concentration gradient, requires energy usage, needs a protein channel, and larger molecules are moved. 31. (2) Name two molecules that would be found in the cell s cytoplasm (cytosol), beside water. Salts, gases, protein, lipids, carbohydrates, and many more molecules can be found in the cytoplasm. 32. The cell s cytoplasm (protoplasm or cytosol) consistency is most like A. concrete. B. liquid water. C. a semi-solid colloid. D. a tootsie roll. 33. (2) Cite two ways in which the nuclear membrane differs from the cell membrane? The nuclear membrane is twice as thick meaning that it contains two phospholipid bi-layers fused together to form essentially four layers of phospholipids while cell membranes only have one bilayer of phospholipids. At various locations, permanent pores covered with a protein meshwork are placed through the nuclear membrane. These pores span the nuclear membrane from inside the nucleus to the outside (like train tunnels) covered and filled with the protein meshwork. 4

5 34. Which of the following organelles would have a triple membrane structure? A. chloroplast B. nucleus C. mitochondria D. all the above 35. (7) Match the organelles in column A with the functions in column B. Use each organelle only once and each function only once. C nucleus A. modifies, concentrates, and packages protein E rough ER B. destroys structural items inside a cell F smooth ER C. stores the genetic material A golgi apparatus D. destroys glucose to produce ATP B lysosome E. builds protein via ribosomes on its surface G peroxisomes F. builds lipids, stores, ions, or detoxifies molecules D mitochondria G. removes atomic waste from the cytoplasm 36. Ribosomes consist of a packet of RNA joined to a molecules of A. carbohydrate. B. genes. C. protein. D. lipid. 37. The cytoskeletal proteins that are contractile and designed to move the cell from place to place are A. actin. B. tubulin. C. keratins. D. megapowerstrokers. 38. Proteins that are specifically designed to maintain the cells shape are called A. microfilaments. B. microtubules. C. intermediate filaments. D. both B and C. 39. Short, moving membrane extensions designed to move substances across the cell are A. cilia. B. microvilli. C. flagella. D. fingerlings. 40. (3) Cite two functional differences between a cell membrane and a cell wall. Cell membranes are designed to regulate what can enter or exit a cell, while the cell wall is designed to maintain a rigid border around a plant, a fungal, or a protistan (algae) cell. 5

6 41. The inter-cellular junction that is designed for cell to cell communication are called A. Comcast connections. B. gap junctions. C. cellular providers. D. desmosomes. 42. The potential energy of molecules, which cells are trying to liberate, is found in the A. kinetic energy. B. bond energy. C. nucleus of atoms. D. protons of atoms. 43. The first law of thermodynamics deals mainly with the? of energy in the universe. A. amount B. type C. organization D. transformation 44. (3) Explain in a diagram or words the cellular concept of energy coupling through the use of ATP. Let s say that two different atoms or molecules could react together if one of them had enough energy to form a bond with the other atom or molecule. ATP can be split into ADP and P (phosphate group) to release energy. The P (or energy) can then be attached to one of the atoms or molecules giving this atom or molecule energy enough to react with the other. Once the reaction has taken place the P is removed, sent back to the mitochondria to be reenergized by being added to an ADP through the breakdown of glucose or other energy releasing molecules, while the joined atoms or molecules remain bonded to each other. 45. In a reduction oxidation reaction the reduced molecule? an electron, hydrogen atom or energy. A. loses B. gains C. shares D. sell 46. (2) Explain how ph changes could effect an enzyme function. Changes in the ph of a protein s environment can alter the shape (conformation) of the enzymes active site and prevent the enzyme from binding to its substrate molecule. In other words the enzyme is denatured. 47. The addition of heat can alter an enzymes function by altering the shape of the A. cofactor binding site. B. active site. C. backbone amino acids. D. jovial personality. 48. An enzymes cofactor binding site usually binds to A. substrate. B. a cell. C. a vitamin or mineral. D. a jovial personality. 40. (2) Explain how enzymes can be controlled by a feedback inhibition mechanism. A feedback inhibition mechanism controls enzyme function by having product bind to the enzyme once the concentration of needed product reaches a critical level. This binding would shut down the enzyme to prevent further production of product until such time as new product would be needed. 6