The following are exam questions written by me and my classmates. Some 15 to 20 of these questions will be the actual questions used on our first exam in organ systems. The answers may be switched around, or re-written in order to be correct. I am going to try to answer these myself, then to match up my answers with those of the person who posted them on the listserve, and then research any differences.
1. Which of the following is not an example of passive transport across the cell membrane?
A. Carbon dioxide
CO2 is not polar and can pass through the membrane passively. Water usually moves through pores, passively. Steroids are lipids and can pass through. Sodium gets transported via the sodium potassium pump, so D is the answer.
2. Sarcoplasmic reticulum is found in which of the following:
A. Tongue muscle
E. Cardiac muscle
A. Tongue muscle. SR is a special kind of smooth ER found in striated and smooth muscle.
3. How far does a chromosome need to unwind in order for transcription to occur?
B. Nucleosome strand
C. DNA strand
D. Solenoid fiber
E. None of the above
C. DNA strand
4. Where are cisternae found?
A. Golgi ap
C. Rough ER
D. A & C
E. All of the above
Definitely in Golgi and also in rough ER: D.
5. Clathrin coated pits are used during:
B. Receptor-mediated endocytosis
D. A + C
B Receptor mediated endocytosis
6. In a Type III protein:
A. N terminus is always in the lumen
B. N terminus is always in the cytoplasm
C. Hydrophilic bits determine the number of times a protein crosses the plasma membrane
D. None of the above
Type III crosses the membrane several times, but it's the hydrophobic bits that cause the crossings, so D, none of the above.
7. Biophoton emission occurs when a chromosome:
A. Is in a heterochromatic state
B. Is in a euchromatic state
C. unwinds only to a solenoid fiber
D. Is in a transcriptionally inactive state
Biophoton emission occurs when a chromosome is in a euchromatic state, so B.
8. ___________ junctions allow the transfer of chemical and electrical signals.
9. What do transcription and translation have in common?
10. The Rough ER synthesizes a protein whose C-terminus is contained inside an endosome. The protein must be a(n):
A. Type I protein
B. Type II protein
C. Insulin precursor
Type II has C end inside endosome, so B.
11. Which is not true of cholesterol? (I helped write this question!)
A. Gives rigidity to membranes
B. High levels are implicated in causing Alzheimer’s
C. Makes membranes more permeable
D. Used in making steroids
E. Is soluble in membranes
C. Cholesterol makes membranes LESS permeable.
12. N-linked glycosylation first happens where?
A. Smooth ER
B. Rough ER
C. Golgi apparatus
Answer is: B. rough ER.
13. Match the type of protein with the insertion of membrane proteins into ER membrane?
A. Type I protein – C-terminus in Lumen
B. Type I protein – N-terminus in Lumen
C. Type III protein – Cross membrane once
D. Type II protein – Cross membrane multiple times
B: Type I has N terminus in Lumen
14. A macrophage will recognize a dead cell when the cell has __________ on its outer surface.
A. Phosphatidyl choline
B. Phosphatidyl serine
D. Cytochrome P450
B. Phosphatidyl serine. and ethanolamine (are on inside when cell is alive).
15. Which of the following is NOT a function of the golgi apparatus?
A. Sorting of newly synthesized proteins and lipids
B. O-linked glycosylation
C. Storage of secretory granules or vesicles
D. Degrade cellular material
D. Degrading materials is done by lysosomes.
16. Which is not characteristic of a human cell?
A. Has organelles
B. Has DNA, RNA and enzymes
C. Has cell wall
D. Has chromosomes
E. Has a nucleus
C Human cells have membranes but not walls.
17. In a membrane protein that inserts into the endoplasmic reticulum:
A. A type I protein begins with the C-terminus inside the endosome
B. A type II protein begins with the C-terminus inside the endosome
C. A type II protein has two hydrophobic bits
D. A type III protein can only cross the membrane once
B. Type II has C end inside endosome
18. What is NOT a function of the rough endoplasmic reticulum?
A. Protein synthesis
B. N-linked glycosylation
D. Formation of disulfide bonds
19. A eukaryotic cell contains all of the following except:
A. Nuclear membrane
B. Nuclear lamina
C. Circular DNA (Mitochondria have this and they are eukaryotic cells)
E. None of the above
Eukaryotes have all of the above, including circular DNA (inside mitochondria) so the correct answer is E None of the above.
20. What type of membrane protein inserts with the N-terminus in the extracellular space?
A. Type I
B. Type II
C. Type III
D. Type IV
A Type I.
21. Which structure is involved with breaking down and reforming the nucleus in cell division?
B. Nuclear lamina
C. Nuclear envelope
B, nuclear lamina, which is MADE of proteins (esp actin) which pull parts apart & together, remember spindles in mitosis...
22. Which one of these statements about active transport is false?
A. Both a protein + energy are required to transport molecules across a membrane
B. An example of directional active transport is called symport, where molecules go in the same direction
C. Active transport is the process of diffusion of O2 and CO2
D. The export of Ca2+ (calcium) and import of sodium to decrease frequency of contractions is an example of antiport active transport
C is false.
