Exam 1

Question 1

Biochemistry

Answer 1

The study of the molecules that function in very specialized ways to sustain life

Question 2

Where is Carbon found in a cell

Answer 2

Glucose, Protein, DNA, Fat,

Question 3

Four most abundant elements in cells

Answer 3

Carbon (60%), Hydrogen (11%), Nitrogen (9%), Oxygen (6%)

Question 4

Biomolecules

Answer 4

Organic molecules, including nucleic acids, carbohydrates, proteins and lipid

Question 5

Order of organization in cells

Answer 5

the cell and its organelles, supramolecular complexes, macromolecules, monomeric units

Question 6

Carbohydrates composed of

Answer 6

Polysaccharides contain disaccharides contain monosaccharides

Question 7

Lipids composed of

Answer 7

Triglycerides composed of fatty acids and glycerol

Question 8

Proteins composed of

Answer 8

Peptides composed of amino acids

Question 9

Nucleic Acids include

Answer 9

RNA and DNA composed of nucleotides

Question 10

High-Energy Compounds include

Answer 10

ATP composed of nucleotide and phosphate groups

Question 11

Organic compounds

Answer 11

Molecules with covalently bonded carbon backbones (linear, branched or cyclic)

Question 12

Carbon has

Answer 12

-4 unpaired electrons (up to 4 different atomic partners)
-can form single bonds with hydrogen
-can form single and double bonds with oxygen and nitrogen

Question 13

What determines a biomolecules chemical properties?

Answer 13

Functional Group

Question 14

Isomers

Answer 14

Molecules that share the same chemical formula

Question 15

Stereoisomers

Answer 15

Two isomers with the same order of bonds but different spacial arrangements

Question 16

How can stereoisomers differ

Answer 16

Configuration or conformation

Question 17

Configuration

Answer 17

Different spatial arragements can only be achieved by breaking and making of bonds (disFIGURE requires breaking)

Question 18

Conformation

Answer 18

Free rotation around a single bond- same molecule can assume many different spacial arrangements

Question 19

Cis-Trans Stereoisomers (geometric stereoisomers)

Answer 19

Arise in presence of C=C (carbon-carbon double bonds)
-same structural formula and order of bonds
-different spatial arrangement of atoms/functional groups
-similar groups on same side of double bond axis - cis
-similar groups on opposite sides of double bond axis - trans

Question 20

What is the basis of our vision

Answer 20

Rapid change in cis-trans configuration

Question 21

Configurational Stereoisomers

Answer 21

Enantiomers & Diastereomers

Question 22

When do configurational stereoisomers arise

Answer 22

In presence of tetrasubstituted, chiral carbons

Question 23

Enantiomers

Answer 23

Chiral molecule, same structural formula, same order of bonds, different spatial arrangement, enantiomers are mirror images of each other

Question 24

Diastereomers

Answer 24

more than 1 chiral center, not mirror images

Question 25

Conformational Isomers

Answer 25

Related to one other by free rotation around a single bond

Question 26

What does the combination of configuration and conformation dictate

Answer 26

Biochemical interactions

Question 27

What do biochemical interactions give rise to

Answer 27

Structure of biomolecules

Question 28

What does the structure of biomolecules give rise to

Answer 28

Biological activities

Question 29

Why is conformation and configuration important

Answer 29

Sterochemical 'fit' of biomolecules with one another underlies most biochemical interactions and biochemical reactions

Question 30

Group transfer reactions

Answer 30

Transfer of an eectrophilic group A from one nucleophile X to the other Y

Question 31

Nucleophile

Answer 31

Atom or functional group with a pari of electrons that can be shared

Question 32

Oxidation and Reduction Reactions

Answer 32

Involves the loss and gain of electrons

Question 33

Oxidation is

Answer 33

Loss of electrons

Question 34

Reduction is

Answer 34

Gain of electrons

Question 35

Thermodynamics

Answer 35

the study of heat and energy exchanges between a 'system' and its surroundings

Question 36

For a reaction to occur spontaneously ∆G must be

Answer 36

∆G >0

Question 37

Entropy

Answer 37

the measure of disorder, more disorder, the increase in entropy

Question 38

Gibbs Free Energy

Answer 38

∆G=∆H-T∆S

Question 39

Kinetics

Answer 39

The study of reaction rates and depends on the activation energy barrier and is independent of ∆G

Question 40

Properties of water

Answer 40

-bent molecule; tetrahedral geometry -hydrogen partially positively charged -oxygen partially negatively charged

Question 41

Hydrogen Bond

Answer 41

Electrostatic interaction between the oxygen of one water molecule and the hydrogen of another water molecule

Question 42

How many hydrogen bonds can form with 1 water molecule

Answer 42

4 because of the tetrahedral structure

Question 43

What atoms can serve as H-bond donors and acceptors

Answer 43

Nitrogen, Oxygen, Sulfur, Chlorine, and Flourine

Question 44

When are hydrogen bonds strongest?

Answer 44

When electrostatic interactions are maximized

Question 45

Solubility

Answer 45

Ability of a solvent to interact more strongly with solute particles than the solute particles interact with each other

Question 46

Ionic interaction

Answer 46

Forces between charged molecules

Question 47

How does water dissolve compounds

Answer 47

By replacining ionic bonds with solute-water hydrogen bonds

Question 48

Van der Waals

Answer 48

Attractive forces between small electric dipoles induced on uncharged atoms

Question 49

Amphipathic Compounds

Answer 49

Contain both polar-uncharged/ionic (hydrophilic) and non-polar (hydrophobic) regions (e.g. in biology: lipids)

Question 50

Micelles

Answer 50

All hydrophobic groups are sequestered from water; ordered shell of H2O molecules is minimized, and entropy is further increased

Question 51

Acids

Answer 51

Proton donors e.g. HCl, H2SO4

Question 52

Bases

Answer 52

Proton acceptors e.g. NaOH, KOH, NH3

Question 53

Buffer

Answer 53

An aqueous solution that tends to resist changes in pH when small amounts of acid or base are added

Question 54

Primary Protein Structure

Answer 54

sequence, proteins are built from a linear "string of amino acids"

Question 55

Secondary Protein Structure

Answer 55

Alpha helix, beta sheet

Question 56

Tertiary Protein Structure

Answer 56

Motifs, folds and domains

Question 57

Quaternary

Answer 57

Assembly of multiple polypeptides

Question 58

Peptides

Answer 58

Small amino acid chains including hormones and pheromones, neuropeptides, antibiotics, and toxins

Question 59

Proteins

Answer 59

large chains of amino acids that are needed for catalysis, nutrient transport, structure and motility

Question 60

Nonpolar, aliphatic group

Answer 60

Cannot make hydrogen bonds or have ionic interactions

Question 61

Aromatic group

Answer 61

Can absorb UV light at 270-280nm

Question 62

Positively charged group

Answer 62

higher pKa

Question 63

What amino acids are ionizable

Answer 63

Aspartate, glutamate, lysine, arginine, histidine