Lecture 2 Chemistry

Question 1

Matter

Answer 1

anything that has mass/takes space

Question 2

element

Answer 2

Substance that cant be broken down into more substances

Question 3

Atom

Answer 3

Bit of matter that cant be divided anymore without losing its properties

Question 4

What is the center of an atom?

Answer 4

Nucleus

Question 5

What is in the nucleus of an atom?

Answer 5

Subatomic particles (protons and neutrons, usually the same nbr)

Question 6

How many electrons are there in an atom?

Answer 6

Same nbr as protons

Question 7

What is the elctrical charge of a proton?

Answer 7

Positive

Question 8

What is the elctrical charge of a neutron?

Answer 8

Neutral

Question 9

What is the elctrical charge of an electron?

Answer 9

Negative

Question 10

Review the periodic table image

Answer 10

You can do this :)

Question 11

What is the atomic nbr?

Answer 11

Nbr of protons (and also electrons)

Question 12

What is the atomic mass?

Answer 12

Total mass of protons + neutrons

Mean of isotopes weight in periodic table

Question 13

What is an isotope?

Answer 13

Atom w a different number of neutrons

Question 14

What are the top 4 elements in the human body?

Answer 14

Carbon
Hydrogen
Oxygen
Nitrogen
Make 96% of body mass

Question 15

Where do electrons move?

Answer 15

Around nucleus, on different shells

Question 16

How many electrons can the first 3 shells contain?

Answer 16

2-8-8

Question 17

After an exchange of electrons, what is the charge of the atom if it:

• Lost an electron?
• Got an electron?

Answer 17

• Positive (bc there are more protons)

- Negative (bc there are more electrons)

Question 18

How do we call an atom after an exchange of electrons?

Answer 18

An ion

Question 19

What is called atoms bonded together?

Answer 19

A molecule

Question 20

What is a covalent bond?

Answer 20

Sharing electrons between atoms (double bond = sharing 2 pairs)

Question 21

What is an ionic bond?

Answer 21

Transferring electrons between atoms, then the 2 oppositely charged atoms attract each other and stay close

Question 22

What are hydrogen bonds?

Answer 22

Whole molecules bonding together held by hydrogen atoms (see polarity card)

Question 23

What is polarity?

Answer 23

When electrons of an atom go more towards another atom in a molecule because the atom is slightly more positively charged
EXAMPLE
Oxygen (8 protons) = slightly positive
Hydrogen (1 proton) = less positive than O
Atoms in covalent bond will gravitate more towards the oxygen atom, making is slightly more negative
Therefore, when 2 molecules of water meet, the hydrogen atom of one molecule (positive) will go towards the oxygen atom (negative), bonding the molecules together

Question 24

What makes water cohesive?

Answer 24

Hydrogen bonds

Question 25

What are the 4 main properties of water?

Answer 25

- Cohesion (bc of hydrogen bonds) (high surface tension) - Large heat capacity (lots of energy required to heat it) - Low density as a solid (because molecules organize in a pattern) - Good solvent (any polar molecule dissolves well bc it attaches to either O- or H+)

Question 26

What is composed a solution of a neutral pH?

Answer 26

When there are equal parts of H+ ions and OH- ions coming from water after the solute was dissolved into it

Question 27

WHat is the pH of a solution with more H+ ions?

Answer 27

More H+ = +acidic | Less = more basic

Question 28

What is the pH of blood?

Answer 28

7.4

Question 29

What are buffers?

Answer 29

Chemicals in our blood that regulate pH by sending more H+ or removing some

Question 30

What are the 4 types of macromolecules in our food?

Answer 30

- Carbohydrates - Lipids - Proteins - Nucleic acids

Question 31

What are examples and features of carbohydrates "monosaccharides/simple sugars"?

Answer 31

Glucose and fructose

Question 32

What is glucose commonly refered to as? What is it used for?

Answer 32

Blood sugar - Used as fuel for activities - Stored temporairly as glycogen in tissues - Converted to fat on the long term

Question 33

What are disaccharides?

