1.1 - The Fundamental Chemistry of Life

Question 1

All ORGANIC COMPOUNDS contain..

Answer 1

CARBON ATOMS and may also contain

HYDROGEN, OXYGEN and NITROGEN

Question 2

Living thins ARE:

94%:

4%:

0.1%:

Answer 2

94% Carbon, Hydrogen, Oxygen, Nitrogen

4% Ca, P, K, S, Na, Cl, Mg

0.1% Iron and Iodide (Trace Elements)

Question 3

Atoms are composed of:

Answer 3

Protons (+), Electrons (-), Neutrons (0)

Question 4

The # of protons determines…

Answer 4

The type of element

Question 5

ATOMS ARE…

Answer 5

Neutral

Question 6

Atomic Mass

Answer 6

is the weight of protons and neutrons (electrons have too little of a mass)

Question 7

What is an ISOTOPE

Answer 7

form of an element that has the
same # of protons but different
# of neutrons

Question 8

What is a Radioisotope

Answer 8

Unstable isotope that decays giving off radiation

• Transforms into an atom of another element

Question 9

Example of a Radioisotope

Answer 9

14C is unstable and one neutron splits into an electron and a proton.

When this happens 14C decays into 14N

Question 10

Radioactive Decay is used for:

Answer 10

• occurs at a steady measurable rate
• used to determine the age of fossils and rocks

Question 11

Radioactive Tracers are:

Answer 11

using RADIOISOTOPES to trace the path of atoms throughout the body

Question 12

Ionic Bonds

Answer 12

Form between two oppositely charged molecules

Cation and Anion

Question 13

Covalent Bonds

Answer 13

Atoms SHARE valence electrons

The strength of the bond depends on the ELECTRONEGATIVITY of the atoms involved

Question 14

ELECTRONEGATIVITY is…

Answer 14

Measure of an atom’s attraction to shared
electrons

• HIGH E.N. = STRONG attraction of e-
• LOW E.N. = WEAK attraction of e-

Question 15

Polar Molecules

Answer 15

An unequal sharing of e- due to
different electronegativities results in a polar covalent bond

Generally water soluble

Question 16

Non-Polar Molecules

Answer 16

Have an equal distribution of charges

The bonds are polar, but the symmetry of the molecule results in a balanced distribution of charges (overall molecule in non-polar)

Generally not water soluble (e.g. oils/fats)

Question 17

An Atom that attracts electrons more strongly carries a..

Answer 17

partial NEGATIVE charge

Question 18

An Atom that attracts electrons less strongly carries a..

Answer 18

partial POSITIVE charge

Question 19

Intermolecular Forces

Answer 19

Attractions that occur between molecules

Question 20

What are Hydrogen Bonds?

Answer 20

attractive force between slightly positive hydrogen atoms and a slightly negative atom in
another molecule

Question 21

Hydrogen Bonds are…

Answer 21

strongest and most biologically
significant form of van der Waals forces

• Strong collectively
• Weak by themselves

Question 22

Hydrogen Bonds are strong when…

Answer 22

• They are in large numbers
• When the temp rises

Question 23

What are other van der Waal forces?

Answer 23

• Very weak attractions between two molecules when they
  are close together
• Form from the momentary attractions of electrons to nuclei of other molecules
• Larger molecules have larger forces of attraction than smaller molecules
• Many bonds of this shape can stabilize the shape of a large molecule (e.g. fat)

Question 24

Dehydration Rxn’s

Answer 24

Removal of water to JOIN two molecules

• One molecule loses a Hydrogen atom while the other loses an –OH group

Question 25

Hydrolysis Rxn’s

Answer 25

Splitting of a larger molecule by ADDING a water molecule

• Adds an –OH group to one molecule and a Hydrogen atom to the
  other

Question 26

Neutralization Rxn’s

Answer 26

The reaction between an acid and base which creates a salt and water

ACID + BASE -> SALT + WATER

Question 27

Redox Rxn’s

Answer 27

• Electron transfer reaction

Responsible for most of the energy transfer within cells

Reduction
- Gaining of electrons

Oxidation
- Loss of electrons

Question 28

LEO the lion says GER

Answer 28

Lose Electrons = Oxidation

Gain Electrons = Reduction

Question 29

What are REDOX Reactions responsible for

Answer 29

Responsible for most of the energy transfer within cells