biol 168 magsobi/cell
When your biceps brachii (upper arm) muscle contracts, ultimately and most directly, what is producing the movement?
Proteins within the cells of the biceps brachii slide past each other lengthwise, shortening the muscle.
What process ultimately pinches a dividing cell to produce two daughter cells? interphase DNA replication cytokinesis mitosis
cytokinesis
Which of the following would decrease the rate of facilitated diffusion? increasing the number of carrier proteins increasing the amount of ATP available decreasing the amount of ATP available decreasing the number of carrier proteins
decreasing the number of carrier proteins
Coupled transporters that move solutes in the same direction are called _______. isoporters symporters antiporters uniporters
symporters
What major function occurs on the specific membranes indicated by A? Anabolic pathway within the endomembrane system. digestion of ingested food synthesis of proteins replication of DNA production of most of the cell's ATP
synthesis of proteins Structure A is the rough endoplasmic reticulum (ER). The figure illustrates how proteins are synthesized on ribosomes bound to the rough ER, sorted and modified in the Golgi apparatus, and delivered to the plasma membrane for secretion or packaged into lysosomes.
In leukemia, an overproduction of abnormal white blood cells can also mean __________. more reactive white blood cells overproduction of normal blood cells that healthy blood cells will die sooner too few normal blood cells
too few normal blood cells
What process allows for the production of molecule B from a template consisting of molecule A? Transcription of a DNA template strand and translation of the resulting RNA into a polypeptide. transcription translation replication transport
transcription Transcription is the synthesis of RNA using DNA as a template
Which organelle is responsible for synthesizing proteins? ribosomes rough endoplasmic reticulum smooth endoplasmic reticulum Golgi apparatus
ribosomes Proteins are synthesized at ribosomes. Free ribosomes float freely in the cytoplasm and produce soluble proteins that function in the cytosol, as well as those imported into mitochondria and some other organelles. Fixed ribosomes, which stud the rough endoplasmic reticulum, synthesize proteins destined either for incorporation into the cell membrane or lysosomes, or for export from the cell.
This figure illustrates which of the following descriptions? the facilitated diffusion of both sodium and glucose through the same carrier protein the use of a sodium concentration gradient to power the pumping of glucose into the cell the reaction between sodium and glucose catalyzed by a membrane-bound enzyme the use of the energy derived from the breakdown of glucose to power the sodium-potassium pump
the use of a sodium concentration gradient to power the pumping of glucose into the cell The sodium ion gradient is generated by the Na+-K+ pump at the left. Diffusion of sodium ions through the Na+-glucose symport transporter (shown at the right) provides the energy necessary to actively transport glucose into the cell. Such a mechanism is used by intestinal cells (to absorb nutrients) and kidney cells (to recover glucose from urine prior to excretion).
What is a membrane potential? a voltage or electrical charge across the plasma membrane the possibility of cell activity cooperation between cells the ability of the cells to perform their specialized functions
a voltage or electrical charge across the plasma membrane The membrane potential is the electrical potential energy (measured in millivolts) resulting from the separation of oppositely charged particles (ions) across the plasma membrane. At rest, membrane potentials are typically negative, ranging from −50 to −100 mV, with more anions (than cations) concentrated along the internal surface of the membrane, and more cations (than anions) concentrated along the external surface.
Which of the following does NOT describe the plasma membrane? differentially permeable impermeable selectively permeable semipermeable
impermeable
Which of the following increased the rate of sodium-potassium transport? increasing the number of membrane pumps increasing the amount of ATP adding glucose to the right beaker decreasing the amount of ATP
increasing the number of membrane pumps
Which of the following would increase the rate of facilitated diffusion? decreasing the number of carrier proteins increasing the steepness of the concentration gradient increasing the amount of ATP available decreasing the concentration of solutes
increasing the steepness of the concentration gradient
Which of the following describes tight junctions?
junctions among epithelial cells lining the digestive tract
What are the two basic steps of polypeptide synthesis? protein coding and release transcription and translation RNA production and DNA intron release transcription and DNA replication
transcription and translation Polypeptide synthesis involves two major steps: (1) transcription, in which DNA's information is encoded into mRNA, and (2) translation, in which the information carried by the mRNA is decoded and used to assemble polypeptides.
