Out of spec knowledge

Question 1

What is telomerase?

Answer 1

• Eukaryotic chromosomes have ends (telomeres) that shorten after replication
• Telomerase extends the ends using an RNA template which is active in stem cells and cancer cells.

Question 2

WHat is proofreading by DNA polymerase?

Answer 2

• DNA polymerase has a 3’ - 5’ exonuclease activity to correct errors immediately during replication which reduces mutation rate significantly

Question 3

Why are fewer tRNA molecules needed to bind?

Answer 3

• The 3rd base of a codon can pair loosely. (explaining how 61 codons are read by 40 tRNAs.

Question 4

How can the cristae change shape and why would it need to change shape?

Answer 4

• Can change shape dynamically depending on energy demand so high surface area correlates with greater capacity for oxidative phosphyrlation

Question 5

Photosynthesis out of spec (ribosome size)

Answer 5

• Chloroplasts contain their own circular DNA and 70S ribosomes, suppporting the endosymbiotic theory where they replicate independetly of the nucleus (used to be their own prokaryotic)

Question 6

What happens when Rubisco binds to O2 rather than CO2

Answer 6

• Rubisco binds oxygen instead of carbon dioxide.
• C4 and CAM plants are evolved to reduce this inefficiency

Question 7

What is the role of symbiotic bacteria?

Answer 7

• Ferment indigestible carbohydrates into short chain fatty acids which are absorbed by the colon and used in energy metabolism.

Question 8

What is the role of gut flora ?

Answer 8

• • Gut flora synthesise vitamin K and B vitamin that aren’t produced by human enzymes.

Question 9

What is the enteric nervous system?

Answer 9

• Sometimes called the second brain and independelty regulates enzyme secretion and blood flow in the guts containing over 100 million neurones.