Isotopes - Tasmin O’Connell guest lecture

Question 1

What are isotopes?

Answer 1

Atoms of the same element that have different numbers of neutrons

Question 2

Protein = C, N, S, H

Answer 2

Bone collagen
Tooth dentine
Soft tissue

Question 3

Mineral= C, O, Sr

Answer 3

Bone mineral
Tooth enamel

Question 4

What can isotopes ratios tell us?

Answer 4

Food - tells us what foods someone has been eating, plant types, trophic levels, marine vs terrestrial

Place - water, climate, geology

Question 5

Two key underlying premises

Answer 5

1. Isotopic patterns vary within ecosystems.
   Therefore different foods & waters are isotopically varied
2. “You are what you consume” body tissues are isotopically linked in predictable way to food/water intake

Question 6

Why food and water groups are isotopically varied?

Answer 6

Because of natural variation
in isotope ratios through
biosphere due to physical,
chemical & biochemical
isotopic fractionation

Question 7

Isotopic variations in plants

Answer 7

C3 verses C4
Marine verses terrestrial

Question 8

Isotopic variations in oxygen

Answer 8

Latitude
Distance from coast

Question 9

Why “you are what you eat?”

Answer 9

Because body tissues are
isotopically linked in
predictable way to
isotopic values of
food/water intake

Question 10

DNA are…

Answer 10

Complex molecules
Same in every cell