Each number above molecule B refers to a codon. If an RNA codon was UAG, what would the corresponding DNA codon be? Transcription of a DNA template strand and translation of the resulting RNA into a polypeptide. AUC UAG ATC CTA
ATC Respectively, uracil, adenine, and guanine in RNA (UAG) are complementary to adenine, thymine, and cytosine (ATC) in DNA
Which of the following is the driving force for the sodium-potassium pump? ATP hydrolysis an electrical gradient a concentration gradient a hydrostatic pressure gradient
ATP hydrolysis
Which of the following statements about genes is not correct? They are part of your chromosomes. They are composed of DNA. They are located in the nucleus. Each single chromosome contains one single gene.
Each single chromosome contains one single gene. Excellent! Each chromosome contains many genes
Which of the following names the three main parts of a human cell?
Human cells have three main parts: the plasma membrane, the cytoplasm, and the nucleus.
Phospholipids provide the specific functions of the plasma membrane.
Integral and peripheral proteins provide a variety of specific functions at the membrane
Which of the following is not true of DNA? It is found in the nucleus. It carries amino acids to the ribosome. It contains the instructions for protein synthesis. It contains our genes.
It carries amino acids to the ribosome Excellent! DNA does not leave the nucleus, so it does not go to the ribosomes, which are in the cytoplasm.
Which of the following can be true of both active transport and facilitated diffusion? Lipid-insoluble solutes are transported across the membrane by a carrier protein. Solutes can move against their concentration gradient. Cellular energy is required for the transport. The cell membrane pinches off to transport materials. A solute pump is required.
Lipid-insoluble solutes are transported across the membrane by a carrier protein.
Which of the following is not a passive process? facilitated diffusion of glucose osmosis oxygen diffusion Na+/K+ pump
Na+/K+ pump Excellent! This pump is a protein in the membrane that moves these ions only in one direction, and up their concentration gradient. This is active transport, and it requires the use of energy.
Which set of membrane proteins in the figure depicts the transport of solute molecules across the membrane?
Panel A shows both passive and active transport processes of solutes mediated by integral membrane proteins.
Which of the following describes the movement of ions by the sodium-potassium pump? Potassium is moved out of the cell and sodium is moved into the cell. Potassium is moved into the cell. Sodium is moved into the cell Potassium is moved out of the cell.
Potassium is moved into the cell.
As you look under a microscope you see a nucleus with a large density of nucleolus. What inference can you make about that cell? The cell is preparing for autophagy. The cell is preparing to divide. The cell has a large energy demand. The cell is producing a large amount of proteins.
The cell is producing a large amount of proteins. The nucleolus is the site where ribosomes and RNA organize in the nucleus in order to start the process of protein production.
What happens to facilitated diffusion when the protein carriers become saturated? The transport rate will increase The maximum rate of transport will occur. ATP will be utilized for transport The protein carriers fall apart.
The maximum rate of transport will occur
Which of the following statements about facilitated diffusion is FALSE? The movement of the solute is passive. The movement of a given solute usually occurs in both directions (into and out of the cell). The movement of the solute is with its concentration gradient. The movement requires a carrier protein.
The movement of a given solute usually occurs in both directions (into and out of the cell).
Which of the following is NOT a reason why a solute would require facilitated diffusion? The solute is hydrophilic. The solute is too large to pass on its own. The solute directly requires ATP for its transport. The solute is lipid insoluble.
The solute directly requires ATP for its transport.
Which of the following would result in NO change in osmotic pressure across a membrane? The solutes can diffuse through the pores and the concentration of solutes is the same on both sides of the membrane. The solutes can diffuse through the pores. The concentration of solutes is the same on both sides of the membrane. Water is moving with its concentration gradient.
The solutes can diffuse through the pores and the concentration of solutes is the same on both sides of the membrane.
What happened when sodium chloride was added as a solute in the left beaker? The transport rate of glucose decreased. The transport rate of glucose increased. Sodium was cotransported with the glucose. There was no change in the transport rate of glucose.
There was no change in the transport rate of glucose.
Which of the following statements about carrier proteins is FALSE? They are found integrated into the plasma membrane. They assist in simple diffusion. They might have to change shape slightly to accommodate a solute. They can become saturated if the maximum transport rate is exceeded.
They assist in simple diffusion.
Which of the following is an incorrect description? Ribosomal RNA (rRNA) is part of the ribosome. Transfer RNA (tRNA) transfers the instructions for protein synthesis to the ribosome. Messenger RNA (mRNA) participates in transcription. DNA determines the amino acid sequence of our proteins.
