CH 2 Lecture

Question 1

What is an atom?

Answer 1

The basic unit of matter

Question 2

What is an isotope?

Answer 2

Atoms of the same element that have a different number of neutrons

Question 3

Define an ion and provide an example.

Answer 3

An electrically charge atom. H+ is positively charged because it has lost an electron

Question 4

Define orbital.

Answer 4

A region in space likely to host an electron

Question 5

What is an atomic shell?

Answer 5

An energy level within an orbital.Electron will choose to occupy the shell closest to the nucleus first

Question 6

What is the periodic table?

Answer 6

Elements are arranged by increasing number of protons, the atomic number. Elements in the same column share similar chemical properties.

Question 7

What is a molecule?

Answer 7

A combination of atoms

Question 8

Define a chemical bond?

Answer 8

A form of attraction between atoms that hold them together

Question 9

What are valence electrons?

Answer 9

Electrons located at the highest energy level. Responsible for chemical bonding

Question 10

What is a molecular orbital?

Answer 10

A merged orbital between two electrons

Question 11

Define covalent bond

Answer 11

It is the sharing of electrons to form a molecular orbital

Question 12

What is a polar covalent bond?

Answer 12

The unequal sharing of electrons. Occurs due to differences in the electro negativity of atoms

Question 13

Define electro negativity?

Answer 13

Increases along the periodic tableAs the number of protons increases electrons are held more tightly to the nucleus therefore less likely to transfer an electron

Question 14

What is a hydrogen bond?

Answer 14

Occurs when a H atom is covalently bonded to an electronegative atom (oxygen or nitrogen) interacts with an electronegative atom of another moleculeWeaker than covalent bonds

Question 15

What are ionic bonds?

Answer 15

Bond between two ionsNa+ and Cl- form NaCl

Question 16

What’s a polar molecule?

Answer 16

A molecule that has a + and a - regions

Question 17

Define hydrophilic?

Answer 17

Water loving

Question 18

Define hydrophobic?

Answer 18

Water fearing

Question 19

What is the hydrophobic effect?

Answer 19

Polar molecules exclude non polar ones.Example cell membrane

Question 20

When does a neutral PH occur?When does a acidic PH occur?When does a basic PH occur?

Answer 20

Neutral PH occurs when H+ = OH-Acidic PH occurs when H+ is greater than OH-Basic PH occurs when H+ is less than OH-

Question 21

Why is ice less dense than water?

Answer 21

When water freezes the molecules bond with four other molecules into a crystal lattice structure. Making ice less dense

Question 22

Define cohesive force?

Answer 22

Tendency to stick together

Question 23

What is surface tension?

Answer 23

Contrastive tendency of the surface of a liquid to resist an external force

Question 24

What is an element?

Answer 24

A pure substance that cannot be broken down further by chemistry

Question 25

What is an organic molecule?

Answer 25

A molecule that contains carbonForms tetrahedronsAbility to rotate around a single bond. Cannot rotate around a double or triple bond

Question 26

Define isomer?Give an example

Answer 26

Molecules that have the same chemical formulae but have different structures.Lucine and isoleucine

Question 27

What do proteins do?

Answer 27

Provide structural support and act as catalysts during chemical reactions

Question 28

What is the role of nuclei acids?

Answer 28

Encode and transmit genetic information

Question 29

What is the role of carbohydrates?

Answer 29

Provide energyMakes up cell wall in plants, bacteria and algae

Question 30

What is the purpose of lipids?

Answer 30

Store energyMake cell membranes Act as a signalling molecule

Question 31

What is a polymer?What are the four main examples?

Answer 31

Complex molecules made up of repeated simpler units connected by covalent bondsAmino acids make up proteins Sugars make up carbohydratesFatty acids make up lipidsNucleotides make up nucleic acid

Question 32

What is an enzyme?

Answer 32

Protein based catalysts that accelerates the rate of chemical reactions

Question 33

Describe a peptide bond

Answer 33

Links amino acids by the C atom of the carboxyl group to the N atom of the amino group

Question 34

What is DNA?

Answer 34

The genetic material in all organisms

Question 35

What's is RNA?

Answer 35

Key player in protein synthesis and regulation of gene expression

Question 36

What is a phosphodiester bond?

Answer 36

Joins adjacent pair of nucleotides using a phosphate group

Question 37

Explain a double helix

Answer 37

Two strands of nucleotides twisted around each other

Question 38

Define saccharides

Answer 38

Simplest form of sugars Form in linear or cyclic molecules

Question 39

What is the composition of sugars and what is the ratio?

Answer 39

Composed of C H O in a 1:2:1 ratio

Question 40

What is a monosaccharide, disaccharide, polysaccharide?

Answer 40

One simple sugar, two simple sugars linked by covalent bonds, combination of simple sugars

Question 41

What is a complex carbohydrates?

Answer 41

Long branched chains of monosaccharides

Question 42

Define aldoses

Answer 42

Monosaccharides with an attached aldehyde group

Question 43

Define ketoses

Answer 43

Monosaccharides with an attached ketone group

Question 44

What are glycosidic bonds?

Answer 44

Covalent bonds that attach monosaccharides

Question 45

Define triacylglycerol

Answer 45

Lipid used for energy storageMade up of three fatty acids joined to glycerol

Question 46

Define saturated fat

Answer 46

Fatty acids that do not contain a double bond

Question 47

Define unsaturated fat

Answer 47

Fatty acids that contain a C-C double bond

Question 48

Why are the kinks found in a fatty acid chain important?

Answer 48

Reduce tightness and therefore lower the melting point

Question 49

Describe van der waal forces

Answer 49

Temporarily polarized molecules weakly bonded to one another due to the attraction of opposite forces

Question 50

Define steroids

Answer 50

Second type of lipids Example cholesterol

Question 51

Define phospholipids

Answer 51

Third type of fatty acids major component of cell membranes

Question 52

Describe the Stanley miller experiment

Answer 52

Water vapour, ammonia, methane and hydrogen gas and collected. A spark is introduced and the formation of 20 amino acids is the result

Question 53

Know difference between RNA and DNA chemical structure

Answer 53

Ok

Question 54

Be able to identify nucleic acids

Answer 54

Ok

Question 55

Identify a phosphodiester bond

Answer 55

Ok

Question 56

Know the three types of carbohydrate molecules

Answer 56

Ok

Question 57

How are amino acids joined in a protein?

Answer 57

By a peptide bond

Question 58

Recognize a fatty acid molecule

Answer 58

Ok