Biology 121

Lecture Guide Chap 2

 

The molecules of life…

 

_________________ are made up of ____________, the smallest unit of an element.

 

Element – _______________________________________________ ________________________________________________________ ________________________________________________________

 

All atoms have one or more _________________ (+).

 

All atoms have one or more _________________ (-).

 

All atoms have one or more _________________ (0).

 

____________________ – the atom’s ________________ containing the _______________________________.

 

___________________  – the number of ______________ in an atom

 

___________________ – the number of _______________ AND

______________________ in an atom

 

 

 

# protons = # electrons

 

 

 

 

 

 

 

 

 

___________________ – atoms that vary in ____________________ ________________________________________________________

 

_________________– ______________________________________ _____________________________________________________________________ (radioactive decay) ___________________________ ________________________________________________________ _______________________________________________________ .

 

 

 

What determines whether an atom will form a molecule?

 

 

The ______________ and _____________of the ________________

 

 

Electrons are ____________ toward the ________________, but are ___________ by other _________________ and thus move around the __________________ in __________________.

 

 

_________________– __________________________ (electron cloud) ______________________________________________ ____________________________________________________.

 

 

1 or at most 2 electrons occupy any orbital

 

 

 

 

 

 

 

 

 

 

 

Shells and Orbitals

 

 

 

 

 

 

 

 

 

 

 

 

 

Atoms with ___________________ may:

__________________

__________________

__________________.

 

_________________ – no orbital _________________ (e.g., __________________).

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Building a molecule…

 

_____________ bond – ____________________________ _______________________________________________

 

_____________– molecules of 2 or more __________ ___________________________________.

 

Types of Bonds

 

1_____________ – ________________________________ ________________________________________________

 

__________ – atom that has ________________________ 1 or more ____________________.

 

________________ is an example of an ________________

 

2. _________________ – ___________________________ ________________________________________________ ________________________________________________

 

nonpolar– _______________________________________

 

 polar– _______________________________________

 

 

3.  ___________________ – ________________________ _______________________________________________ _______________________________________________ _______________________________________________ _______________________________________________

 

 

 

 

 

 

Ions at work: Acid vs Base

 

At any instant in ________________, some molecules are breaking apart into _______________________ (H+) and _______________________ (OH-). 

 

This ionization is the basis for the __________________

 

Acids – _________________________________________ _______________________________________________  ( pH _____). 

 

bases – ________________________________________ ______________________________________________ _____________________________________________  (pH           ) 

 

 

 

salts – release __________________________________.