Energy Storage

Where is sucrose produced?

Leaf cells

How does sucrose travel to the tuber?

Phloem

In which organelle is starch synthesized in tubers?

Amyloplast

What form of sugar is imported into the Amyloplast?

G6P

Not all the energy from sucrose is stored in the starch molecule. At which points is energy lost?

Respiration

Phosphorylation and dephosphorylation of sugars

Consumption of PPi

Which types of amino acid would you expect in the central domain of the oleosin protein?

Hydrophobic

What is the role of proline residues in the middle of the hairpin?

Kinking of the protein chain to cause a hairpin structure

What effect will protease treatment have on the oleosin in oil bodies?

Flanking domains will be degraded

How is an external signal (ABA) recognized in the cell?

Receptor proteins bind to ABA which activates phosphorylation pathways

Where is the response element in the DNA?

In the 5’ of the coding region

What does the transcription of the oleosin gene produce?

mRNA

How is oleosin protein synthesized?

The transcript is read by ribosomes attached to the cytosloic face of the ER

How can the agricultural characteristics of crops be improved?

There are traditional and modern approaches that can be considered. Try to list 2-3 options.

- increased starch storage in tubers
- reduced sugar in tubers (better potato frying characteristics)
- increased protein in seeds
- increased oil in seeds

Methods could include traditional breeding, enhanced breeding by monitoring DNA sequences, and genetic modification