Concept explainers
The “Facts” of Life. Each of these statements was once regarded as a biological fact but is now understood to be untrue. In each case, indicate why the statement was once thought to be true and why it is no longer considered a fact.
(a) Plant and animal tissues are constructed quite differently because animal tissues do not have conspicuous boundaries that divide them into cells.
(b) Living organisms are not governed by the laws of chemistry and physics, as is nonliving matter, but are subject to different laws that are responsible for the formation of organic compounds.
(c) Genes most likely consist of proteins because the only other likely candidate, DNA, is a relatively uninteresting molecule consisting of only four kinds of monomers (
(d) The fermentation of sugar to alcohol can take place only if living yeast cells are present.
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EBK BECKER'S WORLD OF THE CELL
- True or False? The selective permeability of the plasma membrane allows all substances to pass through the membrane, ensuring that the inside of the cell is in constant interaction with its external environment.arrow_forwardTRUE or FALSE: Eukaryotic cells feature membrane bound organelles that create specialized compartments within a single cell. The primary structure of the outer cell membrane is a double layer but the membranes that enclose organelles are only single layer. Choose. 1. Which of the following is one of the ways that will keep the membranes of such vegetables to remain fluid when it is extremely cold? A) by increasing the percentage of unsaturated phospholipids in the membrane B) by decreasing the number of hydrophobic proteins in the membrane C) by increasing the percentage of cholesterol molecules in the membrane D) by co-transport of glucose and hydrogen 2. After a membrane freezes and then defrost, it often turns out to be loose to solutes. The best logical reason for this is that: A) the lipid bilayer loses its fluidity when it freezes. B) transport proteins become nonfunctional during freezing C) the integrity of the lipid bilayer is broken when the membrane freezes D) the…arrow_forwardQIV. Determine if the level of organization is molecular or cellular. Tick True if molecular. Tick False if cellular. Prokaryotic cells have no membrane-bound nucleus, and the organelles have no surrounding membranes. Select one: O True O Falsearrow_forward
- What I Can Do Cells are highly organized structures with parts that perform specific functions. Starting from the cell membrane with its incomparable abilities not only to provide shape and flexibility to the cell but also to determine the nature of its interaction with its environment. For you to recognize these functions, make an illustration (with a title) that shows a place which resembles a cell membrane. Also, write the things that you think they are similar. Your product will be assessed based on the following criteria: organization and content accuracy, appropriateness of elements, creativity, and appearance. The actual rubric to be used in assessing your product will be found on page 21. Assessment Let's see how well you have enjoyed the amazing world of çell cycle and mitosis byarrow_forwardAll living things are organized. For this question, think about the levels of organization in the human body: organ system, organ, tissue, cell, molecule, atom.First, choose any organ system that we covered this semester, and explain its role in the body. Next, choose any organ in that system, and explain its specific function within the system. Next, choose any tissue type in that organ, and explain how it specifically helps the organ do its job. Next choose any cell type in that particular tissue, and explain how it contributes to the tissue’s function. Finally, choose any molecule (or atom) found in that specific cell and explain what the cell uses that molecule for.arrow_forwardThe plasma membrane isa. a carbohydrate layer that surrounds groups of cells to protect them.b. a double lipid layer with proteins inserted in it, which surrounds every cell individually.c. a thin sheet of structural proteins that encloses cytoplasm.d. composed of proteins that form a protective barrier.arrow_forward
- So you have a solid substance. So you start to add heat to it. What happens as you start to do this? Increasing the rate of heating of a substance at its melting point only causes more rapid melting. When the melting point is reached, ther thermal energy is sufficient to overcome intermolecular forces holding the components at their statioinary points. Thermal energy causes the components of the solid to vibrate faster. Heating of the now formed liquid results in increaseing the liquid temperture.arrow_forwardTAGS: Biology, Chemistry, Biochemistry, Cell Biology, Molecular Biology A group of researchers were tasked to design various synthetic cell membranes that could be used to simulatecellular activities of different organisms. Help the researchers assemble the structure of the major lipid component for a cell membrane (draw the strucutres clearly) that is appropriate for the following and briefly explain your answer: a prokaryotic cell thriving in a geyser at the Yellowstone National Park in Wyoming, USA a muscle cell of a salmon fry in the Arctic Ocean a frog neurocyte Chemical structures of the compounds that are available are shown on the image.arrow_forwardThinking about cell membranes. a) The fatty acid tails of the phospholipids that make up cell membranes canbe either saturated or unsaturated. Which type of lipid will lead to a membranewith more mechanical strength? Explain your answer. b) One difference between bacterial and eukaryotic membranes is the presenceof cholesterol in eukaryotic membranes. What is the structure of cholesterol?Explain how adding cholesterol to a phospholipid membrane will affect thestability of the membrane. c) “Anammox” bacteria are unique in that they can perform anaerobic ammoniaoxidation, or the production of nitrogen gas from ammonia (Damasté et al. Nature2002, 419, 708.). Intermediates along this reaction pathway include hydrazine(N2H4) and hydroxylamine (NH2OH), both of which are extremely toxic to the cell.The ammonia oxidation reactions are believed to occur inside a membrane-bound structure within the cell called the “anammoxosome.” The structure of oneof the lipids of the anammoxosome is shown…arrow_forward
- True or False: In most cells, the lipid molecules that form the cell membrane bond to one another to form a firm, impermeable sheet.arrow_forwardHello please solution ? Which of the following statement is correct regarding cells? a. Two choices are correct b. Cells must have cytoskeletal elements which are important to maintain their shapes c. All choices are correct d. Cells are the basic units of life e. In cells, the DNA is transcribed into mRNA and then the mRNA is translated into proteinsarrow_forwardBiological Macromolecules Identifying molecules that could be in a cell membrane te for advanced students: none of these molecules are actually found in cell membranes. Your goal is to use the principles of biochemistry to dec ey could be, if for example they were synthesized and studied as drug candidates. 0 OH H₂N molecule Could be in a membrane? Membrane would be to the..? X CH3 O yes -left right- O no O yes - left right- по Ο O Oyes -left right→ О по Oyes -left right- Ono Garrow_forward
- Biology Today and Tomorrow without Physiology (Mi...BiologyISBN:9781305117396Author:Cecie Starr, Christine Evers, Lisa StarrPublisher:Cengage Learning