Ch 2 Chemistry

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1

matter

anything that occupies space and has mass

2

states of matter

solid, liquid, gas

3

solid

has definite shape and volume

4

liquid

has no definite shape and definite volume

5

gas

has no definite shape and no definite volume

6

energy

the capacity to do work or put matter into motion

7

potential energy

stored energy; has the capability to do work but is not now doing so

8

kinetic energy

energy in action

9

forms of energy

chemical, electrical, mechanical, radiant

10

chemical

stored in the bonds of chemical substances (food molecules, ATP)

11

electrical

movement of charged particles

12

mechanical

energy directly involved in moving matter

13

radiant

energy that travels in waves (electromagnetic spectrum)

14

What is an element

unique substances that cannot be broken down by ordinary chemical methods

15

What are Physical properties

things that can be detected with our senses or measured (color, texture, boiling point)

16

Chemical properties

describe how atoms react with other atoms

17

An atom has three subatomic particles

protons, neutrons, and electrons

18

The central nucleus of an atom is composed of?

protons and neutrons.

19

How are the subatomic particles charged?

Protons are positively charged

neutrons are neutral (no charge)

Electrons Negatively charged

20

Where are electrons located

orbiting the nucleus in an electron cloud

21

Why does an atom have an overall neutral charge?

there are equal numbers of protons and electron

22

What is an atomic nunber

number of protons in an element

23

List the four major elements of the body

carbon, oxygen, hydrogen, and nitrogen (96% of body weight)

24

What are the most important minerals for the body? (9)

calcium, phosphorus, potassium, sulfur, sodium, chlorine, magnesium, iodine, and iron.

25

What are the trace minerals needed? (11)

chromium, cobalt, copper, fluorine, manganese, molybdenum, selenium, silicon, tin, vanadium, and zinc

26

molecule

combination of two or more atoms held together by chemical bonds When the two atoms are identical the resulting substance is called a molecule of that element (H2 is a molecule of hydrogen gas).

27

compound

when two or more different kinds of atoms bind they form molecules of a compound; chemically pure; all molecules identical (H2O is a compound – it is a molecule of water).

28

mixtures

substances composed of two or more substances physically intermixed.

29

solutions

homogeneous mixtures of components that may be gases, liquids, or solids. [air, seawater]

30

solvent

substance in a solution present in the greatest amount (dissolving medium) [water]

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solute

substance in a solution present in smaller amounts (thing that is dissolved) [salt]

32

The outermost energy level is called

valence shell

33

Atoms are most stable when the outermost shell has

8 electrons

(The exception to this is hydrogen and helium, which only have one energy level that is filled to capacity and is stable with only 2 electrons.)

34

Atoms are neutral, but they can gain or lose electrons. When this happens an atom becomes an?

ion

35

An ionic bond is a

chemical bond between atoms formed by the transfer of one or more electrons from one atom to another. An example is sodium chloride (NaCl), table salt.

36

A covalent bond is a

chemical bond formed between two atoms that are sharing a pair of electrons, each atom contributing one electron to the shared pair.

37

If the atoms are shared equally then the resulting molecule is

nonpolar (hydrogen gas).

38

a polar molecule

If one atom has a greater attraction for electrons (a property known as electronegativitiy), the electrons may be shared unequally (water)

39

Hydrogen bonds form when

a hydrogen atom, already covalently linked with one electronegative atom (like oxygen or nitrogen), is attracted by another electronegative atom and forms a bridge between them.

40

synthesis reactions are

constructive (anabolic) and absorb/use energy (endergonic)

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decomposition reactions

break things down (catabolic) and release energy (exergonic)

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exchange reactions

break bonds and then re-form other bonds to make new compounds.

43

Catalyst

speed up the reaction A catalyst is not chemically changed by the process and can be re-used

44

Water has several important properties:

  • high heat capacity – absorbs and releases large amounts of heat before changing appreciably in temperature itself.
  • high heat of vaporization – large amounts of heat are needed to break water’s hydrogen bonds and allow it to change from a liquid to a gas (evaporation).
  • polar solvent properties – the universal solvent. The chemical reactions of the body depend on the reactants being dissolved in water.
  • reactivity – decomposition reactions by hydrolysis; large molecule assembly by dehydration synthesis
45

Acids are

substances that release hydrogen ions (H+) in detectable amounts. (1-6.9)

46

Bases

take up hydrogen ions in detectable amounts and are characterized by the presence of hydroxyl ions (OH-) (7.1-14)

47

Blood must maintain a pH in the range of

7.35-7.45

48

Carbohydrates include

sugars and starches they are composed of carbon, hydrogen, and oxygen

49

Monosaccharides are

simple sugars, example glucose (the major fuel source for the body).

50

Disaccharides are

composed of two sugar units, for example table sugar or sucrose (glucose + fructose).

51

Polysaccharides are

composed of many sugar units, for example starch (the storage carbohydrate of plant tissues) and glycogen (the storage carbohydrate of animal tissues).

52

The primary function of carbohydrates in the body is

to serve as a source of cellular fuel

53

Lipids are

insoluble in water, but dissolve readily in other lipids and organic solvents like alcohol. Lipids include neutral fats, phospholipids, and steroids.

54

Tryglycerides are

neutral fats, composed of a backbone of glycerol with three attached fatty acid chains. Neutral fats provide the body’s most efficient and compact form for storing usable energy fuel

55

Phospholipids are

similar to triglycerides except one fatty acid chain is replaced by a phosphate group.

56

Proteins are composed of building blocks called

amino acids joined by peptide bonds.

57

peptides

Small chains of less than 50 amino acids

58

Proteins are chains of

more than 50 amino acids and often will have 100-10,000 amino acids

59

Fibrous proteins such as collagen make up a large part of

connective tissue

60

Globular proteins include

hormones and enzymes

61

Nucleic acids

DNA and RNA

62

gene

provides the instructions for how to make a single protein chain

63

DNA (deoxyribonucleic acid)

is the genetic material

64

RNA (ribonucleic acid)

assists in gene expression by carrying the code for a protein to the place in the cell that proteins are manufactured

65

ATP (adenosine triphosphate) is

a nucleotide which serves as the energy carrier molecule in the cell