Biology

which of the following would be least likely to diffuse through a plasma membrane without the help of a transport protein

a polar molecule

which of the following is a difference between active transport and facilitated diffusion

active transport requires energy from ATP, and facilitated diffusion does not

imagine two solutions separated by a selectively membrane that allows water to pass, but not sucrose or glucose. The membrane separates a .2 molar sucrose solution from a .2 molar glucose solution. with time , how will the solution change

after sucrose dissociates to two monosaccharides, water will be osmotically drawn to that side of the membrane.

the process of stabilizing the structure of an enzyme in its active form by the binding of a molecule is an example of

allosteric regulation

which one of the following is not in some way involved in facilitated diffusion

an outside energy source

which of the following correctly states the relationship between anabolic and catabolic pathways

anabolic pathways synthesize more complex organix molecules using the energy derived from catabolic pathways

which of the following do mitochondria and chloroplasts have in common

both have a double membrane structure

which one of the following molecules is most likely to diffuse freely across the lipid bilayer of the plasma membrane without the involvement of a transport protein

carbon dioxide

which of the following statements about enzymes is incorrect

enzymes generally slow reaction rates

which of the following statements about enzymes is true

enzymes speed up the rate of the reaction without changing the delta-G for the reaction.

cotransport

is active transport driven by a concentration gradient

which of the following is correct about the extracellular matrix

it contains a mixture of proteins and carbohydrates, it can transmit mechanical information to the cell's interior, contains collagen, and it is attached to the plasma membrane

which of the following statements is true about diffusion

it is a passive process

which of the following is incorrect about the extracellular matrix

it is present in plant and animal cells

one of the functions of cholesterol in animal cell membrane is to

maintain membrane fluidity

what is the voltage across a cell membrane called

membrane potential

which of the following processes includes all others (osmosis, diffusion of a solute across a membrane, facilitated diffusion, and transport of an ion down its electrochemical gradient)

passive transport

which of the following statements is true about passive transport

passive transport permits the transported molecules to move in either direction, but the majority of tranport occurs down the concentration gradient of the molecule

which one of the following pairs matches the name of a membrane transport process with the primary function of that process

pinocytosis-the uptake of water and small solutes into the cell by formation of vesicles at the plasma membrane.

ATP

powers most cellular work, can couple exergonic reactions to endergonic reactions, phosphorylates proteins, and is converted to ADP and Pi by an exergonic process

which of the following are functions of the cytoskeleton

support, and motility

which of the following statements about the active site of an enzyme is correct

the active site may resemble a groove or pocket in the surface of a protein into which the substrate fits

metabolic pathways in cells are typically far from equilibrium. Which of the following processes tend to keep these pathways away from equilibrium

the continuous removal of the products of a pathway to be used in other reactions, and an input of free energy from outside the pathway (eg: food)

according to the second law of thermodynamics, which of the following is true

the decrease in entropy associated with life must be compensated for by an increase in entropy in the environment that life occurs in

a chemical reaction is designated as exergonic rather than endergonic when

the products are less complex than the reactants.