physiology hw reviews
d
A gene codes for a proinsulin protein, which is then cleaved into insulin. This is an example of: a. processing of mRNA b. translation c. transcription d. post translational modification
a
A patient has a mutation that changes the structure of GLUT transporters in beta cells in the pancreas so that these cannot transport glucose. Which of the following would you predict to happen? a. potassium will diffuse into cells through K-ATP channels b. ATP will increase c. calcium will diffuse into cells through voltage-gated channels
a
A protein that no longer functions because its shape has changed (for example, as a result of heating) has been __________. a. denatured b. inhibited c. saturated d. modulated
a
Albuterol is a drug used to treat asthma. Albuterol and epinephrine are both agonists for a receptor that stimulates the dilation of bronchioles. Albuterol and epinephrine are examples of ________ a. competitors b. saturation c. inhibitors d. antagonists
a
An enzyme-catalyzed chemical reaction in which two substrates are joined using the energy of ATP is known as __________. a. ligation b. oxidation c. addition d. reduction
c
Coupled transporters that move solutes in the same direction are called _______. a. uniporters b. isoporters c. symporters d. antiporters
d
Electrons have four important roles in biological systems: forming covalent bonds, transferring energy from the environment, forming free radicals, and which other function? a. forming functional groups b. creating polymers c. allowing the specific paring of nucleic acids in DNA and RNA d. forming ions
b
Enzymes __________. a. allow for chemical reactions to occur that would otherwise not be possible b. increase rate of chemical reactions c. are changed in structure as a result of chemical reactions d. determine the direction of the chemical reaction (in other words, whether molecules are produced or broken down)
a
Exergonic reactions and endergonic reactions are similar because they both ____. a. involve activation energy b. release energy c. produce products with more energy than reactants d. reused to break down ATP
d
How does the intracellular fluid compartment differ from the extracellular fluid compartment? a. There is a higher concentration of bicarbonate ion (HCO3-) inside cells than in either the interstitial fluid or plasma. b. There is a higher concentration of protein in the interstitial fluid than in cells. c. There is a higher concentration of sodium ions inside the cell than in the extracellular space. d. There is a higher concentration of potassium ions inside the cell than in the extracellular space.
d
Hydrolysis is an example of which type of reaction? a. synthesis b. exchange c. dehydration synthesis d. decomposition
c
If a swimmer cuts his foot on a seashell while wading in the ocean and bleeds into the seawater, his erythrocytes will shrink. What does this tell us about the relative tonicities of the solutions? a. The ocean is hypotonic to the erythrocytes. b. The ocean is isotonic to the erythrocytes. c. The ocean is hypertonic to the erythrocytes. d. The cell membrane is not permeable to seawater.
b
In a chemical equation, what are the chemicals on the left side of the arrow called? a. disaccharide b. reactants c. water d. products
a
In most resting cells, the concentration of sodium ions is higher outside of cells compared with the intracellular fluid. When cells are stimulated, sodium ion channels open, and sodium diffuses from the outside of the cell to the inside of the cell. Sodium ion concentrations in a resting cell are an example of ___________, and sodium ion movement in a stimulated cell is an example of ___________. a. potential; kinetic energy b. chemical; energy stored in chemical binds c. the energy to motion; stored d. kinetic energy; potential energy
d
Insulin is an example of a peptide hormone. Insulin is also an example of a: a. membrane transporter b. receptor c. substrate d. ligand
b
Proteins that bind signal molecules and initiate cellular responses are called __________. a. immunoglobins b. receptors c. binding enzymes d. enzymes
b
Steroid hormones are hydrophobic and so are not soluble in the plasma (plasma is made up mostly of water). Which type of protein would help transport steroid hormones in the blood? a. enzymes b. binding proteins c. signal molecules d. antibodies
d
The energy in the chemical bonds of a molecule is known as __________ energy. a. exergonic b. stored c. kinetic d. activation
carbohydrate
The most abundant type of organic molecule is the __________.
a
The permeability of a membrane to a particular solute is related to which two variables, and what is the relationship? a. It is directly proportional to lipid solubility and inversely proportional to the size of the solute. b. It is directly proportional to both lipid solubility and the size of the solute. c. It is inversely proportional to both lipid solubility and size of the solute.
a
The sodium-potassium pump can transport _______. a. only if sodium and potassium are available b. sodium even if potassium is not available c. potassium even if sodium is not available
d
Transport of a substance from the lumen (cavity) of an organ into one side of a cell and out the other side of the cell into the ECF is called __________. a. secretion b. paracellular transport c. transcellular transport d. absorption
b
What is the most abundant energy-capturing molecule produced by the citric acid cycle? a. CO2 b. NADH c. FADH2 d. ATP
b
What is the most important distinction between the membrane transporters known as channel proteins and those known as carrier proteins? a. Channel proteins do not require energy, whereas carrier proteins do require energy. b. Channel proteins create water-filled passages for small substances that do not bind to the protein. Carrier proteins transport larger substances by binding to them. c. Channel proteins transport water-soluble substances. Carrier proteins transport water-insoluble substance.
