exam 1 biological molecules

Question 1

what are cells made from?

Answer 1

a set of carbon-based molecules that are fundamentally the same for all living species

Question 2

are lipids polymers

Answer 2

no

Question 3

what are carbohydrates made of

Answer 3

sugar monomers

Question 4

what do carbohydrates serve as

Answer 4

energy storage and structural support for cells

Question 5

what are lipids composed of

Answer 5

fatty acids, usually linked to glycerol

Question 6

what do lipids serve as

Answer 6

energy storage/source and can assemble into hydrophobic membranes

Question 7

what are proteins made of

Answer 7

amino acids

Question 8

what do proteins do (basic)

Answer 8

perform most cellular functions

Question 9

what are nucleic acids built from

Answer 9

nucleotide monomers

Question 10

what do nucleic acids do

Answer 10

they are the units of info storage and short-term energy storage

Question 11

how do cells reduce entropy

Answer 11

cells build order, but have to expand energy to do so - cells want to go to disorder

Question 12

what is the larger unit of the building block, sugar

Answer 12

polysaccharides

Question 13

what is the larger unit of the building block, fatty acids

Answer 13

fats, lipids, membranes

Question 14

what is the larger unit of the building block, amino acids

Answer 14

proteins

Question 15

what is the larger unit of the building block, nucleotides

Answer 15

nucleic acids

Question 16

what is a condensation reaction

Answer 16

combine two small molecules to make a larger molecules - condensing two molecules into one

Question 17

what is a dehydration reaction

Answer 17

water molecule is removed from two molecules - dehydrates molecule to make water

Question 18

what is hydrolysis

Answer 18

add water to break a bond

Question 19

what is a glycosidic bond between

Answer 19

two sugars

Question 20

what is a peptide bond between

Answer 20

two amino acids

Question 21

what is a phosphodiester bond between

Answer 21

two nucleic acids

Question 22

why are carbohydrates added to proteins and lipids

Answer 22

they’re extremely water soluble, so they provide a surface to bind other dissolved molecules (act as binding surfaces)

Question 23

what are the chemical features of carbohydrates

Answer 23

can be a linear chain form or a ring form; have several OH groups

Question 24

what is the distinction between polymer and monomer form

Answer 24

polymers are only in ring form, monomers are ring or linear chain

Question 25

what is the chemical nature of carbohydrates

Answer 25

highly polar

Question 26

how do you number carbons of a carbohydrate

Answer 26

clockwise starting with oxygen

Question 27

what are the positions of OH groups attached to each carbon in a ring called

Answer 27

UP (above the plane of the ring) = beta | DOWN (below the plane of the ring) = alpha

Question 28

Starch and cellulose are both polymers made up of glucose subunits. why are we able to digest starch but not cellulose

Answer 28

we have enzymes that digest the alpha linkages of starch but not the beta linkages of cellulose

Question 29

what are the chemical features of lipids

Answer 29

hydrocarbon chains with polar COOH at one end

Question 30

what is the chemical nature of lipids

Answer 30

amphipathic

Question 31

how are lipids amphipathic

Answer 31

hydrophobic hydrocarbon tails and hydrophilic carboxylic acid head

Question 32

what is a triglyceride

Answer 32

energy storage in animals

Question 33

what is a phospholipid

Answer 33

makes up membranes in cells - tails face each other in center, heads face water

Question 34

what are gangliosides

Answer 34

similar to phospholipids; have a carbohydrate instead of a phosphate/polar head group

Question 35

what is the importance of the GM2 ganglioside

Answer 35

involved in cell-cell communication and neuronal plasticity

Question 36

what are amino acids

Answer 36

building blocks of proteins; can be metabolized for energy

Question 37

what are the chemical features of amino acids

Answer 37

uniform chemical structure with directionality and side group (R) variability

Question 38

what charge is the n-terminus (amino terminus)

Answer 38

positive

Question 39

what charge is the c-terminus (Carboxyl terminus)

Answer 39

negative

Question 40

what is the net charge of an amino acid

Answer 40

zero, unless R group has a charge

Question 41

are amino acids hydrophobic or hydophilic

Answer 41

intrinsically hydrophilic, but can be amphipathic if the side chain is hydrophobic

Question 42

which amino acids are nonpolar (hydrophobic)

Answer 42

``` 9 - glycine alanine valine leucine isoleucine methionine phenylalanine tryptophan proline ```

Question 43

which amino acids are polar (uncharged)

Answer 43

``` 6 - serine threonine cysteine tyrosine asparagine glutaminne ```

Question 44

which amino acids are acids (negatively charged)

Answer 44

2 - aspartate glutamate

Question 45

which amino acids are basic (positively charged)

Answer 45

3 - lysine arginine histidine

Question 46

what is pK

Answer 46

the pH at which 50% of a molecule is charged and 50% is uncharged

Question 47

when are acidic amino acids charged

Answer 47

at pH 7 (below certain pH they are uncharged, above they are charged - opposite for basic)

Question 48

what happens to acidic amino acids in water

Answer 48

they lose a proton

Question 49

what happens to basic amino acids in water

Answer 49

they gain a proton

Question 50

what are nucleotides

Answer 50

building block of nucleic acids; short term energy carriers

Question 51

what are nucleotides made up of

Answer 51

a pentose sugar, a nitrogenous base, and a phosphate group

Question 52

what are the charges of the parts of nucleotides

Answer 52

``` pentose sugar (hydrophilic) nitrogenous base (mainly hydrophobic) phosphate group (negatively charged) AMPHIPATHIC ```

Question 53

what is the composition of the outer face of nucleotides

Answer 53

hydrophilic

Question 54

what is the composition of the inner face of nucleotides

Answer 54

hydrophobic

Question 55

what are the chemical features of nucleotides

Answer 55

uniform chemical structure with side group variability (from nitrogenous bases)

Question 56

what is the chemical nature of nucleotides

Answer 56

polar, charged

Question 57

what is ATP

Answer 57

the major short term energy carrier in the cell

Question 58

what is the second law of thermodynamics

Answer 58

all processes in the universe are driven in the direction that increases disorder (entropy)

Question 59

what does the universe tend towards

Answer 59

disorder

Question 60

what is the first law of thermodynamics

Answer 60

the amount of energy in a system is constant - energy cannot be created or destroyed, but can be converted

Question 61

when is energy useable

Answer 61

if it's confineable (stored)

Question 62

what are characteristics of reactions that decrease the availability of useable energy

Answer 62

they are energetically favorable and will occur spontaneously

Question 63

what are characteristics of reactions that increase the availability of useable energy

Answer 63

they are NOT energetically favorable and will not occur spontaneously

Question 64

what is a spontaneous reaction

Answer 64

a reaction that will occur without a net addition of energy

Question 65

do cells violate the second law of thermo

Answer 65

NO - cells are not isolated system and thermo laws apply only to isolated systems

Question 66

why are cells not isolated systems

Answer 66

they can exchange energy with their environent

Question 67

what generates order within a cell

Answer 67

energy input

Question 68

how do cells build order

Answer 68

by putting energy into the system

Question 69

how do cells build disorder

Answer 69

the cell converts part of the energy into heat, which is released into the cell's environment, thereby disordering it and thus also increasing entropy overall