Answer 33

2 simple sugars bonded together

Question 34

How are called 2 or more sugars bonded together?

Answer 34

Polysaccharides

Question 35

What is longer to digest; mono or poly saccharides? why?

Answer 35

Polysaccharides, because they have more bonds that need to be broken down (slow sugars)

Question 36

What are 2 examples of indigestible carbs? What are they used for?

Answer 36

Chitin and cellulose; they serve as structural material for plants in nature, and in our diet they are considered "fibers"; help digestion

Question 37

What kind of molecules are lipids?

Answer 37

they are non-polar, hydrophobic molecules (they do not like water)

Question 38

What are called molecules that form Hydrogen bonds w water?

Answer 38

Hydrophilic

Question 39

What are the 2 components of fats?

Answer 39

- Head (glycerol) | - Tail(s) (fatty acids - hydrocarbons)

Question 40

What is called the unit of fat composed of head and tail?

Answer 40

Triglycerides

Question 41

Which breakdown generates mroe energy? cabrs or fat?

Answer 41

Fat

Question 42

What is called a fat solid at room T?

Answer 42

Fat

Question 43

What is called a fat liquid at room T?

Answer 43

oil

Question 44

What is the characteristic of a saturated fat?

Answer 44

Each C in the tail of fatty acids bound to 2 H: makes the tails straight This type of fat is not essential to the diet (harmful) solid at room temp

Question 45

What is the characteristic of a unsaturated fat?

Answer 45

Some C only have one H in the tail, and some C have double bonds together, making the tail kinked This type of fat lowers cholesterol levels, its "healthier" Liquid at room temp

Question 46

What is a mono-unsaturated fat?

Answer 46

When there is only 1 double bond between 2 carbon atoms in the fatty acid tail of a triglyceride

Question 47

What is a poly-unsaturated fat?

Answer 47

When there are 2+ double bonds between 2 carbon atoms in the fatty acid tail of a triglyceride

Question 48

What is hydrogenation? What does it produces?

Answer 48

Adding H to tails of unsaturated fats to make it saturated (never perfect) Creates trans fats: VERY unhealthy

Question 49

What is cholesterol?

Answer 49

Transformed saturated fat (small quantities are essential, but too much is harmful) NOT A FAT, its a STEROL

Question 50

What are the 4 types of sterols?

Answer 50

-Cholesterol -Steroid hormones -Phospholipids -Waxes THESE ARE NOT FATS

Question 51

What are proteins made of?

Answer 51

Amino acids

Question 52

What are the 4 components of a protein?

Answer 52

- Hydrogen atom - Carboxyl group (CO2) - Amino group (NH3) - Side chain (unique to each)

Question 53

What are essential amino acids?

Answer 53

Those that cant be produced by our body

Question 54

What are complete proteins?

Answer 54

Contain all amino acids

Question 55

What is a peptide

Answer 55

The link between 2 amino acids

Question 56

What are the 4 structures of a protein?

Answer 56

1. Polypeptide chain (primary) 2. H bonds throughout chain (Secondary) 3. Chain folds on itself (tertiary) 4. Many chains attach together (quartenary)

Question 57

What is denaturation of a protein?

Answer 57

Unfolding it (heat, pH, etc)

Question 58

What are enzymes?

Answer 58

Proteins that speed up chemical reactions

Question 59

What is an active site?

Answer 59

Where a substrate (molecule) binds on the enzyme so its bonds can be broken

Question 60

What is activation energy?

Answer 60

Needed for any chemical reaction to occur, enzymes lower it

Question 61

The rate of reaction of enzymes depend on:

Answer 61

- Concentration of enzyme/substrate - Temperature - pH - Inhibitors/activators

Question 62

What are Inhibitors?

Answer 62

inhibitors reduce enzyme activity, competitive binds to active site non-competitive alter the enzyme shape

Question 63

What are nucleic acids?

Answer 63

Macromolecules that store info (DNA and RNA)