b
What is the type of transport supplied by the glucose carriers in the activity? a. active transport b. facilitated diffusion c. endocytosis d. exocytosis e. coupled transport
c
What will happen to the cells of a patient who is given an intravenous (IV) solution that is isosmotic to intracellular fluids? a. The cells will keep their normal shape, because isosmotic solutions result in no net change in water concentration. b. The cells will shrink, because isosmotic solutions are hypertonic. c. The question cannot be answered with certainty without knowing which solutes are present in the IV solution.
d
When a protein enters the low-pH environment of the stomach, charges on amino acid side chains are changed. These changes break ionic bonds, which changes the structure of the protein. This will change the: a. amount of buffer in the stomach b. secondary structure of the protein c. primary structure of the protein d. function of the protein
a
Where does the energy come from to power the addition of a high-energy phosphate group to an ADP molecule by ATP synthase in the inner mitochondrial membrane? a. from H+ gradient across the membrane b. from FADH2 made during glycolysis c. NADH reduces ATP synthase, providing the energy it needs to phosphorylate ADP d. oxygen diffusing into the mitochondria drives ATP synthase activity
a
Which could be a mechanism of a drug for type 2 diabetes mellitus that would increase insulin secretion from beta cells in the pancreas? a. closing potassium channels b. decreasing ATP c. hyperpolarizing beta cells d. closing calcium channels
c
Which is a similarity between endocytosis and exocytosis? They both ____. a. are ways that LDL helps bring cholesterol into cells b. need to be stimulated to transport substances c. use membrane-bound vesicles d. are ways that proteins such as insulin are secreted from cells
d
Which membrane proteins bind ligands and trigger another membrane event? a. enzymes b. structural proteins c. transport proteins d. receptors
a
Which of the following are especially important for growth and repair processes? a. synthesis reactions b. exchange reactions c. hydrolysis
b
Which of the following best describes dehydration synthesis? a. Two smaller molecules join together after a water molecule is added to split them apart. b. Two smaller molecules join together after a water molecule is removed from between them. c. Two smaller molecules separate and reorganize into two new molecules after a water molecule is added to them. d. A large molecule is broken down, or splits, to produce salt and water. Submit
d
Which of the following best describes why vitamins are important in the human body? a. vitamins can be converted to ATP b. vitamins are a good source of nitrogen c. vitamins are important because they are needed to activate the mitochondria for energy needs d. many vitamin are precursors of coenzymes
d
Which of the following can be true of both active transport and facilitated diffusion? a. Cellular energy is required for the transport. b. Solutes can move against their concentration gradient. c. A solute pump is required. d. Lipid-insoluble solutes are transported across the membrane by a carrier protein.
a
Which of the following describes the concentration of ions when the cell is at rest? a. The concentration of potassium is higher inside the cell. b. The concentration of potassium is higher outside the cell. c. The concentration of potassium and sodium is equal inside and outside the cell.
a
Which of the following describes the movement of ions by the sodium-potassium pump? a. potassium is moved into the cell b. sodium is moved into the cell c. potassium is moved out of the cell
b
Which of the following increased the rate of sodium-potassium transport? a. increasing the amount of ATP b. increasing the number of membrane pumps c. adding glucose to the right beakers d. decreasing the amount of ATP
b
Which of the following is a similarity among paracellular transport, transcellular transport, and transcytosis? All three: a. Move large substances across epithelial membranes. b. Are ways substances can be absorbed into the body. c. Use protein transporters to absorb substances into the body.
d
Which of the following is a similarity between transcription and translation? a. both use DNA template b. both use tRNA molecules linked to amino acids c. both occur in the nucleus d. both are needed to make proteins
b
Which of the following is an exchange reaction? a. C6H12O6 + C6H12O6 -> C12H24O12 b. HCl + NaOH -> NaCl + H2O c. dehydration d. hydrolysis
c
Which of the following is an important characteristic of lipids? a. they dissolve in water b. they can be linked into long chains c. they are nonpolar d. they are converted to hormones
c
Which of the following is hydrophobic? a. potassium ions b. table salt c. butter d. sugar
b
Which of the following is the best example of feedback inhibition? a. Low blood glucose stimulates alpha cells of the pancreas to release glucagon. As blood glucose rises, it inhibits glucagon release. b. High ATP concentrations in the cell inhibit the action of phosphofructokinase, the third enzyme of glycolysis. c. Low cellular Na+ concentrations prevent the sodium-potassium pump from moving ions across the cell membrane. d. Lower blood pH inhibits the binding of oxygen to hemoglobin and promotes its release at the tissues.
b
Which of the following is the driving force for the sodium-potassium pump? a. electrical gradient b. ATP hydrolysis c. concentration gradient d. hydrostatic pressure gradient
a
Which type of chemical attraction allows water to have surface tension? a. hydrogen bonds b. van der waals force c. ionic bonds d. covalent bonds
b
Which type of molecular movement requires an input of energy (for example, from ATP)? a. passive transport b. active transport c. permeability d. diffusion
d
Why do nonpolar molecules, such as cholesterol, repel water? a. Their electrons tend to cluster around the carbon atoms within the molecule. b. They contain many hydrogen bonds. c. The covalent bonds of lipids create a small charge that repels water molecules. d. They have an even distribution of electrons.
d
Your bus home from school is so full, you cannot get on the bus, and you need to wait for the next one. This is an example of: a. affinity b. specificity c. competition d. saturation
b
what do all organic molecules contain? a. o2 b. carbon c. lipids d. hydrogen bonds
