slide 9

Question 1

Life Requires Energy

Answer 1

Energy flows into an
ecosystem as sunlight
and leaves as heat.

Question 2

Cellular respiration

Answer 2

is
the set of processes that
break down sugars to
produce ATP

Question 3

Waste products of

respiration

Answer 3

(CO2 and H2O)
are raw materials for
photosynthesis

Question 4

Photosynthesis

Answer 4

-anabolic

• endergonic

Question 5

Respiration

Answer 5

-catabolic

• exergonic

Question 6

Energy from
catabolism (exergonic,
energy-releasing
processes)

Answer 6

Energy for cellular
work (endergonic,
energy-consuming
processes

Question 7

The breakdown of organic molecules

Answer 7

is exergonic.

Question 8

anaerobic respiration

Answer 8

Some breakdown of sugars to produce ATP
can occur without oxygen and is referred to
as anaerobic respiration.

Question 9

Aerobic respiration

Answer 9

consumes organic
molecules and oxygen and yields ATP more
efficiently than anaerobic metabolism

Question 10

Cellular respiration

Answer 10

includes both aerobic and
anaerobic respiration but is often used to refer
specifically to aerobic respiration.

Question 11

Although carbohydrates, fats, and proteins are all

consumed as fuel,

Answer 11

it is helpful to trace cellular

respiration with the sugar glucose.

Question 12

In the breaking down of fuel molecules, hydrogen atoms
(electrons and protons) are passed from molecules that
donate electrons (electron donors)

Answer 12

to molecules that
accept electrons (electron acceptors) in redox reactions.

Question 13

electron transport chain.

Answer 13

Energy is released each time an electron is passed from an
interaction with high potential energy to one with lower
potential energy down an electron transport chain.

Question 14

electron donor sodium

Answer 14

electron acceptor chlorine

Question 15

oxidizing agents

Answer 15

Electron acceptors are called oxidizing agents

Question 16

reducing agents

Answer 16

Electron donors are called reducing agents

because electrons are negative

Question 17

Some redox reactions do not completely transfer electrons

from one substance to another

Answer 17

but just change the degree of

electron sharing in covalent bonds between the substances.

Question 18

During cellular respiration,

Answer 18

the fuel (such as
glucose) is oxidized, and O2
is reduced.
Electrons are passed along a series of molecules
between the fuel and O2
, the final electron acceptor.

Question 19

Reactions of an electron transport chain

Answer 19

control the release

of energy so that it can be harnessed in the production of ATP.

Question 20

In cellular respiration, glucose and other organic

molecules are broken down in a series of steps.

Answer 20

Electrons from organic compounds are usually first

transferred to NAD+.

Question 21

Each NADH (the reduced form of NAD+
)

Answer 21

represents stored energy that is tapped to

synthesize ATP

Question 22

NAD+ is a good electron transporter because

Answer 22

it can

cycle easily between oxidized and reduced states.

Question 23

The Stages of Cellular Respiration

Harvesting of energy from glucose has three stages:

Answer 23

– Glycolysis (breaks down glucose into two
molecules of pyruvate)
– The citric acid cycle (completes the
breakdown of glucose)
– Oxidative phosphorylation (accounts for
most of the ATP synthesis)

Question 24

Digestion

Answer 24

n breaks down large molecules
but does not yield useable energy
Digestion of carbohydrates produces
glucose molecules.

Question 25

Glycolysis

Answer 25

is the nearly
universal pathway through which
glucose is first broken down to
two molecules of pyruvate.

Question 26

Glycolysis occurs in the cytoplasm in two phases:

Answer 26

– Energy investment phase

– Energy payoff phase

Question 27

Glycolysis occurs whether or not

Answer 27

O2

is present

Question 28

substrate-level phosphorylation

Answer 28

is the

means of ATP production in the process of glycolysis

Question 29

One way to produce ATP is to directly transfer

Answer 29

a phosphate

group from a sugar molecule to a molecule of ADP

Question 30

Glycolysis yields

Answer 30

two molecule of ATP and two NADH

Question 31

in aerobic metabolism

Answer 31

the two molecules

of pyruvate enter a mitochondrion.

Question 32

in aerobic metabolism

Answer 32

the two molecules

of pyruvate enter a mitochondrion.

Question 33

The citric acid cycle takes the products of glycolysis and yields

Answer 33

CO2
,
electron carriers (NADH and FADH2
), and one molecule of ATP.

Question 34

Electron carriers from glycolysis and the citric acid cycle enter

Answer 34

the electron

transport chain of oxidative phosphorylation to produce the majority of ATP