Ch 3: Proteins, Carbohydrates, and Lipids

Question 1

macromolecules

Answer 1

proteins, lipids, carbohydrates, and nucleic acids

Question 2

proteins

Answer 2

made up of amino acids

aka protein, peptide, polypeptide

has many functions

Question 3

amino acids

Answer 3

make up proteins

20 different types

Question 4

polypeptide chain

Answer 4

single, unbranched, chain of amino acids

Question 5

peptide bond

Answer 5

amino acids bond together covalently in a condensation reaction

Question 6

condensation reaction

Answer 6

loss of H2O molecule

Question 7

hydrophobic amino acids

Answer 7

hydrophobic if R groups don’t contain O or N

glycine (G): smallest amino acid

alanine(A): simplest with aliphatic R-group

Phenylalanine (F): simplest with aromatic R group

Question 8

Hydrophilic amino acids

Answer 8

R group contains O or N

Lysine (K): pos charged

aspartate (D): neg charged

serine (S): -OH, hydroxyl group

Question 9

exceptions to the rule

Answer 9

tyrosine and tryptophan

Question 10

amino acids are often modified after translation

Answer 10

most common modification is phosphorylation,

occurs on the -OH group of serine, threonine, and tyrosine

Question 11

isomers

Answer 11

molecules with the same chemical formula, but atoms are arranged differently

Question 12

structural isomers

Answer 12

differ in how their atoms are joined together

Question 13

primary structure

Answer 13

1˚

amino acid sequence

Question 14

secondary structure

Answer 14

2˚

wavy structure
shape adopted by the amino acid backbone

alpha helix or B pleated sheet

Question 15

tertiary structure

Answer 15

3˚

folded 3-D structure

Question 16

Quaternary structure

Answer 16

4˚

how multiple proteins interact with each other

Question 17

alpha helix

Answer 17

cork screw shaped

right handed

Has all (-C=O) pointing in the same direction (up)

Has all (-N-H)_ pointing in the opposite direction (down)

has all amino acids in parallel (N–>C)

has R groups that stick out

Question 18

B strand

Answer 18

• Looks like a wavy noodle
• Has no handedness
• Has (-N-H) and (-C=O) in an amino acid unit pointing the same direction (both up or both down)
• Amino acid units alternate pointing up and down
• Anti parallel (N→C, C←N)
• R groups interact

Question 19

Disulfide bonds

Answer 19

help hold together 3˚ and 4˚ structure

Question 20

lipids

Answer 20

nonpolar and are almost completely hydrophobic

store energy

Question 21

saturated fatty acids

Answer 21

no double bonds btw carbons; saturated with H atoms

Question 22

unsaturated fatty acids

Answer 22

some double bonds in carbon chain

Question 23

fatty acid structure

Answer 23

one end: carboxyl group (CO2-); hydrophilic

other end: (-CH2) hydrophobic

amphipathic

Question 24

triglycerides

Answer 24

composed of a glycerol, 3 fatty acid chains, and an ester bond

fats and oils

fats are almost completely hydrophobic

Question 25

animal triglycerides

Answer 25

contain saturated fatty acids: solid at room temp (fats)

Question 26

plant triglycerides

Answer 26

contain unsaturated fatty acids: liquid at room temp (oil)

Question 27

phospholipids

Answer 27

like triglycerides, except one of the glycerol hydroxyl groups is bonded to a phosphate, which is bonded to another organic molecule

have a hydrophilic, charged head and a hydrophobic tail

in water they form lipid bilayers

Question 28

Carbohydrates

Answer 28

have the general formula: Cn(H2O)n

aka carbohydrate, saccharide, and sugar

end is ose

Question 29

glucose

Answer 29

most common sugar and has 6 carbons

has two ring forms: alpha anomer and beta anomer

Question 30

alpha anomer

Answer 30

has its hydroxyl group pointing down and it bumbs the hydroxyl group at C2

Question 31

beta-anomer

Answer 31

has its hydroxyl group pointing up and there’s a hydrogen at C2 which is smaller

no bumping occurs

Question 32

glyceraldehyde

Answer 32

3 carbons

Question 33

ribose

Answer 33

5 carbons

Question 34

6 carbons

Answer 34

galactose, fructose

Question 35

disaccharides

Answer 35

galactose+glucose=lactose

glucose + fructose=sucrose

Question 36

polysaccharides

Answer 36

cellulose
starch
glycogen