chapter five part two

Question 1

what are lipids

Answer 1

hydrophobic molecules that don’t mix with water

Question 2

element composition of lipids

Answer 2

C,H, and some O
- mostly hydrocarbon/nonpolar regions

Question 3

composition of fats

Answer 3

glycerol molecule, 3 fatty acids

Question 4

covalent bonds in nucleic acids

Answer 4

phosphodiester

Question 5

covalent bond in lipids

Answer 5

ester linkages between glycerol and fatty acids

Question 6

fatty acids

Answer 6

have long carbon skeleton (16-18) C at one end is part of carboxyl group
- contains carboxyl and methyl groups

Question 7

traicylglycerol
(triglyceride)

Answer 7

fat molecule w/ 3 fatty acids
- “cyl” = fatty acid

Question 8

saturated fats

Answer 8

have all the hydrogen it can hold

Question 9

unsaturated fats

Answer 9

has one or more double bonds
- creates kink in tail
- liquid at room temperature

Question 10

uses of fats

Answer 10

energy storage, cushions vital organs

Question 11

phospholipid composition

Answer 11

glycerol molecule, 2 fatty acids, 3rd hydroxyl group

Question 12

what are phospholipids a major component of?

Answer 12

cell membranes
- hydrophobic tail
- hydrophilic head

Question 13

steroids

Answer 13

lipids characterized by 4 fused rings in carbon skeleton and a functional group

Question 14

cholesterol

Answer 14

precursor of many steroids

Question 15

what is cholesterol good for?

Answer 15

component of animal cell membranes, synthesizes hormones

Question 16

proteins

Answer 16

biologically functional molecule made up of polypeptides and chains of amino acids

Question 17

how abundant are proteins in a cell?

Answer 17

50% of dry mass

Question 18

functions of proteins
(STERCDHS)

Answer 18

1. storage
2. transport
3. enzymatic
4. receptor
5. contractile
6. defense
7. hormone (communication)
8. structural support

Question 19

storage protein ex.

Answer 19

casein protein of milk stores amino acids

Question 20

transport protein ex.

Answer 20

hemoglobin transports oxygen

Question 21

enzymatic protein ex.

Answer 21

digestive enzymes catalyze hydrolysis in bonds of food

Question 22

receptor protein ex.

Answer 22

neuromuscular junction

Question 23

contractile protein ex.

Answer 23

actin and myosin responsible for contraction of muscles

Question 24

defense protein ex.

Answer 24

protection against disease, antibodies help destroy viruses

Question 25

hormone (communication) protein ex.

Answer 25

insulin causes tissues to take up glucose

Question 26

structural support protein ex.

Answer 26

keratin (hair), silk fibers

Question 27

enzymes

Answer 27

protein that regulates metabolism by acting as catalyst

Question 28

catalysts

Answer 28

chemical agents that selectively speed up chemical reactions w/o being consumed
- lowers energy of activation

Question 29

polypeptides

Answer 29

polymer of amino acids

Question 30

amino acids

Answer 30

building blocks of proteins

Question 31

how many different amino acids total?

Answer 31

20

Question 32

what does an amino acids consist of?

Answer 32

• amino group
• carboxyl group
• hydrogen atom
• variable group (R)
  all attached to C

Question 33

4 types of amino acids

Answer 33

1. nonpolar
2. polar
3. asidic
4. basic

Question 34

nonpolar AA

Answer 34

hydrophobic side chain

Question 35

polar AA

Answer 35

hydrophilic side chain

Question 36

acidic AA

Answer 36

negative side chain

Question 37

basic AA

Answer 37

positive side chain

Question 38

what are amino acids held together by?

Answer 38

peptide bonds
- made via dehydration reaction

Question 39

4 levels of protein structure

Answer 39

primary, secondary, tertiary, quaternary

Question 40

primary protein structure

Answer 40

linear chain of amino acids held together by peptide bonds

Question 41

secondary protein structure

Answer 41

regions stabilized by hydrogen bonds between atoms of polypeptide backbone
- alpha helix
- beta pleated sheets

Question 42

alpha helix

Answer 42

coil held together by H-bonding between every 4th AA

Question 43

beta pleated sheet

Answer 43

2+ segments of polypeptide chain connected by H-bonds
- core of globular proteins

Question 44

tertiary protein structure

Answer 44

3D shape stabilized by interactions between side chains
- hydrophobic interactions
- hydrogen bonds
- disulfide bridges

Question 45

hydrophobic interactions in tertiary structure

Answer 45

AA w/ hydrophobic side chains usually end up in clusters at core or protein out of contact w/ water

Question 46

disulfide bonds in tertiary structure

Answer 46

covalent bonds where 2 cysteine monomer (w/ sulfhydryl groups) are brought close together

Question 47

quaternary protein structure

Answer 47

when protein consists of 2+ polypeptide chains
- collagen
- hemoglobin (globular protein)

Question 48

denaturation

Answer 48

breakdown of protein shape

Question 49

causes of denaturation

Answer 49

pH, salt concentration, high temperature, chemicals that break H-bonds

Question 50

chaperonins

Answer 50

assist new proteins to fold/assemble into native shape