Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mitochondria genome and protein synthesis/Mitochondrial diseases > Part 1 > Flashcards

Part 1 Flashcards

1
Q

The mitochondria have their own genome and protein synthetic machinery. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Mitochondria consists of an outer mitochondrial membrane, an inner membrane space and inner mitochondrial membrane. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Where does mitochondrial DNA replication and transcription take place?

A

In the matrix

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Mitochondria are not exported except during apoptosis. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Many copies of mtDNA per organelle is not influenced by degree of organelle fragmentation. TRUE OR FALSE?

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Replication mtDNA is limited to S-phase. TRUE OR FALSE?

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Individual mtDNA replicate at random, some more than others and some not at all. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

The process of mtDNA replication is regulated to ensure that each daughter cells receives the correct complement of mitochondria. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How is mitochondrial DNA distributed?

A

In clusters known as nucleiods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Human mitochondrial is very large compared to the rest of genome. TRUE OR FALSE?

A

FALSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What does the Endosymbiotic theory describe?

A

It tells us that mitochondria is originally prokaryotic and it came from one ancestor.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Most mitochondrial genes are transferred to the nucleus. TRUE O FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What does mtDNA have to adapt to?

A

Nuclear transcription
Cytoplasmic translation
Signal sequence

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Nuclear genes coding mitochondrial proteins resemble bacterial genes. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Both mtDNA are transcribed at the same rate using mitochondrial RNA polymerase. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

The nucleiod is the unit of mtDNA transmission and inheritance. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Which line of mitochondrial DNA is inherited, maternal or paternal?

A

Maternal

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Mitochondrial DNA is non medelian, it is a cytoplasmic inheritance. TRUE OR FALSE?

A

TRUE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the reason for inheriting maternal mtDNA?

A

Eggs contribute more to the zygote

20
Q

What is the reason for having low paternal mtDNA?

A

This is because they get destroyed before cell division

21
Q

What is the process for mitotic mtDNA segregation?

A

Stochastic process

22
Q

Mitochondria are not split into daughter cells randomly, one daughter cell can obtain more wild type than mutant type. TRUE OR FALSE?

A

FALSE

23
Q

What is heteroplasmy?

A

A mix of mitochondria that are both wild type and mutant type

24
Q

What is homoplasmy?

A

Can only be entirely mutant type or entirely mild type

25
Q

What are mitochondrial diseases and what are the two types of mitochondrial diseases?

A

Mitochondrial diseases affects the function of the mitochondria and the two types can be inherited damage to nuclear genome) or acquired which is damage to mtDNA or the protein

26
Q

Diseases of mtDNA does not affect OXPHOS, which does not cause impaired energy ATP production. TRUE OR FALSE?

A

FALSE

27
Q

What are the four different types of mtDNA mutations?

A
  1. Missense mutation - nucleotide substitution AA substitution
  2. Protein synthesis mutation
  3. Insertion and deletion mutations - amount of mutation increases with ageing
  4. Mutation that causes a change in the amount of mitochondrial genome
28
Q

What are the common symptoms of mtDNA diseases?

A

Poor growth
Muscle weaknesses
Visual or hearing problems
Heart, liver and Kidney failure

29
Q

What is mitochondrial myopathies and give examples of symptoms?

A

It is a muscular disease due to mitochondrial abnormalities

Cramps, spams and muscle weakness

30
Q

What does RFF stand for and provide function?

A

Red ragged fibres - which is the accumulation of glycogen and lipids

31
Q

What does MELAS, MERF, KSS and CPEO stand for and provide detail on disease.

A

MELAS - mitochondrial encephalomyopathy - which causes lactic acidosis and stroke like syndrome
MERF - Myoclonic epilepsy and ragged red fibres
KSS- Keanis sayre syndrome - which is progressive myopathy, opthalmopedia
CPEO - Chronic progressive external opthamoplegia

32
Q

What type of mutation causes MELAS , MERF , KSS AND CPEO?

A

MELAS and MERF are caused by mutations

KSS and CPEO are caused by single and large scale deletion

33
Q

How are mtDNA diseases diagnosed?

A
  1. Maternal inheritance
  2. Recognition of classic syndromea e.g MELAS
  3. Involvement of many organ systems
  4. Specific combinations of symptoms
  5. Abnormal clinical or laboratory investigation - e.g Lactic acidosis
34
Q

Describe the ways in which mtDNA diseases can be managed

A
  1. There is no cure, treatment reduces symptoms
  2. Antioxidants such vitamin E and C
  3. Excerise may influence mtDNA level
  4. Allotropic expression - which is expression of a gene in a different cellular compartment to its target location. such as mtDNA gene being expressed in the nucleus
  5. Nuclear transfer techniques - Nuclear chromosome from an oocyte that contains mutated mtDNA can be transferred to an enucleated oocyte with normal mtDNA.
35
Q

Oxygen does not have a strong affinity for electrons. TRUE OR FALSE?

A

FALSE

36
Q

An addition of a single electron to oxygen atom will lead to formation of a super oxide; which is a very reactive species. TRUE OR FALSE?

A

TRUE

37
Q

Oxygen does not bind to COX until it takes up 4 electrons. TRUE OR FALSE?

A

FALSE

38
Q

Where are super oxides mostly generated?

A

In the mitochondria

39
Q

What is hydrogen peroxide (H2O2) converted into in the presence of iron?

A

Hydroxyl radical (.OH)

40
Q

A hydroxyl radical is the most reactive oxygen species known. TRUE OR FALSE?

A

TRUE

41
Q

Name the two steps that leads to formation of a hydroxyl radical

A

Step 1: Haber weiss reaction

Step 2: Fenton reaction

42
Q

Describe the vicious cycle hypothesis in relations to mitochondrial damage and ageing

A
  1. Oxidation damage
  2. mtDNA mutations accumulate
  3. Accelerated rate of oxidation errors
43
Q

What occurs when there is a decrease in mtDNA polymerase?

A

There is a decrease in the mtDNA polymerase proofreading ability which leads to the accumulation of mtDNA mutations, leading to ageing

44
Q

What are the three possible mechanism by which problems with mitochondria DNA can lead to diabetes?

A
  1. Defect in gene glucokinase - leads to low ATP
  2. Mutation in mtDNA coding for LEU and Lys - affects ATP levels
  3. Nicotinamide nucleotide transhydrogenase defective - increase ROS , which leads to low production of ATP
45
Q

Around 90 nuclear genes code proteins to serve mtDNA replication , transcription and translation. TRUE OR FALSE?

A

TRUE

Mitochondria genome and protein synthesis/Mitochondrial diseases (1 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions