Chapter 4 - Proteins

Question 1

a macronutrient that is essential to building muscle mass. It is
commonly found in animal products, though is also present in
other sources, such as nuts and legumes.

Answer 1

Protein

Question 2

Protein

Answer 2

is composed of amino acids, which are
organic compounds made of carbon, hydrogen, nitrogen, oxygen
or sulfur

Question 3

protein is composed of amino acids, which are
organic compounds made of

Answer 3

carbon, hydrogen, nitrogen, oxygen
or sulfur

Question 4

most important and most abundant of all biological compounds

Answer 4

proteins

Question 5

a naturally occurring unbranched polymer in which the monomer
units are _______

Answer 5

amino acids

Question 6

About ______ of cell’s overall mass

Answer 6

15%

Question 7

Contains elements of

Answer 7

carbon, hydrogen, nitrogen and sulfur

Question 8

The presence of _____ and _____ makes protein differs from
carbohydrates and lipids.

Answer 8

nitrogen and sulfur

Question 9

Contains an average of 15.4% by mass of _____

Answer 9

nitrogen

Question 10

____ and _____ are essential constituent of certain specialized protein

Answer 10

Phosphorus and iron

Question 11

main protein in milk contains phosphorus
(very important in the diet of infant and children)

Answer 11

Casein

Question 12

the oxygen – transporting protein of
blood

Answer 12

Hemoglobin

Question 13

Protein color and taste

Answer 13

are colourless and usually tasteless. These are homogeneous and
crystalline.

Question 14

Protein Shape and Size

Answer 14

range in shape from simple crystalloid spherical structures to
long fibrillar structures.

Question 15

Two distinct patterns of shape
have been recognized

Answer 15

Globular proteins and Fibrillar proteins

Question 16

These are spherical in shape and occur mainly in
plants, esp., in seeds and in leaf cells. These are bundles formed by folding
and crumpling of protein chains. e.g., pepsin, edestin, insulin, ribonuclease
etc.

Answer 16

Globular proteins

Question 17

These are thread-like or ellipsoidal in shape and occur
generally in animal muscles. Most of the studies regarding protein structure
have been conducted using these proteins. e.g., fibrinogen, myosin etc.

Answer 17

Fibrillar proteins

Question 18

Protein molecular weight

Answer 18

generally have large molecular weight in between 5000 to 1 million most cases 35,000 to 70,000

Question 19

Protein Colloidal Nature

Answer 19

Because of their giant size, the proteins exhibit many colloidal properties, such
as; Their diffusion rates are extremely slow and they may produce considerable

Question 20

light-scattering in solution, thus resulting in visible turbidity

Answer 20

Tyndall effect

Question 21

refers to the changes in the properties of a protein, In other words, it is the loss of biologic activity

Answer 21

Denaturation

Question 22

a process where denatured protein molecules tend to
form large aggregates and to precipitate from solution.

Answer 22

coagulation

Question 23

they act as acids and alkalies both

Answer 23

amphoteric

Question 24

proteins can form salts with both ___ and ___ based on
their net charge

Answer 24

cations and anions

Question 25

The solubility of proteins is influenced by

Answer 25

pH

Question 26

Solubility is lowest at

Answer 26

isoelectric point

Question 27

Solubility increases with

Answer 27

increasing acidity or alkalinity

Question 28

This is because when the protein molecules exist as either cations or anions, repulsive forces between ions are high, since all the molecules possess excess charges of the same sign.

Answer 28

Thus, they will be more soluble than in
the isoelectric state.

Question 29

Protein Optical Activity

Answer 29

All protein solutions rotate the plane of polarized light to the left, i.e., these are levoratotory