Exam 1 Ch. 2

Question 1

What is chemistry?

Answer 1

Life; BIO is based on chemistry

Question 2

What is an element?

Answer 2

Species of atoms with the same # of protons

Question 3

What is an atom?

Answer 3

fundamental building block of all substances

hydrogen, oxygen, carbon

Question 4

What are the 3 subatomic particles and what are their locations and charges?

Answer 4

Protons (+positive)
Neutron (neutral)
Electron (- negative)

Question 5

Example
Atomic #
Atomic mass
how many protons, neutrons, and electrons

Answer 5

Nitrogen (N)
top #-7 protons which means there are 7 electrons. 
(protons and electrons always the same)
bottom #- 14.00674 atomic mass
14-7=7 neutrons

Question 6

What are isotopes?

Answer 6

form an element that differ in the # of neutrons their atoms carry; change mass # but not the charge

Question 7

What are radioisotopes?

Answer 7

Isotope with an unstable nucleus such as Carbon 14 (14c)

Question 8

What are valence electrons? (also see drawings for examples; will have to draw one on exam)

Answer 8

Electrons in the outermost shell

Question 9

What are ions?

Answer 9

Atoms with a different # of protons and electrons; may carry a charge

Question 10

Which elements are likely to form ionic bonds?

Answer 10

Lithium and fluorine;

Na (sodium) and Cl (chlorine)

Question 11

What are hydrogen bonds?

Answer 11

an attraction between 2 atoms that already participate in other chemical bonds.

Question 12

What about water’s structure allows it to be so versatile?

Answer 12

Hydrogen bonding; water can be solid, liquid, gas. (cohesion and adhesion) Water maintains stable temp

Question 13

What are the 4 properties of water that contribute to providing a suitable environment for life?

Answer 13

Cohesive behavior, ability to moderate temp, expansion upon freezing, can be a solvent

Question 14

What is a solvent?

Answer 14

used to dissolve; water can be a solvent

Question 15

What is a solute?

Answer 15

what needs to be dissolved; sugar

Question 16

What is a solution?

Answer 16

homogenous mixtures; same

Question 17

What is hydrophobic? Example

Answer 17

water fearing; oil molecules are hydrophobic

Question 18

What is hydrophilic?

Example

Answer 18

likes water/wants to interact with water

Question 19

What is pH?

Answer 19

potential of hydrogen; measure of acidity, basicity of a solution

Question 20

How is pH measured?

Answer 20

basicity of a solution measured on a scale 0-14. 7 is neutral. below 7 is acidic and above 7 is base.

Question 21

What are acids?

Answer 21

any substance that INCREASES the H+ (hydrogen ions) concentration of a solution; gives up H+ (pH 1-6)

Question 22

What are bases?

Answer 22

any substance that DECREASES H+ concentration of a solution; accepts H+ above 7

Question 23

What does a buffer do?

Answer 23

minimize changes in concentrations of H+ and OH- in a solution

Question 24

What are polymers?

Answer 24

many monomers linked together-poly means many

Question 25

What are monomers?

Answer 25

single building blocks; mono means 1

Question 26

What are carbohydrates?

Answer 26

sugars, starches and fibers

Question 27

What elements are found in all carbs?

Answer 27

Carbon, Hydrogen, Oxygen

Question 28

What are carbs used for?

Answer 28

energy and cell structure

Question 29

What are monosaccharides?

Answer 29

sugars

Question 30

What disaccharides?

Answer 30

2 sugars linked together through dehydration reaction

Question 31

What are polysaccharides?

Answer 31

Many monomers (glucose) hooked together

Question 32

What are ionic bonds?

Answer 32

bond that form due to the transfer of electrons between atoms

Question 33

What are non-polar covalent bonds?

Answer 33

a bond where atoms share the electrons EQUALLY

Question 34

What is a polar covalent bond?

Answer 34

one atom is more electronegative and the atoms DO NOT SHARE the the electrons equally

Question 35

What does electronegativity have to do with polar covalent bonds?

Answer 35

There is unequal sharing in polar covalent bond bc the more electronegative an atom is, the more it pulls shared electrons toward itself.

Question 36

What are lipids?

Answer 36

greasy, oily or waxy non-polar organic molecules with one or more fatty acid tails

Question 37

What elements are found in all lipids?

Answer 37

C and H atoms linked by non-polar covalent bonds

Question 38

What has more stored energy? Lipids or carbs?

Answer 38

Lipids

Question 39

Levels of organization of living things. Provide an example at each level and a definition of what that level encompasses.

Answer 39

``` Atoms: H, C, O Molecules: protein, DNA Organelles: mitochondrion, chloroplast, ribosome Cells: animal and bacteria cell Tissues: muscle tissue Organs: heart, stomach Organisms: frog ```

Question 40

Describe how a triglyceride is put together.

Answer 40

when 3 hydroxyl (OH-) groups of a single glycerol molecule react with the carboxyl group (COOH-) of 3 fatty acids