Exam 1 - Ch. 3

Question 1

macromolecules

Answer 1

polymers that consist of 1-20 repeating monomeric units

Question 2

informational vs. storage/structural macros

Answer 2

informational macros = the order of the monomers is nonrandom and carries critical info (nucleic acids, proteins)

storage/structural macros = the order is random (polysaccharides)

Question 3

proteins

Answer 3

monomers are amino acids

9 different classes

Question 4

9 classes of proteins

Answer 4

1. enzymes - increase rate of chem. rxn
2. structural - provide physical support/shape
3. motility - contraction/movement
4. regulatory - control timing of cellular functions
5. transport - move substance in/out/within cells
6. hormone - cell communication
7. receptor - response to stimuli
8. defensive - protection against disease
9. storage - store amino acids

Question 5

amino acids

Answer 5

20 different amino acids

R groups are how they differ

Question 6

polypeptides

Answer 6

formed by peptide bonds between amino acids (condensation rxn)

Question 7

protein structure

Answer 7

primary: chain of amino acids
secondary: alpha helices or beta-pleated sheets
tertiary: further folding
quaternary: >1 polypeptide chain; not required

Question 8

domains of polypeptides

Answer 8

discrete parts of tertiary structure that has a specific function

Question 9

protein bonds

Answer 9

disulfide bonds - btwn 2 cysteine amino acids

hydrogen bonds - btwn R groups; stabilize secondary structure

ionic bonds - btwn charged R groups (strongest)

Van Der Waals - between polar molecules

Question 10

nucleic acids

Answer 10

monomers are nucleotides
base + sugar + phosphates
DNA or RNA

Question 11

DNA

Answer 11

stored in nucleus, stores genetic info

Question 12

RNA

Answer 12

expresses genetic info

Question 13

transcription

translation

Answer 13

transcription: DNA to RNA
translation: RNA to proteins

Question 14

polysaccharides

Answer 14

monomers are monosaccharides
act as cell signals
sources of stored energy
-ose

Question 15

glucose

Answer 15

most common monosaccharides

Question 16

dissaccharides

Answer 16

held together by glycosidic bonds

Question 17

starch vs. glycogen

Answer 17

storage of glucose
starch in plants
glycogen in animals

Question 18

cellulose vs. chitin

Answer 18

structural support polysaccharides
cellulose in plants cell walls
chitin in animals exoskeleton

Question 19

lipids

Answer 19

not made of monomers
hydrophobic or amphipathic
3 main functions:
1. energy storage
2. membrane structure
3. biological function (ex: cell communication)

Question 20

6 classes of lipids

Answer 20

1. fatty acids
2. triglycerides
3. phospholipids
4. glycolipids
5. steroids
6. terpenes

Question 21

fatty acids

Answer 21

building blocks for some other lipids

saturated: max. hydrogens; solid
unsaturated: less hydrogens; double bonds; liquid

Question 22

triglycerides

Answer 22

energy storage

a glycerol and 3 fatty acids

Question 23

phospholipids

Answer 23

membrane structure

Question 24

glycolipids

Answer 24

cell recognition component in membrane

Question 25

steroids

Answer 25

4 ringed structure
cholesterol is starting point
hormones function in cell communication

Question 26

cholesterol

Answer 26

steroid keeps membranes insoluble

Question 27

terpenes

Answer 27

some essential oils and vitamins

Question 28

vegetable oils vs. animal fat

Answer 28

vegetable oils are unsaturated and do not pack together efficiently, have low melting point

animal fat is saturated and packs efficiently, higher melting point

Question 29

cholesterol types

Answer 29

HDL is good, takes cholesterol back to liver for removal

LDL is bad, can build up and cause heart disease

Question 30

Trans fats

Answer 30

adding hydrogen to unsaturated fats through hydrogenation

partially hydrogenated oils have high trans fats

increase shelf-life but raise LDL and lower HDL

Question 31

trans fats are formed when

Answer 31

liquid fat is chemically changed to solid fat