23. A protein that crosses the cell membrane multiple times has the following properties and classification
A. Hydrophilic sections, Type I
B. Made in smooth ER, Type II
C. Hydrophobic sections, Type II
D. Hydrophobic sections, Type III
D. dead horse is beaten a few more times
24. Which pair of nitrogenous bases are purines?
A. Adenosine, Cytosine
B. Adenosine, Thymine
C. Adenosine, Guanine
D. Guanine, Cytosine
C. Add (adenosine) batshit (guanine) to your dogfood (purines).
25. What is the function of the sarcoplasmic reticulum?
A. Maintaining potassium / calcium balance in the cell
B. Binding transcription cofactors
C. Active in sequestration and release of calcium ions
D. Transfers polar groups into the cell
C. Ca+ control.
26. Which of the following is NOT characteristic of the Golgi Apparatus?
A. Is involved in the modification of N-linked glycosylation
B. Is involved in the storage of secretory proteins
C. Is involved in the synthesis of bile acid
D. Contains enzymes
C. Doesn't synthesize bile. Bile is synthesized in the peroxisomes!
27. Facilitated diffusion requires one of the following:
A. Diffusion of O2 and CO2
B. Protein to transport a molecule across a membrane
C. Protein and energy to transport a molecule across a membrane
D. Water to cross a membrane
B. The protein does the facilitating.
28. Which of the following is not a part of the cell membrane in eukaryotic cells?
B. Proteoglycans are not part of the cell membrane in eukaryotic cells.
29. What indicates death of a cell membrane?
A. Enzymes start to degrade nucleus
B. The pH changes
C. Cell membrane turns inside out
30. Ribosomes are made in the:
B. Rough endoplasmic reticulum
C. Smooth endoplasmic reticulum
Ribosomes are made in the nucleolus, D.
31. Which of the following is true regarding clathrin –coated pits?
1. They are required for all phagocytosis
2. Are required for receptor-mediated exocytosis
3. Form a lattice structure which is damaged in tattooing
4. Is a simple glycoprotein required for pinocytosis
5. Forms a lattice structure that pulls the membrane in
A. 1 and 2
B. 1, 3, 5
C. 2, 4
D. Only 4
E. Only 5
E. forms lattice from boomerang shaped proteins.
32. Which of the following is true?
A. N-linked glycosylation occurs in the endoplasmic reticulum and modified in the golgi apparatus.
B. O-linked glycosylation occurs in the sarcoplasmic reticulum
C. N-linked glycosylation is modified in the endoplasmic reticulum
D. N-linked glycolysis occurs in the golgi apparatus and modified in the endoplasmic reticulum
Golgi does modifying. N-linked glycosylation occurs in the ER.
33. If the N-terminus of a cell membrane protein is located on the cytoplasmic side of the membrane, what type of protein is it?
A. Type I
B. Type II
C. Type III
D. Type I and/or III
E. Type II and/or III
D or E. It's E. I need to redraw this sequence, I have still not got it firmly in mind and there are a lot of questions about it.
34. The presence of ____________ in the phospholipid bilayer helps to increase rigidity and decrease permeability of the membrane.
35. Where are ribsomes assembled?
D. Nucleolus. Another repeat question.
36. All of the following are characteristics of prokaryotes, EXCEPT:
A. Contains DNA and RNA
B. Has a cell wall
C. Contains chromosomes
D. Has some sub-cellular separation
E. Tends to be small in size
C. No chromosomes.
37. Which function of the nucleus turns RNA into protein?
C. Poorly written question.
38. Which reactions are methods of detoxification within the smooth ER?
A. N-linked glycosylation and disulphide bond formation
B. Hydoxylation and conjugation reactions
C. β-oxidation and degradation of H2O2 to H2O and O2
D. Glycogen degradation and gluconeogenesis
Not B or D. Not C. Guessing A. WRONG! B is correct. Hydroxylation and conjugation reactions are methods of detoxification within the smooth ER.
39. If you have identified an N-linked sugar you can trace the path as to where it was produced. Choose the site it passed through.
D. Both A/C
E. Both A/B
E: An N-linked sugar has been in the golgi and the rER.
40. Which of the following is the pathway for the synthesis and transport of a protein hormone?
A. Synthesized in RER → Golgi apparatus → Secretory vesicles → Plasma membrane / ECM
B. Synthesized in SER → Golgi apparatus → Secretory vesicles → Plasma membrane / ECM
C. Synthesized in RER → SER → Golgi apparatus → Secretory vesicles → Plasma membrane / ECM
D. Synthesized in RER → Golgi apparatus → Secretory vesicles → Nucleus or Peroxisomes or Mitochondrial membrane
A. rough ER to golgi to vesicle to membrane.
41. What organelle fuses with the endosome to facilitate endocytosis?
A. Golgi apparatus
clathrine is not an organelle. golgi doesn't fuse. not sure what a peroxisome does. lysosome fuses with the endosome AFTER endocytosis, so poor Q but D.
42. How does a liver cell differ from a skin cell?
I. It has more sarcoplasmic reticulum
II. It has more cristae in its mitochondria
III. It has more mitochondria
IV. It has adherens junctions
V. It has gap junctions
VI. It has more SER
A. I, IV
B. III, IV
C. II, III, V, VI
D. All of the above
C. So a liver cell has more cristae in its mitochondria and more mitochondria period. A liver cell also. has gap junctions and more smooth ER. Is more metabolically active in general than skin.
43. What is not a part of the rough ER function?
A. Di-sulfide bonds
C. Protein synthesis
D. Co-translational modifications
D. not co-translational, it's post-translational. WRONG! Answer is detox, B. Rough ER has nothing to do with detox. OK.
44. Which of the following is “Not” a function of the proteins in the cell membrane in eukaryotic cell?
A. Ion channels
B. Hormone receptors
C. Transport proteins
D. Co-translational modification
D. Contranslational modification.
45. Which of the following is NOT found in both prokaryotes and Eukaryotes?
46. What are the main functions of the golgi complex?
A. Synthesizes proteins used within the cell
B. Digest substances that enter a cell via endocytosis
C. Synthesizes phospholipids, fats and steroids
D. Modifies, shorts, packages, and transports products received from the rough ER
B. Digesting is a lysosome's job. WRONG! Answer is D but I don't know why. shorting? what's that? packages and transports, yes, that's why I was tricked.