Chapter 2

Question 1

Water is polar or nonpolar?

Answer 1

polar

Question 2

Ion and polar molecules are insoluble or soluble in water?

Answer 2

soluble. (they are hydrophillic) and water is polar so remember, like dissolves like

Question 3

Do nonpolar molecules interact with water?

Answer 3

no they do not. they are poorly soluble because water is polar and nonpolar molecules are not easily dissolve/interact with water. Also nonpolar molecules are hydrophobic

Question 4

What are some inorganic ions

Answer 4

Na^+, K^+, Mg^+2, Ca^+2, HPO4^2-,Cl^-,HCO3^- (ions)

Question 5

What are the four classes of molecules?

Answer 5

carbohydrates, lipids, proteins, nucleic acids

Question 6

what is a glycosidic bond?

Answer 6

this bond allows monosaccharides to be joined together by dehydration reactions (loss of water) and linkage of sugars

Question 7

name two common polysaccharides that are composed entirely of glucose and molecules in alpha configuration

Answer 7

glycogen=storage of glucose in animal cells

starch= storage in plant cells

Question 8

glycogen and amylopectin also contain alpha(1-6) bonds and they serve as____________

Answer 8

branch points

Question 9

cellulose is the main structural component of what?

Answer 9

plant cell walls

Question 10

what is cellulose composed of and in what configuration?

Answer 10

glucose molecules, B configuration

Question 11

why does cellulose have B(1-4)linkages?

Answer 11

This linkage allows the chains to pack more tightly. This allows the cellulose to form long extended chains that pack side by side to form fibers of great mechanical strength

Question 12

What are the 3 main rules of lipids?

Answer 12

• energy storage
• major component of cell membranes
• important in cell signaling as steroid hormones and messenger molecules

Question 13

define fatty acid

Answer 13

are long hydrocarbon chains (16-18 carbons) with a carboxyl group (COO-) at one end

Question 14

define unsaturated fatty acids

Answer 14

have one or more double bonds. therefore it can not bond to as many hydrogens.

Question 15

define saturated fatty acids

Answer 15

HAVE NO DOUBLE BONDS.

Question 16

the hydrocarbon chain of a fatty acid is? hydrophobic or hydrophillic?

Answer 16

hydrophobic

Question 17

name a saturated fatty acid

Answer 17

palmitate or stearate

Question 18

name a unsaturated fatty acid

Answer 18

oleate

Question 19

what are fatty acids stored as?

Answer 19

triacylglycerols

Question 20

what is a triacylglycerol?

Answer 20

it is three fatty acids linked to a glycerol molecule

Question 21

are triacylglycerol insoluble or soluble in water?

Answer 21

they are insoluble in water. this is why they can accumulate as fat droplets in the cytoplasm

Question 22

why are fats more efficient energy storage than carbohydrates?

Answer 22

fats yield more than twice as much energy per weight of the material broken down

Question 23

what is the principle component of the cell membranes?

Answer 23

phospholipids

Question 24

what are phospholipids composed of?

Answer 24

2 fatty acids, joined to a polar head

Question 25

When talking about the phospholipid. The Hydrophobic tails are? The Hydrophillic head is?

Answer 25

hydrophobic tails=hydrocarbon chains hydrophillic head: phosphate group and polar attachment

Question 26

What do you call a molecule that is part water-soluble and part water insoluble? give a example of such a molecule.

Answer 26

amphipathic molecules.... | phospholipids are an example

Question 27

glycerol phopholipids are composed of?

Answer 27

2 fatty acids bound to glycerol. bound to phophate group. which is bonded to another small polar molecule (choline, serine, inositol, ethanolamine)

Question 28

how is sphingomyelin different then other phospholipids?

Answer 28

it is the only nonglycerol phospholipid. meaning the polar head group is formed from serine instead of glycerol

Question 29

what is a glycolipid composed of?

Answer 29

two hydrocarbon chains and a carbohydrate polar head group

Question 30

what is cholesterol composed of

Answer 30

four hydrophobic hydrocarbon rings and a polar hydroxyl (OH) group

Question 31

the steriod hormones are derivatives of __________; that act as chemical messengers

Answer 31

cholesterol

Question 32

what does DNA stand for?

