Best of Chapter Homework Chapt. 5 Fall 2021

Which of these are by-products of cellular respiration? water heat and water ATP and water glucose and water ATP

heat and water

Chemical energy is a form of _____ energy. kinetic potential entropic motion heat

potential

energy for that reaction--a, b, or c? black curve; line a black curve; line b black curve; line c red curve; line a red curve; line b red curve; line c

red curve; line b

Aquaporins are proteins that facilitate the transport of __________ across the membrane. urine water salt proteins

water

Drag the terms on the left to the appropriate blanks on the right to complete the sentences. 1. An enzyme is considered a(n) because it speeds up a chemical reaction without being used up. 2. In a catalyzed reaction, a reactant is often called a(n) . 3. An enzyme is specific because the shape of its matches only particular reactants. 4. An enzyme speeds up reactions by lowering the . 5. The between an active site and its substrate often strains bonds and helps the reaction proceed. 6. A(n) , which is often a vitamin, binds to an enzyme and plays a role in catalysis. 7. High temperatures or changes in pH can an enzyme, causing it to lose its shape and biological activity.

1. An enzyme is considered a(n) catalystbecause it speeds up a chemical reaction without being used up. 2. In a catalyzed reaction, a reactant is often called a(n) substrate . 3. An enzyme is specific because the shape of its active site matches only particular reactants. 4. An enzyme speeds up reactions by lowering the activation energy . 5. The induced fit between an active site and its substrate often strains bonds and helps the reaction proceed. 6. A(n) coenzyme , which is often a vitamin, binds to an enzyme and plays a role in catalysis. 7. High temperatures or changes in pH can denature an enzyme, causing it to lose its shape and biological activity.

1. The ideal osmotic environment for an animal cell is a(n) ___________ environment. 2. An animal cell placed in a(n) ___________ solution will gain water, swell, and possibly burst. 3. There is a net diffusion of water out of an animal cell when it is placed in a(n) __________ solution. 4. The ideal osmotic environment for a plant cell is a(n) ____________ environment. 5. A plant cell placed in a(n) ____________ solution will lose water and plasmolyze. 6. A plant cell surrounded by a(n) __________ solution will be flaccid (limp).

1. The ideal osmotic environment for an animal cell is a(n) isotonic environment. 2. An animal cell placed in a(n) hypotonic solution will gain water, swell, and possibly burst. 3. There is a net diffusion of water out of an animal cell when it is placed in a(n) hypertonic solution. 4. The ideal osmotic environment for a plant cell is a(n) hypotonic environment. 5. A plant cell placed in a(n) hypertonic solution will lose water and plasmolyze. 6. A plant cell surrounded by a(n) isotonic solution will be flaccid (limp).

The sodium-potassium pump uses energy from ATP to move sodium ions out of the cell, and potassium ions into the cell. This is an example of diffusion. facilitated diffusion. exocytosis. active transport. passive transport.

Active transport

Which of the following is a difference between active transport and facilitated diffusion? Active transport involves transport proteins, and facilitated diffusion does not. Active transport requires the expenditure of cellular energy, and facilitated diffusion does not. Facilitated diffusion involves transport proteins, and active transport does not. Facilitated diffusion can move solutes against a concentration gradient, and active transport cannot.

Active transport requires the expenditure of cellular energy, and facilitated diffusion does not.

Cells A and B are the same size and shape, but cell A is metabolically quiet and cell B is actively consuming oxygen. Oxygen will diffuse more quickly into cell _____ because _____. B ... the oxygen molecules inside cell B have a higher kinetic energy A ... the diffusion gradient there is shallower B ... the diffusion gradient there is steeper A ... its membrane transport proteins will not be saturated

B ... the diffusion gradient there is steeper

Why doesn't the antibiotic penicillin harm humans? Penicillin attacks plasma membranes. Human cells do not have cell walls. Penicillin attacks the nervous system. The dosage given to kill bacteria is too low to harm humans.

Human cells do not have cell walls.

Facilitated diffusion is a type of _____. pinocytosis passive transport active transport phagocytosis

Passive transport

Use the graph and your knowledge of enzymes to identify the three true statements about enzymes. Reactants cannot convert to products without an initial input of energy to start the reaction. By binding to reactant molecules, enzymes make it easier for the bonds in the molecules to break apart. Chemical reactions cannot occur without enzymes. Enzymes lower the overall energy input needed for a reaction to occur. Only reactions that are controlled by enzymes require activation energy.

Reactants cannot convert to products without an initial input of energy to start the reaction. By binding to reactant molecules, enzymes make it easier for the bonds in the molecules to break apart. Enzymes lower the overall energy input needed for a reaction to occur.

Which of these statements is TRUE with regard to this animation? Sodium ions are transported down their concentration gradient. The cell is not expending energy. Sodium and potassium ions are transported against their concentration gradients. The cell does not expend ATP. Potassium ions are transported down their concentration gradient.

