2 lecture 2

Question 1

what are The properties of water (H2O) aka hydrogen bonds

Answer 1

as a liquid, the H-bonds between H2O molecules break continuously but randomly
fluidity over a large temp range, mixes molecules for chemical reactions, moderates temperature, surface tension (cohesion)
individual water molecules are weak, many together are strong

Question 2

ionic bonds more likely to break than covalent bonds true or false

Answer 2

true

Question 3

polar water molecules dissolve the salt into what

Answer 3

Na+ and Cl- ions

Question 4

what does hydrophilic mean

Answer 4

tend to “stick together” tend to like to e in an aqueous solution

Question 5

what does hydrophobic mean

Answer 5

cannot dissolve in water does not like water

Question 6

do Polar molecules (like H2O) tend to be hydrophilic or hydrophobic

Answer 6

hydrophilic

Question 7

what does it mean by; Polar molecules (like H2O) tend to be hydrophilic.

Answer 7

Substances that are charged/polar o[en dissolve in water due to hydrogen bonds

Question 8

Nonpolar molecules (like CO2) are called hydrophobic or hyrophillic

Answer 8

hydrophobic

Question 9

what does it mean by; Nonpolar molecules (like CO2) are called hydrophobic

Answer 9

because they tend to aggregate with other nonpolar molecules in water

Question 10

what are the different types of interaction

Answer 10

1) hydrophilic interaction (attraction; polar to polar)
2) hydrophobic interaction (attraction; non-polar to non-polar)
3) repulsion

Question 11

weak forces (collectively called Van der Waals interacTons) are very important in large what

Answer 11

molecules (proteins, lipids etc.)

Question 12

what is an acid

Answer 12

acids release H+ ions

If the reaction (dissociation) is complete, it is a strong acid, such as HCl

Question 13

Bases accept____ (release _____).

Answer 13

H+, OH–

Question 14

what is pH:

Answer 14

H+ in moles* per liter

Question 15

what is the pH range

Answer 15

pH range of 1 - 14

Question 16

molecules interact to form what

Answer 16

larger macromolecules and cells

Question 17

carbon is what kind of atom

Answer 17

a “Tinkertoy” atom

Question 18

why is carbon known as a tinkertoy atom

Answer 18

incredibly flexible - used to build many types of complex macro molecules

Question 19

many molecules are______ with repeating______

Answer 19

biological polymers, subunits

Question 20

carbohydrates are a source of what

Answer 20

energy

example; glucose

Question 21

polysaccharides form what

Answer 21

rigid biological structures such as hard shells of bugs

Question 22

what is a Disaccharide

Answer 22

and of class of sugars whose molecules contain 2 monosaccharide residue

Question 23

what is an example of a Disaccharide

Answer 23

sucrose– glucose + fructose

Question 24

what are amino acids and polypeptides

Answer 24

the basic unit, or monomer

not typically repeating units

Question 25

how do you form a polypeptide

Answer 25

add monomers ate the amino end to form a polypeptide

Question 26

what makes the amino acids different than each other,

Answer 26

R

Question 27

are amino acids an acid or a base

Answer 27

amino acids are both an acid and a base

Question 28

polypeptide of three amino acids linked by what

Answer 28

polypeptide of three amino acids linked by peptide bonds

Question 29

proteins are composed of many what

Answer 29

amino acids

Question 30

for the structure of amino acids, what is the same

Answer 30

the top parts are identical

Question 31

are amino acids polar or non polar

Answer 31

there are both

Question 32

what are the key concepts to identifying non-polar amino acids (proteins)

Answer 32

amino acids have a hydrocarbon side-chain (e.g. alanine; -CH3) exception: glycine; -H sometimes uncharged

Question 33

what are the key concepts to identifyingpolar amino acids (proteins)

Answer 33

``` have side chains with partial charge or net )+) charge or net (-) charge ``` (basically has a little + or = at the one of the bottom chains or is OH)

Question 34

a protein is a folded_____

Answer 34

polypeptide

Question 35

what is an r-group

Answer 35

side chain

Question 36

difference between a protein and a polypeptide?

Answer 36

protein— folded version of polypeptide, active | polypeptide— chain of amino acid, don’t have to be active

Question 37

the shape of the folded protein is encoded in what

Answer 37

the polypeptide sequence

Question 38

what are Lipids

Answer 38

fats steroids phospholipids

Question 39

what is a fat

Answer 39

a fat is a simple 3-carbon lipid has 3 fatty acid tails and is hydrophobic

Question 40

what are phospholipids

Answer 40

a lipid containing phosphate group in its molecule

Question 41

what are the characteristics of a phospholipid

Answer 41

2 fatty acid tails (hydrophobic) | charges phosphate head (hydrophilic)

Question 42

the dual properties of phospholipids allow them to form what

Answer 42

barriers

Question 43

how do that barriers formed by phospholipids work

Answer 43

tails stay in the middle and the heads are on the outside large charged molecules can’t get through because they will encounter the tails and just wont be able together through in an aqueous environment dispersed among the heads and tails are proteins (as seen in this picture) what some of these proteins do is act as channels that move things through

Question 44

the membranes of phospholipids form what kind of barriers

Answer 44

fluid, semi-permeable barriers

Question 45

what parts of the barrier are hydrophobic and what parts or hydrophillic

Answer 45

tails-- hydrophobic | heads-- hydrophillic

Question 46

what do steroids do

Answer 46

help to keep membrane fluid and move

Question 47

a steroid is composed of what

Answer 47

four carbon rings (6 or 5 carbons)

Question 48

what is DNA

Answer 48

Nucleic acids (DNA)

Question 49

what are the 4 bases of DNA

Answer 49

A (adenine)— G (guanine)— T (thymine) — C (cytosines)—

Question 50

which bases of DNA are pyrimidines

Answer 50

T (thymine) — pyrimidines | C (cytosines)— pyrimidines

Question 51

which bases of DNA are purines

Answer 51

A (adenine)— purines | G (guanine)— purines

Question 52

what does it mean by DNA is a doble helix

Answer 52

two strands linked together

Question 53

individually, is DNA strong or weak

Answer 53

individually, the DNA is very weak, but this means for an easy replication of DNA, but together it is VERY strong

Question 54

what is The Pairing rule of DNA

Answer 54

AT CG purines and pyrimidines

Question 55

what is The structure of a DNA molecule

Answer 55

anti-parallel strands of repeating subunits

Question 56

what is the backbone” of DNA

Answer 56

phosphate + sugar (covalent bonds)

Question 57

are the AG and TC pairings covalent or hydrogen

Answer 57

hydrogen

Question 58

what are the 2 types of cells

Answer 58

Eukaryotic vs prokaryotic cells

Question 59

what is the cell theory

Answer 59

Cells are the smallest independent units of life All living things are made of cells Cells are formed by the reproduction of existing cells

Question 60

what all cells have in common

Answer 60

``` a plasma membrane cytoplasm DNA RNA proteins ribosomes (rRNAs and proteins) ```

Question 61

what are the traits of prokaryotic cells

Answer 61

``` are- generally small <1 μm (1/10 the size of a small eukaryotic cell) no nucleus few internal membranes never multicellular cell wall made of peptidoglycan some are- aerobic (use oxygen), or anaerobic (don’t use oxygen) ```

Question 62

traits of eukaryotic cells

Answer 62

``` are- larger than bacteria ~ 5-25 μm has a nucleus many internal membranes membrane-based organelles unicellular or multicellular cell walls- depends on kingdom all are aerobic (use oxygen) ```

Question 63

difference between plant and animal cells

Answer 63

plant cells have a central vacuole, cell walls and chloroplast