Why are mitochondrial defects surprisingly prevalent? a....

Name: Problem 7, Chapter 17: Biotechnology
Uploaded: 2021-05-19T17:11:18-08:00
Duration: 5 min 1 s
Channel: Noah Boudrie
Description: Why are mitochondrial defects surprisingly prevalent? a. Damage to DNA due to reactive oxygen species is much higher. b. Mitochondrial DNA is not protected by histones. c. Mitochondria contain few repair systems. d. Mitochondrial DNA has a much higher mutation rate than nuclear DNA. e. all of the above

Why are mitochondrial defects surprisingly prevalent? a. Damage to DNA due to reactive oxygen species is much higher. b. Mitochondrial DNA is not protected by histones. c. Mitochondria contain few repair systems. d. Mitochondrial DNA has a much higher mutation rate than nuclear DNA. e. all of the above

Why are mitochondrial defects surprisingly prevalent?
a. Damage to DNA due to reactive oxygen species is much higher.
b. Mitochondrial DNA is not protected by histones.
c. Mitochondria contain few repair systems.
d. Mitochondrial DNA has a much higher mutation rate than nuclear DNA.
e. all of the above

Key Concepts

Mitochondrial DNA (mtDNA) Vulnerability

Mitochondrial DNA is more susceptible to damage because it is located near the electron transport chain, where reactive oxygen species are generated. In addition, mtDNA exists in a high copy number in mitochondria, increasing the chances of mutation accumulation over time.

Reactive Oxygen Species (ROS)

Reactive oxygen species are chemically reactive molecules produced as byproducts of normal cellular respiration. They cause oxidative damage to cellular components, including DNA, proteins, and lipids. In mitochondria, the high levels of ROS can lead to significant damage to mtDNA, contributing to defects.

Lack of Histone Protection

Unlike nuclear DNA, mitochondrial DNA is not packaged around histone proteins. Histones provide structural support and protection against DNA damage. The absence of this protective packaging in mitochondria leaves mtDNA more exposed to damage from various environmental and cellular factors.

DNA Repair Mechanisms

Mitochondria have fewer and less efficient repair systems compared to the nucleus. This limited repair capability means that any damage incurred, such as that from ROS or other factors, is less likely to be effectively repaired, allowing mutations to accumulate.

Mutation Rate

The rate of mutation in mitochondrial DNA is higher than that in nuclear DNA. This is largely due to the proximity of mtDNA to sources of oxidative stress, the absence of protective histone proteins, and the reduced efficacy of repair mechanisms. Over time, this leads to a greater prevalence of mutations and mitochondrial defects.

Transcript

00:01 So for this question, we are looking at mitochondrial dna sequences.

00:04 And this is a little bit of application question.

00:08 And you know what? i'll abbreviate this a little bit more extensively.

00:11 So mitochondrial dna sequences.

00:15 And we know the mitochondria, the powerhouse of the cell.

00:17 Right? something that's common on eukaryotes.

00:20 So a smaller subsection of organisms, right? and it's responsible for things such as respiration and all the sorts of stuff.

00:28 But anyway, either way, with all of that.

00:30 That put aside, they're useful in studying recent evolution, closely related species.

00:36 So i'm going to write recent, that's very significant and closely related, closely related, is also very significant as well.

00:46 So what we need to do is think about the things we know about the mitochondria and also what we know about how we choose molecules for selecting more ancient lineages or evolutionary history as opposed to recent.

01:00 That's the key to unload.

01:01 Locking this question.

01:03 So let's start with answer option a and start applying these things as we go through it.

01:06 So answer option a, some mitochondrial genes.

01:10 So i'll just write mite genes accumulate mutations very quickly.

01:20 So i'll just write mutate quick.

01:25 And let's go throughout the rest of these.

01:27 Answer option b.

01:30 They are paternally inherited.

01:33 And just right away.

01:35 Paternally, we need to know what this means.

01:37 Paternally is talking about.