lecture 3

Question 1

element

Answer 1

can’t be broken down
-single atom

Question 2

atom

Answer 2

smallest particle of an element that still retains its properties

Question 3

molecule

Answer 3

two or more atoms join together chemically

Question 4

compound

Answer 4

molecule that contains at least two different elements

Question 5

covalent bond

Answer 5

strong bonds formed by the sharing of electrons between adjacent atoms

Question 6

bond strength/dissociation energy

Answer 6

amount of energy required to break a bond
-covalent= more energy needed to break

Question 7

polar covalent bond

Answer 7

unequal sharing of electrons due to a difference in EN

Question 8

non covalent interactions

Answer 8

bond that does not involve the sharing of electrons
-ex. the components of DNA (A and T, G and C)
-very weak, but cumulatively very stong!!!

Question 9

Ionic bonds

Answer 9

results from the loss or gain of electrons

Question 10

hydrogen bonds

Answer 10

very important in biochemistry!!!!

-covalently bonded H atom on a donor group interacts w a pair of non-bonded electrons on an acceptor group

Question 11

Hydrogen acceptors are

Answer 11

electronegative atoms (generally N or O)

Question 12

polar molecules surrounded by water can dissociate into

Answer 12

acid= releases protons
base= accepts a proton

Question 13

macromolecule: nucleic acid

Answer 13

subunit: nucleotide

Question 14

Macromolecule: triacylglycerol and membrane lipid

Answer 14

subunit: fatty acid

Question 15

macromolecule: polysaccharide

Answer 15

subunit: sugar

Question 16

macromolecule: protein

Answer 16

subunit: amino acid

Question 17

the simplest sugars are

Answer 17

monosaccharides

Question 18

monosaccharides can be joined through glycosidic bonds to form

Answer 18

disaccharides (two monomers together), oligosaccharides (2-10 monomers) or polysaccharides (more than 10 monomers)

Question 19

function of sugars (5)

Answer 19

• energy source
  ex. glucose can be stored as glycogen
• can be used for structure
  ex. cellulose forms cell walls
  ex. chitin found in the insect cytoskeletons
• slime, mucus
  ex. Phlegm is sweet due to the oligosaccharide chains (glycans ) covalently attached to amino acid side-chains of the glycoproteins in phlegm
• modification of proteins and lipids
• information storage (ribose and deoxyribose in DNA)

Question 20

Fatty acids (FA) –> triacylglycerols (TAG) and membrane lipids

Answer 20

FAs for TAG which serve as an energy source

FAs form membrane lipids which contribute to membrane structure and function

Question 21

amino acids have the same basic structure with a

Answer 21

variable side chain

Question 22

polypeptides

Answer 22

long chains of amino acids

Question 23

how is the final 3D structure of a protein formed?

Answer 23

amino acids fold by using covalent and noncovalent interactions

Question 24

Nucleoside components

Answer 24

base+ sugar (e.g. adenosine)

Question 25

Nucleotide components

Answer 25

base+ sugar+ phosphate [e.g. adenosine monophosphate (AMP)]

Question 26

RNA

Answer 26

ribonucleic acid

Question 27

DNA

Answer 27

deoxyribonucleic acid

Question 28

Functions of nucleotides

Answer 28

1. short-term energy carriers (ATP) 2. storage and retrieval of biological information (DNA, RNA)

Question 29

Macromolecules are the most

Answer 29

abundant of the organic molecules in a living cell

Question 30

Examples of macromolecules

Answer 30

DNA, RNA, protein, polysaccharides

Question 31

native state of a molecule (concept)

Answer 31

generally, all molecules of a given protein or RNA species adopt the same 3D conformation despite the countless folding possibilities!!!

Question 32

which type of interactions specify the precise shape of the molecule (native state)

Answer 32

noncovalent interactions (electrostatic interactions, hydrogen bonds, van der waals attractions, hydrophobic interactions)

Question 33

strong binding of macromolecules requires

Answer 33

-good specificity between macromolecules (the cumulative effect of many covalent bonds can be very strong but require multiple points of contact)

Question 34

what interactions act as building blocks to form much larger structures?

Answer 34

noncovalent interactions

Question 35

metabolic intermediates

Answer 35

the compounds formed along the pathways leading to the end product but have no real function

Question 36

weak attractions between adjacent water molecules are

Answer 36

hydrogen bonds