Transfer RNA (tRNA) transfers the instructions for protein synthesis to the ribosome Excellent! The tRNA transfers amino acids to the ribosome so they can be placed according to the DNA instructions that were brought to the ribosome by the mRNA. This process is translation.
Which of the following statements about osmosis is FALSE? It is specific for the movement of water. It is passive. It is a type of diffusion. Water moves toward the solution with the lowest concentration of solutes.
Water moves toward the solution with the lowest concentration of solutes.
If a membrane is impermeable to solutes, which of the following is true? Osmosis will not occur. Water will move toward the more concentrated solutes. Water will move away from the concentrated solutes. Water and solutes will move until equilibrium is reached.
Water will move toward the more concentrated solutes.
Which cellular organelle is seen in this figure? Structure of a mitochondrion. a lysosome a mitochondrion the nucleus the Golgi apparatus
a mitochondrion Mitochondria are characterized by an oblong shape with inner and outer membranes.
In the video clip, which movement process is depicted? simple diffusion osmosis facilitated diffusion active transport
active transport Excellent! Active transport moves substances up their concentration gradient by using a transport protein in the membrane and energy.
Each individual gene does which of the following? carries the instructions for making a single polypeptide controls the expression of several traits controls protein synthesis codes for one amino acid
carries the instructions for making a single polypeptide
When the solutes are evenly distributed throughout a solution, we say the solution has reached _______. velocity permeability equilibrium diffusion
equilibrium
Normal leukocytes use several protective mechanisms in combating disease-causing microbes such as bacteria. Which of the following is NOT a method related to substance uptake by a white blood cell? exocytosis receptor-mediated endocytosis pinocytosis phagocytosis
exocytosis
What process is indicated by C? Anabolic pathway within the endomembrane system. exocytosis of RNA from the cell digestion of food particles exocytosis of ribosomes from the cell exocytosis of secretory proteins
exocytosis of secretory proteins The event indicated by C includes the fusion of a secretory vesicle with the plasma membrane and the subsequent release of the vesicle contents to the extracellular space.
What is the type of transport supplied by the glucose carriers in the activity? active transport endocytosis coupled transport facilitated diffusion exocytosis
facilitated diffusion
Which of the following requires a membrane-bound carrier for transport? filtration osmosis simple diffusion facilitated diffusion
facilitated diffusion
Which of the following would NOT diffuse through the plasma membrane by means of simple diffusion?
glucose Glucose, a small polar solute, uses a membrane transporter (a protein carrier) to cross the plasma membrane via facilitated diffusion. In simple diffusion, small nonpolar and lipid-soluble substances (including gases) diffuse directly through the lipid bilayer.
A not very well-studied A&P student heard about a phenomenon called water intoxication and thought it sounded fun so she decided to try it. She consumed a large amount of water in a short time (Don't try this—water intoxication is often fatal.). Instead of feeling drunk, she felt nauseated, developed a severe headache, began to get confused, and then became unconscious. Her much more prepared A&P student roommate quickly realized the problem and called an ambulance. When the roommate told the Emergency Department doctor what had happened, the doctor quickly began administering IV (intravenous) fluids. Based on this information and your understanding of osmosis and tonicity, what type of IV fluid is the doctor likely administering to try to save the life of the student suffering from water intoxication? isotonic IV fluid hypertonic IV fluid hypotonic IV fluid
hypertonic IV fluid Excellent! Her blood is very hypotonic, causing water to move from her blood into her cells, which caused her brain to swell. Raising the blood tonicity with hypertonic IV fluid should hopefully draw the excess water back out of the cells.
The nucleolus __________. is a dark-staining spherical body found within the mitochondria is the site of lipid production in a cell is the site of ribosome assembly in a cell is the primary site of protein synthesis
is the site of ribosome assembly in a cell Nucleoli ("little nuclei") are the dark-staining spherical bodies found within the nucleus where ribosomal subunits are assembled. They are not membrane bounded. Typically, there are one or two nucleoli per nucleus, but there may be more. Nucleoli are usually large in growing cells that are making large amounts of tissue proteins.
