Mitochondria

Question 1

What is the structure of a mitochondria?

Answer 1

• Mitochondrial matrix
• Outer mitochondrial membrane
• Inner mitochondrial membrane/Cristae
  Space between the two membranes is known as the inter membrane space

Question 2

Why is the inner mitochondrial membrane folded into cristae?

Answer 2

To increase the surface area for oxidative phosphorylatino

Question 3

Theory of mitochondrial evolution

Answer 3

1. Individual aerobic prokaryotic cell with a cell membrane
2. Pre-eukaryotic cell endocytosis smaller prokaryote
3. Membrane derived from eukaryotic cell
   Mitochondria has double membrane as well as its own DNA

Question 4

From whom is mtDNA (mitochondrial DNA) inherited from?

Answer 4

From the mother only

Question 5

Is the rate of mutations higher in mtDNA or DNA in the nucleus?

Answer 5

Higher in mtDNA due to absence of proof-reading enzymes

Question 6

What can analysis of Mitochondrial DNA reveal? How is this linked to the Out of Africa Theory?

Answer 6

• Movements and establishment of new population groups can be tracked from changes in MtDNA - Analysis of large groups of people suggest modern humans have origins in Africa from 100,000 years ago

Question 7

What is the function of mitochondria? How does it achieve this?

Answer 7

Energy production
Pyruvate from Glycolysis enters the mitochondria and is converted to Acetyl CoA before entering the Krebs cycle to generate ATP - Hydrogen ions are used in Oxidative Phosphorylation to generate ATP

Question 8

Which membrane is impermeable to small ions?

Answer 8

The inner membrane

Question 9

Which enzyme is embedded in the inner mitochondrial membrane to aid with energy production?

Answer 9

ATP synthase

Question 10

What is the underlying theme in mitochondrial disorders?

Answer 10

The lack of ability to meet cellular energy demands

Question 11

What other functions do mitochondria serve?

Answer 11

• Calcium storage
• Make iron compound for blood
• Contribute to cell death

Question 12

Structure of peroxisomes

Answer 12

• Single membrane
• No DNA
• No ribosomes

Question 13

What is the function of peroxisomes?

Answer 13

Carry out oxidative reactions with the various enzymes that they contain. Also, aid in detoxification in the liver

Question 14

Peroxisomes’ reaction to remove hydrogen atoms

Answer 14

RH2 + O2 —-> R + H2O2 but hydrogen peroxide is toxic so

H2O2 +R’H2 —> R’ + 2H2O