Mitochondria (Power house of cell )
Mito – thread chondrion – granule
- These are rod shaped structures,
- function as power generators of cell as they convert nutrient and oxygen in to ATP
- It is chemical energy which is essential to carry out the metabolic process of cell.
History-
- 1880 – Koliker – discover in Insects muscles cells and give name – Sarcosome
- 1882 – Flaming – Thread like structure
- 1884 – Altman – Stain – Janus Green (Stain use in Lab), Alizarin +C.V. Give name – Bioplast.
- 1898 – Benda – Give name – Mitochondria
- 1904 – Discover in Plant (Nymphea) by – Meves
- 1953 – Palade and Porter – Study Electron Microscope
- 1963- Nass – Discover mtDNA
Presence and Distribution
- It is present in all eukaryotic cells except RBC and Prokaryotic Cell
- These are freely distributed in cytoplasm
- These are found in large number in which cell where much more energy are required
Number –
In Metabolically active cell – 1 Lakh or more / Cell
Size –
- Generally it is – 0.5 μ wide and 1.5 – 10μ long
- Smallest – Yeast – 1mμ
- It can also 40μ long
Shape –
Cylindrical , Rod, Filamentous, Round Granular, Clubshape, Vesicular.
Basic Structure & Function of Mitochondria
1. What is the primary function of mitochondria?
- A) Protein synthesis
- B) Energy production
- C) DNA replication
- D) Lipid synthesis
- Answer: B
2. Mitochondria generate energy in the form of which molecule?
- A) DNA
- B) RNA
- C) ATP
- D) Glucose
- Answer: C
3. Which of the following is NOT a characteristic of mitochondria?
- A) Rod-shaped
- B) Have their own DNA
- C) Present in RBCs
- D) Double-membrane structure
- Answer: C
4. The term “Mitochondria” was first coined by:
- A) Koliker
- B) Benda
- C) Nass
- D) Palade
- Answer: B
5. Mitochondria are absent in:
- A) Liver cells
- B) Muscle cells
- C) Red blood cells
- D) Nerve cells
- Answer: C
Discovery & History of Mitochondria
6. Who first discovered mitochondria in insect muscle cells?
- A) Nass
- B) Koliker
- C) Altman
- D) Benda
- Answer: B
7. Who gave the name ‘Sarcosome’ to mitochondria?
- A) Koliker
- B) Benda
- C) Flaming
- D) Meves
- Answer: A
8. Who first observed mitochondria as thread-like structures?
- A) Benda
- B) Flaming
- C) Altman
- D) Koliker
- Answer: B
9. What stain was used by Altman to study mitochondria?
- A) Safranin
- B) Janus Green
- C) Methylene Blue
- D) Eosin
- Answer: B
10. Mitochondria were discovered in plant cells (Nymphea) by:
- A) Meves
- B) Koliker
- C) Benda
- D) Porter
- Answer: A
Structure & Components of Mitochondria
11. How many membranes do mitochondria have?
- A) One
- B) Two
- C) Three
- D) None
- Answer: B
12. What is the inner membrane of mitochondria called?
- A) Cristae
- B) Thylakoid
- C) Stroma
- D) Matrix
- Answer: A
13. The mitochondrial matrix contains:
- A) Ribosomes
- B) Enzymes
- C) DNA
- D) All of the above
- Answer: D
14. The space between the inner and outer mitochondrial membranes is called:
- A) Intermembrane space
- B) Stroma
- C) Thylakoid space
- D) Periplasmic space
- Answer: A
15. The inner membrane of mitochondria is folded into:
- A) Vesicles
- B) Granules
- C) Cristae
- D) Filaments
- Answer: C
Mitochondrial DNA & Function
16. Who discovered mitochondrial DNA (mtDNA)?
- A) Altman
- B) Nass
- C) Koliker
- D) Meves
- Answer: B
17. Mitochondrial DNA is inherited from:
- A) Father
- B) Mother
- C) Both parents
- D) Grandparents
- Answer: B
18. The number of mitochondria in a cell depends on:
- A) The cell’s energy requirement
- B) The cell’s size
- C) The cell’s shape
- D) Random distribution
- Answer: A
19. Mitochondrial DNA is:
- A) Linear
- B) Circular
- C) Double-stranded
- D) Both B and C
- Answer: D
20. The major function of cristae in mitochondria is to:
- A) Store ATP
- B) Increase surface area for ATP production
- C) Store oxygen
- D) Synthesize proteins
- Answer: B
Metabolism & Energy Production
21. Which metabolic process occurs in mitochondria?
- A) Glycolysis
- B) Krebs Cycle
- C) Photosynthesis
- D) Fermentation
- Answer: B
22. What is the end product of mitochondrial respiration?
- A) Oxygen
- B) ATP
- C) Water
- D) Carbon dioxide
- Answer: B
23. The electron transport chain occurs in which part of mitochondria?
- A) Cristae
- B) Matrix
- C) Outer membrane
- D) Cytoplasm
- Answer: A
24. The powerhouse of the cell is called so because it:
- A) Stores ATP
- B) Generates ATP
- C) Transports nutrients
- D) Breaks down proteins
- Answer: B
25. The enzyme ATP synthase is located in:
- A) Inner mitochondrial membrane
- B) Outer mitochondrial membrane
- C) Matrix
- D) Ribosomes
- Answer: A
Miscellaneous Facts & Advanced Topics
26. Which shape is NOT associated with mitochondria?
- A) Rod-shaped
- B) Club-shaped
- C) Spherical
- D) Star-shaped
- Answer: D
27. Which type of cells have the highest number of mitochondria?
- A) Nerve cells
- B) Skin cells
- C) Muscle cells
- D) Bone cells
- Answer: C
28. The smallest mitochondria are found in:
- A) Yeast
- B) Bacteria
- C) Algae
- D) Fungi
- Answer: A
29. Which of the following is NOT a feature of mitochondria?
- A) Self-replicating
- B) Circular DNA
- C) Ribosomes
- D) Cell wall
- Answer: D
30. Which molecule acts as the final electron acceptor in the mitochondrial electron transport chain?
- A) ATP
- B) Oxygen
- C) Carbon dioxide
- D) NADH
- Answer: B
Advanced Topics in Mitochondria
31. What is the primary role of mitochondria in apoptosis (programmed cell death)?
- A) DNA replication
- B) Energy storage
- C) Release of cytochrome c
- D) Protein synthesis
- Answer: C
32. What is the role of cytochrome c in mitochondria?
- A) ATP synthesis
- B) Electron transport chain
- C) Cell division
- D) Lipid breakdown
- Answer: B
33. Which of the following mitochondrial enzymes is responsible for ATP production?
- A) DNA polymerase
- B) ATP synthase
- C) RNA polymerase
- D) Catalase
- Answer: B
34. Which of the following mitochondrial functions is crucial for cell survival?
- A) Glycolysis
- B) Photosynthesis
- C) Oxidative phosphorylation
- D) Fermentation
- Answer: C
35. Mitochondrial dysfunction is linked to which of the following diseases?
- A) Diabetes
- B) Alzheimer’s
- C) Parkinson’s
- D) All of the above
- Answer: D
36. Which hypothesis explains the origin of mitochondria?
- A) Cell Theory
- B) Endosymbiotic Theory
- C) Spontaneous Generation
- D) Germ Theory
- Answer: B
37. Which evidence supports the endosymbiotic theory of mitochondrial origin?
- A) Presence of circular DNA
- B) 70S ribosomes similar to bacteria
- C) Ability to self-replicate
- D) All of the above
- Answer: D
38. The TCA (Krebs) cycle occurs in which part of mitochondria?
- A) Cristae
- B) Matrix
- C) Outer membrane
- D) Intermembrane space
- Answer: B
39. Mitochondria use which molecules as fuel for ATP production?
- A) Proteins
- B) Lipids
- C) Carbohydrates
- D) All of the above
- Answer: D
40. The mitochondria in sperm cells are located in:
- A) The head
- B) The tail
- C) The midpiece
- D) The acrosome
- Answer: C
Mitochondrial Inheritance & Evolution
41. Which type of inheritance is followed by mitochondrial DNA?
- A) Maternal
- B) Paternal
- C) Both maternal and paternal
- D) Random inheritance
- Answer: A
42. Which type of ribosomes are present in mitochondria?
- A) 80S
- B) 60S
- C) 70S
- D) 90S
- Answer: C
43. What is the role of mitochondria in thermogenesis (heat production)?
- A) ATP synthesis
- B) Uncoupling protein (UCP) activation
- C) Oxygen storage
- D) Water production
- Answer: B
44. Which type of specialized fat cells contain many mitochondria for heat generation?
- A) White adipose tissue
- B) Brown adipose tissue
- C) Yellow adipose tissue
- D) Red adipose tissue
- Answer: B
45. Which process occurs when mitochondria generate ATP without oxygen?
- A) Oxidative phosphorylation
- B) Anaerobic respiration
- C) Glycolysis
- D) Fermentation
- Answer: B
46. Mitochondria have a protein-import system called:
- A) TOM and TIM complexes
- B) SOS system
- C) ABC transporters
- D) Endocytosis
- Answer: A
47. The presence of mitochondrial diseases can be diagnosed by:
- A) Muscle biopsy
- B) DNA sequencing
- C) Enzyme activity tests
- D) All of the above
- Answer: D
48. Which organelle works closely with mitochondria in lipid metabolism?
- A) Ribosome
- B) Endoplasmic reticulum
- C) Golgi apparatus
- D) Lysosome
- Answer: B
49. Which mitochondrial disorder is caused by mutations in mtDNA?
- A) Leigh syndrome
- B) Alzheimer’s disease
- C) Parkinson’s disease
- D) Cystic fibrosis
- Answer: A
50. In which part of mitochondria is oxygen consumed?
- A) Outer membrane
- B) Intermembrane space
- C) Matrix
- D) Cristae
- Answer: D