histo L6

Question 1

what is Mitochondria ?

Answer 1

membrane-enclosed organelles with arrays of enzymes specialized for aerobic respiration and production of adenosine
triphosphate (ATP)

Question 2

what is glycolysis ?

Answer 2

converts glucose anaerobically to pyruvate in the cytoplasm,
releasing some energy

Question 3

. Mitochondrial enzymes yield 15 times more ATP
than is produced by glycolysis alone

Answer 3

.

Question 4

do all the energy
released in mitochondria is stored in ATP ?

Answer 4

no , some of the energy is dissipated as heat that maintains body temperature

Question 5

what is the diameters of the mitochondria ?

Answer 5

0.5 -1 μm

Question 6

The number of mitochondria is related to what ?

Answer 6

to the
cell’s energy needs: cells with a high-energy metabolism (eg,
cardiac muscle, cells of some kidney tubules) have many
mitochondria, whereas cells with a low-energy metabolism
have few mitochondria

Question 7

Where are mitochondria concentrated in cells?

Answer 7

concentrated in cytoplasmic regions where
energy utilization is more intense.

Question 8

Mitochondria are large enough to be seen with a light microscope

Answer 8

.

Question 9

mitochondrion is seen
to have two separated and very different membranes that
together create two compartments, what are they ?

Answer 9

the innermost matrix
a narrow intermembrane space

Question 10

what is on the outer membrane ?

Answer 10

many transmembrane proteins called porins

Question 11

what The inner membrane has ?

Answer 11

many long folds called
cristae

Question 12

what is the function of the cristae ?

Answer 12

increase
the membrane’s surface area

Question 13

The number
of cristae in mitochondria also corresponds to the energy
needs of the cell.

Answer 13

.

Question 14

what make the inner membrane selectively
permeable to the small molecules ?

Answer 14

Integral proteins include transport proteins

Question 15

Where are enzymes included in the mitochondria?

Answer 15

they are embedded in the inner membrane

Question 16

Where does the oxidative phosphorylation take place?

Answer 16

inner membrane

Question 17

what is the process that produces
most of the ATP in animal cells. ?

Answer 17

oxidative phosphorylation

Question 18

oxidative phosphorylation
enzymes occurs by what ?

Answer 18

chemiosmotic process

Question 19

How is ATP made in the mitochondria?

Answer 19

ATP is generated in the inner membrane by oxidative phosphorylation involving several membrane protein complexes
when NADH(high-energy electrons) used by the protein complexes to pump protons from the matrix to the intermembrane space and that creates a proton gradient which make the the protons re enter the matrix through the ATP synthase protein complex they catalyze the production of ATP

Question 20

synthase complexes can produce more than 100 molecules of
ATP per second

Answer 20

.

Question 21

when the another role for mitochondria occurs ?

Answer 21

at times of cell
stress when the protein cytochrome c is released from the
inner membrane’s electron-transport chain

Question 22

what is the function of the cytochrome c ?

Answer 22

activates sets of proteases that degrade all cellular components in a regulated process called apoptosis which
results in rapid cell death

Question 23

How do new mitochondria originate?

Answer 23

by growth and division of preexisting mitochondria

Question 24

how is the mitochondria are partly autonomous of nuclear genes and activities.

Answer 24

The mitochondrial
matrix contains a small circular chromosome of DNA, ribosomes, mRNA, and tRNA similarities to the one in the bacteria

Question 25

what is Peroxisome ?

Answer 25

spherical organelles enclosed by a single
membrane and named for their enzymes

Question 26

what is the main function of the Peroxisomes
?

Answer 26

producing and
degrading hydrogen peroxide, H2
O2

Question 27

. Oxidases ?

Answer 27

producing
H2O2
.

Question 28

catalase ?

Answer 28

immediately break down H2O2
,
which is potentially damaging to the cell

Question 29

What do the reactions in protosomes produce?

Answer 29

the formation of bile acids and cholesterol

Question 30

what is the Cytoplasmic inclusions ?

Answer 30

nutrients or pigments that can be found within the cell, but do not have activity like other organelles.

Question 31

inclusions are structures not enclosed by membrane

Answer 31

.

Question 32

Examples of cell inclusions are glycogen, lipids, and pigments

Answer 32

.