Bio Chem

Question 1

Important chemical characteristics of life

Answer 1

1. Growth and Reproduction- adds more biomolecules
2. Transform energy- ie chemical to kinetic or glucose to ATP
3. Homeostasis- maintaining balance in the cell

Question 2

Elements of life

Answer 2

95% of total mass- oxygen, carbon, hydrogen, nitrogen

>1% - calcium, chlorine, magnesium, phosphorus, potassium, sodium, sulfur

Question 3

Atomic number

Answer 3

Number of protons(+) and electrons (-)
first number on top of element in period table
( elements are in order based on atomic number)

Question 4

Valence shells

Answer 4

1st shell - 2 electrons
2nd shell- 8 electrons
3rd shell- 8 electrons

Question 5

Covalent bonds

Answer 5

Electrons being shared between two atoms

Question 6

Ionic bonds

Answer 6

“transfer” of an electron btwn atoms that have large difference in electronegativity

• atoms that gains electron creates negative charged anion and atom that loses electron becomes positive cation. This happens so that both outer shells become filled and both atoms are more stable.

-the opposite charges are what attracts, and creates the bond
atoms that gains protons become more electronegative

Question 7

Polar molecules

Answer 7

the more electronegative an atom is, the more time the shared electron (covalent bond) spends near the electronegative atom.

PARTIAL negative and positive charges are a result b/c the shared electron spends more time near the more electronegative atom so it becomes partially negative, and the atom that the electron doesn’t spend as much time around becomes partially positive.

a non-polar molecule has equal sharing.

Question 8

Hydrogen bonds

Answer 8

Partial charges permit hydrogen bonding, which is a much weaker bond.
The partial negative and positive charges attract and create a weak bond.

i.e. water, hydrogen (+) and oxygen (-) create hydrogen bonds.

Water is most dense at intermediate temperatures because the hydrogen bonds are close and not yet crystalized (ice)