Exam 2 (Ch. 2 Chemistry) Flashcards Preview

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Flashcards in Exam 2 (Ch. 2 Chemistry) Deck (68):
1

define molecule and give 1 example

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

2

define atom

the smallest component of a pure substance

3

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

positive; nucleus

4

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

neutral; nucleus

5

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

negative; outside the nucleus

6

define a chemical element

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

7

define a compound and give an example

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

8

why do molecules hold together

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

9

how do atoms form bonds

by either gaining or losing electrons or by sharing electrons

10

define ion

a negatively or positively charged atom or atoms

11

define ionic bonding and give an example

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

12

define cation and give 3 examples

positively charges ions; ex: potassium, calcium, sodium

13

define anion and give 2 examples

negatively charges ions; ex: iodine, chlorine, sulfur

14

define a covalent bond

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

15

define hydrogen bond

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

16

define energy

the ability to do work

17

define kinetic energy

energy in motion

18

define potential energy

the energy an object has because of its position

19

chemical energy occurs whenever...

bonds between atoms are formed or broken during chemical reactions

20

synthesis (anabolic) reaction (3 things)

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

21

decomposition (catabolic) reaction (3 things)

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

22

example of an exchange reaction

NaOH + HCl -> NaCl + H2O

23

define enzyme

a chemical that catalyzes or speeds up a reaction

24

ATP stands for

adenosine triphospate

25

ATP is a type of

potential or stored energy

26

when ATP is broken down energy is

released

27

define inorganic compound

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

28

give 4 examples of inorganic compounds

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

29

define organic compound

always contain carbon and hydrogen and typically are structurally complex

30

give 3 examples of organic compounds

polysaccharides, proteins, nucleic acids

31

name 8 characteristics of water

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

32

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

proton donor; ex: HCl

33

pH of an acid

less that 7

34

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

proton acceptor; ex: NaOH

35

pH of a base

greater than 7

36

neutral pH

7

37

3 functions of carbohydrates

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

38

3 elements that make up a carbohydrate

carbon, hydrogen, oxygen

39

ratio of hydrogen to oxygen in carbohydrates

2 : 1

40

name 3 examples of carbohydrates (with formulas)

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

41

what is a monosaccharide

a simple sugar

42

2 ex of monosaccharides

deoxyribose and glucose

43

what is a disaccharide

formed when 2 monosaccharides bond in a dehydration synthesis reaction

44

give 2 ex of disaccharides

disaccharide sucrose and disaccharide lactose

45

what is a polysaccharide

consists of tens or hundreds of monosaccharides joined through dehydration synthesis

46

give four examples of polysaccharides

gylcogen, cellulose, chitin, starch

47

name 3 elements that compose lipids

carbon hydrogen and oxygen

48

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

no

49

give 2 functions of lipids

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

50

give 2 lipid ex

fats and triglycerides

51

the building blocks of simple lipids are ___ and _____

glycerol and fatty acids

52

name the 4 elements that compose proteins

C, H, N, O and sometimes S

53

name the 4 functions of proteins

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

54

name the building block of proteins

amino acids

55

how many amino acids occur naturally in proteins

20

56

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

peptide bonds

57

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

amino acids

58

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

twisting or folding of the polypeptide chain

59

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

3-D structure

60

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

or more individual polypeptide chains

61

define denaturation of proteins

when a protein unravels and loses its characteristic shape

62

name 3 ways proteins can be denatured

temp, pH, salt concentration

63

2 ex of nucleic acids

DNA and RNA

64

name the building blocks of nucleic acids

nucleotides

65

name the 3 components of nucleotides

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

66

name the 5 nitrogenous bases

thymine, adenine, guanine, cytosine, uracil

67

the 5 carbon sugar found in DNA is

deoxyribose

68

the 5 carbon sugar found in RNA is

ribose