Name ______Date ______Period _____

The Chemistry of Life

Raven Ch.2

Big Idea 2: BIOLOGICAL SYSTEMS UTILIZE FREE ENERGY AND MOLECULAR

BUILDING BLOCKS TO GROW, TO REPRODUCE AND TO MAINTAIN HOMEOSTASIS.

Essential Knowledge:

  • All living systems require constant input of free energy.
  • Organisms capture and store free energy for use in biological processes.
  • Organisms must exchange matter with the environment to grow, reproduce and maintain organization.
  • Organisms exhibit complex properties due to interactions between their constituent parts.
  • Interactions between molecules affect their structure and function.
  • Variation in molecular units provides cells with a wider range of functions.

Why are we studying chemistry? ______

Basics: Everything is made of ______. Matter is made of ______

Subatomic Particles:

Charge?______

Protons:______Protons:______

Neutrons:______Neutrons:______

Electrons:______Electrons:______

______

Protons:______

Neutrons:______

Electrons:______

Life requires ~25 chemical elements

  • About 25 elements are essential for life
  • Four elements make up 96% of living matter:

• ______(C)• ______(H)

• ______(O)• ______(N)

  • Four elements make up most of remaining 4%:

• ______(P)• ______(Ca)

• ______(S)• ______(K)

Bonding properties

  • Effect of electrons
  • ______determine ______of atom
  • depends on numberof electrons in atom’s outermost shell
  • ______
  • chemical behavior of an atom depends on number of electrons in its valence shell

______

  • Elements in the same row (period) have the same ______
  • Moving from left to right, each element has a sequential addition of electrons (& protons)
  • Elements in the same column (group) have the ______

Consequence of having the same chemical properties and reactivity? ______

______

______

  • Chemical reactivity
  • Atoms tend to
  • ______a partially filled valence shell

or

  • ______a partially filled valence shell

This tendency drives chemical reactions…and creates bonds

Bonds in Biology

  • Bio bonds take place in ______

Weak bonds

  • ______bonds (attraction between δ+ and δ–)
  • Hydro______& hydro______interactions
  • interaction with ______
  • van derWaals forces(interactions)-attractions and repulsions between atoms, molecules, and surfaces, as well as other intermolecular forces
  • ______

Strong bonds

  • ______
  • Why are covalent bonds strong bonds?
  • Two atoms ______a pair of electrons
  • ______atoms holding onto the electrons
  • Very ______
  • Forms ______

Multiple covalent bonds

  • 2 atoms can share >1 pair of electrons
  • ______bonds
  • ___ pairs of electrons
  • ______bonds
  • ___pairs of electrons

Very strong bonds

Nonpolar covalent bond

  • Pair of electrons ______by 2 atoms
  • example: hydrocarbons = CxHx
  • ______(CH4 )

Polar covalent bonds

  • Pair of electrons ______by 2 atoms
  • example: ______= ______
  • oxygen has stronger “attraction” for the
    electrons than hydrogen does
  • oxygen has higher ______
  • water is a ______molecule
  • + vs. – poles
  • leads to many interesting

properties of water…

Hydrogen bonding

  • Polarity of water creates attractions ______molecules
  • attraction between ______in one H2O molecule to ______in another H2O.
  • also can occur wherever an ______exists in a larger molecule

Examples: ______

Weak bond

What type of bonds are within the water molecule? ______

What type of bonds are between the water molecules? ______

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