What is Biochemistry Flashcards
Consumption of preformed building blocks selected…
for the ability to synthesize necessary components
What are conserved in all organisms:
Nucleotide
amino acid biosynthetic
pathways
glycolysis
H+ gradient
driven ATP synthesis
They are all likely present in universal ancestor
Reciprocal relationship:
The study of various aspects of health & disease has opened up new areas of biochemistry
Biochemical studies have illuminated many
aspects of health & disease
All disease has a…
biochemical basis:
Biochemical studies contribute to diagnosis,
prognosis & treatment
Structural models
- different ways of representing the same molecule, emphasizing different aspects.
Ex:
– Wireframe (skeletal) -connections
– Spacefill - shape
– Ball and stick - both
– Ribbon - architecture of proteins
Stereoisomers have…
the same bonds and atoms, different configurations around a chiral center
Stereoisomers differ in biological activity:
Most activities in cells are mediated by proteins.
- Interaction of proteins with other molecules depends on complementarity of shapes and charges.
- Changing configuration of a
molecule alters its ability to interact with proteins and therefore its biological activity.
Enantiomers
mirror images
Geometric isomers
configuration restricted by double bond
Free energy (G) changes during a chemical reaction…
depends on temperature, change in intrinsic energy of molecules (DH), and change in entropy (DS)
DG = DH –TDS
Diastereomers
stereoisomers that are not mirror images
Even if energetically favorable, rates of most reactions would be too…
slow for cellular needs
– enzymes accelerate reaction rates by lowering activation energy
1) DG<0
2) DG=0
3) DG>0
1) Reaction is spontaneous
2) reaction is at equilibrium
- no net change
3) additional energy is required for reaction to proceed
Biochemical pathways are sequences of…
enzyme-catalyzed reactions.
- Catabolic pathways release energy & are used to produce ATP (exergonic)
- Anabolic pathways hydrolyze ATP (endergonic) to synthesize cellular molecules
Energy released by an exergonic reaction can
drive an endergonic reaction
