exam 2 bio

A tube with a membrane covering the bottom is placed in a beaker. The membrane allows water to flow through but not salt or glucose. The tube contains an aqueous solution with 4% salt and 20% glucose and the beaker contains an aqueous solution with 12% salt and 6% glucose. In terms of osmosis, how would you describe the solution in the tube compared to the solution in the beaker?

The solution in the tube is hypertonic to the solution in the beaker.

Which energy association is correct?

A fish swimming through the water is an example of kinetic energy.

Which of the following is an example of simple diffusion?

A sugar cube dissolves in coffee.

Considering the ATP cycle, which of the following would have the most potential energy to perform work for cell activities?

ATP

Which of the following statements about ATP is inaccurate?

ATP is comprised of a sugar, base, and two phosphate groups.

Eggs are often preserved in a 20-30% salt solution called brine. How does this method prevent contamination by microorganisms?

Bacteria can't survive in a hypertonic solution because they lose water.

Which of the following is an example of osmosis?

Cells in our kidneys reabsorb water to reduce the amount of water lost in our urine.

Which of the following statements correctly describes an energy transformation in living organisms?

Chloroplasts convert solar energy to the chemical energy of nutrient molecules.

Which of the following statements most accurately describes the first law of thermodynamics?

Energy can neither be created nor destroyed, but it can be changed from one form to another.

Which statement most accurately describes the second law of thermodynamics?

Energy cannot be changed from one form to another without a loss of usable energy.

Intestinal cells absorb glucose via active transport. What would happen if all the mitochondria within these intestinal cells were destroyed?

Glucose absorption would decrease.

Why do metabolic pathways require tens to hundreds of different enzymes?

Since each step in a pathway utilizes a new substrate, a different enzyme is required for each step.

Which of the following is best associated with a coupled reaction?

The breakdown of ATP generally releases more energy (and heat) than is needed to power the metabolic reaction.

Both starch and cellulose are polysaccharides made by stringing together many glucose molecules, but starch is easily digested by humans, while cellulose is indigestible. Starch has every bond occurring below the sugar rings while the bonds in cellulose alternate between one bond above the ring and the next below the ring. How can you explain humans' inability to digest starch but not cellulose?

The enzyme that breaks down polysaccharides can only fit the specific bond configuration within a starch molecule.

A tube with a membrane covering the bottom is placed in a beaker. The membrane allows water to flow through but not salt or glucose. If the tube contains an aqueous solution with 12% salt and 6% glucose and the beaker contains an aqueous solution with 13% salt and 10% glucose, what would happen to the level of the water in the tube?

The level of the solution in the tube would lower because there are more dissolved solutes present in the beaker.

What is the biological risk of using salt on icy roads in parts of the country that have a cold winter season?

The salt has the risk of leeching into the ground and creating a hypertonic environment for plant cells.

The second law of thermodynamics states that all energy transformations result in an increase in entropy (disorder). If so, how does photosynthesis, which is an energy transformation, create order rather than disorder?

The tree takes in small disordered molecules like carbon dioxide from the air and water from the earth and using solar energy produce highly ordered sugar molecules like glucose.

When a potted houseplant is wilting, the addition of water quickly changes the look of the plant. This can be accounted for by which of the following statements?

The water creates a hypotonic environment causing the cells to gain water.

Which of the following is an example of potential energy rather than kinetic energy?

a bowl of oatmeal made up of energy-rich macromolecules

ATP releases energy when

a phosphate is removed.

Which of the following is an example of kinetic energy?

a roller coaster traveling downhill

The part of the enzyme into which the substrate fits is called the

active site.

The concentration of calcium in a cell is 3%. The concentration of calcium in the surrounding fluid is 1%. Which of the following processes could the cell use to obtain more calcium?

active transport

Which of these words should be classified separately from the others?

active transport

Which of the areas shown in the figure below indicates the presence of an enzyme?

c

Which one of the following molecules is able to move across the cell membrane by simple diffusion?

carbon dioxide

ATP breakdown provides the energy necessary for building a protein. This is an example of which concept?

coupled reactions

Which of the following terms best describes entropy?

disorder

Simple diffusion across a plasma membrane is called passive transport because it

does not require energy from the cell.

Enzymes are usually named based on the substrate that they bind. This is possible because

each type of enzyme generally only binds one specific substrate.

When a car burns gasoline, much of the energy is released in the form of heat. Which of the following best describes this process in relation to the first law of thermodynamics?

energy can be changed from one form to another

Metabolic pathways, which are facilitated by________ begin with a particular________ and terminate with an end________.

enzymes; reactant; product

When neurons release their neurotransmitters, they release them in secretory vesicles that fuse with the plasma membrane. What type of cellular transport is this?

exocytosis

What function do the carrier proteins embedded in the cell membrane serve?

facilitated diffusion

Which of the following is a passive process?

facilitated diffusion

Molecules move from greater to lesser concentration through a carrier protein in

facilitated diffusion.

What process typically regulates the enzymes involved in metabolic reactions?

feedback inhibition

Which of the following is a mechanism used to regulate enzyme activity?

feedback inhibition

During an osmosis experiment in class, you look at some cells under the microscope. You notice the cells look crenated. What type of solution were the cells immersed in?

hypertonic

During an osmosis experiment, you place some plant cells under the microscope. You notice the cells seem very swollen. What type of solution were the cells immersed in?

hypotonic

Jarrod wants to make a salad but realizes that the celery he purchased a few days ago is very wilted. What type of solution could Jarrod use to help firm up the celery in order to make it crunchy again?

hypotonic

Simple diffusion of molecules occurs

in non-living systems as well as living systems.

The changing of an enzyme's shape as the substrate binds to the active site is called the

induced fit model.

Energy of activation

is the energy required for molecules to react with each other.

If the concentration of the solute is the same in the cell as it is in the surrounding solution, the cell is in a(n)________ environment.

isotonic

ATP is a good source of energy for a cell because

its breakdown is coupled with energy-requiring reactions.

When an enzyme is present

less energy is needed to bring about a reaction.

Enzymes are able to speed up the rate of a reaction by

lowering the energy needed for the reaction to proceed.

Where within the cell is the majority of ATP produced?

mitochondria

What process allows water to move across a cell membrane?

osmosis

Which of the following is a by-product of photosynthesis that is used during cellular respiration?

oxygen

Which of the types of cellular activities listed below can proceed without ATP energy?

passive transport

A white blood cell surrounds and engulfs a bacterial cell. This process is called

phagocytosis.

The opposite of a turgid plant cell is a

plasmolyzed plant cell.

Which of the following methods of transport uses a coated pit to take in a specific type of molecule?

receptor-mediated endocytosis

Which form of passive transport allows small noncharged molecules, such as oxygen, to cross the cell membrane?

simple diffusion

What prevents a plant cell from bursting in a hypotonic solution?

the presence of a cell wall

Which of the following correctly lists the order in which energy flows through an ecosystem?

solar energy - chloroplast - mitochondria

If blood cells are placed in a hypotonic solution, the cells will

swell due to osmosis.

Once the substrate moves into the active site of the enzyme,

the enzyme alters in shape to more closely fit the substrate.

In feedback inhibition of a metabolic pathway, where does the inhibitor bind?

to the first enzyme in the pathway