Mitochondrial genetics

Question 1

What percentage of our cell volume consists of mito?

Answer 1

22%

Question 2

The ox phos ETC comes from what kind of DNA?

Answer 2

Mitochondrial AND nuclear genes

Question 3

What happens if nuclear and mitochondrial genes don’t perfectly align the parts of the ETC?

Answer 3

Leak of reactive oxygen species (ROS) and then apoptosis

Question 4

The majority of the mitochondrial genome codes for what?

Answer 4

Proteins

Question 5

Does mitochondrial DNA pack with histones like nuclear DNA?

Answer 5

No

Question 6

Which are subject to higher mutation rates: nuclear or mitochondrial genes?

What is an exception to this?

Answer 6

Mitochondrial except for ETC-coding genes in nuclear DNA

Question 7

What is a common system that is negatively affected by mitochondrial diseases?

Answer 7

CNS

Question 8

Why do mitochondrial diseases inherit differently?

Answer 8

Heteroplasmic inheritance

• random segregation of mitochondria during duplication and cell division
• there is often a threshold above which a disease becomes symptomatic based on the ratio of good:bad mito acquired

Question 9

How are mitochondria inherited (mostly)?

Answer 9

Maternally. Vast majority come from oocyte.