Answer 32

deoxyribonucleic acid

Question 33

what does RNA stand for?

Answer 33

ribonucleic acid

Question 34

what does messenger RNA do?

Answer 34

carries information from DNA to the ribosomes

Question 35

what does ribosomal RNA and transfer RNA do?

Answer 35

they are involve in protein synthesis.

Question 36

still other _______ are involved in the regulation of gene expression and processing and transport of RNAs and protiens

Answer 36

other RNAS

Question 37

DNA and RNA are polymers of ________ which consists of ___________- and _________ bases linked to a phosphorylated sugars

Answer 37

nucleotides purine pyrimidine

Question 38

DNA has what two purines?

Answer 38

adenine and guanine

Question 39

DNA has what two pyrimidines?

Answer 39

cytosine and thymine

Question 40

RNA has what two purines?

Answer 40

adenine and guanine

Question 41

RNA has what two pyrimidines?

Answer 41

cytosine and uracil

Question 42

What do you call the sugar component in RNA?

Answer 42

ribose

Question 43

what do you call the sugar component in DNA?

Answer 43

2'-deoxyribose

Question 44

nucleoside + _____________= nucelotide

Answer 44

phosphate group

Question 45

a nucleoside is composed of what?

Answer 45

it is composed of a base, and a sugar...... addition of phosphate group turns nucleoside to nucleotide

Question 46

in nucleotides which carbon does the phosphate group link to

Answer 46

the 5th carbon of sugars

Question 47

what is a phosphodiester bond?

Answer 47

joins nucleotides it is between the 5' phospate of one nucleotide and the 3' hydroxyl of another

Question 48

define oligonucleotides

Answer 48

are polymers of only a few nucleotides

Question 49

RNA and DNA are _________ and may contain thousands or even millions of nucleotides

Answer 49

polynucleotides

Question 50

what is connected to the 5' carbon of the polynucleotide? | what is connected to the 3' carbon of the polynucleotide?

Answer 50

phosphate group, hydroxyl group

Question 51

polynucleotides are always synthesized in what direction?

Answer 51

5' to 3' direction

Question 52

DNA is made up of two polynucleotide chains. how are the bases on the inside joined

Answer 52

hydrogen bonds

Question 53

what bases pair with the following: Guanine adenine

Answer 53

cytosine | thymine

Question 54

what are the most diverse of all molecules

Answer 54

protiens

Question 55

name five functions of protiens

Answer 55

structural components transport and storage of small molecules transmit information between cells (protein hormones) defense against infection (antibodies) enzymes

Question 56

proteins are polymers of how many amino acids

Answer 56

20

Question 57

when talking about an amino acid. what is connected to the alpha carbon?

Answer 57

side chain, amino group, carboxyl group, and hydrogen

Question 58

what are some basic amino acids

Answer 58

lysine, arginine, histidine

Question 59

what are some acidic amino acids

Answer 59

aspartic acid, glutamic acid

Question 60

amino acids are grouped based on characteristics of the side chains including properties such as (4)?

Answer 60

nonpolar side chains polar side chains side chains with charged basic groups acidic side chains terminating in carboxyl groups

Question 61

amino acids are joined by what bonds?

Answer 61

peptide bonds

Question 62

define peptide bond

Answer 62

its how amino acids are joined

Question 63

define polypeptide

Answer 63

chains of amino acids, hundreds or thousands of amino acids in length

Question 64

one end of a polypeptide terminates in a ____ (N terminus) and the other in an ____________ (C terminus)

Answer 64

alpha amino group alpha carboxyl group

Question 65

insulin consist of two

Answer 65

polypeptide chains

Question 66

the side chains of three pairs of cysteine residue are joined by ?

Answer 66

disulfide bonds

Question 67

the sequence of amino acids in a protein is determined by

Answer 67

order of nucleotides bases in a gene

Question 68

proteins also have distinct _____________________________ that are critical to their function

Answer 68

3- dimensional (3-d) conformations

Question 69

the shape and function of proteins is determined by their____________

Answer 69

amino acid sequences

Question 70

who demonstrated the importance of proteins 3- structure?

