WEEK3

Question 1

What is a non-polar covalent bond?

Answer 1

Bonds formed between two non-metals with the same electronegativity value

Question 2

what is a polar covalent bond?

Answer 2

bonds formed between elements with different electronegativity value, resulting in an electric dipole

Question 3

what is an ionic bond?

Answer 3

when two atoms are so unequal in their attraction for valence electrons that the more electronegative atom strips an electron completely away from its partner

Question 4

How are weak bonds important in biology?

Answer 4

many large biomolecules are held in their functional form by weak bonds

Question 5

What are Van der Waals forces

Answer 5

these are attractions between molecules not caused by covalent bonds or ionic bonds, but rather by tiny fluctuations in the electron clouds surrounding the atom and molecules.

Question 6

What are the types of Van der Waals forces?

Answer 6

-Dipole-Dipole Forces
-Hydrogen Bonding
-London Dispersion Force

Question 7

What are London Dispersion forces?

Answer 7

London dispersion forces are caused by fluctuations in charge. sometimes electrons are concentrated more to one side of an atom or molecule, resulting in a temporary imbalance in charge, causing brief attractions.

Question 8

Dipole-Dipole moment:

Answer 8

Some molecules have a permanent imbalance in charge, with one side being partially negative and the other side being partially positive, these are called dipole molecules. when they get together they attract.

Question 9

What are hydrogen bonds?

Answer 9

when a hydrogen atom is covalently bonded to an electronegative atom, the hydrogen atom has a partial positive charge causing it to attract to nearby electronegative atoms. These bonds are relatively weak but are critical in stabilizing the structure of proteins, nucleic acids and macromolecules

Question 10

What are some importance of Van der Waals forces?

Answer 10

-solubility
-biology and biochemistry
-Adhesion and cohesion

Question 11

In the 1950s, two scientists recreated the conditions of early Earth and discovered that organic molecules formed spontaneously. What are the names of these scientists and what is the name of their experiment.

Answer 11

Stanley Miller and Harold Urey. Miller-Urey Experiment

Question 12

What makes the water molecule polar?

Answer 12

The unequal sharing of charge and its V-like shape

Question 13

How are water molecules held together?

Answer 13

Hydrogen Bonds

Question 14

The extraordinary properties of water are emergent properties resulting from?

Answer 14

Hydrogen bonding

Question 15

What are the four emergent properties of water that contribute to earths suitability for life?

Answer 15

• Cohesive/adhesive behavior
• ability to moderate temperature
• expansion upon freezing
• versatility as a solvent

Question 16

What is the difference between cohesion and adhesion?

Answer 16

Cohesion- Water - water
Adhesion- water- other substances

Question 17

what is surface tension?

Answer 17

it is the measure of how hard it is to stretch or break the surface of a liquid.

Question 18

Pure water has a neutral pH of 7. where concentration of H+ equals that of OH-. Describe acidic and basic conditions.

Answer 18

Acidic conditions- Higher H+ conc.
Basic conditions- Higher OH- conc.

Question 19

What is a buffer?

Answer 19

A system in dynamic equilibrium that maintains the pH of its surrounding.

Question 20

What is an example of a buffer system?

Answer 20

Bicarbonate (HCO3-) in blood plasma resists changes in pH by absorbing or releasing H+ ions

Question 21

How does Carbon enter the biosphere?

Answer 21

Through the action of photosynthetic plants that convert atmospheric carbon (CO2) into molecules of life, which is then taken in by plant-eating animals.

Question 22

the four valence electrons of carbon can covalently bond to:

Answer 22

Oxygen, hydrogen, nitrogen,

Question 23

What are functional groups?

Answer 23

components of biological molecules that are most commonly involved in chemical reactions

Question 24

What are the 7 most important groups in biological processes?

Answer 24

1. hydroxyl
2. carbonyl
3. carboxyl
4. amino
5. sulfhydryl
6. phosphate
7. methyl group

Question 25

6 major elements of life?

Answer 25

1. Hydrogen
2. Nitrogen
3. carbon
4. calcium
5. oxygen
6. phosphorus