protein metabolism

Question 1

protein digestion mainly occur in

Answer 1

the stomach and duodenum

Question 2

what helps in the digestion of proteins in the stomach

Answer 2

pepsin & renin in children, gastric juice

Question 3

what helps in the digestion of proteins in the duodenum

Answer 3

pancreatic and peptidase enzymes

Question 4

needed for amino acid absorption

Answer 4

Vitamin B6 (PLP in its active form)

Question 5

first step of amino acid catabolism

Answer 5

deamination (removal of amino group)

Question 6

alpha-keto acid enters in the synthesis of

Answer 6

glucose (glucogenic), ketone bodies (ketogenic)

Question 7

the assembly of amino acids in body

Answer 7

amino acid pool

Question 8

sources of amino acids in blood

Answer 8

dietary proteins & body proteins

Question 9

the process of breaking down of proteins

Answer 9

proteolysis

Question 10

end product of ammonia after deamination

Answer 10

urea and NH4

Question 11

the site of synthesis of urea

Answer 11

liver

Question 12

the causes of increasing ammonia in blood

Answer 12

liver failure

Question 13

site of occurrence of first two steps of urea cycle

Answer 13

mitochondria of liver

Question 14

functions of proteins

Answer 14

1- components of cell membranes
2- form tissue proteins(muscles, bones& cartilage, haemoglobin, myoglobin, connective tissue)
3- plasma proteins(albumin-globulin-fibronigen-others)
4- plasma proteins are important buffers to help regulate acid/base balance in blood ph and keep blood viscosity)
5- some enzymes and hormones are proteins in nature

Question 15

oxygen transporter in RBCsof blood

Answer 15

haemoglobin

Question 16

oxygen transporter for the muscles

Answer 16

myoglobin

Question 17

plasma protein that maintains osmotic pressure

Answer 17

albumin

Question 18

plasma protein that forms antibodies

Answer 18

globulin

Question 19

importance of plasma proteins

Answer 19

plasma proteins are important buffers to help regulate acid/base balance in blood ph and keep blood viscosity

Question 20

factors affecting solubility of proteins

Answer 20

1. electrostatic charges,2. hydration shell

Question 21

physical methods of precipitation of proteins

Answer 21

1. salting out
2. precipitation at IEP
3. precipitation with alcohols at IEP

Question 22

causes protein dehydration

Answer 22

alcohols

Question 23

chemical methods of precipitation of proteins

Answer 23

1. alkaloidal agents ex: picric acid, tannic acid, perchloric acid, trichloroacetic acid
2. heavy metals

Question 24

combine with proteins to form insoluble protein salts

Answer 24

alkaloidal agents

Question 25

form bonds with carboxylic groups of amino acid to help in precipitation

Answer 25

heavy metals (silver nitrate - mercuric chloride)

Question 26

a series of processes intended to isolate one/few proteins from a complex mixture

Answer 26

purification of proteins

Question 27

vital for specification of function/structure/interactions of proteins

Answer 27

purification of proteins

Question 28

a device used for renal failure

Answer 28

hemodialysis device

Question 29

main principle of a hemodialysis device

Answer 29

the movement of solutes from high concentration to low concentration by osmotic pressure through a semi-permeable membrane

Question 30

two types of solutes

Answer 30

1- crystalloids (small)
2- colloids (large)

Question 31

a laboratory technique used to separate DNA, RNA or protein molecules based on their size and electrical charge

Answer 31

electrophoresis

Question 32

type of gel in electrophoresis device

Answer 32

agarose gel

Question 33

rate of movement of particles in electrophoresis device depend on

Answer 33

1- number of charges
2- shape of particles
3- molecular size
4- IEP of particles