Biochemistry, Cells, and Cellular Transport Exam Test Corrections

Include any pictures, links, video, etc. that supports your answer. After you've finished your part of the assignment, look over other answers and add/edit where needed!

3. E. Water has a HIGH heat capacity, not low
Lauren, why? -Miss Baker

4. E. A hydrogen bond is the attraction between the oxygen of one molecule (h2o) and the hydrogen of an adjacent molecule.

5. D. Disaccharide. If lactose is composed of one glucose molecule and one galactose molecule, it is made up of two saccharides (glucose and galactose), meaning its a di(2)saccharide.

7. A. The molecule shown on the page is a simple sugar molecule. If 128 joined together, they would create a complex chain of these molecules, resulting in what is called a polysaccharide.

8. D. A nucleotide is made of a base, a sugar, and a phosphate group. (check link)

12. C. This structure is an impossible covalently bonded moleucle because two carbons are linked by a single, covalent bond. In A,B, and D, no two carbons are connected, and in E, the two carbons have a double bond.

13. C. The R group (an organic compound found on the 20 amino acids making up polypeptides)is attached to the alpha carbon.

14. B. A Transmission Electron Microscope. Because cells are so tiny, and the scientist wants to see the internal structure of one, they would need a transmission electron microscope because it has the highest magnification. It uses electrons as a source of light instead of light because electrons have a lower wavelength. Click here for more information on the transmission electron microscope.

15. B. A prokaryotic cell is a cell lacking a true nucleus, and has a DNA concentrated region in the nucleoid. It also has ribosomes, which synthesize proteins.

17. C. Protiens are created by ribosomes in the Rough Endoplasmic Reticulum

20. B. Microtubules: helps in cell division, found in a plant cell in the cytoskeleton, cilia, and flagella. Also found in all eukaryotic cells.

21. E. The answer is shown in this diagram:
external image sf5x8b.jpg

22. D. Cholesterol. Cells regulate membrane fluidity by varying the amount of cholesterol in the cell membrane. The cholesterol is embedded in the membrane.external image ch1_cellmembrane.jpg

23. C. Aquaporin channels allow water to pass through while allowing everything else to pass. So if the Aquaporins were not working the water would stay in the blood.

24. C. The animal cell would shrink when placed in a hypertonic solution because water would move out of the cell where there was more of a concentration to outside of the cell where there is less of concentration of water, while the solute would move from outside the cell into the cell, from high to low concentration, therefore leaving the cell with less water and more solute, causing it to shrink.

25. A. Glucose from the dialysis bag will move into the beaker solution becuase of its higher quantity inside the dialysis bag. To reach an equal, it ruses outside of the bag where there is only a quantity of .4 M of gluecose.

29. Oxygen is carried in the blood by attaching to hemoglobin. Once the oxygen has been deposited, carbon dioxide is carried by the
blood in the form of bicarbonate ions:
external image medica56.jpg
external image medica56.jpg

31. E. Veins. The veins transport oxygen-poor blood back to the heart from the cells.

external image MMHE_03_020-03.gif
external image MMHE_03_020-03.gif

33. D. Capillaries. The Capillaries are tiny blood vessels between arteries and veins the distribute oxygen-rich blood to the body

34. B. Right Ventricle. The Right Ventricle is the side of the heart which receives and pumps oxygen-poor blood. (See image on #35)

35. A. The left ventricle recieves oxygen recieves and pumps oxygen rich blood to the body through arteries.
external image pul-circ.gif
external image pul-circ.gif

36. B. More members in a population are created than can survive. This creates competition for resources, which leads to survival of the fittest. Only the members that are best suited to their environment will survive and reproduce. Those that are not best suited can not compete, and therefore will not survive and reproduce