What is the specific role of the enzyme indicated by B during the formation of the new DNA strands? Replication mechanism for DNA showing leading and lagging strands. joining the fragments of DNA that are formed during lagging-strand synthesis producing an RNA primer that will be extended into the new DNA strand transferring nucleotides from the old DNA strand to the new DNA strand joining the nucleotides that form the new DNA strand
joining the nucleotides that form the new DNA strand DNA polymerase catalyzes formation of bonds between sugar groups and phosphate groups that link the DNA nucleotides together
Osmotic pressure is measured in units of _______. mM/min mm Hg ml/min mM/sec
mm Hg
What is the function of the organelle indicated by B? Anabolic pathway within the endomembrane system. assembling proteins from amino acids cellular division catabolism of fats and sugars modification and packaging of proteins
modification and packaging of proteins The Golgi apparatus within the endomembrane system functions in the sorting and modifying of membrane- bound proteins being transported to various cellular locations.
Simple diffusion and facilitated diffusion both _______. move solutes with their concentration gradient utilize a membrane-embedded carrier protein require ATP move solutes against their concentration gradient
move solutes with their concentration gradient
Which of the following processes allows cells to concentrate material that is present only in very small amounts in the extracellular fluid? receptor-mediated endocytosis pinocytosis transcytosis phagocytosis
receptor-mediated endocytosis Receptor-mediated endocytosis is the main mechanism for the specific endocytosis and transcytosis of most macromolecules by body cells, and it is exquisitely selective. The mechanism also allows cells to concentrate material that is present only in very small amounts in the extracellular fluid.
Molecule B and molecule C are expected to interact within which of the following cellular locations? Transcription of a DNA template strand and translation of the resulting RNA into a polypeptide. nucleus ribosome rough endoplasmic reticulum Golgi apparatus
ribosome The codons within the mRNA (B) are recognized by corresponding tRNA molecules within cytoplasmic ribosomes during protein translation.
Which of the following generated osmotic pressure? glucose sodium chloride, glucose and albumin generated osmotic pressure. sodium chloride albumin
sodium chloride, glucose and albumin generated osmotic pressure.
___ is a molecule that brings amino acids to the ribosome during translation. DNA t-RNA mRNA rRNA
t-RNA t-RNA serves as an adapter molecule; it ferries amino acids to the ribosome and participates in translation (the process by which amino acids are assembled into proteins).
What is the structure at A? Cell nucleus with surrounding endomembrane system. the nuclear envelope the nucleolus a chromosome the nucleus
the nucleolus The nucleolus is an area within the nucleus associated with ribosome construction.
Which of the following is NOT a passive process?
vesicular transport facilitated diffusion osmosis filtration vesicular transport
A Hypertonic solution:_______. will induce no net movement of water will induce cell shrinkage will induce cell bursting will induce cell swelling
will induce cell shrinkage
What is the difference between active and passive transport across the plasma membrane? Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane. Active transport means that the cell is actively going after substances that it wants to bring into the cell, whereas passive transport means that the cell just waits for the substance to cross the membrane. Active transport implies that the cell is working with other cells, whereas passive transport implies that the cell does not cooperate with other cells. Active transport is used to move substances down their concentration gradient, whereas passive transport is used to move substances against their concentration gradient.
Active transport is ATP dependent, whereas passive transport uses only the kinetic energy of the particles for movement across the plasma membrane. In active transport, the cell provides the metabolic energy (ATP) needed to move substances across the plasma membrane (against their concentration gradient). In passive transport, substances cross the plasma membrane (down their concentration gradient) using kinetic energy, without any energy input from the cell.
The region of molecule B that encodes a polypeptide is 24 nucleotides in length. Consider another such molecule with a coding region of 300 nucleotides. What is a reasonable estimate for the length of the corresponding polypeptide that will be produced during protein synthesis? Transcription of a DNA template strand and translation of the resulting RNA into a polypeptide. 30 amino acids 100 amino acids 300 amino acids 900 amino acids
Each amino acid corresponds to a codon of 3 nucleotides. Therefore, a coding region of 300 nucleotides contains 100 codons and will produce a polypeptide of 100 amino acids in length. 100 amino acids
During DNA replication, the covalent bonding of nucleotides into a new strand of DNA is performed by __________. DNA polymerase primase RNA polymerase DNA ligase
DNA polymerase DNA polymerase is the enzyme that positions complementary nucleotides along the template strand and then covalently links them together into a new strand of DNA.
