ch 1 introduction to chemistry of life

summary of biomolecular properties

1. biomolecules are constructed hierarchically, from a limited number of elements

2. certain functional groups (reactive portions) and linkages (bonding arrangements) characterize different types of biomolecules

3. simple molecules condense to form more complex ones, like polymers

4. self-replicating molecules make copies are are subjected to natural selection

5. the properties of biomolecules reflect their fitness to living conditions

covaent bonds

formed by sharing e- pairs, making H, C, N, O appropriate to support life

bond energy

energy required to break a covalent bond

how does DNA relate to covalency

2 polynucleotide chains bind through hydrogen bonds, giving rise to non-covalent, structural complementarity

• replication is possible because each member of a pair can recognize the identity and orientation of its partner

intra

within

inter

between

properties of biomolecules that reflect their fitness

1. macromolecules and their building blocks have a “sense” or directionality

2. some macromolecules are informational

3. biomolecules have characteristic 3D architecture

4. weak forces maintain biological structure and determine interactions

which four elements occur in virtually all biological molecules?

CHON

summarize the major stages of chemical evolution

1. form biomolecules

2. assemble biomolecules into organized molecular systems

3. results in self-replicating collections of molecules

practice drawing a simple condensation and hydrolysis reaction

explain why complementarity would have been necessary for the development of self-replicating molecules

because it allows pairs to recognize the identity and orientation of its partner

summary of cell as unit of life

1. compartmentalization of cells promotes efficiency by maintaining high local concentrations of reactants

2. metabolic pathways evolved to synthesize molecules and generate energy

3. the simplest cells are prokaryotes

4. eukaryotic cells are characterized by numerous membrane-bounded, including a nucleus

5. the phylogenetic tree of life includes three domains: bacteria, archaea, and eukarya

6. evolution occurs as natural selection acts on randomyly occuring variations among individuals

prokaryotic cells vs eukaryotic cells

prokaryotic:

• dingle cell

• no nucleus or organelles

eukaryotic:

• larger than prokaryotes (10³- 10^4 times bigger)

• nucleus + many organelles

high local concentration of biomoleucles

bacterial flagellar motor relies on high concentrations of biomolecules to work