1-The protein that transport free fatty acid in the blood :

a)Actin

b)myoglobin

c)Albumin

d)hemoglobin

2-The function of insulin hormone is to :

a) protect against infections

b) coordinate activities of different cells.

c) transport substances into and out of the blood .

d) prevent loss of blood.

3-All of the following amino acids are nonpolar except :

a)threonine

b)glycine

c)proline

d)leucine

4-All off the following amino acids are hydrophilic except :

a)serine

b)lysine

c)histidine

d)valine

5-All of the following about glycine is correct except :

a)It is the simplest amino acid

b)it is a non polar amino acid

c)no real contribution to hydrophobic interactions

d)It has carbon bound to four different groups.

6-The only non-polar amino acid that contain sulfur group is :

a) proline

b)threonine

c)cysteine

d)Methionine

7-The amino acid that reduce the structural flexibility of polypeptides and has cycled structure is :

a)valine

b)proline

c)alanine

d)lysine

8-Tyrosin is :

a)Aromatic , non polar

b)Aromatic , polar

c)Aliphatic , polar

d)Aliphatic , non polar

9-Thrionine is polar amino acid because it contains :

a)Hydroxyl group

b)sulfhydryl group

c)amide group

d)carboxyl group

10-All of the following about cystine is correct except :

a) It is non-polar a.a

b)formed by oxidation of 2 molecules

c)It is polar a.a

d)It Has S-S bond

11-Which of the following is essential amino acid :

a)Arginine

b)cysteine

c)tyrosine

d)proline

12-Methionine is :

a)Glycogenic , essential

b)Ketogenic , essential

c)mixed a.a , non essential

d)ketogenic , non essential

13-Amino acid at isoelectric pl called :

a) isoelectric ion

b)zwitter ion

c)dipolar ion

d)tripolar ion

14-Amino acids in proteins connected to each other by :

a)hydrogen bonds

b)peptide bonds

c)ionic bonds

d)hydrophobic interactions

15- The local and spatial arrangement of the polypeptide’s backbone is :

a) primary structure

b)secondary structure

c)tertiary structure

d)quaternary structure

16-The side chains project above and below the plane in :

a)alpha helix

b)tertiary structure

c)Beta-plated sheet

d)primary structure

17-Number of domains in tertiary structure depends on :

a) no. of polypeptide chains

b)The length of polypeptide chain

c)The type of bonds between amino acids

d)loops and turns

18-Insulin is an important hormone and it contains :

a)two disulfide bonds

b)one disulfide bond

c)two ionic bonds

d)one ionic bond

19-Which of the following is Olgiomeric protein:

a) protein with two subunits

b) protein with four subunits

c) protein with 8 subunits

d) protein with three subunits

20-The prosthetic group of glycoprotein is :

a)lipids

b)carbohydrates

c)nucleic acid

d)phosphate group

21-Hemoglobin is formed of :

a) 4 heme groups , 4 polypeptide chains

b) 1 heme group , 1 polypeptide chain

c) 4 heme groups , 1 polypeptide chain

d) 1 heme group , 4 polypeptide chains

22-The protein part’ globin’ formed of single polypeptide chain with :

a) 100 amino acid

b)153 amino acid

c) 80 amino acid

d) 400 amino acid

23-The fifth coordination of the iron atom is bonded to a ring nitrogen of the :

a) His F8

b)His E8

c)His F7

d)His E7

24- In unoxygenated Mb , the heme iron resides about ……………… nm outside the plane :

a) 0.3

b)0.1

c)0.03

d)0.01

25- Oxygen dissociation curve of myglobin is ………….. , and Oxygen dissociation curve of hemoglobin is …………… :

a) sigmoidal , hyperbolic

b)hyperbolic , sigmoidal

c) sigmoidal , sigmoidal

d)hyperbolic , hyperbolic

26- Th tense form of hemoglobin present in ……………… with …………… oxygen affinity , while the relaxed form present in ……………… with …………………… oxygen affinity .

a)tissues , high , lungs , low

b)lungs , high , tissues , low

c)tissues , low , lungs , high

d)lungs , low , tissues , high

compare between the following :

Alpha helix Beta plated sheetHydrogen bonds

Structure

Fibrous proteins Globular protiensFunction

Shape

Alpha helix can be disrupted by many factors . write three of them ?

……………………………………………………………………………………………………..

………………………………………………………………………………………………………

………………………………………………………………………………………………………

Write all levels of protein structure and describe one of them ?

…………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

Write three characteristics of peptide bonds ?

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

Write three forces that can stabilize tertiary protein structure ?

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….

How can denaturing agents effect in proteins ? write four of them .

………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………………….