MastBio - Chapter 5 AppliedContent

Which statement is true about enzymes in the human body?

Enzymes in the human body usually work best at normal body temperature.

This reporter is participating in a study within a room that is heated. Why is he also on a treadmill?

Exercising causes a faster increase in his core temperature.

What are three true statement about enzymes?

(1) By binding to reactant molecules, enzymes make it easier for the bonds in the molecules to break apart. (2) Enzymes lower the overall energy input needed for a reaction occur. (3) Reactants cannot convert to products without an initial input of energy to start the reaction.

WATER BALANCES IN CELLS 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 y a(n) _____ solution will be flaccid (limp).

1. Isotonic 2. Hypotonic 3. Hypertonic 4. Hypotonic 5. Hypertonic 6. Isotonic

THE WORKING CELL 1. There are three main types of cellular work; chemical, transport, and movement. Most of this work is powered by the transfer of a phosphate group from one molecule to another in a process known as _____. 2. Through energy coupling, cells use _____, or energy-releasing, reactions to drive _____, or energy-requiring, reactions. The molecule _____ is the energy shuttle between these two types of reactions. 3. A specific _____ speeds up each of a cell's chemical reactions. 4. Mechanisms such as __________ enable precise control over a cell's _____ - all of its chemical reactions.

1. Phosphorylation 2. Exergonic / Endergonic / ATP 3. Enzyme 4. Feedback Inhibition / Metabolism

Which of the following is an example of potential energy?

A bowling ball placed on the top shelf of a closet.

This concentration of calcium in a cell is 0.3%. The concentration of calcium in the surrounding fluid is 0.1%. How could the cell obtain more calcium?

Active transport.

Having a low-grade fever of 100° to 102°(F) is a common side effect of a bacterial infection. Which of the following statements provides the most reasonable explanation for why this could be beneficial?

An increase in body temperature could denature enzymes in heat-sensitive bacteria without denaturing the enzymes of the person with the infection.

When cells are placed in hypotonic solutions, both animal and plant cells accumulate water as a result of osmosis. This causes the cells to swell. Why can plnt cells better tolerate hypotonic solutions?

Animal cells can burst in such situations. In plants, however, rigid cell walls limit how far cells can expand and exert a back pressure to limit further water uptake.

In order to decrease the effect of electronic devices tricking the brain into thinking it is daytime, companies should limit the use of which of the following kinds of light in these devices?

Blue.

Molecules of food have a form of potential energy called...

Chemical energy.

You spend two hours memorizing dates you were previously unaware of for an upcoming history exam. During which phase of your sleep will these facts be stored?

Deep sleep.

Why does an enzyme cease to function when it has become denatured?

Denaturation changed the three-dimensional shape of the active site of the enzyme, preventing it from binding to the substrate.

Which one of the following statements about energy is correct?

Energy cannot be created or destroyed.

Your brother is 14. Why is he likely to have the urge to stay up later than he used to?

His sleep hormone is released later in the day.

You are a sleep scientist working on developing a drug for people who lack the proper amount of sleep hormone. What are you looking to supplement?

Melatonin.

Which term is used to describe an animal's ability to survive if the cells are exposed to a hypotonic or hypertonic environment?

Osmoregulation.

Intense dreaming occurs during the phase of sleep in which the brain is actively sorting and categorizing data. Which phase is this?

REM sleep.

Just as heat can denature enzymes, so can a change in the pH. Enzymes that normally work in an acidic environment in the body can become denatured if the pH becomes too alkaline. Enzymes that normally work in alkaline environments in the body can become denatured if the pH becomes too acidic. Taking an antacid to reduce the acidity (and increase the pH) of the stomach and to relieve heartburn can make a person more comfortable. What would be the major drawback to taking too many antacids?

Taking too many antacids could denature the enzyme that break down food in the stomach.

Why does the reporter have a tube up his nose?

To accurately measure core temperature.

Which of the following is an example of osmosis?

Water enters a plant by passing through the root cell membranes.

Which of the following is generally true within the human body?

When a person is warm, blood flow near the skin and in the extremities increases.