Sodium and potassium ions are transported against their concentration gradients.

Biologists use the fluid mosaic model to describe membrane structure. Which statements about the fluid mosaic structure of a membrane are correct? Select the three correct statements. The kinky tails of some proteins help keep the membrane fluid by preventing the component molecules from packing solidly together. The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center. The diverse proteins found in and attached to membranes perform many important functions. Because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane. Membranes include a mosaic, or mix, of carbohydrates embedded in a phospholipid bilayer.

The framework of a membrane is a bilayer of phospholipids with their hydrophilic heads facing the aqueous environment inside and outside of the cell and their hydrophobic tails clustered in the center. The diverse proteins found in and attached to membranes perform many important functions. Because membranes are fluid, membrane proteins and phospholipids can drift about in the membrane.

Taq polymerase is an enzyme isolated from the organism Thermophilus aquaticus. This organism has been found living in the hot springs of Yellowstone National Park. This enzyme is used to copy human DNA from crime scenes. Most reactions are performed at ranges similar to those of the human body; however, what considerations should be made for optimum use of this enzyme? The pH should be decreased. The temperature should be raised. The enzyme will not work on human DNA. Nothing should be altered.

The temperature should be raised.

Lactase is essential for digesting lactose in milk. This enzyme is specific for this sugar. Why? Specificity refers to the action of the enzyme, such as hydrolysis, and relatively few molecules can be hydrolyzed. There is a precise compatibility between the active site and the lactose molecule. Reaction-specific enzymes assume a fit by folding around the most numerous substrate molecules. Molecules and active sites vary in size; only properly sized molecules can fit.

There is a precise compatibility between the active site and the lactose molecule.

In this diagram of the plasma membranes of two adjoining cells, identify the protein indicated by the white arrow, including its function. a glycoprotein that is involved in cell-cell recognition an attachment protein that provides structural support a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell a protein involved in enzymatic activity an active transport protein that moves molecules across a membrane against their concentration gradient

a receptor protein that binds with a signaling molecule and relays the message into the cell by activating other molecules inside the cell

Which of these is exhibiting kinetic energy? a person sitting on a couch while watching TV a space station orbiting Earth a rock on a mountain ledge the high-energy phosphate bonds of a molecule of ATP an archer with a flexed bow

a space station orbiting earth

Drag the terms to the appropriate locations on the concept map.

a- kinetic b- potential c- motion d- chemical energy e- entropy f- heat g- first law of thermodynamics h- second law of thermodynamics

Drag the labels to the appropriate locations in this diagram. a, b, c, d, e, f, g, h, i

a- phospholipid bilayer b- fibers of extracellular matrix (ecm) c- enzymatic activity d- microfilaments of cytoskeleton e- attachment to ECM and Cytoskeleton f- signal reception and relay g- transport h- intercellular junctions i- cell-cell recognition

Drag the labels to their appropriate locations on the diagram. a, b, c, d, e

a- plasma membrane b- side with higher concentration of molecules c- side with lower concentration of molecules d- facilitated diffusion causes a net movement of molecules down their concentration gradient e- transport protein

Drag the labels to their appropriate locations on the diagram.

a- side with higher concentration of molecules b- plasma membrane c- side with lower concentration of molecules d- diffusion causes a net movement of molecules down their concentration gradient

Drag the labels to their appropriate locations on the diagram. a, b, c, d, e

a- side with lower concentration of square molecules b- transport protein c- energy input from the cell d- plasma membrane e- side with higher concentration of square molecules

When in solution, a molecule that moves slowly across an artificial membrane moves rapidly across a plasma membrane. This molecule rapidly enters the cell regardless of whether its concentration is higher inside or outside the cell. Using this information, which transport mechanism is most likely to be responsible for the movement of the molecule across a plasma membrane? phagocytosis exocytosis active transport passive transport

active transport

requires energy from the cell. molecules move against their concentration gradient.

active transport

Utah's Great Salt Lake has an average salinity seven times higher than that of the oceans. Very few multicellular organisms live in this harsh environment. An example is the brine shrimp, which must devote a large portion of its metabolic energy to osmoregulation. These brine shrimp must _____. synthesize membranes that are impermeable to substances that upset osmotic balance actively pump salt back out of their cells to counter its inflow due to osmosis actively pump water back into their cells to counter its loss due to osmosis actively pump water back out of their cells to counter its inflow due to osmosis

actively pump water back into their cells to counter its loss due to osmosis

In your body, what process converts the chemical energy found in glucose into the chemical energy found in ATP? cellular respiration redox digestion anabolism potentiation

cellular respiration

Azidothymidine (AZT) is an antiretroviral drug used in the treatment of HIV. It shares a structural similarity to a nucleotide. What might be the mode of action for this drug? mixed inhibition noncompetitive inhibition feedback inhibition competitive inhibition

competitive inhibition

a form of passive transport. molecules move across the plasma membrane by crossing the lipid bilayer.