Which of the following statements is true? Unlike endocytosis, exocytosis does not rely on protein interactions with the plasma membranes. During exocytosis, substances from inside the cell are moved outside. Exocytosis involves infolding of the plasma membrane. Endocytosis and exocytosis are passive transport mechanisms.
During exocytosis, substances from inside the cell are moved outside. Vesicular transport processes that eject substances from the cell interior into the extracellular fluid are called exocytosis. Exocytosis is a form of active transport; thus, it requires energy, usually in the form of ATP.
Which of the following statements about genes is not correct? They are part of your chromosomes. They are composed of DNA. They are located in the nucleus. Each single chromosome contains one single gene.
Each single chromosome contains one single gene. Previous Answers Correct Excellent! Each chromosome contains many genes.
According to the Cell Theory, which of the following statements is incorrect ?
Excellent! Some organisms are unicellular—they are a single cell.
Which of the following is the best situation for maintaining homeostasis? Extracellular fluid should be isotonic to intracellular fluid. Extracellular fluid should be hypertonic to intracellular fluid. Extracellular fluid should be hypotonic to intracellular fluid. Tonicity has no impact on homeostasis.
Extracellular fluid should be isotonic to intracellular fluid. Excellent! Isotonic solutions have the same tonicity, and water will move between them at about equal rates in each direction.
Drinking alcohol makes the blood hypertonic. Which option best describes the consequences of this hypertonic blood?
Hypertonic blood draws water out of the interstitial fluid, which makes the interstitial fluid hypertonic. This, in turn, draws water out of the cells If the blood is hypertonic compared to the interstitial fluid (IF), the IF has a greater concentration of water. This means water will move from the IF toward the blood. As water leaves the IF space, that space would then become hypertonic compared to the cell, causing the same movement to occur.
Which of the following is a difference between primary and secondary active transport? In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. Energy is required for primary active transport, but energy is not required for secondary active transport. Primary active transport is driven by secondary active transport. Primary active transport is used to transport sugars and amino acids across the plasma membrane, while secondary active transport includes the sodium-potassium pump.
In primary active transport, the transport protein gets phosphorylated; in secondary active transport, the transport protein is not phosphorylated. In primary active transport, energy comes directly from the hydrolysis of ATP and the subsequent phosphorylation of the primary active transporter. In secondary active transport, the solute (usually Na+) concentration gradient produced by primary active transport provides the (kinetic) energy to move other solutes, such as ions and glucose, against their concentration gradients. For example, glucose can be transported against its concentration gradient through a Na+-glucose symporter as Na+ moves down its concentration gradient (a gradient produced by the Na+-K+ pump).
What must happen before a body cell can begin mitotic cell division? The DNA is expelled from the cell so that it will not be affected by the division process. Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring. The DNA undergoes mutation in order to increase variation in the cell population. Its DNA must be divided in half so that half can go to one daughter cell and half can go to the other daughter cell.
Its DNA must be replicated exactly so that identical copies of the cell's genes can be passed on to each of its offspring. Before a body cell begins mitosis, it must replicate its DNA so that each daughter cell will have the same DNA as the parent cell.
Which letter is pointing to an mRNA molecule? Transcription of a DNA template strand and translation of the resulting RNA into a polypeptide. A B C D
Molecule B is a complement of the DNA template (A) and contains ribonucleotides, as indicated by the presence of uracil (U). This is consistent with molecule B being an mRNA molecule.b
In this illustration, the three compartments are separated by semipermeable membranes. The red balls represent solutes, and the lightly shaded area represents water. Which of the following is a true statement? The figure shows the system of three compartments that are separated by semipermeable membranes and designated by capital letters A, B, and C from left to right. The red balls represent solute particles. The compartments respectively contain: A - twelve, B - five, C - two balls. Each compartment initially contains the same volume of water. Solution B is hypotonic to solution A, but hypertonic to solution C. Both solutions B and C are hypertonic to solution A. Solution B is hypertonic to solution A, but hypotonic to solution C. Solution A is hypotonic to solution C.
Solution B is hypotonic to solution A, but hypertonic to solution C.
If a person goes to the hospital for surgery and requires IV (intravenous) fluids, which of the following should you expect? The IV fluid should be hypotonic to the patient's blood. The IV fluid should be hypertonic to the patient's blood. The IV fluid should be isotonic to the patient's blood. The tonicity of the IV fluid doesn't matter—the patient won't be in the operating room that long so any tonicity would be OK for a couple of hours.
