Exam 2 (Ch. 2 Chemistry)

Question 1

define molecule and give 1 example

Answer 1

molecules are formed from 2 or more atoms, ex: O2

Question 2

define atom

Answer 2

the smallest component of a pure substance

Question 3

what is the charge of a proton? location in the atom?

Answer 3

positive; nucleus

Question 4

what is the charge of a neutron? location in the atom?

Answer 4

neutral; nucleus

Question 5

what is the charge of an electron? location in the atom?

Answer 5

negative; outside the nucleus

Question 6

define a chemical element

Answer 6

all atoms with the same number of protons that behave the same way chemically

Question 7

define a compound and give an example

Answer 7

a molecule that contains at least 2 different kinds of atoms, ex: H2O

Question 8

why do molecules hold together

Answer 8

because the valence electrons of the combining atoms form attractive forces called chemical bonds

Question 9

how do atoms form bonds

Answer 9

by either gaining or losing electrons or by sharing electrons

Question 10

define ion

Answer 10

a negatively or positively charged atom or atoms

Question 11

define ionic bonding and give an example

Answer 11

an attraction between ions of opposite charge that hold them together to form a stable molecule, ex: sodium chloride

Question 12

define cation and give 3 examples

Answer 12

positively charges ions; ex: potassium, calcium, sodium

Question 13

define anion and give 2 examples

Answer 13

negatively charges ions; ex: iodine, chlorine, sulfur

Question 14

define a covalent bond

Answer 14

a chemical bond formed by 2 atoms sharing one or more pairs of electrons. They are stronger and more common than ionic bonds

Question 15

define hydrogen bond

Answer 15

this occurs when a hydrogen atom is covalently bonded to one oxygen or nitrogen is attached to another nitrogen or oxygen atom. Hydrogen bonds are the weakest bonds and the easiest to break of all bonds

Question 16

define energy

Answer 16

the ability to do work

Question 17

define kinetic energy

Answer 17

energy in motion

Question 18

define potential energy

Answer 18

the energy an object has because of its position

Question 19

chemical energy occurs whenever…

Answer 19

bonds between atoms are formed or broken during chemical reactions

Question 20

synthesis (anabolic) reaction (3 things)

Answer 20

1. a reaction that builds new molecules
2. energy is required (endergonic)
3. ex: ADP+P -> ATP

Question 21

decomposition (catabolic) reaction (3 things)

Answer 21

1. a reaction that breaks down molecules
2. energy is released (exergonic)
3. ex: ATP -> ADP + P

Question 22

example of an exchange reaction

Answer 22

NaOH + HCl -> NaCl + H2O

Question 23

define enzyme

Answer 23

a chemical that catalyzes or speeds up a reaction

Question 24

ATP stands for

Answer 24

adenosine triphospate

Question 25

ATP is a type of

Answer 25

potential or stored energy

Question 26

when ATP is broken down energy is

Answer 26

released

Question 27

define inorganic compound

Answer 27

molecules, usually small and structurally simple which typically lack carbon and in which ionic bonds may play an important role

Question 28

give 4 examples of inorganic compounds

Answer 28

water, molecular oxygen, carbon dioxide and many salts , acids and bases

Question 29

define organic compound

Answer 29

always contain carbon and hydrogen and typically are structurally complex

Question 30

give 3 examples of organic compounds

Answer 30

polysaccharides, proteins, nucleic acids

Question 31

name 8 characteristics of water

Answer 31

1. one of the most abundant and important compounds 2. facilitates the passage of nutrients into the cell 3. medium for most chemical reactions inside the cell 4. neutral charge 5. polar molecule 6. can form hydrogen bonds with nearby water molecules 7. boils at 100 degrees celsius 8. can be a liquid or solid

Question 32

an acid can be defines as a (and give an ex.)

Answer 32

proton donor; ex: HCl

Question 33

pH of an acid

Answer 33

less that 7

Question 34

a base can be defined as a (and give example)

Answer 34

proton acceptor; ex: NaOH

Question 35

pH of a base

Answer 35

greater than 7

Question 36

neutral pH

Answer 36

7

Question 37

3 functions of carbohydrates

Answer 37

1. building block of DNA 2. synthesis of amino acids and fats 3. food reserves

Question 38

3 elements that make up a carbohydrate

Answer 38

carbon, hydrogen, oxygen

Question 39

ratio of hydrogen to oxygen in carbohydrates

Answer 39

2 : 1

Question 40

name 3 examples of carbohydrates (with formulas)

Answer 40

1. glucose (C6 H12 O6) 2. ribose (C5 H10 O5) 3. sucrose (C12 H22 O11)

Question 41

what is a monosaccharide

Answer 41

a simple sugar

Question 42

2 ex of monosaccharides

Answer 42

deoxyribose and glucose

Question 43

what is a disaccharide

Answer 43

formed when 2 monosaccharides bond in a dehydration synthesis reaction

Question 44

give 2 ex of disaccharides

Answer 44

disaccharide sucrose and disaccharide lactose

Question 45

what is a polysaccharide

Answer 45

consists of tens or hundreds of monosaccharides joined through dehydration synthesis

Question 46

give four examples of polysaccharides

Answer 46

gylcogen, cellulose, chitin, starch

Question 47

name 3 elements that compose lipids

Answer 47

carbon hydrogen and oxygen

Question 48

do lipids have a 2:1 ratio for hydrogen and oxygen

Answer 48

no

Question 49

give 2 functions of lipids

Answer 49

1. provide structure in membrane and in some cell walls | 2. function in energy storage

Question 50

give 2 lipid ex

Answer 50

fats and triglycerides

Question 51

the building blocks of simple lipids are ___ and _____

Answer 51

glycerol and fatty acids

Question 52

name the 4 elements that compose proteins

Answer 52

C, H, N, O and sometimes S

Question 53

name the 4 functions of proteins

Answer 53

1 speed up biochemical reactions 2. transport certain chemicals in and out of cell 3. part of cell structures such as wall and membrane 4. regulatory functions

Question 54

name the building block of proteins

Answer 54

amino acids

Question 55

how many amino acids occur naturally in proteins

Answer 55

20

Question 56

what type of bond is found between amino acids in a protein

Answer 56

peptide bonds

Question 57

in terms of proteins: the primary structure is a unique sequence in which the _____ are linked together

Answer 57

amino acids

Question 58

in terms of proteins: the secondary structure is the repetitious...

Answer 58

twisting or folding of the polypeptide chain

Question 59

in terms of proteins: the tertiary structure refers to the overall ________ of the polypeptide chain

Answer 59

3-D structure

Question 60

in terms of proteins: the quaternary structure consists of 2..

Answer 60

or more individual polypeptide chains

Question 61

define denaturation of proteins

Answer 61

when a protein unravels and loses its characteristic shape

Question 62

name 3 ways proteins can be denatured

Answer 62

temp, pH, salt concentration

Question 63

2 ex of nucleic acids

Answer 63

DNA and RNA

Question 64

name the building blocks of nucleic acids

Answer 64

nucleotides

Question 65

name the 3 components of nucleotides

Answer 65

1. nitrogen-containing base 2. pentose sugar 3. phosphate group

Question 66

name the 5 nitrogenous bases

Answer 66

thymine, adenine, guanine, cytosine, uracil

Question 67

the 5 carbon sugar found in DNA is

Answer 67

deoxyribose

Question 68

the 5 carbon sugar found in RNA is

Answer 68

ribose