Assignment 1.3: Cell
If the DNA triplet is ATC, the tRNA anticodon will be __________.
AUC
Many toxins and poisons block certain enzymes in the mitochondria. For example, many fruits, including apricots, apples, plums, peaches, and cherries, contain seeds and pits that can cause the formation and release of the poison cyanide if they are ground and ingested. Cyanide binds to an enzyme in the inner mitochondrial membrane critical to energy production. Why would this be fatal for a cell?
Cells could have inadequate distribution of ions, cells would not be able to reproduce, cells would not be able to undergo adequate organelle functioning
Which of the following is not a major difference between DNA and RNAwhich
DNA is found in the nucleus and cytoplasm, but RNA is only found in the nucleus
Oleander (Nerium oleander) is a common but poisonous ornamental shrub. All parts of the plant contain chemicals that inhibit the Na+/K+ pump. How would this affect sodium-glucose symporters (secondary active transport) of a given cell?
Glucose levels within the cell would decrease
When a biologist is trying to isolate DNA from a cell, he or she must first add enzymes that degrade (break down) proteins. Why is this step necessary?
Histone proteins have to be disintegrated.
Based on your understanding of structure and function between our cells versus bacterial cells, which of the following characteristics is the most correct?
Human cells are more efficient in protein synthesis and waste handling due to intricate, compartmentalized organelles.
Your friend has been using a tanning bed and, unbeknownst to him, the radiation from the tanning bed has damaged the DNA in his skin cells. In one particular gene, the triplet TGA has mutated to TGC. Will this change the structure of the protein coded for by this gene? (Hint: Refer to Figure 3.28 for the genetic code.)
No. The codon does not change the corresponding amino acid.
The disease Duchenne muscular dystrophy is caused by a defective membrane protein called dystrophin. This protein normally provides structural stability to the plasma membrane of skeletal muscle cells. Predict what happens to the skeletal muscle cells of patients with this disease.
Patients would encounter muscle weakness.
Which of the following membrane transport mechanisms requires ATP?
Primary active transport
The deadly poison ricin, found in castor beans, binds to and inhibits free and bound ribosomes. Select why this effect is lethal.
Production of lysozyme enzyme would decrease.
Which of the following functions is NOT one of the functions associated with the cytoskeleton?
Serves as the site for metabolic reactions such as protein synthesis
Cancer cells lose their original characteristic features and become more like the cell shown in Figure 3.1 from the textbook. Predict what impact this would have on cell's ability to function.
The cancerous cell would overproduce proteins disproportionately.
Detergents are similar to phospholipids in that they are amphipathic compounds with both polar and nonpolar parts. What do you think would happen to a cell placed in a solution containing a detergent?
The cell membrane would break and dissolve in the detergent, spilling the contents equally throughout the solution.
Which of the following statements is true? Which of the following statements is true?
The process of osmosis can be reversed by altering the pressure gradient.
Ricin inhibits the functioning of ribosomes. What part of protein synthesis would be affected by ricin? What effect would this have on a cell's ability to synthesize pr
Translation process would be inhibited.
Predict the cellular effects of a disorder that prevents the assembly of microtubules. (Hint: Why is it equally important for a microtubule to be easily assembled and disassembled?pr
Vesicles will not be able to fuse towards the plasma membrane.
Solution A and solution B are separated by a semipermeable membrane, which is permeable to NaCl and water. Solution A contains 10% NaCl, and solution B contains 2% NaCl. By osmosis, __________.
Water will move from solution B to solution A
If a red blood cell has a cytosol concentration of 0.9% sodium chloride (NaCl), and this red blood cell is placed in an environment containing 2% NaCl, which of the following substrates—i.e., the solute (NaCl) or solvent (water)—will move, and in which direction?
Water will move out the cell.
The nucleolus __________.
assembles ribosomes
The bristle-like structures on this cell that are also shown in cross-section are __________.
cilia
Which of the following is a function of lysosomes?
digest and recycle damaged organelles
Which of the following is used to export large molecules out of the cell?
exocytosis
The coding sequences, which are kept during RNA processing, are called __________.
exons
Regions of the body which require large surface area for absorption, such as the cells covering the inner surface of the small intestine, often have __________.
microvilli
Golgi apparatus
modify, sort, and package proteins and lipids
The paired and identical copies of a chromosome, which are joined at a centromere, are called __________.
sister chromatids
The liver is an organ that can synthesize lipids, such as cholesterol, and detoxify poisons, such as alcohol. Which of the following organelles is abundant in liver cells
smooth endoplasmic reticulum
Cholesterol in the plasma membrane __________.
stabilizes the structure of the plasma membrane when the temperature changes
If a cell''s translation machinery is impaired, the cell will be unable to __________.
synthesize proteins
The role of tRNA in translation is __________.
to bring amino acids to the ribosome
