Biology Chapter 1

Front 1

organisms

Back 1

living things. organisms are composed of chemicals

Front 2

biochemistry

Back 2

the chemistry of living organsims

Front 3

molecules

Back 3

smallest units into which something can be subdivided and still have the essential chemical properties of that substance.

Front 4

elements

Back 4

substances that cannot be broken down chemically into simpler substances

Front 5

atoms

Back 5

discovered by dalton. they are the smallest unit of an element that still has the chemical properties of that element

Front 6

atomic theory

Back 6

most important of all chemical theories. Dalton;s principles for the basis of theory.

Front 7

subscript

Back 7

shows the number of atoms of each element in a molecule

Front 8

model

Back 8

makes it easier to understand how something is built and how it operates, but not the real thing

Front 9

inferences

Back 9

conclusions that follow logically from laboratory data

Front 10

what are molecules made of?

Back 10

atoms that have chemically combined

Front 11

about 97% of the compounds present in organisms contain only what six elements?

Back 11

carbon, hydrogen, oxygen, phosphorous, nitrogen, and sulfur.

Front 12

subatomic particles

Back 12

these particles are smaller than, or "below" the level of atoms

Front 13

electron

Back 13

carries a negative charge in atom

Front 14

proton

Back 14

carries a postive charge in the atom

Front 15

neutron

Back 15

has a neutral charge in the atom

Front 16

elecron shells

Back 16

energy levels or attraction surrounding nucleus

Front 17

isotopes

Back 17

atoms of the same element that differ in their number of neutrons

Front 18

protons and neutrons are in the nucleus of the atom aile electrons are where?

Back 18

around the nucleus and are attracted to the positive nucleus.

Front 19

electrons in shells near the nucleus are held more tightly than?

Back 19

those in shells farther from the nucleus.

Front 20

chemical bonds

Back 20

the attraction, sharing, or transfer of outer shell electrons from one atom to another.

Front 21

chemical reactions

Back 21

involves the making and breaking of chemical bonds

Front 22

cells

Back 22

basic units of life

Front 23

conservation of matter

Back 23

states that matter is neither created nor destroyed in chemical reactions

Front 24

activation energy

Back 24

energy needed to get a chemical reaction started

Front 25

chemical equations

Back 25

a representation of chemical reactions as short statements

Front 26

cell membrane

Back 26

in an animal cell it encloses the cell

Front 27

chemical reactions are important to the cell for what two reasons?

Back 27

1. they are the only way to form new molecules that the cell requires for such things as growth and maintenance.
2. the making and breaking of bonds involves changes in energy. as a result energy may be stored, used to do work, or released.

Front 28

ion

Back 28

is an atom or a molecule that has acquired a positive or negative charge as a result of gaining or losing electrons

Front 29

ionic bonds

Back 29

the attracion between oppositely charged ions.

Front 30

covalent bonds

Back 30

two atoms share one or more pairs of electrons

Front 31

polar covalent bond

Back 31

if the electrons of a bond are not shared equally

Front 32

non-polar

Back 32

electrons in a molecule are shared equally

Front 33

hydrogen bond

Back 33

a weak attraction between hydrogen atoms and oxygen, nitrogen, or flourine aroms; hold together the strands of DNA in their double helix.

Front 34

pH scale

Back 34

the level of Hydrogen and hydroxide ions in soution is described by this range of numbers

Front 35

acidic

Back 35

has more hydrogen than hydroxide ions and has a low pH.

Front 36

basic/alkaline

Back 36

has a high pH and has more hydroxide ions

Front 37

ionization

Back 37

when a nonionic compound, such as water, is converted to ions.

Front 38

soultion

Back 38

mixture in water

Front 39

logarithmic scale

Back 39

change of one pH unit is equal to a tenfold change in the level of H+ ions

Front 40

structural formula

Back 40

models that show both the number and arrangement of atoms in molecules.

Front 41

Why is pH important to biology?

Back 41

because the pH of a cell's interior helps regulare the cell's chemical reactions

Front 42

organic

Back 42

refers to compounds that are made up of carbon atoms and other elements; origainlly thought to be associated only with living things.

Front 43

macromolecules

Back 43

a large complex molecule

Front 44

carbon atoms can combine in large chains that form what

Back 44

carbon skeleton of macromolecules

Front 45

other atoms and molecules can attach to the carbon skeleton which give what to each macromolecule?

Back 45

a particular structure and therefore a particular function

Front 46

what are the four most important classes of molecules in living things?

Back 46

carbohydrates, lipids, proteins, and nucleic acids

Front 47

carbohydrates

Back 47

an orgain compound made of carbon, hydrogen, and oxygen with the hydrogen and oxygen atoms in a 2:1 ratio; examples are sugars, starches, and cellulose.

Front 48

monosaccharides

Back 48

a simple sugar with three to seven carbon atoms in its carbon skeleton

Front 49

disaccharide

Back 49

a double sugar composed of two chemically bonded simple sugars

Front 50

polysaccharides

Back 50

a complex carbohydrate composed of many simple sugars chemically bonded in a chain; for example starch and cellulose

Front 51

polymers

Back 51

long chains of monomers

Front 52

monomers

Back 52

sub-units that make up polymers

Front 53

most organisms use what as a source of energy?

Back 53

glucose

Front 54

the energy in molecules is contained where?

Back 54

in the bonds of the molecules itself.

Front 55

sugar phosphate

Back 55

biologically important sugars often have a phosphate group attached to the carbon skeleton

Front 56

lipids

Back 56

a fat, an oil, a wax, or a fatlike compound that usually ahs fatty acids in its molecular structure; an important component of the plasma membrane

Front 57

saturated fatty acids

Back 57

fatty acids with single bonds

Front 58

unsaturated fatty acids

Back 58

fatty acids with double bonds

Front 59

what are the two functions of lipids?

