Chapter 2

Question 1

What are the atomic structures of an atom?

Answer 1

proton: positive particle in nucleus
neutron: uncharged particle in nucleus
electron: negative charged particle in electron cloud

Question 2

Interpret atomic structure using a periodic table

Answer 2

atomic mass: protons + neutrons (on top of isotope)
atomic number: protons (on bottom of isotope)
atomic symbol: letter

Question 3

radioactive versus stable isotopes

Answer 3

isotopes indicate various amounts of neutrons but radioactive have a nucleus with excess neutrons and emits energy as it decays

Question 4

Uses for radioactive isotopes

Answer 4

Low amount of radioactivity can be used as tracer to detect molecular changes like a positron emission tomography to determine comparative activity in tissues (thyroid). High levels of radiation kills bacteria and fungi. Physicians use radiation therapy to kill cancer cells

Question 5

How are elements combined into molecules?

Answer 5

A molecule is formed when 2 or more atoms bond together thus 2 or more different elements makes a compound

Question 6

What are the different types of chemical bonds?

Answer 6

ionic bond: ions are attracted to one another by opposite charges
covalent bond: atoms share 1 pair of electrons (polar means sharing is unequal, nonpolar means sharing is equal)
hydrogen bond: weak bond arises between slightly positive hydrogen atom of 1 molecule and slightly negative negative atom of another molecule (negative oxygen, positive hydrogen)

Question 7

How do the characteristics of water relate to its chemical structure?

Answer 7

high heat capacity: hydrogen bonds that link water molecules help water absorb heat without much temperature change

high heat vaporization: hydrogen bonds must be broken before the water boils and changes to vaporized state

solvent: when ionic salts are out into water, negative ends are attracted to sodium ions and positive ends are attracted to chloride

cohesive and adhesive: water molecules can form hydrogen bonds with 4 other water molecules and cling to other polar surfaces

Question 8

how do those characteristics of water help with everyday life?

Answer 8

keep a normal body temp (homeostasis) lubricate and cushion joints, allow for the passage of nutrients, get rid of wastes through urination, allows chemistry of life

Question 9

Acid vs basic solutions

Answer 9

acids: molecules raise hydrogens ion concentration in a solution lowering pH
bases: molecules lowering hydrogen ion concentration in a solution raise pH

Question 10

organic vs inorganic molecules

Answer 10

organic: contain carbo, hydrogen, and oxygen, are associated with living organisms, include carbs, proteins, lipids, and nucleic acids
inorganic: DO NOT contain carbon, hydrogen molecules together (H2O, NaCl, CO2)

Question 11

functional groups

Answer 11

carboxyl: R group, carbon, double bond to oxygen, and OH
hydroxyl: r group, OH
amino: R group, nitrogen, 2 hydrogen bonds
phosphate: R group, oxygen, double bond oxygen, 2 OH

Question 12

build up and break down of polymers

Answer 12

monomers: small molecule that is a subunit of a polymer
polymer: macromolecule with covalently bonded monomers
(build up) dehydration reaction: chemical reaction in which a water molecule is released during covalent bond formation
(breakdown) hydrolysis: splitting chemical bond by adding water with H+ going to one molecule and the OH- going to another

Question 13

basic chemical formula for carbohydrates

Answer 13

SHORT TERM ENERGY STORAGE
contain 1 carbon, 2 hydrogen, 1 oxygen
glucose is C6H12O6

Question 14

define the saccharides

Answer 14

monosaccharide: simple sugar, cannot be broken down by hydrolysis (glucose, fructose, and galactose)
disaccharide: sugar containing TWO monosaccharide units (maltose, sucrose, lactose)
polysaccharide: polymer made up of carb monosaccharides

Question 15

important polysaccharides

Answer 15

EX: starch (sugar stored in plant) glycogen (animals store sugar and polymer of glucose), cellulose (found in cell wall in plant, polymer of glucose)
chitin (insects and exoskeleton)

Question 16

Parts of a lipid

Answer 16

oxygen, carbon, and hydrogen + 1 glycerol backbone, 2 fatty acid tails (hydrophobic) and a phosphate group

Question 17

different lipids

Answer 17

tryglyceride: fat composed of 1 glycerol and 3 fatty acids for energy storage
fatty acid: contains hydrocarbon chain and ends with acid group
phospholipid: forms bilayer of membrane, polar hydrophilic head bonded with 2 nonpolar hydrophobic tails (2 fatty acids, glycerol, phosphate group)

Question 18

healthy vs unhealthy fats

Answer 18

unsaturated fatty acids: more than 1 double bond (causes oils to be liquids at room temp)
saturated fatty acid: can hold all hydrogens, 1 or less double bonds
trans fat: increases shelf life for food, allows for reheating, and reduces need for animal fat (VERY UNHEALTHY)

Question 19

steroids

Answer 19

has 4 carbon rings
cholesterol: steroid formed by body and entered through diet (animal cell plasma membrane and precursor)

Question 20

function of protein cells

Answer 20

metabolism: enzyme proteins increase rate of metabolic reactions
support: structures such as hair, nails ,skin
transport: channel/carrier proteins in plasma membrane regulate enter/exit of substances
defense: assist in immune system
regulation: influence cell behavior (intercellular messages to influence cell metabolism)

Question 21

amino acids

Answer 21

amino group, acidic carboxyl group, R group
contains nitrogen

peptides: amino group+carboxyl group, a single chain of amino acids
peptide bond: joins 2 amino acids

Question 22

4 levels of protein structure

Answer 22

primary: linear sequence of amino acids
secondary: protein makes different structures (alpha helix and beta sheet)
tertiary: 3D shape of polypeptide
quaternary: proteins with multiple polypeptides (lactose contains 4 polypeptides for final structure

Question 23

denatured

Answer 23

protein loses structure and function and occurs when exposed to extreme pH and heat

Question 24

DNA

Answer 24

nucleic acids with genetic information
has adenine, thymine, guanine, and cytosine (AT and CG)
2 rungs held together by hydrogen bonds

Question 25

RNA

Answer 25

nucleic acid with ribose sugar
has adenine, uracil, guanine, and cytosine
has no helix
is complementary to DNA

Question 26

ATP

Answer 26

adenine and ribose is modified by adding 3 phosphate groups, is energy carrier

Question 27

Water is a liquid at room temperature. This is due to

Answer 27

hydrogen bonding between water molecules.

Question 28

You notice that rain water forms “beads” on your car. This is an example of what property of water

Answer 28

cohesion

Question 29

When two glucose molecules combine they form a disaccharide molecule and

Answer 29

a water molecule.

Question 30

A genetic mutation can cause a change in the sequence of the 20 amino acids used to build proteins. Such a change is a change to the protein’s

Answer 30

primary structure, but this will likely alter higher levels of structure as well.

Question 31

Hemoglobin is a protein composed of two pairs of polypeptide chains. What is the highest level of protein structure represented by hemoglobin

Answer 31

quaternary

Question 32

What type of reaction is necessary to produce a dipeptide from individual amino acids

Answer 32

dehydration reaction