Download Diversity in Structure and Function

Big Idea 4: Biological Systems
Interact
…in Structure and
Function
Essential Knoweledge
• Essential knowledge
4.C.1: Variation in
molecular units
provides cells with a
wider range of
functions.
• Diversity in structures increases flexibility
• Allows organisms to survive diff. challenges
Diversity in Macromolecules
More types of macromolecules =
more possible functions
Making of Diversity?
1. Having different genes
Having Different Genes, MHC Markers
Video Clip!
Organ
Transplant
Making of Diversity?
2) RNA splicing / modifications
Making of Diversity?
3) Post-translational
protein modifications:
protein gets add’nl
biochemical molecules
on it (lipids, carbs) or
structural changes
(disulfide bridges w/
tertiary structure)
Multiple copies of alleles or genes
(gene duplication) may provide
new phenotypes
Ex: Heterozygotes
• May express both alleles which can have
benefits
• Ex: In sickle cell- heterozygotes have some
normal RBCs and some sickle cells
Gene Duplication
• Genes can
get copied
• New copies
may change
and
produce
new
proteins
Example, Antifreeze Gene in Fish
• Arctic cod: enzyme in cells called Sialic Acid
Synthase
• Through duplication and slight alterations it
became a protein in blood that allows fish to
swim in water below freezing point
More Protein Diversity than Gene
Diversity
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