Bio 1310 chapter 5

Which of the following statements regarding thermodynamics is false

An automobile engine is a closed system because it does not exchange energy and matter with its surroundings

Which of the following statements regarding diffusion is true?

Diffusion occurs when particles spread from areas where they are less concentrated to areas where they are more concentrated.

Frequently, transplanted organs are rejected by the recipient's body. How is this reaction related to plasma membranes?

Each person has a unique set of carbohydrate chains attached to his or her plasma membranes.

Which of the following statements regarding enzyme function is false?

Enzymes are used up when they catalyze a chemical reaction so must be synthesized for each new chemical reaction.

Which statement regarding enzyme function is true?

Excessive salt ions can cause an enzyme to denature.

What is the basic difference between exergonic and endergonic reactions?

Exergonic reactions release energy; endergonic reactions absorb it

Which of these statements describes what occurs in facilitated diffusion?

Facilitated diffusion of solutes occurs through protein pores in the membrane.

In a theoretical world where all things are possible, how could you increase the amount of energy that could be stored in a molecule of ATP?

Increase the negative charge of each phosphate group

Which of the following statements about ATP is true?

It releases energy when one phosphate group leaves ATP.

The eukaryotic cell has multiple membrane-enclosed compartments. This evolutionary innovation provides what advantage to the cell?

The different membrane-enclosed spaces allow different parts of the cell to perform specific functions

According to the second law of thermodynamics, which of the following is true?

The ordering of one system depends on the disordering of another

plasma/cell membrane

a semi-permeable layer around the cell made up of phospholipids

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

active transport

Which of the following processes can move a solute against its concentration gradient?

active transport

passive diffusion

also known as active transport- requires a specific protein to cross the membrane but no energy

simple diffusion

also known as active transport- requires energy but no protein to cross the membrane

Membrane phospholipids

are able to drift about in the plasma membrane

Heating inactivates enzymes by

changing the enzyme's three-dimensional shape

mitochondria

contains cell's DNA, creates energy for the cell

The fluid mosaic model describes the plasma membrane as consisting of

diverse proteins embedded in a phospholipid bilayer

The plasma membrane forms a pocket that pinches inward, forming a vesicle that contains material from outside the cell. This describes the process of

endocytosis

isotonic

equal amount of solute in both the solution and the cell and osmosis does not need to happen, no net flow of water

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

facilitated diffusion

You are working in the medical tent at an Ironman triathlon. A finisher comes into the tent and appears to be suffering from hyponatremia. Which of the following would be best for you to do?

give them sodium

You are a high school soccer coach. One of your players appears to be overheated. Which of the following would be best for you to do?

have them sit in the shade

Which of the following direct energy transfers is impossible in living systems?

heat to light energy

hypertonic solution

higher concentration of solute in the solution, water leaves the cell to dilute the solution, cell membrane deflates

A plant cell placed in what kind of solution will lose water and plasmolyze.

hypertonic

There is a net diffusion of water out of an animal cell when it is placed in what kind of solution.

hypertonic

An animal cell placed in what solution will gain water, swell, and possibly burst.

hypotonic

The ideal osmotic environment for a plant cell is what kind of environment.

hypotonic

Some protozoans have special organelles called contractile vacuoles that continually eliminate excess water from the cell. The presence of these organelles tells you that the environment

is hypotonic to the protozoan

A plant cell surrounded by what kind of solution will be flaccid (limp).

isotonic

The ideal osmotic environment for an animal cell is what kind of environment

isotonic

hypotonic solution

lower concentration of solute in the solution, water goes inside the cell to dilute, cell membrane expands

The mechanism of enzyme action is to

lower the energy of the activation of a reaction

In active transport

molecules move across the plasma membrane against their concentration gradient

eukaryote characteristics

multicellular organisms, contain DNA, mitosis

organelles

organized structure within the cell

Hyponatremia is the result of what process

osmosis

The process of a white blood cell engulfing a bacterium is

phagocytosis

The transfer of a phosphate group to a molecule or compound is called

phosphorylation.

an energy barrier

prevents the spontaneous breakdown of molecules in the cell

Most of a cell's enzymes are

proteins

prokaryote characteristics

single celled organisms, no DNA, binary fission

For an enzyme to catalyze a reaction there must be a specific fit between the __________ and the enzyme's __________.

substrate, active site

ENdocytosis

the cell ENgulfs a molecule or substance outside of it's membrane

EXocytosis

the cell EXcretes substance

chloroplast

the differing organelle between animal and plant cells

Osmosis can be defined as

the diffusion of water

Plasma membranes are selectively permeable. This means that

the plasma membrane allows some substances to enter or leave a cell more easily than others

In the reaction A → B + C + heat,

the potential energy of the products is less than that of the reactant.

Which of the following statements is true of an exergonic reaction, but NOT true of an endergonic reaction?

the potential energy of the products is less than the potential energy of the reactants

The active site of an enzyme is

the region of an enzyme that attaches to a substrate.

Which of the following processes is endergonic?

the synthesis of glucose from carbon dioxide and water

Water crosses the plasma membrane

through facilitated diffusion or diffusion