Exam eview

Question 1

Name two features common to bacterial and animal cells

Answer 1

cytoplasm
Plasma membrane
Ribosomes

Question 2

Biological macromolecules are polymers made up of monomeric building blocks. Name the monomers used to synthesize the macromolecules given below. (4 pts) Macromolecule Building blocks
a) Protein
b) DNA
c) Membranes
d) Starch

Answer 2

a. amino acid
b. Nucleotides
c. lipids
d. glucose

Question 3

Name two uncommon amino acids that occur in proteins.

Answer 3

4- hydroxyproline
5- hydrolysine

Question 4

What level of structures includes α-helix and β-sheets (primary, secondary, tertiary or quaternary)?

Answer 4

secondary structure

Question 5

(a)Name the two major orientations of β-sheets. (b) What type of β-sheets has stronger H-bonding?

Answer 5

a.Parralel and anti-parallel
b. Anti parallel

Question 6

Match the characteristics given below with the best matching amino acids at physiological pH 7.4
a. acidic side chain____
B) non-chiral amino acid___
C) positively charged side chain___

Answer 6

a. aspartate
b. glycine
c. lysine and histidine

Question 7

Match the characteristics given below with the best matching amino acids at physiological pH 7.4
D) involved in disulfide cross-links____
E) has an amide group____
F) acts as a biological buffer system____

Answer 7

d. cystine
e.asparagine
f. histidine

Question 8

Match the characteristics given below with the best matching amino acids at physiological pH 7.4
G) polar, non-charged side chain___
H) UV absorbing at 250-300 nm___
I) amino acids that are infrequently found in an α-helix____

Answer 8

g. cystine and serine
h. phenylalanine and tryptophan
i. proline and glycine

Question 9

In an α-helix, the R groups on the amino acid residues are

Answer 9

found on the outside of the helix spiral

Question 10

Which element is NOT among the four most abundant in living organisms?

Answer 10

phousphorus

Question 11

Answer 11

right-handed rule

Question 12

Answer 12

hydroxyl and aldehyde

Question 13

Answer 13

Question 14

A loss of HCO3- accompanies severe diarrhea-. If untreated, will the condition result in acidosis or alkalosis? Use the bicarbonate buffer system and Le Chatelier’s Principle to explain your answer.

Answer 14

Loss of HC)3-, leads to increased concentration of H+ according to the Le Chatelier principle. this leads to acidosis.

Question 15

Explain why ethanol is more soluble in water than in ethane

Answer 15

Ethanol: polar molecule with O-H, can form Hydrogen bond in H2O. Can dissolve in water

Ethane: can not form H bond in water