📘
TL PhD Comprehensive Exam
  • Introduction
  • Tasklist
  • 1. Basics
    • 1.1 Basic Biology Review
    • 1.2 Basic Genetics Review
    • 1.3 Light & Photosynthesis
  • 2. Coral Biology
    • 2.1 Basic Coral Biology
      • 2.1a Food Webs
    • 2.2 Reef Structure
    • 2.3 Growth & Reproduction
    • 2.4 Morphology
    • 2.5 Physiology
    • 2.6 Mixotrophy & Energy
    • 2.7 Symbiosis
    • 2.8 Reef Mortality
      • 2.8a Conservation
  • 3. Ecology & Evolution
    • 3.1 Evolution & Plasticity
    • 3.2 General Ecology
    • 3.3 Species
    • 3.4 Cryptic Species
  • 4. Isotopes
    • 4.1 Isotope Basics
      • 4.1a Instrumentation & methodology
      • 4.1b Environmental O & H
      • 4.1c Environmental C and N
      • 4.1d Organismal Isotopes
    • 4.2 Fractionation in Corals
    • 4.3 Trophic Niche Analysis
    • 4.4 CSIA
      • 4.4a C: Essential vs. Nonessential
      • 4.4b N: Trophic vs. Source
  • 5. Other
    • 5.1 Science & Society
    • 5.2 Stats
  • 6. Summary & Resources
    • 6.1 Glossary
    • 6.2 Resources
    • 6.3 Questions From Exam
    • 6.4 Recommendations & Reflections
Powered by GitBook
On this page
  1. 4. Isotopes
  2. 4.4 CSIA

4.4a C: Essential vs. Nonessential

15

Last updated 1 year ago

What differentiates EAAs from NEAAs?

  • essential amino acids take additional steps to synthesize

  • essential amino acids have a complex r group sidechain (see red above)

Essential amino acids (EAAs)

  • Can not be synthesized by most metazoans, so they must come from the diet

  • there is very low fractionation of EAAs between trophic positions

  • The ∆C of EAAs will reflect the base source of C (e.g. zooplankton, algae, etc.)

  • Can be used to assess pure routing of diet to consumer

Nonessential amino acids (NAAs)

  • can be synthesized by metazoans by breaking up other AAs and restructuring them

  • synthesized de novo from a bulk carbon pool

  • huge amount of variability in NAAs

  • Can be used to represent pure mixing of diet into consumer

Amino Acid C isotope fingerprinting

  • every source that can synthesize EAAs leaves a specific fingerprint, or ratio, of the EAAs based on the biosynthetic pathways involved in making the EAAs

  • Currently very broad - because most plants use the same pathways, we group them all together.

  • End members will have very specific fingerprints that can be seen to segregate using a PCA