The IV fluid should be isotonic to the patient's blood.
What can we infer if we see a large number of mitochondria in a cell? The cell builds a lot of cholesterol. The cell has a great metabolic demand. The cell produces a great deal of protein. The cell packages a great deal of proteins for secretion.
The cell has a great metabolic demand. Mitochondria are threadlike or lozenge-shaped membranous organelles. In living cells they squirm, elongate, and change shape almost continuously. They are the power plants of a cell, providing most of its ATP supply.
A cell is immersed in a beaker of solution. The cell membrane is permeable to water but impermeable to solutes. If the intracellular concentration is 10 mM and the solution is 20 mM, which of the following is true? The cell will shrink. The solution is hypotonic. The net movement of water is into the cell. There is no net change in the movement of water into the cell.
The cell will shrink.
Which of the following describes the concentration of ions when the cell is at rest? The concentration of potassium is higher outside the cell. The concentration of sodium is higher inside the cell. The concentration of potassium is higher inside the cell. The concentration of potassium and sodium is equal inside and outside the cell.
The concentration of potassium is higher inside the cell.
With the experimental conditions set at 10 mM glucose and 9 mM albumin, and the 200 MWCO membrane in place, which of the following is true? The net movement of water is away from the albumin. The net movement of water is toward the glucose. The net movement of water is toward the albumin. Albumin and glucose diffuse through the membrane.
The net movement of water is toward the albumin.
Which of the following is characteristic of cilia? They move substances in many directions across a cell's surfaces. They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. They are used for cellular adhesion. They are substantially longer than flagella, and are less common than flagella in humans.
They are whiplike, motile cellular extensions that occur in large numbers on the exposed surfaces of certain cells. Cilia are whiplike, motile cellular extensions that occur, typically in large numbers, on the exposed surfaces of certain cells. Ciliary action moves substances in one direction across cell surfaces. Centrioles forming the bases of cilia and flagella are commonly referred to as basal bodies.
In their resting state, all body cells exhibit a resting membrane potential; therefore, all cells are polarized. True False
True All cells have a resting membrane potential (RMP), such that the inside (interior surface) of the cell membrane has a net negative charge while the outside (external surface) of the membrane has a net positive charge. Given the different (opposite) charges on either side of the cell membrane, the cell is considered to be polarized. This RMP, which results from separation of charged particles (ions) across the cell membrane, can be measured in millivolts (typically ranging from −50 to −100 mV depending on the cell type).
Lysosomes perform digestive functions within a cell. True False
True Born as endosomes that contain inactive enzymes, lysosomes are spherical, membranous organelles containing activated digestive enzymes. Lysosomes are large and abundant within phagocytes, the cells that dispose of invading bacteria and cell debris. Lysosomal enzymes can digest almost all kinds of biological molecules. They work best in acidic conditions and so are called acid hydrolases.
During which phase of mitosis do the chromosomes separate? metaphase prophase anaphase telophase
anaphase Excellent! The chromosomes are very precisely separated during anaphase to ensure that each daughter cell gets a complete set.
Each individual gene does which of the following? carries the instructions for making a single polypeptide controls the expression of several traits controls protein synthesis codes for one amino acid
carries the instructions for making a single polypeptide Excellent! Indeed, a single gene codes for, or carries, the instructions for making a single polypeptide
After DNA replication is completed, what does each DNA double helix consist of? Replication mechanism for DNA showing leading and lagging strands. strands that are mixtures of old and new nucleotides two newly synthesized strands that replace the old parent strands either two old strands or two new strands one old parent strand and one new daughter strand
one old parent strand and one new daughter strand This mechanism is called semiconservative replication and is based on the ability of each strand of the DNA double helix to function as a template for the synthesis of the opposite stran
The sodium-potassium pump can transport _______. sodium even if potassium is not available sodium even if potassium is not available and potassium even if sodium is not available only if sodium and potassium are available potassium even if sodium is not available
only if sodium and potassium are available
Which of the following organelles is correctly paired with its function? lysosome: protein synthesis Golgi apparatus: produce energy for the cell smooth endoplasmic reticulum: metabolism of lipids mitochondrion: packaging proteins and lipids
smooth endoplasmic reticulum: metabolism of lipids This answer is correct. The smooth ER also plays a role in synthesizing steroid hormones, absorbing and transporting fats, detoxifying toxins, and breaking down glycogen.