Back 59

1. long term storage of energy
2. carbon building of structural parts of cell membranes

Front 60

biologically important properties of simple fats depend on what?

Back 60

their fatty acids and properties of fatty acids depend on the length of the carbon chains and the type of bonds between the carbons

Front 61

when do phospholipids form?

Back 61

when a molecule of glycerol combines with two fatty acids and a phsophate group. for celluar membranes with proteins which are critical to cell survival because they separate a cell's internal chemical reactions from the outside environment.

Front 62

proteins

Back 62

an organic compound composed of one or more poplypeptide chanis of amino acids; most structural materials and enzymes in a cell are proteins

Front 63

amino acids

Back 63

an organic compound composed of central carbon atom to which are bonded a hydrogen atom. an amino acid group, an acid group, and one variety of other atoms or groups of atoms; the building blocks of polypeptides and protiens

Front 64

peptide bonds

Back 64

a covalent chemical bond formed between two amino acids; bonds the amino group of each amino acid to the carboxyl group of the next.

Front 65

polypeptide

Back 65

a long chain of chemically bonded amino acids

Front 66

primary structure

Back 66

the first level of organization of a protein or nucleic acid; refers to the specific sequence of amino acids or nucleotides.

Front 67

secondary structures

Back 67

in proteins, the shape of a folded polypeptide chain; results from hydrogen bond between adjacent parts of the molecule

Front 68

tertiary structure

Back 68

the three dimensional folded structure of a polypeptide or protein molecule

Front 69

hydrophobicity

Back 69

the tendency to repel water; substances that are hydrophobic are non-polar and cannot hydrogen bond to water

Front 70

quaternary structure

Back 70

the shape of a complex protien defined by the three-dimensional arrangement of its polypeptide sub-units.

Front 71

what is the protiens most essential role?

Back 71

enzymes

Front 72

what determines the three dimensional shape in a protein

Back 72

the sequence of amino acids

Front 73

nucleic acids

Back 73

DNA or RNA; a polymer of nucleotides important in encoding instuctions for cell processes.

Front 74

nucleotides

Back 74

a subunit of DNA or RNA composed o a 5-carbon sugar, a nitrogen-containg base, and a phosphate group

Front 75

RNA

Back 75

ribonucleic acid; a nucleic acid similar to DNA but hagin the sugar ribose rather than deoxyribose and uracil rather than thymine as one of the bases

Front 76

DNA

Back 76

deoxyribonucleic acid; the hereditary material of most organisms; a nuclic acid composed of deoxyrobose sugar, phospate groups, and four nitrogen containg bases

Front 77

what is the source of genetic information in chromosomes?

Back 77

nucleic acids

Front 78

What are the four different bases of DNA

Back 78

adenine, thymine, guanine, or cytosine

Front 79

What is different about RNA as far as bases?

Back 79

has uracil rather than thymine

Front 80

What is the difference in shape for DNA and RNA?

Back 80

DNA always occurs in double helic. RNA is single stranded.

Front 81

James Watson and Francis Crick proposed what?

Back 81

a model for the structure of DNA molecules that is still accepted todaay.

Front 82

Who found the DNA was a double helix?

Back 82

Rosalind Frankilin and Maurice Wilins.

Front 83

What is a double helix composed of?

Back 83

two long chains of nucleotides which are connected between their DR sugars.

Front 84

genes

Back 84

the fundamental physical unit of heredity, which transmits a set of specifications from one gereration to the next; a segment of DNA that codes for a specific product.

Front 85

DNA stores informationin a code consisting of uits that are three nucleotides called?

Back 85

triplet codons

Front 86

The sequence of amino acids determines its shape which then determines the function. What is the function?

Back 86

1. perform most of the chemical reactions that keep cells alive.
2. can be copied and passed through inheritance from one generation to the next.

Front 87

How do monomers connect?

Back 87

dehydration synthesis.

Front 88

what is dehydration synthesis?

Back 88

bringing out hydrogen and HO out which forms H2O. which makes an available bond and polymer gets bigger.

Front 89

covalent bonds connecting monomers are disconnected how?

Back 89

using hydrolysis

Front 90

what are carbs made of?

Back 90

sugars and polysaccharides

Front 91

what is the monosaccharide formula?

Back 91

CH2O

Front 92

what is the formula for glucose?

Back 92

C6H12O6

Front 93

how are sugars clasified?

Back 93

by the number of carbons in the backbone.

Front 94

what is an isomer?

Back 94

same molecular and empirical formula but different structural formulas.

Front 95

what makes something rich in energy?

Back 95

carbon and hydrogen

Front 96

what is another name for starch?

Back 96

amylose

Front 97

starch

Back 97

made only by plants. energy storage.

Front 98

cellulose

Back 98

made by plants. complex polysaccharide. structural thing in plant's cell walls. commenly called fiber.

Front 99

glycogen

Back 99

how animals store glucose. Eventually stores as body fat.

Front 100

Why are lipids an exception to macromolecules?

Back 100

because they dont form polymers

Front 101

3 fatty acids + 1 glycerol =

Back 101

triglyceride

Front 102

Who proposed a model for the structure of the DNA molecule that is still accepted today?

Back 102

James Watson and Francis Crick

Front 103

Who found that DNA was a double helix?

Back 103

Rosalind Franklin and Maurice Wilkins.

Front 104

What is a double helix composed of?

Back 104

two long chaings of nucleotides which are connected between their sugars.

Front 105

genes

Back 105

the fundamental physical unit of heredity which transmits a set of specifications from one generation to the next; a segment of DNA that codes for a specific product.