Unit 1: Chemistry Of Life

Question 1

What are the three subatomic particles, and their significance?

Answer 1

Protons: positively charged particles found in the nucleus of an atom
Neutrons: particles with no charge, they are also found in the nucleus. They can vary in the same element, resulting in isotopes.
Electrons: negatively charged particles found in the electron shell around the nucleus. They determine chemical properties and reactivity of the element. 

Question 2

What is a chemical bond?

Answer 2

Interactions between the valence electrons of different atoms. atoms are held together by chemical bond to form molecules. 

Question 3

What is a Convelent bond?

Answer 3

Occurs when valence electrons are shared by two atoms. 

Question 4

What is a nonpolar convelent bond?

Answer 4

Occurs when the electrons are being shared equally between two atoms.

Question 5

What is electronegativity? What two atoms are strongly electronegative?

Answer 5

A tendency to attract electrons of a convoluted bond. Oxygen and nitrogen are strongly electronegative. 

Question 6

What is a polar convelent bond?

Answer 6

One atom has greater electronegativity than the other, resulting in unequal sharing of electrons. 

Question 7

What are Ionic bonds?

Answer 7

Ones in which two atoms attract valence electrons so unequally that the more electronegative atom steals electron away from the less electronegative one 

Question 8

What are Hydrogen bonds?

Answer 8

Relatively weak bonds that form between the partial positively charged hydrogen atom of one molecule in the strongly, electronegative, oxygen or nitrogen of another molecule. 

Question 9

What are Van der Waals interactions? 

Answer 9

Very weak, connections that last for a short time, that a result of a symmetrical distribution of electrons within a molecule 

Question 10

What chemical bonding plays a major role in three-dimensional shape of proteins and nucleic acids ?

Answer 10

Hydrogen bonds 

Question 11

What interaction contributes to three-dimensional shape of molecules?

Answer 11

Van der Walls (disulfide bridges a little as well)

Question 12

Is water polar or nonpolar?

Answer 12

Water is polar . The oxygen region of the molecule has a slightly negative charge, and each hydrogen has a slightly positive charge. 

Question 13

What bond forms between water molecules?

Answer 13

Hydrogen bonds.

Question 14

Hydrogen bonds are key to what properties of water?

Answer 14

-Cohesion: (also adhesion and transpiration)
-Moderation of temperature is possible cause of water is high specific heat capacity
-Insulation of bodies of water by floating ice
-Water is an important solvent

Question 15

What is cohesion? What is one property of water that was that is caused by this?

Answer 15

Linking of like molecules. Surface tension is a result of this property. 

Question 16

What is adhesion?

Answer 16

 Clinging of one substance to another 

Question 17

What is transpiration?

Answer 17

The movement of water molecules up the very thin, xylem tubes, and their evaporation from the stomata in plants.

Question 18

What is specific heat?

Answer 18

The amount of heat required to raise or lower a temperature of a substance of 1°C 

Question 19

Why does ice float?

Answer 19

Water is less dense as a solid than as a liquid. Because it’s less dense, it floats. This helps keep larger bodies of water from freezing solid, allowing life to live in freezing temps.

Question 20

What is hydrophilic?

Answer 20

Substances that are water soluble. These are ionic compounds, polar molecules, and some proteins.

Question 21

What is Hydrophobic?

Answer 21

Substances that are nonpolar and do not dissolve in water.

Question 22

How does the pH scale work?

Answer 22

Runs between 0-14 and measures the relatively acidity and alkalinity of aqueous solutions.

Question 23

What’s an acid?

Answer 23

Has excess H+ ions, and has a pH below 7.0. 

Question 24

What is an base?

Answer 24

An excess of OH- ions and pH above 7.0. 

Question 25

What is a buffer?

Answer 25

Minimize changes in pH. They accept H+ from solutions when they are in excess and donate H+ when it’s depleted.

Question 26

What is an isomer?

Answer 26

Molecules that have the same molecular formula but differ in their arrangement of these atoms.

Question 27

What is a functional group?

Answer 27

They are attached to a carbon skeleton and have diverse functions.

Question 28

What are polymers, and what is something that is a polymer?

Answer 28

Long chain molecules made of repeating subunit made up of monomers. A macromolecules is a polymer.

Question 29

What is a dehydration reaction?

Answer 29

Creates polymers from monomers. Two monomers are joined by removing one molecule of water.

Question 30

What is hydrolysis?

Answer 30

Occurs when water is added to split into large molecules.

Question 31

What are Carbohydrates?

Answer 31

Both monosaccharides: simple sugars (glucose, fructose, galactose, etc) and polymers like starch made from these and other subunits.

Question 32

What ratio of atoms does carbs have?

Answer 32

1 carbon: 2 hydrogen: 1 oxygen or CH2O

Question 33

What are monosaccharides?

Answer 33

Monomers of carbohydrates. These can be stuff like glucose and ribose. They also have the 1:2:1 ratio

Question 34

What are Polysaccharides?

Answer 34

Polymers of monosaccharides. This is stuff like starch or glycogen.

Question 35

What are all lipids?

Answer 35

Hydrophobic

Question 36

What are fats made up of?

Answer 36

Glycerol molecules and three fatty acid molecules.

Question 37

What are fatty acids?

Answer 37

They include hydrocarbon chain of variable lengths. These chains are nonpolar and therefore hydrophobic.

Question 38

What’s the difference between saturated and unsaturated fatty acids?

Answer 38

Saturated has no double bonds between carbons. Solid in room temp (butter).

Unsaturated have some double carbon bonds, which results in kinks. Tends to be liquid at room temp (olive oil)

Question 39

What is the function of lipids?

Answer 39

Energy storage, protection of vital organs, insulation.

Question 40

Function of polysaccharides

Answer 40

Energy storage and structural support

Question 41

What are phospholipids and what is their structure? What do they make up?

Answer 41

The have a polar, hydrophilic head that includes a phosphate group
They have two fatty acid tails, which are hydrophobic.
They make up cell membranes.

Question 42

What are proteins made up of?

Answer 42

Polymers made up of amino acid monomers.