diffusion

A nursing infant is able to obtain disease-fighting antibodies, which are large protein molecules, from its mother's milk. These molecules probably enter the cells lining the baby's digestive tract via __________. endocytosis osmosis passive transport active transport

endocytosis

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of exocytosis. endocytosis. diffusion. active transport. passive transport.

endocytosis

the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell.

endocytosis

"Conservation of energy" refers to the fact that _____. the net amount of disorder is always increasing the entropy of the universe is always increasing if you conserve energy you will not be as tired energy cannot be created or destroyed but can be converted from one form to another no chemical reaction is 100 percent efficient

energy cannot be created or destroyed but can be converted from one form to another

a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell.

exocytosis

A molecule moves down its concentration gradient using a transport protein in the plasma membrane. This is an example of endocytosis. active transport. diffusion. facilitated diffusion. exocytosis.

facilitated diffusion

a form of passive transport. Molecules move across the plasma membrane using a transport protein.

facilitated diffusion

This cell is in a(n) _____ solution. hypertonic hypotonic and isotonic hypotonic hypertonic or isotonic isotonic

hypertonic

You know that this cell is in a(n) _____ solution because it _____. hypotonic ... is turgid hypertonic solution ... lost water hypertonic ... lysed hypertonic ... gained water hypotonic ... lysed

hypertonic solution ... lost water

You know that this cell is in a(n) _____ solution because the cell _____. hypotonic ... swelled hypertonic ... gained water isotonic ... neither lost nor gained water hypertonic ... lost water hypotonic ... shrunk

hypotonic ... swelled

Endocytosis moves materials _____ a cell via _____. out of ... diffusion out of ... membranous vesicles into ... facilitated diffusion into ... a transport protein into ... membranous vesicles

into ... membranous vesicles

In active transport, a vesicle inside the cell fuses with the plasma membrane and releases its contents outside the cell. molecules move across the plasma membrane by crossing the lipid bilayer directly, rather than by using a transport protein.no energy input is required from the cell. molecules move across the plasma membrane against their concentration gradient. the plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell.

molecules move across the plasma membrane against their concentration gradient.

When molecules move down their concentration gradient, they move from where they are ____________ to where they are ____________. Diffusion across a biological membrane is called __________.

more concentrated; less concentrated; passive transport

The synthesis of an amino acid follows this pathway: precursor A > intermediate B > amino acid C. Each reaction is catalyzed by a different enzyme. This metabolic pathway is controlled by feedback inhibition with amino acid C inhibiting the conversion of precursor A to intermediate B. Amino acid C acts as a _____ of the first enzyme in the pathway. substrate competitive inhibitor catalyst noncompetitive inhibitor

noncompetitive inhibitor

What name is given to the process by which water crosses a selectively permeable membrane? osmosis diffusion phagocytosis pinocytosis passive transport

osmosis

A white blood cell engulfing a bacterium is an example of _____. pinocytosis phagocytosis facilitated diffusion receptor-mediated endocytosis exocytosis

phagocytosis

Structure A is a _____. phospholipid solute water molecule solvent transport protein

solute

You can recognize the process of pinocytosis when _____. the cell is engulfing extracellular fluid the cell is engulfing a large particle a receptor protein is involved

the cell is engulfing extracellular fluid

Osmosis is often viewed incorrectly as a process driven directly by differences in solute concentration across a selectively permeable membrane. What really drives osmosis? the difference in sugar or ion concentration across a selectively permeable membrane the difference in water concentration across a selectively permeable membrane the difference in the height of water columns on either side of a selectively permeable membrane the first law of thermodynamics

the difference in water concentration across a selectively permeable membrane

You are working on a team that is designing a new drug. For this drug to work, it must enter the cytoplasm of specific target cells. Which of the following would be a factor that determines whether the molecule selectively enters the target cells? the concentration of the drug molecule that is transported in the blood the similarity of the drug molecule to other molecules that are transported into the target cells the nonpolar, hydrophobic nature of the drug molecule the phospholipid composition of the target cells' plasma membrane

the similarity of the drug molecule to other molecules that are transported into the target cells

Water crosses the plasma membrane using a process that requires energy from the cell. through active transport. through cotransport. through facilitated diffusion or diffusion. against its concentration gradient.

through facilitated diffusion or diffusion.

Structure B is a _____. solvent transport protein water molecule phospholipid solute

transport protein

In the figure below, working from the inside out, what would be the order of components observed? water, hydrophilic tail, hydrophobic head, hydrophobic head, hydrophilic tail, water water, hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic head, water water, hydrophobic tail, hydrophilic head, hydrophilic head, hydrophobic tail, water hydrophobic tail, water, hydrophilic head, hydrophilic head, water, hydrophobic tail

water, hydrophilic head, hydrophobic tail, hydrophobic tail, hydrophilic head, water