Mitochondria and energy production

Question 1

Endosymbiotic theory (symbiogenisis)

Answer 1

• Evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms

-This theory states that the organelles distinguishing eukaryote cells evolved through the symbiosis of individual single celled prokaryotes (bacteria and archaea)

Question 2

Symbiosis

Answer 2

-Living together
- Close and long term-biological interactions

Question 3

People that discovered endosymbiotic theory

Answer 3

-First proposed by Russian botanist Konstantin Mereschkowski (1905- 1910)

• Later advanced by Lynn Margulis (1967)

Question 4

Supporting evidence of the endosymbiotic theory

Answer 4

1. Binary fission of mitochondria and plasmids
2. Circular DNA inside these organelles similar to bacteria

Question 5

Aerobic respiration

Answer 5

• Converts in the presence of oxygen energy tored in food molecules (glucose) into chemical energy stored in ATP
• This process produces CO2 as a by product (waste)

Question 6

Outer mitochondrial membrane (OMM)

Answer 6

• Contains many enzymes with diverse metabolic functions

-OMM also has porins, which are large channels permeable (passive diffusion) to many molecules when opened

Question 7

Inner mitochondrial membrane (IMM)

Answer 7

• High protein to lipid ratio (3:1)
• Contains cristae
• Rich in cardiolipin

Question 8

Cristae

Answer 8

• Doubled - layered folds in the IMM
• Increase membrane surface area and contain machinery for aerobic respiration and ATP formation

Question 9

Cardiolipin

Answer 9

• Phospholipid which is Characteristic of bacterial membranes and needed for optimal function of many enzymes

Question 10

Matrix

Answer 10

A high protein content - gel like consitency space containing mitochondrial ribosomes and DNA

In mammals, mitochondrial DNA encodes a total of 37 genes (13 polypeptides, like ATP synthase, cytochrome C ect…)

Question 11

Cellular respiration

Answer 11

Uses chemical energy stored in molecules such as carbohydrates (glucose) and lipids to produce ATP

Involves a series of catabolic reactions

Question 12

Substrate level phosphorylation

Answer 12

• Hydrolysis reaction releases enough energy to drive the phosphorylation of ADP to ATP

Question 13

Oxidative phosphorylation

Answer 13

-Chemical energy of organic molecules is transferred first to electron carriers to create an electrochemical gradient that can power ATP synthesis

Question 14

Oxidized

Answer 14

• Can accept electrons
  (FAD, NAD+)

Question 15

Reduced

Answer 15

-Can donate electrons (when returning to their oxidized state)
(FADH2, NADH)