chapter mitochondria

Question 1

oxydation=

Answer 1

loose electrons or gain of oxygen or loss of hydrogen.

Question 2

reduction =

Answer 2

receive electrons or loss of oxygen or gain of hydrogen.

Question 3

Electrons are attracted to the atom that has greater _

Answer 3

electronegativity

Question 4

As a result, the reduced atom acquires a _; conversely, the oxidized atom acquires a _

Answer 4

partial negative charge (δ–)
partial positive charge (δ+)

Question 5

The equilibrium constant,
K, for the reaction A + B → AB depends on _

Answer 5

the concentrations of A, B, and AB.

Question 6

association rate =

Answer 6

association rate constant x concentration of A x concentration of B

Question 7

dissociation rate=

Answer 7

dissociation rate constant x concentration of AB

Question 8

AT EQUILIBRIUM:
association rate =

Answer 8

dissociation rate

Question 9

why does The terminal phosphate of ATP can be readily transferred to other molecules.

Answer 9

Because an energy- rich phosphoanhydride bond in ATP is converted to a less energy-rich phosphoester bond in the phosphate- accepting molecule, this reaction is energetically favorable, having a large negative ΔGo

Question 10

ATP acts as a power source by transferring its _ group to glutamic acid (= _ phase), making it _ to combine with ammonia and form glutamine (= _ phase).

Answer 10

phosphate
activation
reactive enough
condensation

Question 11

NADPH accepts and donates electrons via its _.

Answer 11

nicotinamide ring

Question 12

NADPH donates its high-energy _ together with _. This reaction, which oxidizes NADPH to _, is energetically favorable because the _.

Answer 12

electrons
_
a proton
_
NADP+
_
nicotinamide ring is more stable when these electrons are absent

Question 13

In animals, the breakdown
of food molecules occurs in three stages.:

Answer 13

STAGE 1:
BREAKDOWN OF LARGE FOOD MOLECULES
TO SIMPLE SUBUNITS

STAGE 2: glycolysis = glucose –> pyruvate –> acetyl groups on acetyl CoA

STAGE 3: citric acid cycle in the mitochondrial matrix–> oxidative phosphorylation on the mitochondrial inner membrane.
stage 2 NADH + citric acid cycle NADH = large amounts of ATP by oxidative phosphorylation.

Question 14

Pyruvate is broken down in _

Answer 14

the absence of oxygen by fermentation. =converted to lactate in the cytosol

Question 15

In some microorganisms that can
grow anaerobically, pyruvate is converted into _. Again, this pathway regenerates _ from NADH, as required to enable _
to continue.

Answer 15

carbon dioxide and ethanol
NAD+
glycolysis

Question 16

In step 6, the energy released by the energetically favorable oxidation of a C–H bond in glyceraldehyde 3-phosphate (blue arrow) is large enough to drive
_ energetically costly reactions: the formation of _in 1,3-bisphosphoglycerate (red arrows).
The subsequent energetically favorable hydrolysis of that high-energy phosphate bond in step 7 then drives
the _

Answer 16

two
_
both NADH and a high-energy phosphate bond
_
formation of ATP.

Question 17

Fatty acids derived from fats are also converted to _ in the _.

Answer 17

acetyl CoA
mitochondrial matrix

Question 18

When the body needs energy, enzymes called lipases break these fats into:_
Free fatty acids are then “activated” by attaching to a molecule called _, creating _. This step requires energy from _.

Answer 18

Glycerol
Free fatty acids
Coenzyme A (CoA)
fatty acyl CoA
ATP

Question 19

The citric acid cycle catalyzes _ supplied by _.

Answer 19

the complete oxidation of acetyl groups
_
acetyl CoA

Question 20

NET RESULT of citric acid cycle: ONE TURN OF THE CYCLE PRODUCES _

Answer 20

THREE NADH,
ONE GTP,
AND ONE FADH2,
AND RELEASES TWO MOLECULES OF CO2

Question 21

Oxidative phosphorylation is the final step in breaking down food molecules and produces _

Answer 21

most of the cell’s ATP (energy).

Question 22

Membrane systems create ATP (energy) by using the _.
STAGE 1: ENERGY OF _ IS USED TO PUMP _ ACROSS MEMBRANE.
STAGE 2: ENERGY IN THE _ IS EXPLOITED BY _ TO MAKE ATP

Answer 22

energy from a proton gradient
ELECTRON TRANSPORT
PROTONS
PROTON GRADIENT
ATP SYNTHASE

Question 23

A mitochondrion can divide like a _. (A) It undergoes a _ that is conceptually similar to _.

Answer 23

bacterium
fission process
bacterial division

Question 24

Acetyl CoA is produced in _.

Answer 24

the mitochondria

Question 25

In animal cells and other eukaryotes, pyruvate produced during _ and fatty acids derived from the _ enter the mitochondrion from the _. Once inside the mitochondrial _, both of these food- derived molecules are converted to _ and then _.

Answer 25

glycolysis
breakdown of fats
cytosol
matrix
acetyl CoA
oxidized to CO2

Question 26

NADH donates its
_ to an electron-transport chain.

Answer 26

“high-energy” electrons
= This energy pumps protons (H⁺) across the mitochondrial membrane, creating a gradient.

Question 27

As electrons are transferred from _ to _, protons are pumped across the inner mitochondrial membrane.

Answer 27

activated carriers
oxygen

Question 28

To produce ATP, mitochondria catalyze a major conversion of energy. The net equation for this process, in which _ electrons pass from NADH to oxygen

Answer 28

four

Question 29

The intermembrane space is _ acidic than the matrix, because the higher the concentration of protons, the _

Answer 29

slightly more
more acidic the solution

Question 30

Both the _ and the _ combine to generate the proton-motive force, which _

Answer 30

membrane potential
pH gradient
pulls H+ back into the mitochondrial matrix.

Question 31

Both the membrane potential and the pH gradient combine to generate the _, which pulls H+ back into the mitochondrial matrix.

Answer 31

proton-motive force

Question 32

when proton enters ATP synthase, what happens with ATP?

Answer 32

it’s produced from ADP+Pi

Question 33

when proton leaves ATP synthase, what happens with ATP?

Answer 33

hydrolysed to ADP+Pi

Question 34

_ and _ are moved into the matrix along with protons, as the protons move down their electrochemical gradient. Both are _, so their movement is _ by the
negative membrane potential; however,
the _—is harnessed (exploited) in a way that
nevertheless drives their inward transport.

Answer 34

Pyruvate
_
inorganic phosphate (Pi)
_
negatively charged
_
opposed
_
H+ concentration gradient—the pH gradient
_

Question 35

ADP is pumped into the matrix and ATP
is pumped out by an _ process
that uses the _ across the membrane to drive the exchange.

Answer 35

antiport
voltage gradient

Question 36

the outer mitochondrial membrane is freely
permeable to all of these compounds due to the presence of _ in the membrane (not shown).

Answer 36

porins

Question 37

Redox potential, also known as reduction potential, measures _

Answer 37

how easily a molecule can gain (reduce) or lose (oxidize) electrons.

Question 38

The diagram shows “redox potential” _ (measured in mV). This means the electrons are moving to _, _ at each step.

Answer 38

increasing
more stable states
releasing energy