Answer 70

Christian Anfinsen

Question 71

Christian Anfinsen disrupted proteins by treatments such as heating, which breaks ______________

Answer 71

non-covalent bonds (denaturation)

Question 72

protein structure has what four levels

Answer 72

primary secondary= alpha helix and beta sheet tertiary quaternary

Question 73

when talking about the secondary structure of a protein, both the alpha helix and beta sheet are held together by _________ between the ____________ groups of _________

Answer 73

hydrogen bonds CO and NH peptide bonds

Question 74

hemoglobin is composed of

Answer 74

four polypeptide chains

Question 75

what is the basic unit of a teritary structure (protien wise)

Answer 75

domains

Question 76

what is the fundamental properties of an enzyme?

Answer 76

increase rate of chemical reactions WITHOUT THEMSELVES BEING CONSUMED or permanently altered increase reaction rates without altering the CHEMICAL EQUILIBRIUM between reactants and products

Question 77

When a _________ is converted to a __________ the chemical equilibrium between S and P is determined by the laws of thermodynamics

Answer 77

a substrate a product

Question 78

equilibrium is determined by the

Answer 78

final energy states of S and P

Question 79

The substrate must be first converted to a higher energy state called?

Answer 79

transition state

Question 80

the energy required to reach transition state=

Answer 80

activation energy

Question 81

a fundamental rule of proteins is to __________

Answer 81

act as enzymes

Question 82

what are enzymes

Answer 82

they are catalysts that increase the rate of all chemical reactions in cells

Question 83

enxymes must bind to their substrate to form an?

Answer 83

enzyme-substrate complex (ES)

Question 84

define active site

Answer 84

this is where a substrate binds to a specific region of an enzyme

Question 85

specific side chains in the ____________ and form bonds with reaction intermediates

Answer 85

active site may react with the substrate

Question 86

chymotrypsin digest protiens by?

Answer 86

catalyzing the hydrolysis of peptide bonds

Question 87

chymotrypsin is a _______: these enzymes cleave peptide bonds adjacent to specific types of amine acids

Answer 87

a serine protease

Question 88

chymotrypsin

Answer 88

digests bonds adjacent to hydrophobic amino acids

Question 89

trypsin

Answer 89

digest bonds next to basic amino acids

Question 90

what are active sites

Answer 90

these are clefts or grooves on the surface of an enzyme formed by the tertiary structures

Question 91

substrates originally bond by

Answer 91

hydrogen bonds, ionic bonds, and hydrophobic interactions

Question 92

trypsin

Answer 92

digests bonds next to basic amino acids

Question 93

the active sites of serine proteases contain _____, _______, ______

Answer 93

serine, histidine aspartate

Question 94

substrates bind by insertion of the _________ adjacent to the cleavage site into a pocket at the active site

Answer 94

amino acid

Question 95

define lock and key model

Answer 95

the substrate fits precisely into the active site

Question 96

define induce fit (for enzyme related )

Answer 96

conformation of both enzyme and substrate is modified

Question 97

define coenzymes

Answer 97

small organic molecules that work together with enzymes to enhance reaction rates THESE ARE NOT ALTERED BY REACTION

Question 98

what is nicotinamide adenine dinucleotide (NAD)

Answer 98

it is a coenzyme that carries electrons in oxidation-reduction reactions

Question 99

NAD can accept ______ and __ electrons from one substrate, forming NADH

Answer 99

H+ and two electrons

Question 100

NADH can then donate the _________ to a second substrate, re-forming NAD

Answer 100

electrons

Question 101

define prosthetic groups

Answer 101

small molecules bound to protiens that have critical functional roles

Question 102

feedback inhibition is a type of ?

Answer 102

allosteric regulation

Question 103

define allosteric regulation

Answer 103

enzyme activity is controlled by the binding of small molecules regulatory sites on an enzyme

Question 104

many coenzymes are closely realted to vitamins, which?

Answer 104

contribute part or all of the structure of the coenzyme

Question 105

phosphate groups are added to the side chain OH groups of ??????

Answer 105

serine, threonine, or tyrosine residues

Question 106

in feedback inhibition what happens?

Answer 106

the product of a metabolic pathway inhibits an enzyme involved in it synthesis

Question 107

if delta G <0, this reaction will proceed?

Answer 107

in the forward direction

Question 108

if delta G >0, this reaction will proceed?

Answer 108

in the reverse direction; B will be converted to A