VI. Marine Biotechnology: Fish Sperm Extender

Question 1

how many requirements are there for an optimal extender and what are they?

Answer 1

1. isotonic with sperm fluid
2. neutral or slightly basic pH
3. contains nutrients
4. buffer

Question 2

why should the extender be isotonic with sperm fluid?

Answer 2

to prevent cell damage caused by a difference in osmotic pressure

Question 3

why should the extender have a neutral or slightly basic pH?

Answer 3

7.2 - 7.8

to match the natural pH of sperm fluid

Question 4

why should the extender contain nutrients?

Answer 4

simple sugars (glucose, fructose) provide the sperm cells with energy

Question 5

what buffers should the extender have and why?

Answer 5

Tris or phosphate keeps the pH stable during storage

Question 6

what is the optimal pH for sperm extenders and why?

Answer 6

7.2 - 7.8

supports metabolic activity and sperm motility

Question 7

what happens to sperm fluid at an overly acidic or basic pH?

Answer 7

• damage to cell membrane
• reduced viability and motility

Question 8

what temperature is sperm fluid cooled? what happens to it during cooling?

Answer 8

4 C
metabolism slows, extending sperm viability for short term storage

Question 9

what temperature and medium is sperm fluid frozen in? what happens to it during freezing?

Answer 9

-196 C, liquid nitrogen
long term storage using cryoprotectants to prevent cell damage

Question 10

what happens to sperm fluid at high temperatures?

Answer 10

• accelerates metabolism
• quickly deplete energy
• reduces viability