Concept explainers
QUANTITATIVE Sizing Things Up. To appreciate the sizes of the subcellular structures shown in Figure 1-3b, consider the following calculations:
(a) All cells and many subcellular structures are surrounded by a membrane. Assuming a typical membrane to be about 8 nm wide, how many such membranes would have to be aligned side by side before the structure could be seen with the light microscope? How many with the electron microscope?
(b) Ribosomes are the cell structures in which the process of protein synthesis takes place. A human ribosome is a roughly spherical structure with a diameter of about 30 nm. How many ribosomes would fit in the internal volume of the human liver cell described in Problem 1-2 if the entire volume of the cell were filled with ribosomes?
(c) The genetic material of the Escherichia coli cell described in Problem 1-2 consists of a circular DNA molecule with a strand diameter of 2 nm and a total length of 1.36 mm. To be accommodated in a cell that is only a few micrometers long, this large DNA molecule is tightly coiled and folded into a nucleoid that occupies a small proportion of the cell’s internal volume. Approximating the DNA molecule as a very thin cylinder, calculate the smallest possible volume the DNA molecule could fit into, and express it as a percentage of the internal volume of the bacterial cell that you calculated in Problem 1-2a.
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Becker's World of the Cell (9th Edition)
- Integral membrane proteins... Choose all that could apply are bound to the membrane by only interacting with the phospholipid's polar head O contain many amino acids with hydrophobic residues O contain alpha-helical membrane spanning domains O would not be digested by trypsin in a permeabilized cell O interact with the phospholipid core of the phospholipid bilayerarrow_forwardIsotonic, Hypotonic and Hypertonic solution. There are three different solutions; 0.9% NaCl, 10% NaCl, and distilled water. 1. Write a conclusion about the effect variation tonicity has on the two cell types(Plant cell and Red blood cell). 2. Describe the differences you observed comparing plant cells and animal cells placed into the three solutions.arrow_forwardTONICITY DRAG THE WORDS INTO THE BLANK SPACES BEL@W TO ACCURATELY COMPLETE THE PARAGRAPH Hypertonic Isotonic Hypotonic Hypertonic Lsotonic Hypotonic animal cell plant cell A Above are a represented plant cell and an animal cell. Refer to the key on slide 5 and fill in the blanks below. (If you find yourself counting solute dots, you're working much too hard!) Assume that the cell membranes are allow only water (not the solutes) to pass through. Because the cytoplasms of the plant and the animal cell have equal concentrations of solutes, we can say that their cytoplasms are to each other. If we put both the plant and the animal cells into Solution A, we would expect no change in the cells, because Solution A is to the cytoplasm of each cell.arrow_forward
- Select all that apply. This is an image of a plasma membrane, which consists of two layers of phospholipids. The red bubbles are the hydrophilic heads of phospholipids, facing the cell interior and exterior. The yellow strings facing inside of the plasma membrane are the fatty acid tails. Which of the following bonds/interactions do you think could regulate the assembly of the plasma membrane and the adhesion or fatty acid tails to each other? Select all that apply. hydrogen bonds covalent bonds electrostatic forces van der Waals forces hydrophobic force ionic bonds O O 0 0 O 0arrow_forwardasap please.arrow_forwardNo explanation needed just answer to MCQarrow_forward
- 11:14 structure. They provide the matrix or ground substance of extracellular tissue spaces in which collagen and elastin fibers are embedded. Hyaluronic acid, chondroitin 4-sulfate, heparin, are among the important glycosaminoglycans. 10. Glycoproteins are a group of biochemically important compounds with a variable composition of carbohydrate (1-90%), covalently bound to protein. Several enzymes, hormones, structural proteins and cellular receptors are in fact glycoproteins. Chapter 2: CARBOHYDRATES SELF-ASSESSMENT EXERCISES I. Essay questions 1. Define and classify carbohydrates with suitable examples. Add a note on the functions of carbohydrates. 2. Describe the structure and functions of mucopolysaccharides. 3. Give an account of the structural configuration of monosaccharides, with special reference to glucose. 4. Discuss the structure and functions of 3 biochemically important disaccharides. 5. Define polysaccharides and describe the structure of 3 homopolysaccharides. III. Fill…arrow_forwardPart A - Comparing plant cells and animal cells Plant cells and animal cells share many of the same structures, but each type of cell also has unique structures. In this activity, you will indicate which cell structures are found only in plant cells, only in animal cells, or in both plant and animal cells. Drag each cell structure to the appropriate bin. If a structure is found in both plant cells and animal cells, drag it to the "both" bin. ► View Available Hint(s) chloroplast plant cell only cellulose cell wall mitochondrion endoplasmic reticulum nucleus animal cell only central vacuole plasma membrane Golgi apparatus both centriole Reset Help cytoskeletonarrow_forwardExample Problem: FRAP Data Interpretation The diffusion rate of four different membrane proteins (A, B, C, and D) was measured using a FRAP experiment with purified liposomes. The FRAP recovery curves are shown below. Fluorescence intensity ROI A 3 Time B Time Post-bleaching imaging с Time D Time Pre-bleaching Bleaching imaging imaging (a) Which membrane protein exhibits the higher rate of diffusion in the lipid bilayer? A or B? C or D? (b) Explain the most likely cause of the difference in the recovery curves for proteins A and C.arrow_forward
- Membrane Protein Insertion in the ER This figure displays five small hypothetical proteins. The a-helix secondary structure of the protein is bracketed and the number of amino acids in the helix is indicated. If the hypothetical ER localization sequence is green-yellow-yellow-green-yellow-red, what protein could potentially be a transmembrane protein in the plasma membrane? = Acidic = Basic = Polar (uncharged) O = Hydrophobic CO₂ T 20 CO2 T 20 NH₂ A. T 20 NH₂ B. NH₂ C. T 20 NH₂ D. NH₂ E. tot 10arrow_forwardPart I. Protein structure You have the toy model for a protein in the water (W) environment of the cell shown. a) How many residues (amino acids) does this toy protein have? b) How many hydrophobic (H), hydrophilic (P), and charged (C) residues are there? c) Sketch the molecule on your answer sheet and then show the positions of the favorable C-C (charge-charge) interactions on the figure.arrow_forwardCan you please help me matchingarrow_forward
- Human Heredity: Principles and Issues (MindTap Co...BiologyISBN:9781305251052Author:Michael CummingsPublisher:Cengage Learning