MITOCHONDRIA

Question 1

Where is the site of respiration?

Answer 1

happens in inner membrane space of mitochondria.

Question 2

what does mitochondria do?

Answer 2

1. site of respiration
2. site of krebs cycle
3. site of fermentation
4. site of non- shivering thermogenesis
5. site of calcium homeostasis
6. site of regulation of cell division

Question 3

differences between outer and inner membrane of mitochondria

Answer 3

outer membrane :
1. contains many porins and gated ion channels.
2. contains long chain fatty-acid-CoA ligase and enzyme monoamine oxidase.
3. apoptosis - breaking the outer membrane kills cell
inner membrane:
1. site of membrane proteins of respiratory chain and H+
- transporting two-sector ATPase
2. rich in cardiolipin.

Question 4

what is the mitochondrial matrix?

Answer 4

1. contains enzymes of pyruvate oxidation and krebs cycle.

Question 5

what is mtDNA?

Answer 5

• mitochondrial genome

Question 6

what are the phototrophy associated plastids?

Answer 6

1. chloroplasts
2. rhodoplasts
3. cyanoplasts
4. chromoplasts - synthesise and store pigments
5. leucoplasts

Question 7

what are leucoplasts?

Answer 7

• synthesises into 4 types:
  1. amyloplasts - stores starch and detects gravity
  2. elaioplasts - stores fats
  3. proteinoplasts - stores and modifies protein
  4. tannosomes - synthesises polyphenols and condensed tannins.

Question 8

what do chloroplasts do?

Answer 8

1. site of phototrophic electron transport chain
2. plant immunity - chloroplasts can trigger apoptosis.
3. fatty acid biosynthesis
4. sugar and starch biosynthesis.

Question 9

structure of chloroplasts?

Answer 9

1. cpDNA
2. lamella or frets - stromal thylakoids.
3. plastoglobulus
4. starch granule
5. granum - stack of thylakoids
6. stroma

Question 10

diff between inner and outer membrane of chloroplasts?

Answer 10

1. outer and inner membrane are each about 7 nm thick.
2. outer membrane contains mainly phospholipids and galactolipids and small fraction of sulfolipids.
3. thylakoid membrane is similar to inner membrane with addition of light harvesting pigments.
4. protons are translocated from stroma to the thylakoid lumen to generate Δp

Question 11

characteristics of chloroplast stroma?

Answer 11

1. equivalent to bacterial cytoplasm or mitochondrial matrix
2. contains plastoglobuli
3. contains starch granules
4. contains enzymes for calvin cycle
5. chloroplast ribosomes
6. contains cpDNA 120-170 kbp
7. encodes chloroplast ribosomes

Question 12

what are chromoplasts?

Answer 12

1. formed from chloroplasts
2. found in fruits and flowers
3. cpDNA is found in chromoplasts but with high level of methylation
4. synthesise and store carotenoids, anthocyanins and flavonoids.

Question 13

what are xanthophylls?

Answer 13

• caretonoids containing oxygen