Week 4

The energy input needed to start a chemical reaction is the ______energy.

Activation

If provided with the proper conditions, enzymes recovered from living tissues can be used in cell-free industrial processes; for example,

All of the above

_____ reactions use energy to build complex molecules.

Anabolic

All molecules have a combination of kinetic and potential energy. If an external heat source were used to increase the kinetic energy of a group of molecules, the potential energy of the group would

Be unaffected because no changes in the bonding pattern of the molecule had taken place

The metabolism of living organisms consists of a series of catabolic and anabolic reactions; the latter are very carefully controlled, allowing the organism to

Capture as much of the released energy as possible.

When humans cut down trees for lumber to build permanent structures, what aspect of metabolic cycling is disrupted?

Carbon and other atoms tied up in wooden structures are not being recycled into other living organisms

The reuse of the same carbon molecules by plants, animals, and their environments through time is known as

Carbon cycling.

Heat speeds up chemical reactions by

Causing reactants to collide more often.

Carbon dioxide is one product of the metabolic process called ________that occurs in both plants and animals.

Cellular respiration

Carbon dioxide is one product of the metabolic process called ______that occurs in both plants and animals.

Cellular respiration

Physiologists monitored metabolite concentrations generated during exercise in three groups of individuals (those with poor fitness, average fitness, and exceptional fitness); which statement best summarizes their findings?

Exercise produced an almost immediate positive metabolic effect in which the strength and duration was proportional to the fitness level; exercise was beneficial to all participants.

All of the chemical energy in ATP is used during a chemical reaction.

False

Enzymes catalyze only anabolic chemical reactions.

False

Photosynthesis creates energy and cellular respiration destroys energy.

False

Fitness appears to have effects even at the cellular level; the ability of cells to process _________ to support exercise appears to be proportional to the amount of exercise they have experienced.

Fat

It is possible to predict the amount of energy released during a chemical reaction (as shown in the illustration below) because the _____ law of thermodynamics states that _____.

First; the total amount of energy in a defined system remains constant

The Calvin cycle involves fixation, which means incorporating

Gas into organic molecules.

Which of the following colors of light is used the least in photosynthesis?

Green

Living systems must work to remain ordered. They pass off their disorder in the form of

Heat

Photosynthesis relies on which photo systems ?

I and II

The capture and use of energy by living organisms involves numerous chemical reactions. Collectively these processes are known as

Metabolism

A molecule of sugar slowly "burns" in one of your cells. The products of these catabolic reactions are _____ than the original sugar molecules.

More stable and have less energy

The mobile electron carrier in the light reactions is the molecule

NADPH

In a human cell,

Nearly all chemical reactions are catalyzed by enzymes.

Which gas does photosynthesis add to the Earth's atmosphere?

Oxygen

The group of molecules in the thylakoid that collect sunlight is called the

Photosystem

In the reaction C6H12O6 + 6 O2 à 6 CO2 + 6 H2O, the 6 CO2 molecules are some of the

Products

In photosynthesis, the carbon used to make sugars is

Provided by carbon dioxide

Why is heat shown flowing from the worker in the illustration below?

The conversion of metabolic energy into muscle contraction is not 100 percent efficient and some of the energy is lost as heat.

As a molecule becomes more oxidized, it loses electrons.

True

The image below diagrams the action of an enzyme.

When a substrate locks into the active site of an enzyme, the enzyme changes shape to mold itself around the substrates.

When ATP breaks down into ADP and a phosphate group,

energy is released and can power cellular activities.